WorldWideScience

Sample records for fish stock assessment

  1. Statistical aspects of fish stock assessment

    DEFF Research Database (Denmark)

    Berg, Casper Willestofte

    2013-01-01

    Fish stock assessments are conducted for two main purposes: 1) To estimate past and present fish abundances and their commercial exploitation rates. 2) To predict the consequences of different management strategies in order to ensure a sustainable fishery in the future. This thesis concerns statistical aspects of fish stocks assessment, which includes topics such as time series analysis, generalized additive models (GAMs), and non-linear state-space/mixed models capable of handling missing data and a high number of latent states and parameters. The aim is to improve the existing methods for stock assessment by application of state-of-the-art statistical methodology. The main contributions are presented in the form of six research papers. The major part of the thesis deals with age-structured assessment models, which is the most common approach. Conversion from length to age distributions in the catches is a necessary step in age-based stock assessment models. For this purpose, GAMs and continuation ratio logits are combined to model the probability of age as a smooth function of length and spatial coordinates, which constitutes an improvement over traditional methods based on area-stratification. GAMs and delta-distributions are applied for the calculation of indices of abundance from trawl survey data, and different error structures for these are investigated. Two extensions to the state-space approach to age-structured stock assessment modelling are presented. The first extension introduces multivariate error distributions on survey catch-at-age data. The second extension is an integrated assessment model for overlapping sub-stocks subject to joint exploitation in the area of overlap. Estimation and inference is carried out using maximum likelihood. Finally, a biomass dynamic model based on stochastic differential equations is presented. This work extends the classical approaches to biomass modelling by incorporating observation errors on the catches, and allowing for missing and non-equidistant samples in time.

  2. Report of the Workshop on Methods of Fish Stock Assessment [Reykjavik, 6 -12 July, 1988

    OpenAIRE

    ICES

    1988-01-01

    Introduction: For the purposes of this report, the meaning of "fish stock assessment" is restricted to any procedure by which the historical and current state of a fish stock is estimated. This definition includes no reference to prediction of possible future states of the stock and no attention was given to prediction in the course of this meeting. It should also be noted that, in real-life assessments, recruitment estimates for the most recent data years are often obtained by tech...

  3. InterCatch - a tool for fish stock assessment, status and methods

    DEFF Research Database (Denmark)

    Kjems-Nielsen, Henrik; Larsen, Lena Inger

    2006-01-01

    InterCatch is a web-based system for handling fish stock assessment data focusing on documenting characteristics of the catches. These national fish stock data are uploaded to InterCatch by national data submitters. After all data are uploaded the stock coordinators (working for the fish stock assessment group) can then check and set up allocation schemes for unsampled catches. After applying the best allocation scheme to the unsampled catches, the catch data are aggregated as required and exported for analysis, e.g. XSA or ICA.

  4. FishFrame : Fisheries and stock assessment data framework

    DEFF Research Database (Denmark)

    Degel, Henrik; Jansen, Teunis

    2006-01-01

    Many research and advisory tasks needs quality assured data on a disaggregated level to make the re-stratification needed to answer a specific question. It is a slow process to gather international datasets for these analyses, because the raw data are spread between labs. Even when gathering data for fixed reoccurring tasks like assessment working groups, data are often late and the quality can be unsatisfactory. The current situation of this “semi-manual distributed datawarehouse” can be improved technically. Methods for quality control, raising and calculation can be discussed and unified. Development and test of software modules can be done once and reused by all. The biggest challenge in this is not technical – it is in organisation, coordination and trust. This challenge has been addressed by FishFrame - a web-based datawarehouse application. The “bottom-up” approach with maximum involvement of end users from as many labs and user groups as possible has been rather slow but quite successful in building international trust and cooperation around the system. This is mandatory prerequisites when our primary goal is not the programming project itself, but the creation of a tool that adds real value to users and in the end improves the way we work with our data. FishFrame version 4.2 is presented and the lessons learned from the process are discussed.

  5. Fishing impact and environmental status in European seas: A diagnosis from stock assessments and ecosystem indicators

    DEFF Research Database (Denmark)

    Gascuel, Didier; Coll, Marta

    2014-01-01

    Stock-based and ecosystem-based indicators are used to provide a new diagnosis of the fishing impact and environmental status of European seas. In the seven European marine ecosystems covering the Baltic and the North-east Atlantic, (i) trends in landings since 1950 were examined; (ii) syntheses of the status and trends in fish stocks were consolidated at the ecosystem level; and (iii) trends in ecosystem indicators based on landings and surveys were analysed. We show that yields began to decrease everywhere (except in the Baltic) from the mid-1970s, as a result of the over-exploitation of some major stocks. Fishermen adapted by increasing fishing effort and exploiting a wider part of the ecosystems. This was insufficient to compensate for the decrease in abundance of many stocks, and total landings have halved over the last 30 years. The highest fishing impact took place in the late 1990s, with a clear decrease in stock-based and ecosystem indicators. In particular, trophic-based indicators exhibited a continuous decreasing trend in almost all ecosystems. Over the past decade, a decrease in fishing pressure has been observed, the mean fishing mortality rate of assessed stocks being almost halved in all the considered ecosystems, but no clear recovery in the biomass and ecosystem indicators is yet apparent. In addition, the mean recruitment index was shown to decrease by around 50% in all ecosystems (except the Baltic). We conclude that building this kind of diagnosis is a key step on the path to implementing an ecosystem approach to fisheries management. © 2014 John Wiley & Sons Ltd.

  6. FISH STOCK ASSESSMENT USING MARINE ACOUSTICS DETECTION AND OCEANOGRAPHICAL CHARACTERISTICS IN JAVA SEA

    Directory of Open Access Journals (Sweden)

    Bonar P. Pasaribu

    2004-01-01

    Full Text Available Study on the movements of pelagic fish as a benchmark of pelagic fish stock assessments were investigated by using marine acoustics detection and oceanographical characteristics. Several surveys during 1992 to1994 using a dual-beam BioSonics 120 kHz echo-sounder installed on R/V Bawal Putih (192 GT were carried out in the middle part of Java Sea. The objective was to verify the importance of seasonal shifting on fish abundance under strong influence of environmental changes. Data were systematically stored using Ines-Movies acquisition and processing system along isobaths 50m to100m. A depth layer was adjusted under 10m stratifications. Descriptions on environmental frame were done through measurements of temperature and salinity by using Seabirds CTD profiler. The result shows higher saline water above 34 ppm is stronger influenced on the east and central of Java Sea during south-east monsoon (September to October 1992 and 1993. This condition is strongly related to the occurrence of higher fish density. The vertical and horizontal distribution of fish density shows that several group of fish populations seasonally occupied in the area. These observations clarified that coldwater intrusion from the Flores Sea and Makassar Strait play an important role in the west-eastward movements of Java Sea pelagic fish stocks

  7. FISH STOCK ASSESSMENT USING MARINE ACOUSTICS DETECTION AND OCEANOGRAPHICAL CHARACTERISTICS IN JAVA SEA

    Scientific Electronic Library Online (English)

    Bonar P., Pasaribu; Djisman, Manurung; Duto, Nugroho.

    Full Text Available Study on the movements of pelagic fish as a benchmark of pelagic fish stock assessments were investigated by using marine acoustics detection and oceanographical characteristics. Several surveys during 1992 to1994 using a dual-beam BioSonics 120 kHz echo-sounder installed on R/V Bawal Putih (192 GT) [...] were carried out in the middle part of Java Sea. The objective was to verify the importance of seasonal shifting on fish abundance under strong influence of environmental changes. Data were systematically stored using Ines-Movies acquisition and processing system along isobaths 50m to100m. A depth layer was adjusted under 10m stratifications. Descriptions on environmental frame were done through measurements of temperature and salinity by using Seabirds CTD profiler. The result shows higher saline water above 34 ppm is stronger influenced on the east and central of Java Sea during south-east monsoon (September to October 1992 and 1993). This condition is strongly related to the occurrence of higher fish density. The vertical and horizontal distribution of fish density shows that several group of fish populations seasonally occupied in the area. These observations clarified that coldwater intrusion from the Flores Sea and Makassar Strait play an important role in the west-eastward movements of Java Sea pelagic fish stocks

  8. Implementing ecosystem-based fisheries management: from single-species to integrated ecosystem assessment and advice for Baltic Sea fish stocks

    DEFF Research Database (Denmark)

    Möllmann, Christian; Lindegren, Martin

    2014-01-01

    Theory behind ecosystem-based management (EBM) and ecosystem-based fisheries management (EBFM) is nowwell developed. However, the implementation of EBFM exemplified by fisheries management in Europe is still largely based on single-species assessments and ignores the wider ecosystem context and impact. The reason for the lack or slow implementation of EBM and specifically EBFM is a lack of a coherent strategy. Such a strategy is offered by recently developed integrated ecosystemassessments (IEAs), a formal synthesis tool to quantitatively analyse information on relevant natural and socio-economic factors, in relation to specified management objectives. Here, we focus on implementing the IEA approach for Baltic Sea fish stocks. We combine both tactical and strategic management aspects into a single strategy that supports the present Baltic Sea fish stock advice, conducted by the International Council for the Exploration of the Sea (ICES). We first review the state of the art in the development of IEA within the current management framework. We then outline and discuss an approach that integrates fish stock advice and IEAs for the Baltic Sea. We intentionally focus on the central Baltic Sea and its three major fish stocks cod (Gadus morhua), herring (Clupea harengus), and sprat (Sprattus sprattus), but emphasize that our approach may be applied to other parts and stocks of the Baltic, as well as other ocean areas

  9. Quantifying relative fishing impact on fish populations based on spatio-temporal overlap of fishing effort and stock density

    OpenAIRE

    Vinther, Morten; Eero, Margit

    2013-01-01

    Evaluations of the effects of management measures on fish populations are usually based on the analyses of population dynamics and estimates of fishing mortality from stock assessments. However, this approach may not be applicable in all cases, in particular for data limited stocks, which may suffer from uncertain catch information and consequently lack reliable estimates of fishing mortality. In this study we develop an approach to obtain proxies for changes in fishing mortality based on eff...

  10. The true picture of a lake or reservoir fish stock: a review of needs and progress.

    Czech Academy of Sciences Publication Activity Database

    Kube?ka, Jan; Hohausová, Eva; Mat?na, Josef; Peterka, Ji?í; Amarasinghe, U. S.; Bonar, S. A.; Hateley, J.; Hickley, P.; Suuronen, P.; Tereschenko, V.; Welcomme, R.; Winfield, I. J.

    2009-01-01

    Ro?. 96, ?. 1 (2009), s. 1-5. ISSN 0165-7836. [Fish Stock Assessment Methods for Lakes and Reservoirs: Towards the true picture of fish stock. ?eské Bud?jovice, 11.09.2007-15.09.2007] Institutional research plan: CEZ:AV0Z60170517 Keywords : fish stock asessment * intercalibration * standardization * accuracy * ground truthing * interpretation * catch statistics Subject RIV: GL - Fishing Impact factor: 1.531, year: 2009

  11. Intelligent Fish Freshness Assessment

    OpenAIRE

    Deena Benjamin; Hongxiu Liu; Guanggui Xu; Dehan Luo; Hamid Gholam Hosseini

    2008-01-01

    Fish species identification and automated fish freshness assessment play important roles in fishery industry applications. This paper describes a method based on support vector machines (SVMs) to improve the performance of fish identification systems. The result is used for the assessment of fish freshness using artificial neural network (ANN). Identification of the fish species involves processing of the images of fish. The most efficient features were extracted and combined with the down-sa...

  12. Quantifying relative fishing impact on fish populations based on spatio-temporal overlap of fishing effort and stock density

    DEFF Research Database (Denmark)

    Vinther, Morten; Eero, Margit

    2013-01-01

    Evaluations of the effects of management measures on fish populations are usually based on the analyses of population dynamics and estimates of fishing mortality from stock assessments. However, this approach may not be applicable in all cases, in particular for data-limited stocks, which may suffer from uncertain catch information and consequently lack reliable estimates of fishing mortality. In this study we develop an approach to obtain proxies for changes in fishing mortality based on effort information and predicted stock distribution. Cod in the Kattegat is used as an example. We use GAM analyses to predict local cod densities and combine this with spatio-temporal data of fishing effort based on VMS (Vessel Monitoring System). To quantify local fishing impact on the stock, retention probability of the gears is taken into account. The results indicate a substantial decline in the impact of the Danish demersal trawl fleet on cod in the Kattegat in recent years, due to a combination of closed areas, introduction of selective gears and changes in overall effort.

  13. 75 FR 6058 - Federal Sport Fish Restoration; California Department of Fish and Game Fish Hatchery and Stocking...

    Science.gov (United States)

    2010-02-05

    ...on the Fund. CDFG has been rearing and stocking fish in the inland waters of California...Program are to continue the rearing and stocking of fish for the recreational use of...including potential increases in fish rearing and stocking in the...

  14. Fish otoliths analysis by PIXE: application to stock discrimination

    International Nuclear Information System (INIS)

    Fish otoliths are continuously deposited from fish birth to its death along with encoding environmental information. In order to decode the information, PIXE was adopted as trace elemental analysis of the otoliths. Strontium to calcium concentration ratios of red sea bream otoliths varied among rearing stations. The Sr/Ca ratios of Lake Biwa catfishes also varied between male and female and among fishing grounds. The PIXE analysis was applied to the fish stock discrimination. (author)

  15. Intelligent Fish Freshness Assessment

    Directory of Open Access Journals (Sweden)

    Deena Benjamin

    2008-04-01

    Full Text Available Fish species identification and automated fish freshness assessment play important roles in fishery industry applications. This paper describes a method based on support vector machines (SVMs to improve the performance of fish identification systems. The result is used for the assessment of fish freshness using artificial neural network (ANN. Identification of the fish species involves processing of the images of fish. The most efficient features were extracted and combined with the down-sampled version of the images to create a 1D input vector. Max-Win algorithm applied to the SVM-based classifiers has enhanced the reliability of sorting to 96.46%. The realisation of Cyranose 320 Electronic nose (E-nose, in order to evaluate the fish freshness in real-time, is experimented. Intelligent processing of the sensor patterns involves the use of a dedicated ANN for each species under study. The best estimation of freshness was provided by the most sensitive sensors. Data was collected from four selected species of fishes over a period of ten days. It was concluded that the performance can be increased using individual trained ANN for each specie. The proposed system has been successful in identifying the number of days after catching the fish with an accuracy of up to 91%.

  16. Breathing life into fisheries stock assessments with citizen science.

    Science.gov (United States)

    Fairclough, D V; Brown, J I; Carlish, B J; Crisafulli, B M; Keay, I S

    2014-01-01

    Citizen science offers a potentially cost-effective way for researchers to obtain large data sets over large spatial scales. However, it is not used widely to support biological data collection for fisheries stock assessments. Overfishing of demersal fishes along 1,000?km of the west Australian coast led to restrictive management to recover stocks. This diminished opportunities for scientists to cost-effectively monitor stock recovery via fishery-dependent sampling, particularly of the recreational fishing sector. As fishery-independent methods would be too expensive and logistically-challenging to implement, a citizen science program, Send us your skeletons (SUYS), was developed. SUYS asks recreational fishers to voluntarily donate fish skeletons of important species from their catch to allow biological data extraction by scientists to produce age structures and conduct stock assessment analyses. During SUYS, recreational fisher involvement, sample sizes and spatial and temporal coverage of samples have dramatically increased, while the collection cost per skeleton has declined substantially. SUYS is ensuring sampling objectives for stock assessments are achieved via fishery-dependent collection and reliable and timely scientific advice can be provided to managers. The program is also encouraging public ownership through involvement in the monitoring process, which can lead to greater acceptance of management decisions. PMID:25431103

  17. Rebuilding EU fish stocks and fisheries, a process under way?

    DEFF Research Database (Denmark)

    Cardinale, M.; Dörner, H.

    2013-01-01

    As a signatory to the World Summit on Sustainable Development (WSSD), the European Union (EU) has made a commitment to maintain or restore fish stocks to levels that can produce the maximum sustainable yield (MSY), and where possible not later than 2015. So how has the EU's Common Fisheries Policy (CFP) fared in trying to achieve this objective? The development of the status of 41 commercially exploited fish stocks from the North East Atlantic, North Sea and Baltic Sea (FAO Area 27) was analysed together with the economic performance of the fleets exploiting those stocks. The analyses indicate that the exploitation status for many of the stocks has greatly improved during the last 10 years while the economic performance of the fleets over the same period has been highly variable. The main economic indicators (gross value added (GVA) and operating cash flow (OCF)) have gradually improved at a time when the general economic situation, which has a great influence on the markets, costs and purchase power, has worsened. While recognizing that much remains to be done to achieve the objective of the WSSD, the analyses indicate that actions implemented in the last decade under the CFP have led to an improvement in the status of many commercially important fish stocks and their fleets towards levels that are closer to those producing MSY.

  18. Coupling age-structured stock assessment and fish bioenergetics models: a system of time-varying models for quantifying piscivory patterns during the rapid trophic shift in the main basin of Lake Huron

    Science.gov (United States)

    He, Ji X.; Bence, James R.; Madenjian, Charles P.; Pothoven, Steven A.; Dobiesz, Norine E.; Fielder, David G.; Johnson, James E.; Ebener, Mark P.; Cottrill, Adam R.; Mohr, Lloyd C.; Koproski, Scott R.

    2015-01-01

    We quantified piscivory patterns in the main basin of Lake Huron during 1984–2010 and found that the biomass transfer from prey fish to piscivores remained consistently high despite the rapid major trophic shift in the food webs. We coupled age-structured stock assessment models and fish bioenergetics models for lake trout (Salvelinus namaycush), Chinook salmon (Oncorhynchus tshawytscha), walleye (Sander vitreus), and lake whitefish (Coregonus clupeaformis). The model system also included time-varying parameters or variables of growth, length–mass relations, maturity schedules, energy density, and diets. These time-varying models reflected the dynamic connections that a fish cohort responded to year-to-year ecosystem changes at different ages and body sizes. We found that the ratio of annual predation by lake trout, Chinook salmon, and walleye combined with the biomass indices of age-1 and older alewives (Alosa pseudoharengus) and rainbow smelt (Osmerus mordax) increased more than tenfold during 1987–2010, and such increases in predation pressure were structured by relatively stable biomass of the three piscivores and stepwise declines in the biomass of alewives and rainbow smelt. The piscivore stability was supported by the use of alternative energy pathways and changes in relative composition of the three piscivores. In addition, lake whitefish became a new piscivore by feeding on round goby (Neogobius melanostomus). Their total fish consumption rivaled that of the other piscivores combined, although fish were still a modest proportion of their diet. Overall, the use of alternative energy pathways by piscivores allowed the increases in predation pressure on dominant diet species.

  19. The Effect of Marine Fish Biomass Stock Reduction to Fishers Revenue (A Case Study of Sardinella Lemuru Fisheries on Bali Strait)

    OpenAIRE

    Ratna Purwaningsih; Sjarief Widjaja; Sri Gunani Partiwi

    2011-01-01

    Stock assessment studies indicate that Sardinela Lemuru fisheries of Bali strait have been overfishing. This research attempts to (1) Identify the effect of biomass stock reduction to fishers revenue per trip, (2) Analyze the economic feasibility study for purse seine of Muncar, Banyuwangi. System Dynamic approach is used for simulation modeling. Simulation output shows a strong correlation between fish stock reduction and fisher revenue. The growth of fishing effort per year results on the r...

  20. 78 FR 19446 - Marine Mammal Stock Assessment Reports

    Science.gov (United States)

    2013-04-01

    ...the distribution and abundance of the stock, population growth rates and trends, the stock's Potential Biological Removal (PBR...guidelines, (2) recalculating their PBR values, (3) updating the stock assessment reports accordingly,...

  1. Biological reference points for fish stocks in a multispecies context

    DEFF Research Database (Denmark)

    Collie, J.S.; Gislason, Henrik

    2001-01-01

    Biological reference points (BRPs) are widely used to define safe levels of harvesting for marine fish populations. Most BRPs are either minimum acceptable biomass levels or maximum fishing mortality rates. The values of BRPs are determined from historical abundance data and the life-history parameters of the fish species. However, when the life-history parameters change over time, the BRPs become moving targets. In particular, the natural mortality rate of prey species depends on predator levels; conversely, predator growth rates depend on prey availability. We tested a suite of BRPs for their robustness to observed changes in natural mortality and growth rates. We used the relatively simple Baltic Sea fish community for this sensitivity test, with cod as predator and sprat and herring as prey. In general, the BRPs were much more sensitive to the changes in natural mortality rates than to growth variation. For a prey species like sprat, fishing mortality reference levels should be conditioned on the level ofpredation mortality. For a predator species, a conservative level of fishing mortality can be identified that will prevent growth overfishing and ensure stock replacement. These first- order multispecies interactions should be considered when defining BRPs for medium-term (5-10 year) management decisions.

  2. Swimming Performance Assessment in Fishes

    OpenAIRE

    Tierney, Keith B.

    2011-01-01

    Swimming performance tests of fish have been integral to studies of muscle energetics, swimming mechanics, gas exchange, cardiac physiology, disease, pollution, hypoxia and temperature. This paper describes a flexible protocol to assess fish swimming performance using equipment in which water velocity can be controlled. The protocol involves one to several stepped increases in flow speed that are intended to cause fish to fatigue. Step speeds and their duration can be set to capture swimming ...

  3. The effect of fish impingement at Sizewell 'A' Power Station, Suffolk, on North Sea fish stocks

    International Nuclear Information System (INIS)

    Samples collected from the cooling water intake screens of Sizewell 'A' power station over a 12 month period contained 73 species of fish. Of these, only 20 species were present on more than 50% of sampling dates and only 7 commercially exploited species were caught in quantities of more than a few hundred over the year; namely sprat, herring, cod, whiting, sole, dab and plaice. These species formed the basis of analysis of the impact of the Power Station on commercial species. Commercial species found in the Sizewell area are part of major North Sea stocks. The impact of the losses due to the Power Station is spread over these stocks, hence the effect is minimal. The mortality rate caused by the Power Station is one thousandth to one hundred-thousandth, depending on species, of that caused by commercial fishing and the effect is less than that of a small, inefficient commercial trawler. (author)

  4. Size-based estimation of the status of fish stocks: simulation analysis and comparison with age-based estimations

    DEFF Research Database (Denmark)

    Kokkalis, Alexandros; Thygesen, Uffe HØgsbro

    Estimation of the status of fish stocks is important for sustainable management. Data limitations and data quality hinder this task. The commonly used age-based approaches require information about individual age, which is costly and relatively inaccurate. In contrast, the size of organisms is linked to physiology more directly than is age, and can be measured easier with less cost. In this work we used a single-species size-based model to estimate the fishing mortality (F) and the status of the stock, quantified by the ratio F/Fmsy between actual fishing mortality and the fishing mortality which leads to the maximum sustainable yield. A simulation analysis was done to investigate the sensitivity of the estimation and its improvement when stock specific life history information is available. To evaluate our approach with real observations, data-rich fish stocks, like the North Sea cod, were investigated and our estimations were compared to the ICES advice. Only size-specific catch data were used, in order to emulate data limited situations. The simulation analysis reveals that the status of the stock, i.e. F/Fmsy, is estimated more accurately than the fishing mortality F itself. Specific knowledge of the natural mortality improves the estimation more than having information about all other life history parameters. Our approach gives, at least qualitatively, an estimated stock status which is similar to the results of an age-based assessment. Since our approach only uses size-based catch data, it is a suitable tool for data-limited situations

  5. The Effect of Marine Fish Biomass Stock Reduction to Fishers Revenue (A Case Study of Sardinella Lemuru Fisheries on Bali Strait

    Directory of Open Access Journals (Sweden)

    Ratna Purwaningsih

    2011-08-01

    Full Text Available Stock assessment studies indicate that Sardinela Lemuru fisheries of Bali strait have been overfishing. This research attempts to (1 Identify the effect of biomass stock reduction to fishers revenue per trip, (2 Analyze the economic feasibility study for purse seine of Muncar, Banyuwangi. System Dynamic approach is used for simulation modeling. Simulation output shows a strong correlation between fish stock reduction and fisher revenue. The growth of fishing effort per year results on the reduction of catch per unit effort and total catch per year. Feasibility study concludes that purse seine (30 GT which operates 120 trips per year is no longer a profitable business since 2020.

  6. Simulation testing the robustness of stock assessment models to error: some results from the ICES strategic initiative on stock assessment methods

    DEFF Research Database (Denmark)

    Deroba, J. J.; Butterworth, D. S.

    2015-01-01

    The World Conference on Stock Assessment Methods (July 2013) included a workshop on testing assessment methods through simulations. The exercise was made up of two steps applied to datasets from 14 representative fish stocks from around the world. Step 1 involved applying stock assessments to datasets with varying degrees of effort dedicated to optimizing fit. Step 2 was applied to a subset of the stocks and involved characteristics of given model fits being used to generate pseudo-data with error. These pseudo-data were then provided to assessment modellers and fits to the pseudo-data provided consistency checks within (self-tests) and among (cross-tests) assessment models. Although trends in biomass were often similar across models, the scaling of absolute biomass was not consistent across models. Similar types of models tended to perform similarly (e.g. age based or production models). Self-testing and cross-testing of models are a useful diagnostic approach, and suggested that estimates in the most recent years of time-series were the least robust. Results from the simulation exercise provide a basis for guidance on future large-scale simulation experiments and demonstrate the need for strategic investments in the evaluation and development of stock assessment methods

  7. Sushi or fish fingers? Seafood diversity, collapsing fish stocks, and multi-species fishery management

    OpenAIRE

    Quaas, Martin F.; Requate, Till

    2012-01-01

    We present a model of a multi-species fishery and show that (i) consumer preferences for seafood diversity may trigger a sequential collapse of fish stocks under open-access fishery, (ii) the stronger the preferences are for diversity the higher is the need for coordinated multi-species regulation, (iii) second-best optimal management of only one (or a few) species is less strict than socially optimal management of the same species. Finally, (iv) myopic regulation of one species, ignoring spi...

  8. Effects of marine protected areas on overfished fishing stocks with multiple stable states.

    Science.gov (United States)

    Takashina, Nao; Mougi, Akihiko

    2014-01-21

    Marine protected areas (MPAs) have attracted much attention as a tool for sustainable fisheries management, restoring depleted fisheries stocks and maintaining ecosystems. However, even with total exclusion of fishing effort, depleted stocks sometimes show little or no recovery over a long time period. Here, using a mathematical model, we show that multiple stable states may hold the key to understanding the tendency for fisheries stocks to recover because of MPAs. We find that MPAs can have either a positive effect or almost no effect on the recovery of depleted fishing stocks, depending on the fish migration patterns and the fishing policies. MPAs also reinforce ecological resilience, particularly for migratory species. In contrast to previous reports, our results show that MPAs have small or sometimes negative effects on the recovery of sedentary species. Unsuitable MPA planning might result in low effectiveness or even deterioration of the existing condition. PMID:24083999

  9. Biology and management of fish stocks in Bahir Dar Gulf, Lake Tana, Ethiopia.

    OpenAIRE

    Wudneh, T.

    1998-01-01

    The biology of the fish stocks of the major species in the Bahir Dar Gulf of Lake Tana, the largest lake in Ethiopia, has been studied based on data collected during August 1990 to September 1993. The distribution, reproduction patterns, growth and mortality dynamics and gillnet selectivity of these stocks are described.The major fish categories, Barbus spp., Clarias gariepinus, and Oreochromis niloticus contribute equally to the catches. O. niloticus is most abundant in the shallow littoral ...

  10. Effects of Marine Protected Areas on Overfished Fishing Stocks with Multiple Stable States

    OpenAIRE

    Takashina, Nao; Mougi, Akihiko

    2015-01-01

    Marine protected areas (MPAs) have attracted much attention as a tool for sustainable fisheries management, restoring depleted fisheries stocks and maintaining ecosystems. However, even with total exclusion of fishing effort, depleted stocks sometimes show little or no recovery over a long time period. Here, using a mathematical model, we show that multiple stable states may hold the key to understanding the tendency for fisheries stocks to recover because of MPAs. We find t...

  11. Resident Fish Stock Status above Chief Joseph and Grand Coulee Dams; 2001 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Connor, Jason M. (Kalispell Department of Natural Resources, Usk, WA); McLellan, Jason G. (Washington Department of Fish and Wildlife, Spokane, WA); O' Connor, Dick (Washington Department of Fish and Wildlife, Olympia, WA)

    2003-01-01

    In 1980, the United States Congress enacted the Northwest Power Planning and Conservation Act (PL 96-501, 1980), which established the Northwest Power Planning Council (NPPC). The NPPC was directed by Congress to develop a regional Power Plan and also the Columbia River Basin Fish and Wildlife Program (FWP) to restore or replace losses of fish caused by construction and operation of hydroelectric dams in the Columbia River Basin. In developing the FWP, Congress specifically directed NPPC to solicit recommendations for measures to be included in the Program from the region's fish and wildlife agencies and Indian tribes. All measures adopted by the Council were also required to be consistent with the management objectives of the agencies and tribes [Section 4.(h)(6)(A)], the legal rights of Indian tribes in the region [Section 4.(h)(6)(D)] and be based upon and supported by the best available scientific knowledge [Section 4.(h)(6)(B)]. The Resident Fish Stock Status above Chief Joseph and Grand Coulee Dams Project, also known as the Joint Stock Assessment Project (JSAP) specifically addresses NPPC Council measure 10.8B.26 of the 1994 program. The Joint Stock Assessment Project is a management tool using ecosystem principles to manage artificial fish assemblages and native fish in altered environments existing in the Columbia River System above Chief Joseph and Grand Coulee Dams (Blocked Area). A three-phase approach of this project will enhance the fisheries resources of the Blocked Area by identifying data gaps, filling data gaps with research, and implementing management recommendations based on research results. The Blocked Area fisheries information is housed in a central location, allowing managers to view the entire system while making decisions, rather than basing management decisions on isolated portions of the system. The JSAP is designed and guided jointly by fisheries managers in the Blocked Area and the Columbia Basin Blocked Area Management Plan (1998). The initial year of the project (1997) identified the need for a central data storage and analysis facility, coordination with the StreamNet project, compilation of Blocked Area fisheries information, and a report on the ecological condition of the Spokane River System. These needs were addressed in 1998 by acquiring a central location with a data storage and analysis system, coordinating a pilot project with StreamNet, compiling fisheries distribution data throughout the Blocked Area, identifying data gaps based on compiled information, and researching the ecological condition of the Spokane River. In order to ensure that any additional information collected throughout the life of this project will be easily stored and manipulated by the central storage facility, it was necessary to develop standardized methodologies between the JSAP fisheries managers. Common collection and analytical methodologies were developed in 1999. In 1999, 2000, and 2001 the project began addressing some of the identified data gaps throughout the Blocked Area. Data collection of established projects and a variety of newly developed sampling projects are ongoing. Projects developed and undertaken by JSAP fisheries managers include investigations of the Pend Orielle River and its tributaries, the Little Spokane River and its tributaries, and water bodies within and near the Spokane Indian Reservation. Migration patterns of adfluvial and reservoir fish in Box Canyon Reservoir and its tributaries, a baseline assessment of Boundary Reservoir and its tributaries, ecological assessment of mountain lakes in Pend Oreille County, and assessments of seven streams and four lakes on the Spokane Indian Reservation were completed by 2000. Assessments of the Little Spokane River and its tributaries, tributaries to the Pend Oreille River, small lakes in southern Pend Oreille County, and water bodies within and near the Spokane Indian Reservation were conducted in 2001. This work was done in accordance with the scope of work approved by Bonneville Power Administration (BPA).

  12. Resident Fish Stock above Chief Joseph and Grand Coulee Dams; 2002 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Connor, Jason M. (Kalispel Department of Natural Resources, Usk, WA); McLellan, Jason G. (Washington Department of Fish and Wildlife, Spokane, WA); Butler, Chris (Spokane Tribe of Indians, Department of Natural Resources, Wellpinit, WA)

    2003-09-01

    In 1980, the United States Congress enacted the Northwest Power Planning and Conservation Act (PL 96-501, 1980), which established the Northwest Power and Conservation Council (NPCC), formerly the Northwest Power Planning Council. The NPCC was directed by Congress to develop a regional Power Plan and also the Columbia River Basin Fish and Wildlife Program (FWP) to restore or replace losses of fish caused by construction and operation of hydroelectric dams in the Columbia River Basin. In developing the FWP, Congress specifically directed NPCC to solicit recommendations for measures to be included in the Program from the region's fish and wildlife agencies and Indian tribes. All measures adopted by the Council were also required to be consistent with the management objectives of the agencies and tribes [Section 4.(h)(6)(A)], the legal rights of Indian tribes in the region [Section 4.(h)(6)(D)] and be based upon and supported by the best available scientific knowledge [Section 4.(h)(6)(B)]. The Resident Fish Stock Status above Chief Joseph and Grand Coulee Dams Project, also known as the Joint Stock Assessment Project (JSAP) specifically addresses NPPC Council measure 10.8B.26 of the 1994 program. The Joint Stock Assessment Project is a management tool using ecosystem principles to manage artificial fish assemblages and native fish in altered environments existing in the Columbia River System above Chief Joseph and Grand Coulee Dams (Blocked Area). A three-phase approach of this project will enhance the fisheries resources of the Blocked Area by identifying data gaps, filling data gaps with research, and implementing management recommendations based on research results. The Blocked Area fisheries information is housed in a central location, allowing managers to view the entire system while making decisions, rather than basing management decisions on isolated portions of the system. The JSAP is designed and guided jointly by fisheries managers in the Blocked Area. The initial year of the project (1997) identified the need for a central data storage and analysis facility, coordination with the StreamNet project, compilation of Blocked Area fisheries information, and a report on the ecological condition of the Spokane River System. These needs were addressed in 1998 by acquiring a central location with a data storage and analysis system, coordinating a pilot project with StreamNet, compiling fisheries distribution data throughout the Blocked Area, identifying data gaps based on compiled information, and researching the ecological condition of the Spokane River. In order to ensure that any additional information collected throughout the life of this project will be easily stored and manipulated by the central storage facility, it was necessary to develop standardized methodologies between the JSAP fisheries managers. Common collection and analytical methodologies were developed in 1999. In 1999, 2000, and 2001 the project began addressing some of the identified data gaps throughout the Blocked Area. Data collection of established projects and a variety of newly developed sampling projects are ongoing. Projects developed and undertaken by JSAP fisheries managers include investigations of the Pend Orielle River and its tributaries, the Little Spokane River and its tributaries, and water bodies within and near the Spokane Indian Reservation. Migration patterns of adfluvial and reservoir fish in Box Canyon Reservoir and its tributaries, a baseline assessment of Boundary Reservoir and its tributaries, ecological assessment of mountain lakes in Pend Oreille County, and assessments of streams and lakes on the Spokane Indian Reservation were completed by 2001. Assessments of the Little Spokane River and its tributaries, tributaries to the Pend Oreille River, small lakes in Pend Oreille County, WA, and water bodies within and near the Spokane Indian Reservation were conducted in 2002. This work was done in accordance with the scope of work approved by Bonneville Power Administration (BPA).

  13. Impacts of the local environment on recruitment: a comparative study of North Sea and Baltic Sea fish stocks

    DEFF Research Database (Denmark)

    Pécuchet, Lauréne; Nielsen, J. Rasmus

    2014-01-01

    While the impact of environmental forcing on recruitment variability in marine populations remains largely elusive, studies spanning large spatial areas and many stocks are able to identify patterns common to different regions and species. In this study, we investigate the effects of the environment on the residuals of a Ricker stock–recruitment (SR) model, used as a proxy of prerecruits’ survival, of 18 assessed stocks in the Baltic and North Seas. A probabilistic principal components (PCs) analysis permits the identification of groups of stocks with shared variability in the prerecruits’ survival, most notably a group of pelagics in the Baltic Sea and a group composed of gadoids and herring in the North Sea. The first two PCs generally grouped the stocks according to their localizations: the North Sea, the Kattegat–Western Baltic, and the Baltic Sea. This suggests the importance of the local environmental variability on the recruitment strength. Hence, the prerecruits’ survival variability is studied according to geographically disaggregated and potentially impacting abiotic or biotic variables. Time series (1990–2009) of nine environmental variables consistent with the spawning locations and season for each stock were extracted from a physical–biogeochemical model to evaluate their ability to explain the survival of prerecruits. Environmental variables explained .70% of the survival variability for eight stocks. The variables water current, salinity, temperature, and biomass of other fish stocks are regularly significant in the models. This study shows the importance of the local environment on the dynamics of SR. The results provide evidence of the necessity of including environmental variables in stock assessment for a realistic and efficient management of fisheries

  14. The CUSUM out-of-control table to monitor changes in fish stock status using many indicators

    OpenAIRE

    Petitgas, Pierre

    2009-01-01

    One method to assess fish stocks using a suite of indicators is the traffic light approach. In this approach, the time series of the different indicators are mapped on a common colour scale to highlight alerts that occur when indicators cross reference limit values. Until now, however, the procedure has lacked a statistical framework. Here, we propose the cumulative sum (CUSUM) monitoring scheme as a suitable statistical framework. CUSUM is a statistical process control method that detects de...

  15. Fish stocking density induced growth responses of some biogeochemical cycling bacterial population

    Directory of Open Access Journals (Sweden)

    J. N. Bhakta

    2010-02-01

    Full Text Available Experiment was performed to ascertain the effect of fish stocking density on population growth performance of some biogeochemical cycling bacteria in carp culture system. Advanced fry of Catla catla L., Labeo bata Ham. and Cyprinus carpio L. were introduced into tanks @ 8, 13, 16 and 32 fry tank-1 maintaining the ratio of C. catla -2 : L. bata -3 : C. carpio -3. Each tank was fertilized with mixed fertilizer @ 200 g week-1 during the rearing period of 150 days. Water samples were collected for examination of bacterial population, primary productivity and water quality parameters at weekly and biweekly intervals. Growth of fish was recorded at regular intervals. Statistical analysis of collected data was done by ANOVA and LSD for separation of mean (P < 0.05. Bacterial growth rate and productivity tended to rise with increasing stocking density showing maximum at stocking density 32 fry tank-1 whereas, fish growth exhibited an increasing trend upto stocking density 16 fry tank-1 and declined in further increment of fish density. Stocking density dependent growth efficiency of different bacteria (heterotrophic bacteria, cellulose decomposing bacteria, denitrifying bacteria and phosphate solubilizing bacteria varied from 18 to 62.7%, 45 to 140%, 61 to 238% and 79 to 382% in stocking density 8, 13, 16 and 32 fry tank-1 , respectively. Results clearly revealed that higher stocking density of fishes liberates higher quantity of faecal matter containing proportionately greater amount of nutrients having more scope for bacteria to act upon the faecal matter resulting in higher bacterial population and productivity in one hand and fish growth inhibition due to stressful and uncongenial environmental condition developed by means of heavy nutrient load on the other hand. Therefore, it may be concluded that stocking density influencing the growth of biogeochemical cycling bacterial population in fish culture system.

  16. Resident Fish Stock Status above Chief Joseph and Grand Coulee Dams; 2002-2003 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Connor, Jason M. (Kalispel Tribe of Indians, Usk, WA); McLellan, Jason G. (Washington Department of Fish and Wildlife); Butler, Chris (Spokane Tribe of Indians, Wellpinit, WA)

    2006-02-01

    In 1980, the United States Congress enacted the Northwest Power Planning and Conservation Act (PL 96-501, 1980), which established the Northwest Power and Conservation Council (NPCC), formerly the Northwest Power Planning Council. The NPCC was directed by Congress to develop a regional Power Plan and also the Columbia River Basin Fish and Wildlife Program (FWP) to restore or replace losses of fish caused by construction and operation of hydroelectric dams in the Columbia River Basin. In developing the FWP, Congress specifically directed NPCC to solicit recommendations for measures to be included in the Program from the region's fish and wildlife agencies and Indian tribes. All measures adopted by the Council were also required to be consistent with the management objectives of the agencies and tribes [Section 4.(h)(6)(A)], the legal rights of Indian tribes in the region [Section 4.(h)(6)(D)] and be based upon and supported by the best available scientific knowledge [Section 4.(h)(6)(B)]. The Resident Fish Stock Status above Chief Joseph and Grand Coulee Dams Project, also known as the Joint Stock Assessment Project (JSAP) specifically addresses NPPC Council measure 10.8B.26 of the 1994 program. The Joint Stock Assessment Project is a management tool using ecosystem principles to manage artificial and native fish assemblages in altered environments existing in the Columbia River System above Chief Joseph and Grand Coulee Dams (Blocked Area). A three-phase approach of this project will enhance the fisheries resources of the Blocked Area by identifying data gaps, filling data gaps with research, and implementing management recommendations based on research results. The Blocked Area fisheries information is housed in a central location, allowing managers to view the entire system while making decisions, rather than basing management decisions on isolated portions of the system. The JSAP is designed and guided jointly by fisheries managers in the Blocked Area. The initial year of the project (1997) identified the need for a central data storage and analysis facility, coordination with the StreamNet project, compilation of Blocked Area fisheries information, and a report on the ecological condition of the Spokane River System. These needs were addressed in 1998 by acquiring a central location with a data storage and analysis system, coordinating a pilot project with StreamNet, compiling fisheries distribution data throughout the Blocked Area, identifying data gaps based on compiled information, and researching the ecological condition of the Spokane River. In order to ensure that any additional information collected throughout the life of this project will be easily stored and manipulated by the central storage facility, it was necessary to develop standardized methodologies between the JSAP fisheries managers. Common collection and analytical methodologies were developed in 1999. The project began addressing identified data gaps throughout the Blocked Area in 1999. Data collection of established projects and a variety of newly developed sampling projects are ongoing. Projects developed and undertaken by JSAP fisheries managers include investigations of the Pend Orielle River and its tributaries, the Little Spokane River and its tributaries, and water bodies within and near the Spokane Indian Reservation. Migration patterns of adfluvial and reservoir fish in Box Canyon Reservoir and its tributaries, a baseline assessment of Boundary Reservoir and its tributaries, ecological assessment of mountain lakes in Pend Oreille County, and assessments of streams and lakes on the Spokane Indian Reservation were completed by 2001. Assessments of the Little Spokane River and its tributaries, Spokane River below Spokane Falls, tributaries to the Pend Oreille River, small lakes in Pend Oreille County, WA, and water bodies within and near the Spokane Indian Reservation were conducted in 2002 and 2003. This work was done in accordance with the scope of work approved by Bonneville Power Administration (BPA).

  17. Resident Fish Stock above Chief Joseph and Grand Coulee Dams; 2003-2004 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Connor, Jason M. (Kalispel Tribe of Indians, Usk, WA); McLellan, Jason G. (Washington Department of Fish and Wildlife, Olympia, WA); Butler, Chris (Spokane Tribe of Indians, Wellpinit, WA)

    2005-11-01

    In 1980, the United States Congress enacted the Northwest Power Planning and Conservation Act (PL 96-501, 1980), which established the Northwest Power and Conservation Council (NPCC), formerly the Northwest Power Planning Council. The NPCC was directed by Congress to develop a regional Power Plan and also the Columbia River Basin Fish and Wildlife Program (FWP) to restore or replace losses of fish caused by construction and operation of hydroelectric dams in the Columbia River Basin. In developing the FWP, Congress specifically directed NPCC to solicit recommendations for measures to be included in the Program from the region's fish and wildlife agencies and Indian tribes. All measures adopted by the Council were also required to be consistent with the management objectives of the agencies and tribes [Section 4.(h)(6)(A)], the legal rights of Indian tribes in the region [Section 4.(h)(6)(D)] and be based upon and supported by the best available scientific knowledge [Section 4.(h)(6)(B)]. The Resident Fish Stock Status above Chief Joseph and Grand Coulee Dams Project, also known as the Joint Stock Assessment Project (JSAP) specifically addresses NPPC Council measure 10.8B.26 of the 1994 program. The Joint Stock Assessment Project is a management tool using ecosystem principles to manage artificial and native fish assemblages in altered environments existing in the Columbia River System above Chief Joseph and Grand Coulee Dams (Blocked Area). A three-phase approach of this project will enhance the fisheries resources of the Blocked Area by identifying data gaps, filling data gaps with research, and implementing management recommendations based on research results. The Blocked Area fisheries information is housed in a central location, allowing managers to view the entire system while making decisions, rather than basing management decisions on isolated portions of the system. The JSAP is designed and guided jointly by fisheries managers in the Blocked Area. The initial year of the project (1997) identified the need for a central data storage and analysis facility, coordination with the StreamNet project, compilation of Blocked Area fisheries information, and a report on the ecological condition of the Spokane River System. These needs were addressed in 1998 by acquiring a central location with a data storage and analysis system, coordinating a pilot project with StreamNet, compiling fisheries distribution data throughout the Blocked Area, identifying data gaps based on compiled information, and researching the ecological condition of the Spokane River. In order to ensure that any additional information collected throughout the life of this project will be easily stored and manipulated by the central storage facility, it was necessary to develop standardized methodologies between the JSAP fisheries managers. Common collection and analytical methodologies were developed in 1999. The project began addressing identified data gaps throughout the Blocked Area in 1999. Data collection of established projects and a variety of newly developed sampling projects are ongoing. Projects developed and undertaken by JSAP fisheries managers include investigations of the Pend Orielle River and its tributaries, the Little Spokane River and its tributaries, and water bodies within and near the Spokane Indian Reservation. Migration patterns of adfluvial and reservoir fish in Box Canyon Reservoir and its tributaries, a baseline assessment of Boundary Reservoir and its tributaries, ecological assessment of mountain lakes in Pend Oreille County, and assessments of streams and lakes on the Spokane Indian Reservation were completed by 2001. Assessments of the Little Spokane River and its tributaries, Spokane River below Spokane Falls, tributaries to the Pend Oreille River, small lakes in Pend Oreille County, WA, and water bodies within and near the Spokane Indian Reservation were conducted in 2002 and 2003. This work was done in accordance with the scope of work approved by Bonneville Power Administration (BPA).

  18. Influence of spawning stock size and environment on abundance and survival of juveniles in commercially important fish stocks in the Barents Sea

    OpenAIRE

    Dingsør, Gjert Endre

    2006-01-01

    Stock-recruitment relationships are fundamental in management of fish stocks and fish recruitment is highly variable. Hence, a mechanistic understanding of the factors causing the variability in recruitment is a necessity to be able to predict the development of a harvestable stock. To get continuity in the management it is also important to get an early indication of the size of future year-classes recruiting to the fisheries. Survey-based abundance indices are often used to a...

  19. 77 FR 47043 - Draft 2012 Marine Mammal Stock Assessment Reports

    Science.gov (United States)

    2012-08-07

    ...Mammal Stock Assessment Reports AGENCY: National Marine...mammal stock assessment reports (SARs) in accordance...electronic form via the Internet at http://www.nmfs...requests for copies of reports to: Chief, Marine Mammal...population growth rates and trends, estimates of...

  20. 75 FR 46912 - Draft 2010 Marine Mammal Stock Assessment Reports

    Science.gov (United States)

    2010-08-04

    ...Mammal Stock Assessment Reports AGENCY: National Marine...mammal stock assessment reports (SARs) in accordance...electronic form via the Internet at http://www.nmfs...requests for copies of reports to: Chief, Marine Mammal...population growth rates and trends, estimates of...

  1. Changes in the fish community and water quality during seven years of stocking piscivorous fish in a shallow lake

    DEFF Research Database (Denmark)

    Skov, Christian; Perrow, M.R.

    2002-01-01

    1. Piscivores (annual stocking of 1000 individuals ha(-1) of 0+ pike and a single stocking of 30 kg ha(-1) of large 20-30 cm perch) were stocked in seven consecutive years in a shallow eutrophic lake in Denmark. The stocking programme aimed at changing food-web structure by reducing zooplanktivorous and benthivorous fish, with resultant effects on lower trophic levels and ultimately water quality. 2. The fish community and water quality parameters (Secchi depth, concentrations of total phosphorus, chlorophyll a and suspended solids) were monitored between 1996 and 2000 and relationships were evaluated between predatory fish and potential prey and between zooplanktivorous or benthivorous fish and water quality parameters. In addition, potential consumption of piscivorous fishes was calculated. 3. The density of fish feeding on larger zooplankton or benthos (roach >15 cm, crucian carp >15 cm) declined distinctly during the study period. This effect was attributed to predation by large (>50 cm) pike. Based on scale readings, we cautiously suggest that the stocking of 0+ pike boosted the adult pike population to produce an unexpected impact in later years. Conversely, no direct impact of stocked 0+ pike was detected on 0+ roach. 4. A major decline in the recruitment strength of 0+ roach was observed in 2000. A combination of (i) the indirect effect of large pike preying on adult roach, with negative effect on roach reproduction and (ii) the direct predation effect of 0+ pike and or 1+ and 2+ perch recruited in the lake, provides the most likely explanation of this phenomenon. 5. A marked increase in Secchi depth in 2000 and declining trends in suspended solids, chlorophyll-a and total phosphorus concentrations were observed. These changes may also be attributable to changes in the fish community, although the relationships were not straightforward. 6. This 7-year study indicates that piscivorous fish may be a significant structuring force in shallow eutrophic lakes, suggesting that stocking piscivores can increase predation pressure on cyprinids. However, the general lack of impact of 0+ pike points to the need of refining current stocking practices in several countries across Europe

  2. Annual Stock Assessment - CWT [Coded Wire Tag program] (USFWS), Annual Report 2007.

    Energy Technology Data Exchange (ETDEWEB)

    Pastor, Stephen M. [U.S. Fish and Wildlife Service, Columbia River Fisheries Program Office

    2009-07-21

    In 1989 the Bonneville Power Administration (BPA) began funding the evaluation of production groups of juvenile anadromous fish not being coded-wire tagged for other programs. These groups were the 'Missing Production Groups'. Production fish released by the U.S. Fish and Wildlife Service (FWS) without representative coded-wire tags during the 1980s are indicated as blank spaces on the survival graphs in this report. This program is now referred to as 'Annual Stock Assessment - CWT'. The objectives of the 'Annual Stock Assessment' program are to: (1) estimate the total survival of each production group, (2) estimate the contribution of each production group to fisheries, and (3) prepare an annual report for USFWS hatcheries in the Columbia River basin. Coded-wire tag recovery information will be used to evaluate the relative success of individual brood stocks. This information can also be used by salmon harvest managers to develop plans to allow the harvest of excess hatchery fish while protecting threatened, endangered, or other stocks of concern. All fish release information, including marked/unmarked ratios, is reported to the Pacific States Marine Fisheries Commission (PSMFC). Fish recovered in the various fisheries or at the hatcheries are sampled to recover coded-wire tags. This recovery information is also reported to PSMFC. This report has been prepared annually starting with the report labeled 'Annual Report 1994'. Although the current report has the title 'Annual Report 2007', it was written in fall of 2008 using data available from RMIS that same year, and submitted as final in January 2009. The main objective of the report is to evaluate survival of groups which have been tagged under this ongoing project.

  3. Ageing of Fish

    OpenAIRE

    Institute, Marine

    2006-01-01

    In order to assess the state of any fish stock it is vital that the age structure of that stock is known. The age profile of a stock gives an indication on how healthy the stock is. If there is a broad range of ages present, then the stock would appear to be in good shape. If there are no young fish, then recruitment (spawning) may have failed and there will be problems in the future. If there are no old fish in the stock, then there may be overfishing of the stock. Age data give a good insig...

  4. A model of estimating biological attachment of fish stocks to exclusive economic zones

    OpenAIRE

    Hamre, Johannes

    1993-01-01

    The paper describes a model of calculating indices of attachment of fish stock to fisheries zones based on biological parameters. Input data are weight by age, mortality rate and thepercentage area distribution of an "average" year class of the stock throughout its lifespan, The model calculates indices of biomass distribution and biomass production by area on a per recruit basis for any predetermined stage of life (age groups, spawners, etc.). Assuming that these indices of an aver...

  5. Forecasting Fish Stock Recruitment and Planning Optimal Harvesting Strategies by Using Neural Network

    Directory of Open Access Journals (Sweden)

    Lin Sun

    2009-11-01

    Full Text Available Recruitment prediction is a key element for management decisions in many fisheries. A new approach using neural network is developed as a tool to produce a formula for forecasting fish stock recruitment. In order to deal with the local minimum problem in training neural network with back-propagation algorithm and to enhance forecasting precision, neural network’s weights are adjusted by optimization algorithm. It is demonstrated that a well trained artificial neural network reveals an extremely fast convergence and a high degree of accuracy in the prediction of fish stock recruitment.

  6. Effects of fish stocking on ecosystem services: an overview and case study using the Stockholm Archipelago.

    Science.gov (United States)

    Holmlund, Cecilia M; Hammer, Monica

    2004-06-01

    In this article, we focus on documented and possible effects of fish stocking in terms of ecosystem services. The increasing use of fish stocking between 1970 and 2000 in the semiurban setting of Stockholm archipelago, Sweden, is used as case study. The objective is to analyze this management practice from an ecosystem perspective, accounting for both the ecological and social context of releasing fish. The results show that enhancements of four native species (Salmo S. trutta, Salmo salar, Stizostedion lucioperca, and Anguilla anguilla) have dominated over new introductions of one nonnative species. (Oncorhynchus mykiss). The major objective has been to increase fish catches for local resource users. Involved stakeholders include three management agencies, one hydropower company, and several local sport fishing associations. Documented effects focus on recapture and production rates. However, our analysis suggests that additional positive or negative effects on biodiversity, food web dynamics, mobile links, or ecological information may also result, with possible consequences for the long-term provision of food, game, and aesthetic values. We conclude that a more adaptive and cooperative management approach could benefit from a deeper analysis of where, when, and what species is released, by whom, which stakeholders that use the fish and those ecosystem services the fish generate, and of the role of formal and informal institutions for monitoring and evaluating the success of releasing fish. PMID:15156349

  7. Estimating the sustainable lobster ( Panulirus ornatus) catch in Torres Strait, Australia, using an age-structured stock assessment model

    Science.gov (United States)

    Ye, Yimin; Dennis, Darren; Skewes, Tim

    2008-09-01

    The ornate rock lobster ( Panulirus ornatus) is distributed across Torres Strait between Australia and Papua New Guinea and supports the most important commercial fishery to Islanders in the region. The long-term sustainability of the fishery is of importance not only to local island communities but also to the bilateral relationship between the two countries. In this paper, we developed an age-structured fishery model to assess the current stock status and estimate the long-term sustainable catch. The model was fitted to catch statistics and survey-based population estimates through a weighted maximum likelihood approach. Natural mortality was estimated at 0.732 yr -1, and fishing mortality ranged from 0.19 to 0.65 yr -1 from 1989 to 2005. The maximum sustainable yield was estimated at about 640 tonnes whole weight with a corresponding fishing mortality of 0.5 yr -1. A stock-recruitment model was established based on outputs of the stock assessment model. To obtain the maximum sustainable yield, spawning stock should be maintained at 120×10 4 lobsters. The lobster spawning stock has been fished down below this level twice since 1989, in 1999 and 2002, and was higher than this level in 2004 and 2005. These results suggest that the Torres Strait lobster stock is not over-fished and that the current harvest strategy is likely to maintain the stock at or above the level that would support the maximum sustainable yield if the current cap on fishing effort remains in place.

  8. Resident Fish Stock Status above Chief Joseph and Grand Coulee Dams; 2000 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Crossley, Brian (Spokane Tribe of Indians, Department of Natural Resources, Wellpinit, WA); Lockwood, Jr., Neil W. (Kalispel Tribe of Indians, Usk, WA); McLellan, Jason G. (Washington Department of Fish and Wildlife, Spokane, WA)

    2001-01-01

    The Resident Fish Stock Status above Chief Joseph and Grand Coulee Dams Project, commonly known as the Joint Stock Assessment Project (JSAP) is a management tool using ecosystem principles to manage artificial fish assemblages and native fish in altered environments existing in the Columbia River System above Chief Joseph and Grand Coulee Dams (blocked area). The three-phase approach of this project will enhance the fisheries resources of the blocked area by identifying data gaps, filling data gaps with research, and implementing management recommendations based on research results. The Blocked Area fisheries information housed in a central location will allow managers to view the entire system while making decisions, rather than basing management decisions on isolated portions of the system. The JSAP (NWPPC program measure 10.8B.26) is designed and guided jointly by fisheries managers in the blocked area and the Columbia Basin blocked area management plan (1998). The initial year of the project (1997) identified the need for a central data storage and analysis facility, coordination with the StreamNet project, compilation of blocked area fisheries information, and a report on the ecological condition of the Spokane River System. These needs were addressed in 1998 by acquiring a central location with a data storage and analysis system, coordinating a pilot project with StreamNet, compiling fisheries distribution data throughout the blocked area, identifying data gaps based on compiled information, and researching the ecological condition of the Spokane River. In order to ensure that any additional information collected throughout the life of this project will be easily stored and manipulated by the central storage facility, it was necessary to develop standardized methodologies between the JSAP fisheries managers. The use of common collection and analytical tools is essential to the process of streamlining joint management decisions. In 1999 and 2000 the project began to address some of the identified data gaps, throughout the blocked area, with a variety of newly developed sampling projects, as well as, continuing with ongoing data collection of established projects.

  9. Resident fish stock status above Chief Joseph and Grand Coulee dams : 2000 annual report; ANNUAL

    International Nuclear Information System (INIS)

    The Resident Fish Stock Status above Chief Joseph and Grand Coulee Dams Project, commonly known as the Joint Stock Assessment Project (JSAP) is a management tool using ecosystem principles to manage artificial fish assemblages and native fish in altered environments existing in the Columbia River System above Chief Joseph and Grand Coulee Dams (blocked area). The three-phase approach of this project will enhance the fisheries resources of the blocked area by identifying data gaps, filling data gaps with research, and implementing management recommendations based on research results. The Blocked Area fisheries information housed in a central location will allow managers to view the entire system while making decisions, rather than basing management decisions on isolated portions of the system. The JSAP (NWPPC program measure 10.8B.26) is designed and guided jointly by fisheries managers in the blocked area and the Columbia Basin blocked area management plan (1998). The initial year of the project (1997) identified the need for a central data storage and analysis facility, coordination with the StreamNet project, compilation of blocked area fisheries information, and a report on the ecological condition of the Spokane River System. These needs were addressed in 1998 by acquiring a central location with a data storage and analysis system, coordinating a pilot project with StreamNet, compiling fisheries distribution data throughout the blocked area, identifying data gaps t the blocked area, identifying data gaps based on compiled information, and researching the ecological condition of the Spokane River. In order to ensure that any additional information collected throughout the life of this project will be easily stored and manipulated by the central storage facility, it was necessary to develop standardized methodologies between the JSAP fisheries managers. The use of common collection and analytical tools is essential to the process of streamlining joint management decisions. In 1999 and 2000 the project began to address some of the identified data gaps, throughout the blocked area, with a variety of newly developed sampling projects, as well as, continuing with ongoing data collection of established projects

  10. Forecasting fish stock dynamics under climate change: Baltic herring (Clupea harengus) as a case study

    DEFF Research Database (Denmark)

    Bartolino, V.; Margonski, P.

    2014-01-01

    Climate change and anthropogenic disturbances may affect marine populations and ecosystems through multiple pathways. In this study we present a framework in which we integrate existing models and knowledge on basic regulatory processes to investigate the potential impact of future scenarios of fisheries exploitation and climate change on the temporal dynamics of the central Baltic herring stock. Alternative scenarios of increasing sea surface temperature and decreasing salinity of the Baltic Sea from a global climate model were combined with two alternative fishing scenarios, and their direct and ecosystem-mediated effects (i.e., through predation by cod and competition with sprat) on the herring population were evaluated for the period 2010-2050. Gradual increase in temperature has a positive impact on the long-term productivity of the herring stock, but it has the potential to enhance the recovery of the herring stock only in combination with sustainable fisheries management (i.e., Fmsy). Conversely, projections of herring spawning stock biomass (SSB) were generally low under elevated fishing mortality levels (Fhigh), comparable with those experienced by the stock during the 1990s. Under the combined effects of long-term warming and high fishing mortality uncertainty in herring SSB projections was higher and increasing for the duration of the forecasts, suggesting a synergistic effect of fishery exploitation and climate forcing on fish populations dynamics. Our study shows that simulations of long-term fish dynamics can be an informative tool to derive expectations of the potential long-term impact of alternative future scenarios of exploitation and climate change

  11. Duck Valley Reservoirs Fish Stocking and Operation and Maintenance, 2006-2007 Annual Progress Report.

    Energy Technology Data Exchange (ETDEWEB)

    Sellman, Jake; Dykstra, Tim [Shoshone-Paiute Tribes

    2009-05-11

    The Duck Valley Reservoirs Fish Stocking and Operations and Maintenance (DV Fisheries) project is an ongoing resident fish program that serves to partially mitigate the loss of anadromous fish that resulted from downstream construction of the hydropower system. The project's goals are to enhance subsistence fishing and educational opportunities for Tribal members of the Shoshone-Paiute Tribes and provide resident fishing opportunities for non-Tribal members. In addition to stocking rainbow trout (Oncorhynchus mykiss) in Mountain View, Lake Billy Shaw, and Sheep Creek Reservoirs, the program is also designed to maintain healthy aquatic conditions for fish growth and survival, to provide superior facilities with wilderness qualities to attract non-Tribal angler use, and to offer clear, consistent communication with the Tribal community about this project as well as outreach and education within the region and the local community. Tasks for this performance period are divided into operations and maintenance plus monitoring and evaluation. Operation and maintenance of the three reservoirs include fences, roads, dams and all reservoir structures, feeder canals, water troughs and stock ponds, educational signs, vehicles and equipment, and outhouses. Monitoring and evaluation activities included creel, gillnet, wildlife, and bird surveys, water quality and reservoir structures monitoring, native vegetation planting, photo point documentation, control of encroaching exotic vegetation, and community outreach and education. The three reservoirs are monitored in terms of water quality and fishery success. Sheep Creek Reservoir was very unproductive this year as a fishery. Fish morphometric and water quality data indicate that the turbidity is severely impacting trout survival. Lake Billy Shaw was very productive as a fishery and received good ratings from anglers. Mountain View was also productive and anglers reported a high number of quality sized fish. Water quality (specifically dissolved oxygen and temperature) is the main limiting factor in our fisheries.

  12. The use of coded wire tags to estimate cormorant predation on fish stocks in an estuary

    DEFF Research Database (Denmark)

    Jepsen, Niels; Klenke, Reinhard

    2010-01-01

    One of the main obstacles to resolving the conflict between an increasing population of cormorants, Phalacrocorax carbo sinensis, and the fishing industry is the lack of documentation of the effect of the birds’ predation on fish stocks. Tagging and releasing fish with coded wire tags followed by intensive cormorant pellet sampling may be a viable method to measure the impact of cormorants on fish populations. To test this new method, we studied cormorant predation in a shallow estuary, where nearly 100 000 fish were tagged and more than 10 000 cormorant pellets were collected over a 3-year study period. A total of 112 tags were recovered from the collected pellets. Analyses of tag recovery data indicated considerable cormorant predation on tagged flounder, eel and salmon smolts, but the method did not deliver high-quality documentation, mainly because of limitations in pellet sampling. We conclude with recommendations to enhance the value of this method.

  13. Stock assessment methods used for cephalopod fisheries

    OpenAIRE

    Pierce, Graham J.; Guerra, Ángel

    1994-01-01

    Cephalopods are of increasing importance as a fishery resource and many species are taken in directed and bycatch fisheries around the world. Owing to the short life-cycles and variable growth rates of most cephalopods, stocks may be highly volatile, both highly susceptible to recruitment overfishing and, conversely, capable of rapid recovery. Many species have protracted spawning seasons so that multiple microcohorts may be present in the population at any one time. Many as...

  14. State of marine fish stock in the Caspian Sea (from results of the research in 2011

    Directory of Open Access Journals (Sweden)

    Khodorevskaya Raisa Pavlovna

    2013-04-01

    Full Text Available The paper analyzes the state of the main commercially valuable marine fish stock in the Caspian Sea. It was established that the present-day kilka fishery harvested the minimal amount of anchovy and big-eyed kilka. Their abundance has decreased drastically, natural spawning has declined, commercial stock becomes depleted rapidly. Annually common kilka reproduction remains at an average long-term level. The stock of marine shad is quite stable with the most abundant Dolginka shad. Population replenishment depends on the abundance of food organisms and water temperature in the northern part of the Caspian Sea. The silverside is taken as a by-catch when common kilka are harvested. Its stock is stable. It is recommended that the species harvest should be increased. Only one mullet species (golden gray mullet may be seen in catch. Its stock is quite stable while commercial catches depend on fishery management. Marine fish resources (except for anchovy and big-eyed kilka make it possible to increase their commercial exploitation.

  15. Growing stock-based assessment of the carbon stock in the Belgian forest biomass

    OpenAIRE

    Vande Walle, Inge; Van Camp, Nancy; Perrin, Dominique; Raoul Lemeur,; Verheyen, Kris; Van Wesemael, Bas; Laitat, Eric

    2005-01-01

    Belgian forests covered 693 181 ha in 2000, representing 22.7% of the total land area. As no biomass or carbon stock data are included in the Flemish and Walloon regional forest inventories, species-specific wood densities, biomass expansion factors s.s. and carbon content values were critically selected from the literature. Based on these conversion and expansion factors, and on data from the forest inventories, the total C-stock in the living biomass of productive Belgian forests was assess...

  16. Water Quality, Stocking Density and Parasites of Freshwater Fish in Four Selected Areas of Bangladesh

    Directory of Open Access Journals (Sweden)

    A.N.H. Banu

    2004-01-01

    Full Text Available Stocking density, water quality (depth, temperature, dissolved oxygen, pH, total ammonia, hardness as CaCO3 and total alkalinity and parasites of fishes were investigated in four selected areas (Bogra, Chandpur, Jessore and Mymensingh for a period of three years. Stocking density varied from 15.74x103 to 34.38x103 ha-1. Water quality parameters (except ammonia varied significantly from one area to another. Among the parasites, the prevalence of Trichodinids was dominant followed by Monogenians, Chilodonella spp. and Myxosporidian. Correlation on physico-chemical parameters and incidence of parasites were studied.

  17. Climate, competition and the management of shared fish stocks

    OpenAIRE

    Miller, Kathleen; Munro, Gordon R.; Bjørndal, Trond

    2004-01-01

    Long-term climate regime shifts have profound impacts on ocean temperature and circulation patterns, and on the dynamics of fish populations. Climate regime shifts can disrupt otherwise satisfactory international management agreements. Game theory provides a perspective on the difficulty of maintaining cooperative management of shared fishery resources in the face of environmental changes. This paper draws upon two case studies -- Pacific salmon and Norwegian spring-spawning herring -- to dem...

  18. Brown trout ( Salmo trutta ) stocking impact assessment using microsatellite DNA markers

    DEFF Research Database (Denmark)

    Hansen, Michael MØller; Ruzzante, D.E.

    2001-01-01

    The genetic integrity of many salmonid fish populations is threatened by stocking of domesticated conspecifics. The purpose of this study was to assess the utility of microsatellite DNA markers for detecting loss of genetic diversity in hatchery strains, for estimating their genetic relationships, and for monitoring the genetic impact of stocking activity on wild populations of salmonid fishes. Brown trout from ten hatchery strains, one supportive breeding "strain," and five wild populations were screened for variation at eight loci. In most hatchery strains, genetic variation was comparable to that of wild populations, but three strains showed loss of allelic variation. In six of the hatchery strains, significant differentiation was observed between age classes. Genetic differentiation among all populations was moderate (F-ST = 0.065, p(ST) = 0.076), and only a minor part of genetic diversity was distributed between the wild and hatchery populations. We assessed whether wild populations were introgressed by stocked hatchery trout by performing assignment tests to determine population of origin and estimating maximum potential introgression rates. The results suggested that genetic introgression by hatchery trout had occurred for only two of the five populations potentially influenced by stocking. In one of these two rivers, microsatellite data obtained from a limited number of old scale samples indicated that individuals from the original population were genetically divergent from these of the present population, suggesting that extinction of the original population had taken place. The study demonstrates that microsatellite analysis provides a useful tool for distinguishing heavily introgressed populations from those unaffected by stocking. The information can be used to assist in (1) prioritizing populations for conservation and (2) the choice of wild populations to be used as sources for the reintroduction of salmonids in areas where local, indigenous gene pools have been extirpated.

  19. Jack-Mackerel stock assessment simulation

    OpenAIRE

    Hintzen, N. T.

    2009-01-01

    IMARES has been tasked to perform an ICA assessment on a simulated Jack Mackerel dataset. This in order to provide management advice within the SPRFMO framework. The results of the assessments are only briefly discussed, as the Assessment Simulation Task Team mainly focused on agreeing on the underlying simulated dataset and assessment settings during the 8th SPRFMO meeting in Auckland, New Zealand. The summarized outcome of these discussions was that more realistic characteristics of the rea...

  20. Forecasting Fish Stock Recruitment and Planning Optimal Harvesting Strategies by Using Neural Network

    OpenAIRE

    Lin Sun; Hongjun Xiao; Shouju Li; Dequan Yang

    2009-01-01

    Recruitment prediction is a key element for management decisions in many fisheries. A new approach using neural network is developed as a tool to produce a formula for forecasting fish stock recruitment. In order to deal with the local minimum problem in training neural network with back-propagation algorithm and to enhance forecasting precision, neural network’s weights are adjusted by optimization algorithm. It is demonstrated that a well trained artificial neural network reveals an extre...

  1. An Individual-based Probabilistic Model for Fish Stock Simulation

    Directory of Open Access Journals (Sweden)

    Federico Buti

    2010-08-01

    Full Text Available We define an individual-based probabilistic model of a sole (Solea solea behaviour. The individual model is given in terms of an Extended Probabilistic Discrete Timed Automaton (EPDTA, a new formalism that is introduced in the paper and that is shown to be interpretable as a Markov decision process. A given EPDTA model can be probabilistically model-checked by giving a suitable translation into syntax accepted by existing model-checkers. In order to simulate the dynamics of a given population of soles in different environmental scenarios, an agent-based simulation environment is defined in which each agent implements the behaviour of the given EPDTA model. By varying the probabilities and the characteristic functions embedded in the EPDTA model it is possible to represent different scenarios and to tune the model itself by comparing the results of the simulations with real data about the sole stock in the North Adriatic sea, available from the recent project SoleMon. The simulator is presented and made available for its adaptation to other species.

  2. Risk Assessment of Fishing Vessels

    OpenAIRE

    KÖSE, Ercan; D?NÇER, A. Cemal; DURUKANO?LU, H. Fehmi

    1998-01-01

    The work described in this paper is concerned with the systematic analysis of the hazards of fishing vessels. Statistical data is reviewed and analysed and fault tree analysis is applied to find the relative importance of each component with respect to system reliability. In this analysis, the loss of vessel is chosen as the top event, then branching out to the basic events such as human error, structural failure, fish on deck etc. This method is considered an essential approach for...

  3. 78 FR 32377 - Draft 2012 Marine Mammal Stock Assessment Reports

    Science.gov (United States)

    2013-05-30

    ...mammal stock assessment reports (SARs) in accordance...estimates. These ten reports are final and available...electronic form via the Internet at http://www.nmfs...United States. These reports must contain information...population growth rates and trends, estimates of...

  4. Duck Valley Reservoirs Fish Stocking and O&M, Annual Progress Report 2007-2008.

    Energy Technology Data Exchange (ETDEWEB)

    Sellman, Jake; Perugini, Carol [Department of Fish, Wildlife, and Parks, Shoshone-Paiute Tribes

    2009-02-20

    The Duck Valley Reservoirs Fish Stocking and Operations and Maintenance Project (DV Fisheries) is an ongoing resident fish program that serves to partially mitigate the loss of anadromous fish that resulted from downstream construction of the federal hydropower system. The project's goals are to enhance subsistence fishing and educational opportunities for Tribal members of the Shoshone-Paiute Tribes and provide fishing opportunities for non-Tribal members. In addition to stocking rainbow trout (Oncorhynchus mykiss) in Mountain View (MVR), Lake Billy Shaw (LBS), and Sheep Creek Reservoirs (SCR), the program is also designed to: maintain healthy aquatic conditions for fish growth and survival, provide superior facilities with wilderness qualities to attract non-Tribal angler use, and offer clear, consistent communication with the Tribal community about this project as well as outreach and education within the region and the local community. Tasks for this performance period fall into three categories: operations and maintenance, monitoring and evaluation, and public outreach. Operation and maintenance of the three reservoirs include maintaining fences, roads, dams and all reservoir structures, feeder canals, water troughs, stock ponds, educational signs, vehicles, equipment, and restroom facilities. Monitoring and evaluation activities include creel, gillnet, wildlife, and bird surveys, water quality and reservoir structures monitoring, native vegetation planting, photo point documentation, and control of encroaching exotic vegetation. Public outreach activities include providing environmental education to school children, providing fishing reports to local newspapers and vendors, updating the website, hosting community environmental events, and fielding numerous phone calls from anglers. The reservoir monitoring program focuses on water quality and fishery success. Sheep Creek Reservoir and Lake Billy Shaw had less than productive trout growth due to water quality issues including dissolved oxygen and/or turbidity. Regardless, angler fishing experience was the highest at Lake Billy Shaw. Trout in Mountain View Reservoir were in the best condition of the three reservoirs and anglers reported very good fishing there. Water quality (specifically dissolved oxygen and temperature) remain the main limiting factors in the fisheries, particularly in late August to early September.

  5. Duck Valley Reservoirs Fish Stocking and Operation and Maintenance, 2005-2006 Annual Progress Report.

    Energy Technology Data Exchange (ETDEWEB)

    Sellman, Jake; Dykstra, Tim [Shoshone-Paiute Tribes

    2009-05-11

    The Duck Valley Reservoirs Fish Stocking and Operations and Maintenance (DV Fisheries) project is an ongoing resident fish program designed to enhance both subsistence fishing, educational opportunities for Tribal members of the Shoshone-Paiute Tribes, and recreational fishing facilities for non-Tribal members. In addition to stocking rainbow trout (Oncorhynchus mykiss) in Mountain View, Lake Billy Shaw, and Sheep Creek Reservoirs, the program also intends to afford and maintain healthy aquatic conditions for fish growth and survival, to provide superior facilities with wilderness qualities to attract non-Tribal angler use, and to offer clear, consistent communication with the Tribal community about this project as well as outreach and education within the region and the local community. Tasks for this performance period are divided into operations and maintenance plus monitoring and evaluation. Operation and maintenance of the three reservoirs include fences, roads, dams and all reservoir structures, feeder canals, water troughs and stock ponds, educational signs, vehicles and equipment, and outhouses. Monitoring and evaluation activities included creel, gillnet, wildlife, and bird surveys, water quality and reservoir structures monitoring, native vegetation planting, photo point documentation, control of encroaching exotic vegetation, and community outreach and education. The three reservoirs are monitored in terms of water quality and fishery success. Sheep Creek Reservoir was the least productive as a result of high turbidity levels and constraining water quality parameters. Lake Billy Shaw trout were in poorer condition than in previous years potentially as a result of water quality or other factors. Mountain View Reservoir trout exhibit the best health of the three reservoirs and was the only reservoir to receive constant flows of water.

  6. Risk assessment in airlines stocks market

    Directory of Open Access Journals (Sweden)

    Renato Cesar Sato

    2013-04-01

    Full Text Available In this paper we compared the results between stock portfolios of North American and European airlines. The model accesses the market risk using Value-at-Risk approach in both portfolios over one month period. The analysis was performed through the use of GARCH-EVT methods and Student’s-t Copula with a Monte Carlo Simulation. The assets in the financial market usually present heavy tails in their probability distributions, so, a process capable to deal with this issue is crucial to measure the risk of loss. We analyzed the period from mid-2007 to mid-2012 to compose comparison between these two portfolios. The financial crisis of 2008 had a great impact in the North America market in relative to the European market. The central role of transport in the economy makes studies dealing with investment risk measure in this sector crucial for the industrial development. The volatility of risk in the airline market happens by internal and external motives and the methodological development of financial tools can offer an important contribution due the investment flux dependency.

  7. Biochemical Assessment of Selected Fresh Fish

    OpenAIRE

    Azam, K.; Ali, M. Y.; Asaduzzaman, M.; Basher, M. Z.; Hossain, M. M.

    2004-01-01

    Ten fresh fish samples of different species (Mugil cephalus, Setipinna phasa, Coilia dussumieri, Scatophagus argus, Sillanopsis panijus, Arius caelatus, Hilsa ilisha, Polynemus paradiseus, Platicephalus indicus and Pelamys chiliensis) collected from Kuakata, Bangladesh were assessed biochemically (proximate composition, total volatile basic nitrogen, tri-methyl amine and pH). Moisture content of fresh fish varied over a range from 65.33 to 78.92%. Likewise, protein (8.58 to 19.06%), fat (6.12...

  8. Unintentional selection, unanticipated insights: introductions, stocking and the evolutionary ecology of fishes.

    Science.gov (United States)

    Hutchings, J A

    2014-12-01

    Natural environmental change has produced countless opportunities for species to disperse into and persist in habitats where they previously did not exist. Introduction and stocking programmes have facilitated similar sorts of colonization opportunities across considerably greater geographical scales and often in much shorter periods of time. Even though the mechanism of colonization differs, the result can be the same: evolutionary change in the colonizing population in response to novel selection pressures. As a consequence, some human-mediated fish transfers have unintentionally yielded novel research opportunities to study how phenotypes and genes interact with their environment and affect ecological and evolutionary change. The primary purpose here is to explore how work, directly or indirectly involved with human-mediated transfers, has unintentionally yielded novel research and research opportunities in fish ecology and evolution. Insights have produced new knowledge or altered previously held perceptions on topics such as local adaptation, rate of evolutionary change, phenotypic plasticity, alternative reproductive strategies, population structure and colonization probability. Well-documented stocking programmes, especially in terms of history, numbers and original population sources, can provide highly fertile ground for generating further insights on the ecology and evolution of fishes and of the factors likely to influence the success of conservation-based, restoration programmes. PMID:25469951

  9. 78 FR 23284 - Marine Mammal Protection Act; Draft Revised Stock Assessment Reports for the Pacific Walrus and...

    Science.gov (United States)

    2013-04-18

    ...indicate to which revised stock assessment report(s...Alaska northern sea otter stock--your comments apply...telephone). Persons who use a telecommunications device for the deaf (TDD...draft revised marine mammal stock assessment reports...

  10. Impact of discontinuous harvesting on fishery dynamics in a stock-effort fishing model

    Science.gov (United States)

    Guo, Zhenyuan; Zou, Xingfu

    2015-02-01

    We consider a stock-effort fishing model with discontinuous harvesting strategies. Under some reasonable assumptions on the discontinuous harvesting function, we are able to confirm the well-posedness of the model, describe the structure of possible equilibria as well as establish the stability/instability of the equilibria. Most interestingly, we find that the solutions of the fishing model can arrive at a sliding mode in finite time. A qualitative analysis shows that the goal of maintaining the system at a sustainable equilibrium and optimizing the harvesting can be achieved by introducing the discontinuous harvesting strategies. From the viewpoint of optimal harvesting, we can obtain that discontinuous harvesting strategies are superior to continuous harvesting strategies, which are usually adopted in previous literature. The main difficulty resides in the discontinuity of the model, and is conquered by exploiting the theory of differential equations with discontinuous righthand sides and variable structure system theory.

  11. 75 FR 12498 - Marine Mammal Stock Assessment Reports

    Science.gov (United States)

    2010-03-16

    ...distribution and abundance of the stock, population growth rates and trends, the stock's Potential Biological Removal...been calculated for abundance of the stock and that NMFS used an assumed value for CV in estimating Nmin from...

  12. Caracterización genética de lotes de peces usados en programas de repoblamiento y su importancia en la conservación genética en la piscicultura / Genetic characterization of fish stocks used in stocking programas and their importance in the fish farm genetic conservation

    Scientific Electronic Library Online (English)

    Nelson M, Lopera Barrero; Ricardo, Pereira Ribeiro; Jayme A, Povh; Patrícia C, Gomes; Lauro, Vargas; Sheila, Nogueira de Oliveira.

    2008-12-01

    Full Text Available En las últimas décadas se ha verificado la desaparición de varias especies de peces debido principalmente a impactos generados por acciones humanas. Programas de repoblamiento vienen siendo cada vez más usados como métodos de conservación de la ictiofauna. Sin embargo, sin una correcta orientación g [...] enética y reproductiva de los lotes utilizados en estos programas, poblaciones naturales de peces y el ecosistema pueden ser afectados. El objetivo del siguiente estudio fue determinar la variabilidad genética de seis lotes de peces usados en programas de repoblamiento, mediante el marcador molecular RAPD. Se analizaron 180 alevines de tres especies de peces (Leporinus elongatus, Piaractus mesopotamicus y Prochilodus lineatus) en tres estaciones piscícolas, ubicadas en las ciudades de Rolândia, Andirá y Palotina en el estado de Paraná, Brasil. Los valores de variabilidad genética estimados por el porcentaje de fragmentos polimórficos y por el índice de diversidad de Shannon mostraron una alta variabilidad genética entre los lotes de L. elongatus y P. lineatus, debido posiblemente al efecto fundador y al manejo reproductivo adoptado en cada piscícola. Se determinó que existió baja diferenciación genética entre los lotes de P. mesopotamicus. Los resultados de este estudio posibilitaran el correcto manejo reproductivo y genético de los lotes de cada piscícola y la orientación objetiva de programas de repoblamiento, permitiendo la conservación de la variabilidad genética, factor de gran importancia en ambientes en cautiverio. Abstract in english In the last decades it has been verified the decrease and extinction of fish several species mainly to impacts generated by human actions. Stocking programs are being used as conservation methods of the ichthyofauna. However, without a correct genetic and reproductive orientation of the stocks used [...] in these programs, natural fish populations and the ecosystem can be affected. The objective of the following study was to determine the genetic variability of six fish stocks used in stocking programs, by means of the RAPD molecular marker. There were analyzed 180 juveniles of three fish species (Prochilodus lineatus, Piaractus mesopotamicus, and Leporinus elongatus) from three fish farms, located in the Rolândia, Andirá, and Palotina cities in Paraná state, Brazil. The genetic variability values estimated by the percentage of polymorphic fragments and by the Shannon diversity index showed a high genetic variability between the P. lineatus and L. elongatus stocks, due possibly to the founder effect and the reproductive management adopted in each fish farm. It was determined that low genetic differentiation existed among the P. mesopotamicus stocks. The results of this study facilitated the correct reproductive and genetic management of the stocks of each fish farm and the objective orientation of stocking programs, allowing the conservation of the genetic variability, factor of great importance in captivity environments.

  13. Uncertainties in stock assessment and the precautionary management suggestions for the anchovy (Engraulis japonicus) stock in the Yellow Sea

    Science.gov (United States)

    Wang, Yanjun; Liu, Qun; Ma, Yuxia

    2007-07-01

    Anchovy (Engraulis japonicus) is an abundant fish species in the Yellow Sea, and its natural stock is decreasing rapidly in recent years. Based on the stock-recruitment (SR) data from 1987 to 2002 published in Zhao et al. (2003), the criterion BIC (Baycsian Information Criterion) is applied to selecting a suitable model from six normal and lognormal crror structured SR statistical models, the age-structured model is used to calculate the biological reference points (BRPs), and the precision of the SR parameters and BRPs are calculated using bootstrap method. The results indicate that the anchovy fishery resource in the Yellow Sea is in an over-fished state. The precaution management principle requires that the fishery should be closed immediately.

  14. Horizontal distribution and overlap of planktivorous fish stocks in the Norwegian Sea during summers 1995–2006

    OpenAIRE

    Kjell, Utne; Geir, Huse; Geir, Ottersen; Vladimir, Zabavnikov; Jane Arge, Jacobsen; Óskarsson, Gu?mundur; Nøttestad, Leif

    2012-01-01

    The Norwegian Sea harbours several large pelagic fish stocks, which use the area for feeding during the summer. The period 1995–2006 had some of the highest biomass of pelagic fish feeding in the Norwegian Sea on record. Here we address the horizontal distribution and overlap between herring, blue whiting and mackerel in this period during the summers using a combination of acoustic, trawl and LIDAR data. A newly developed temperature atlas for the Norwegian Sea is used to present the horiz...

  15. Fish stock assessment of piraputanga Brycon microlepis in the Cuiabá River basin, Pantanal of Mato Grosso, Brazil Avaliação do estoque pesqueiro da piraputanga Brycon microlepis na bacia do rio Cuiabá, Pantanal Mato-grossense

    Directory of Open Access Journals (Sweden)

    L. A. de F. MATEUS

    2002-02-01

    Full Text Available Fork length measurements of individuals of Brycon microlepis landed and commercialized at the Porto Market in Cuiabá, MT, from May-October 1996 to May-October 1997 were used to estimate growth and mortality parameters for this species. The average estimated populational parameters were: L¥ = 705 mm, k = 0.275 year--1, C = 0.775, WP = 0.465, Lc = 164 mm, M = 0.585 year--1, Z = 0.822 year--1, with F = 0.237 year--1. Yield per recruit analysis suggests that the stock is not yet overexploited.Medidas de comprimento furcal obtidas de exemplares de Brycon microlepis desembarcados e comercializados no Mercado do Porto em Cuiabá, MT, no período de maio a outubro de 1996 e de maio a outubro de 1997, foram utilizadas para a obtenção de estimativas dos parâmetros de crescimento e mortalidade da espécie. Os parâmetros populacionais médios estimados foram: L¥ = 705 mm; k = 0,275 ano--1; C = 0,775; WP = 0,465; Lc = 164 mm; M = 0,585 ano--1; Z = 0,822 ano--1, sendo F = 0,237 ano--1. A análise do rendimento por recruta e a taxa de explotação indicam que o rendimento máximo sustentável não foi alcançado. Portanto, o estoque ainda não está sobreexplotado.

  16. Impact Assessment of the Role of Nigerian Stock Exchange on the Economic Development of Nigeria

    OpenAIRE

    Okoh, Lucky; Ekane, O. R.

    2011-01-01

    The stock exchange is a specialized market for the buying and selling of securities. These securities include stocks and shares which represent ownership interests in business, debentures and government bonds. The study assessed the impact that the Nigerian stock exchange has created on the development of the Nigerian economy. To achieve the objectives, this study reviewed stock exchange, its functions, activities, roles, and legislation. The advantages and disadvantages of listing on the sto...

  17. Rebuilding EU fish stocks could generate substantial financial resources for the European economy

    OpenAIRE

    Villasante, Sebastian; Sumaila , Rashid

    2013-01-01

    On 6 February, the European Parliament voted in favour of proposals to reform the EU’s Common Fisheries Policy. Sebastian Villasante and Rashid Sumaila assess the problem posed by overfishing in Europe’s waters and outline some of the key areas which need to be addressed if the Common Fisheries Policy is to achieve its aim of ensuring sustainable fishing.

  18. Age dependent sensitivity of oil on fish larvae, used in assessment of potential oil pollution damages on fish resources

    OpenAIRE

    Føyn, Lars; Serigstad, Bjørn

    1987-01-01

    Oil exploration in Norwegian waters will probably be extended further north into the Barents Sea. The Barents Sea is the nursery ground for important fish stocks spawning outside the norwegian coast, north of 62°N. Fish eggs and larvae are transported with the current systems northwards ending up as 0-group fish no longer dependent of the transportation provided by the currents. Some place between the egg/larval stage and mature fish, the fish is not longer vulnerable for oil pollution. This...

  19. Biochemical Assessment of Selected Fresh Fish

    Directory of Open Access Journals (Sweden)

    K. Azam

    2004-01-01

    Full Text Available Ten fresh fish samples of different species (Mugil cephalus, Setipinna phasa, Coilia dussumieri, Scatophagus argus, Sillanopsis panijus, Arius caelatus, Hilsa ilisha, Polynemus paradiseus, Platicephalus indicus and Pelamys chiliensis collected from Kuakata, Bangladesh were assessed biochemically (proximate composition, total volatile basic nitrogen, tri-methyl amine and pH. Moisture content of fresh fish varied over a range from 65.33 to 78.92%. Likewise, protein (8.58 to 19.06%, fat (6.12 to 12.99% and ash (1.07 to 8.41% content indicated wide variation in the ten fresh fish analysed. TVB-N and TMA-N values of fresh fish were found ranging between 10.92 ± 0.23 to 25.75 ± 0.80 mg N 100 g-1 and 7.70 ± 0.67 to 18.50 ± 0.77, respectively. The values of pH of the samples ranged from 7.03 ± 0.05 to 6.7 ± 0.07.

  20. Parasites as biological tags for stock discrimination in marine fish from South American Atlantic waters.

    Science.gov (United States)

    Timi, Juan T

    2007-06-01

    The use of parasites as biological tags in population studies of marine fish in the south-western Atlantic has proved to be a successful tool for discriminating stocks for all species to which it has been applied, namely: Scomber japonicus, Engraulis anchoita, Merluccius hubbsi and Cynoscion guatucupa, the latter studied on a broader geographic scale, including samples from Uruguayan and Brazilian waters. The distribution patterns of marine parasites are determined mainly by temperature-salinity profiles and by their association with specific masses of water. Analyses of distribution patterns of some parasite species in relation to gradients in environmental (oceanographic) conditions showed that latitudinal gradients in parasite distribution are common in the study area, and are probably directly related to water temperature. Indeed, temperature, which is a good predictor of latitudinal gradients of richness and diversity of species, shows a latitudinal pattern in south-western Atlantic coasts, decreasing southwards, due to the influence of subtropical and subantarctic marine currents flowing along the edge of the continental slope. This pattern also determines the distribution of zooplankton, with a characteristic specific composition in different water masses. The gradient in the distribution of parasites determines differential compositions of their communities at different latitudes, which makes possible the identification of different stocks of their fish hosts. Other features of the host-parasite systems contributing to the success of the parasitological method are: (1) parasites identified as good biological tags (i.e. anisakids) are widely distributed in the local fauna; (2) many of these species show low specificity and use paratenic hosts; and (3) the structure of parasite communities are, to a certain degree, predictable in time and space. PMID:17578590

  1. Environmental Assessment of Sport Fishing : Meredosia National Wildlife Refuge

    US Fish and Wildlife Service, Department of the Interior — This is the EA for the Meredosia NWR Sport Fishing Plan. This Environmental Assessment considers the biological, environmental, and socioeconomic effects of...

  2. A reliable method for ageing of whiting (Merlangius merlangus) for use in stock assessment and management

    DEFF Research Database (Denmark)

    Ross, Stine Dalmann; Hüssy, Karin

    2013-01-01

    Accurate age estimation is important for stock assessment and management. The importance of reliable ageing is emphasized by the impending analytical assessment of whiting (Merlangius merlangus) in the Baltic Sea. Whiting is a top predator in the western Baltic Sea, where it is fished commercially although less extensively compared to the North Sea. Although the species is considered one of the most difficult gadoids to age, few efforts have been made to shed light on the ageing problems. The aim of the present study was to identify and validate the 1st winter ring and to examine the visibility of the subsequent winter rings. Microstructure analysis was used to confirm the 1st winter ring. Additionally, otolith growth trajectories were obtained, confirming the allometric growth as seen in many fish species. The method for ageing of whole otoliths presented in this study can be directly implemented in future ageing of whiting otoliths from the Baltic Sea – and potentially also adjacent areas where the conspecifics have similar growth rates

  3. Development and sensitivity analysis of impact assessment equations based on stock-recruitment theory

    International Nuclear Information System (INIS)

    A central and unresolved problem in assessing the impact of power plant operations on Hudson River fish populations was the prediction of long-term population changes resulting from impingement and entrainment mortality. A series of equations was developed from the Ricker and Beverton-Holt stock-recruitment models to address this issue. It was assumed that compensation occurs during a brief period early in the life cycle rather than throughout the life cycle. Equations were developed for the added power plant-induced mortality occurring before or after compensation in each model. Mortality added after compensation resulted in larger estimates of population reduction than mortality added before compensation. The simple deterministic and more complex age-structured models provided identical predictions of long-term changes in population size in most cases. Similarly, the simple models predicted population changes that were nearly identical to the average age-structured model with variable survival except when levels of variation were quite high and the population modeled was semelparous. Advantages of the equations developed herein are their simplicity, generality, and minimal data requirements. The predictions of long-term population changes resulting from impingement and entrainment mortality were not attained. The magnitude and form of the compensatory responses of Hudson River fish populations remained undetermined, so that an agreement on this critical component ofan agreement on this critical component of prediction models could not be reached. 33 refs., 4 figs., 2 tabs

  4. [Stocking with bluegill sunfish, Lepomis macrochirus, by fisheries experimental stations, fishing tackle makers, and anglers in Japan, 1960-1975].

    Science.gov (United States)

    Watanabe, Hiroyuki

    2014-07-01

    This paper discusses some facts that were pivotal in the process of the introduction of Bluegill Sunfish, Lepomis macrochirus, into various places in Japan, however have not been considered in the existing literature. This paper points out that L. macrochirus escaped, and also was stocked, to the open water in Osaka as a result of experiments by a fisheries experimental station in the 1960s and early 1970s. In Shiga Prefecture too, the fish escaped into Lake Biwa as a result of experiments by a fisheries experimental station in about 1969. Neither Osaka nor Shiga are mentioned, by previous studies based on questionnaire research, as the prefectures in which L. macrochirus inhabited in the years between 1960, when the fish was first introduced into Japan, and 1979. In addition, anglers, who considered L. macrochirus an ideal game fish, stocked ponds and lakes in some prefectures with L. macrochirus in around 1970 on purpose to multiply the species. During this process, a network among not only local governments, fisheries experimental stations, and fish farmers, but also industries targeting anglers, such as fishing tackle makers and a magazine for anglers, was being formed, which however did not get established after all. These findings will contribute to enrich the basis of today's genetic research on the distribution of L. macrochirus in Japan. PMID:25296515

  5. Juvenile Fish Data (Stock Assessment and Improvement Program)

    National Oceanic and Atmospheric Administration, Department of Commerce — This project currently supports two main efforts: 1. A bi-weekly sampling regime of the hydrology and plankton along a transect over the Continental Shelf starting...

  6. The effects of EU fisheries partnership agreements on fish stocks and fishermen: The case of Cape Verde

    OpenAIRE

    Mundt, Matthias

    2012-01-01

    The viewpoints of 30 Cape Verdean fishermen are used together with an analysis of the state of tuna stocks in the Atlantic Ocean to question the EU's claim that their fleet only targets surplus species. Additionally, local marine catches of the artisanal and semi-industrial fleet are evaluated and the importance of the fisheries sector for the inhabitants of Cape Verde is shown. It is argued that even though the EU condemns illegal, unreported and unregulated fishing (IUU); their approach to ...

  7. Spawner-recruit relationships and fish stock carrying capacity in aquatic ecosystems

    DEFF Research Database (Denmark)

    MacKenzie, Brian; Myers, R.A.

    2003-01-01

    Few marine ecologists have addressed important questions about the relative productivity and carrying capacity of different ecosystems required to support fish populations. Whereas many researchers have investigated interannual variability in recruitment within a stock, we asked whether relationships between spawner abundance and subsequent recruitment are similar among populations (n = 3 to 20) of the same species, and among species (n = 14). We found that a large and significant amount of the variation (R 2 = 75 to 95 %) in mean- log recruitment is explained by mean-log spawner biomass when the spawner-recruit relationship is examined among populations of the same species. The slopes of these relationships are close to 1 (i.e. proportional). However, mean recruitment per spawner varies greatly among species (range 3 to 10). Some ecosystems allowed cod Gadus morhua, haddock Melanogrammus aeglefinus and herring Clupea harengus populations to produce an average of ca. 8-fold more recruits per spawner than other ecosystems. Also, the abundance of at least 1 species (cod) is strongly related to habitat size. Reasons for the differences in recruit production per spawner between ecosystems are unclear, but the differences themselves may need to be considered in marine ecosystem management contexts.

  8. Evolutionary impact assessment: Accounting for the evolutionary consequences of fishing in an ecosystem approach to fisheries management

    DEFF Research Database (Denmark)

    Laugen, Ane T.; Engelhard, Georg H.

    2014-01-01

    Managing fisheries resources to maintain healthy ecosystems is one of the main goals of the ecosystem approach to fisheries (EAF). While a number of international treaties call for the implementation of EAF, there are still gaps in the underlying methodology. One aspect that has received substantial scientific attention recently is fisheries-induced evolution (FIE). Increasing evidence indicates that intensive fishing has the potential to exert strong directional selection on life-history traits, behaviour, physiology, and morphology of exploited fish. Of particular concern is that reversing evolutionary responses to fishing can be much more difficult than reversing demographic or phenotypically plastic responses. Furthermore, like climate change, multiple agents cause FIE, with effects accumulating over time. Consequently, FIE may alter the utility derived from fish stocks, which in turn can modify the monetary value living aquatic resources provide to society. Quantifying and predicting the evolutionary effects of fishing is therefore important for both ecological and economic reasons. An important reason this is not happening is the lack of an appropriate assessment framework. We therefore describe the evolutionary impact assessment (EvoIA) as a structured approach for assessing the evolutionary consequences of fishing and evaluating the predicted evolutionary outcomes of alternative management options. EvoIA can contribute to EAF by clarifying how evolution may alter stock properties and ecological relations, support the precautionary approach to fisheries management by addressing a previously overlooked source of uncertainty and risk, and thus contribute to sustainable fisheries

  9. AFSC/REFM: Isolation by distance (IBD) Alaskan fish stock structure modeling

    National Oceanic and Atmospheric Administration, Department of Commerce — There is no established management protocol for stocks subject to isolation-by-distance (IBD) stock structure. This study examines several management strategies for...

  10. Assessment of Fish Biodiversity in Oni River, Ogun State, Nigeria

    Directory of Open Access Journals (Sweden)

    Obe Bernardine Wuraola

    2011-09-01

    Full Text Available For the purpose of sustainable exploitation of the fishery resourcesof Oni River, Ogun State, Nigeria, the fish biodiversity assessment was carried out. This was conducted by enumerating and identifying fish species composition, measuring the fish length, fish weight, assessing the fish abundance and biomass, determining the length-weight relationships and the length-frequency of the fishes. Altogether, 592 fishes were sampled comprising twenty-eight (28 species belonging to sixteen (16 families. The families identified included: Cichlidae, Mormyridae, Clariidae, Channidae, Malapteruridae, Gymnarchidae, Bagridae, Mochokidae, Polypteridae, Pantodontidae,Schilbeidae, Anabantidae, Osteoglossidae, Characidae, Notopteridaeand Distichodontidae. The family Mormyridae was the most abundant with 163 members followed by Cichlidae with 161 members. The least represented family was Schilbeidae with only two (2 members. On the species level, Tilapia zillii had the greatest number of representation with seventy (70 members, followed by Oreochromis niloticus with fifty-eight (58 members.

  11. Influencia del medio ambiente en evaluación de stock: una aproximación con modelos globales de producción The influence of environment on stock assessment: an approach with surplus production models

    Directory of Open Access Journals (Sweden)

    Pierre Fréon

    1995-01-01

    Full Text Available Los modelos de producción convencionales no son adecuados para ciertos stocks, porque las variaciones del esfuerzo de pesca explican sólo una parte de la variabilidad total de las capturas anuales. A menudo la variación residual es originada por fenómenos ambientales, que afectan la abundancia y/o la capturabilidad del stock de un año a otro. En consecuencia, se ha incluido en los modelos convencionales una variable ambiental para mejorar la exactitud. Esta variable aparece en las fórmulas a nivel de la abundancia, de la capturabilidad, o de ambas. Estos modelos son desarrollados a partir del modelo de producción lineal de Schaefer, del exponencial de Fox o del generalizado de Pella y Tomlinson. CLlMPROD es un sistema-experto experimental que proporciona una descripción estadística y gráfica de los datos y permite la selección del modelo correspondiente según los criterios objetivos del usuario. El software ajusta los modelos usando rutinas de regresión no-lineal, evalúa el ajuste a través de tests paramétricos y no-paramétricos, y proporciona una representación gráfica de los resultados. Se consideran las limitaciones de este tipo de modelos. No obstante, éstos pueden proporcionar una interpretación bastante acertada de la historia de la pesquería, particularmente en el caso de stocks que colapsan inesperadamente sin ningún aumento apreciable del esfuerzo de pesca. Estos modelos también pueden ser útil en el manejo eficiente de este tipo de pesquerías, cuando los fenómenos climáticos pueden ser pronosticados o cuando su influencia esté restringida a la explotación del año(s anterior. Finalmente se presenta el análisis de dos pesquerías colapsadas por una combinación de sobrepesca y cambios ambientales: la pesquería de sardina de Senegal y la de anchoveta del Pacífico surorientalConventional global production models are not suitable for certain stocks, because fishing effort variations explain only a part of the total variability of annual catches. Often the residual variability originates from the influence of environmental phenomena, which affect either the abundance or the catchability of a stock from one year to the next. Therefore, an additional environmental variable has been inserted into conventional models in order to improve their aeeuracy. This variable appear in simple formulae concerning either stock abundance, or the catchability coefficient, or both. The models were developed from Schaefer's linear production model, Fox's exponential model or Pella and Tomlinson generalised model. CLlMPROD is an experimental expert-system, using artificial intelligence, which provides a statistical and graphical description of the data set and helps the user to select the model corresponding to his case according to objective eriteria. The software fits the model to the data set using a non-linear regression routine, assesses the fit with parametric and non-parametric tests, and provides a graphical representation of the results. Limitations of this kind of model are considered. The models can provide a fairly good interpretación of fishery history, particularly when a stock collapses unexpectedly without any appreciable increase in the nominal fishing effort. These models can also pro vide a useful tool efficient management of a fishery in those instances where climatic phenomena can be forecast, or when their influence is restricted to the year(s preceding exploitation. Finally, the analysis of two fisheries collapsed by a combination of overfishing and environmental changes is presented: the Senegalese sardine fishery and the south-east Pacific anchovy fishery

  12. Influencia del medio ambiente en evaluación de stock: una aproximación con modelos globales de producción / The influence of environment on stock assessment: an approach with surplus production models

    Scientific Electronic Library Online (English)

    Pierre, Fréon; Eleuterio, Yáñez R.

    Full Text Available Los modelos de producción convencionales no son adecuados para ciertos stocks, porque las variaciones del esfuerzo de pesca explican sólo una parte de la variabilidad total de las capturas anuales. A menudo la variación residual es originada por fenómenos ambientales, que afectan la abundancia y/o l [...] a capturabilidad del stock de un año a otro. En consecuencia, se ha incluido en los modelos convencionales una variable ambiental para mejorar la exactitud. Esta variable aparece en las fórmulas a nivel de la abundancia, de la capturabilidad, o de ambas. Estos modelos son desarrollados a partir del modelo de producción lineal de Schaefer, del exponencial de Fox o del generalizado de Pella y Tomlinson. CLlMPROD es un sistema-experto experimental que proporciona una descripción estadística y gráfica de los datos y permite la selección del modelo correspondiente según los criterios objetivos del usuario. El software ajusta los modelos usando rutinas de regresión no-lineal, evalúa el ajuste a través de tests paramétricos y no-paramétricos, y proporciona una representación gráfica de los resultados. Se consideran las limitaciones de este tipo de modelos. No obstante, éstos pueden proporcionar una interpretación bastante acertada de la historia de la pesquería, particularmente en el caso de stocks que colapsan inesperadamente sin ningún aumento apreciable del esfuerzo de pesca. Estos modelos también pueden ser útil en el manejo eficiente de este tipo de pesquerías, cuando los fenómenos climáticos pueden ser pronosticados o cuando su influencia esté restringida a la explotación del año(s) anterior. Finalmente se presenta el análisis de dos pesquerías colapsadas por una combinación de sobrepesca y cambios ambientales: la pesquería de sardina de Senegal y la de anchoveta del Pacífico suroriental Abstract in english Conventional global production models are not suitable for certain stocks, because fishing effort variations explain only a part of the total variability of annual catches. Often the residual variability originates from the influence of environmental phenomena, which affect either the abundance or t [...] he catchability of a stock from one year to the next. Therefore, an additional environmental variable has been inserted into conventional models in order to improve their aeeuracy. This variable appear in simple formulae concerning either stock abundance, or the catchability coefficient, or both. The models were developed from Schaefer's linear production model, Fox's exponential model or Pella and Tomlinson generalised model. CLlMPROD is an experimental expert-system, using artificial intelligence, which provides a statistical and graphical description of the data set and helps the user to select the model corresponding to his case according to objective eriteria. The software fits the model to the data set using a non-linear regression routine, assesses the fit with parametric and non-parametric tests, and provides a graphical representation of the results. Limitations of this kind of model are considered. The models can provide a fairly good interpretación of fishery history, particularly when a stock collapses unexpectedly without any appreciable increase in the nominal fishing effort. These models can also pro vide a useful tool efficient management of a fishery in those instances where climatic phenomena can be forecast, or when their influence is restricted to the year(s) preceding exploitation. Finally, the analysis of two fisheries collapsed by a combination of overfishing and environmental changes is presented: the Senegalese sardine fishery and the south-east Pacific anchovy fishery

  13. Fish behaviour in relation to fishing operations

    OpenAIRE

    Fre?on, Pierre; Gerlotto, Franc?ois; Misund, O. A.

    1993-01-01

    The influence of fish behaviour on the most common stock assessment methods is reviewed. Fish behaviour may be divided into four major groups : habitat selection, aggregation pattern, avoidance reactions, and learning. Examples of temperate and tropical species are presented. (Résumé d'auteur)

  14. Stock Assessment of the Common Octopus (Octopus vulgaris in Monastir; the Mid-eastern Coast of Tunisia

    Directory of Open Access Journals (Sweden)

    Widien Khoufi

    2012-11-01

    Full Text Available The common octopus, (Octopus vulgaris Cuvier, 1797 is widely distributed through the world. It represents an important resource with high economic value. It is exploited by trawl and by other gears such as trammel net, pots and it is also captured by diving. Although the multitude of assessment techniques, few fisheries cephalopods were well managed. In Tunisia, common octopus (Octopus vulgaris is captured particularly in southern coast and the Sahel defined by three regions (Mahdia, Sousse and Monastir. Our study constitutes the first assessment stock in Monastir situated in the mid of the eastern coasts of Tunisia. Using surplus production models, an under fishing state of Octopus in the East of Tunisia is shown. This study confirms also the necessity of the incorporation of environmental parameters for a better explanation of the variability of common octopus abundance and the importance of these results in the assessment and management of this species.

  15. Relationship between horizontal hydroacoustic stock estimates and gillnet catches of surface-oriented fish in shallow Lake Balaton (Hungary

    Directory of Open Access Journals (Sweden)

    György Á.I.

    2012-06-01

    Full Text Available We examined whether gillnetting and hydroacoustics provide comparable relative fish density and fish size distribution estimates in the uppermost water layer of a shallow turbid lake and whether the inclusion of environmental and stock parameters could improve comparability of data between different gears. According to gillnetting, most fish shorter than 14 cm in total length were Alburnus alburnus, and most fish longer than 14 cm were Pelecus cultratus. Size distributions and median sizes obtained from gillnetting and acoustics differed. Pure acoustics-derived density estimates accounted for only <8.8% of the variation in the gillnet catch by number and no correlation was found in biomass indices. Most variances observed in the gillnet catch-per-unit-effort data were associated with water transparency, none of the other investigated variables had significant explanatory power. We conclude that the feasibility of establishing a powerful model describing the relationship between fish density estimates of gillnetting and acoustics is low in shallow and turbid habitats, and it might be successful only if the crucial sampling and environmental parameters affecting catch efficiency of gillnets and post-processing of acoustic data are considered. This study cautions again that gillnetting should be used carefully to analyse trends of fish abundance.

  16. Fish sampling with active methods.

    Czech Academy of Sciences Publication Activity Database

    Kube?ka, Jan; Godo, O. R.; Hickley, P.; Prchalová, Marie; ?íha, Milan; Rudstam, L.; Welcomme, R.

    2012-01-01

    Ro?. 123, July (2012), s. 1-3. ISSN 0165-7836 Institutional support: RVO:60077344 Keywords : fish stock assessment * active and passive gear * intercalibration Subject RIV: EH - Ecology, Behaviour Impact factor: 1.695, year: 2012

  17. Genetic structure and diversity in natural and stocked populations of the mandarin fish (Siniperca chuatsi) in China.

    Science.gov (United States)

    Yang, M; Tian, C; Liang, X-F; Zheng, H; Zhao, C; Zhu, K

    2015-01-01

    The Chinese perch, or mandarin fish (Siniperca chuatsi), is a freshwater fish that is endemic to East Asia. In this study, we investigated the genetic diversity and structure of nine natural mandarin fish populations (from the Yangtze River and Amur River basins) and six hatchery stocks (from central and south China) using microsatellite markers. The results show that the genetic diversity of the Yangtze River populations was high and stable, and genetic differences between them were not significant. In contrast, a low level of genetic diversity and strong genetic structure were detected in the Amur River population. These results suggest that the Yangtze River region and the Amur River region should be treated as two separate units in conservation programs. The hatchery stocks exhibited low genetic diversity and significant genetic differentiation compared to natural populations; this may result in a significant impact on the species if escape events occur. Therefore, a scientific aquaculture management strategy is necessary for the long-term development of hatcheries. PMID:26125708

  18. Nondestructive spectroscopic and imaging techniques for quality evaluation and assessment of fish and fish products.

    Science.gov (United States)

    He, Hong-Ju; Wu, Di; Sun, Da-Wen

    2015-01-01

    Nowadays, people have increasingly realized the importance of acquiring high quality and nutritional values of fish and fish products in their daily diet. Quality evaluation and assessment are always expected and conducted by using rapid and nondestructive methods in order to satisfy both producers and consumers. During the past two decades, spectroscopic and imaging techniques have been developed to nondestructively estimate and measure quality attributes of fish and fish products. Among these noninvasive methods, visible/near-infrared (VIS/NIR) spectroscopy, computer/machine vision, and hyperspectral imaging have been regarded as powerful and effective analytical tools for fish quality analysis and control. VIS/NIR spectroscopy has been widely applied to determine intrinsic quality characteristics of fish samples, such as moisture, protein, fat, and salt. Computer/machine vision on the other hand mainly focuses on the estimation of external features like color, weight, size, and surface defects. Recently, by incorporating both spectroscopy and imaging techniques in one system, hyperspectral imaging cannot only measure the contents of different quality attributes simultaneously, but also obtain the spatial distribution of such attributes when the quality of fish samples are evaluated and measured. This paper systematically reviews the research advances of these three nondestructive optical techniques in the application of fish quality evaluation and determination and discuss future trends in the developments of nondestructive technologies for further quality characterization in fish and fish products. PMID:24915393

  19. Population Dynamics and Stock Assessment of Blue Swimming Crab (Portunus pelagicus Linnaeus, 1758 in the Coastal Area of Trang Province, Thailand

    Directory of Open Access Journals (Sweden)

    Amonsak SAWUSDEE

    2009-06-01

    Full Text Available The population dynamics and stock assessment of blue swimming crab (Portunus pelagicus Linnaeus, 1758 in the coastal area of Trang province, Southern Thailand was done through stratified sampling of 7,499 crabs that were caught by crab gill nets and crab traps. The sampling was done from September 2006 to August 2007. The carapace width and weight relationship was measured, including parameters such as asymptotic outer carapace width (OCWa, curvature (K, asymptotic inner carapace width (ICWa, total mortality coefficient (Z, natural mortality coefficient (M, fishing mortality coefficient (F, exploitation rate (E, and total stock at first catch (Lc. The maximum sustainable yield (MSY, maximum economic yield (MEY and total biomass (B were estimated. Results showed that the asymptotic outer carapace width was 17.30. The asymptotic inner carapace width was 16.70 cm and its curvature was 1.5 per year. The total mortality coefficient was 8.96 per year, natural mortality coefficient was 1.61 per year and fishing mortality coefficient was 7.35 per year. The exploitation rate was 0.82. The total stock of blue swimming crab at first catch  at 2.5 - 3.0 cm was 7,895,170 individuals. Results of stock assessment also showed that the maximum sustainable yield was 364.33 tons, maximum economic yield was 25.29 million Baht (1 Baht = US$ 33 and total biomass was 139.83 MT. A 40 % decrease in the level of fishing effort is recommended to ensure sustainability of the blue swimming crab stock.

  20. Evaluación talla estructurada de los stocks de Ensis macha y Tagelus dombeii en el Golfo de Arauco, Chile / Size structured stock assessment of Ensis macha and Tagelus dombeii in the Gulf of Arauco, Chile

    Scientific Electronic Library Online (English)

    Aldo F, Hernández; Luis A, Cubillos; Renato A, Quiñones.

    2011-08-01

    Full Text Available Se evaluaron los stocks de Ensis macha y Tagelus dombeii, para la pesquería desarrollada en el Golfo de Arauco, Chile, entre 1996 y 2007. Se utilizó un modelo de evaluación de stock, que consiste en: i) un modelo general de dinámica poblacional especie-específica, ii) modelos para las observaciones [...] de capturas anuales, composición por tamaños y captura por unidad de esfuerzo; iii) funciones de log-verosimilitud para cada segmento de información y penalizaciones y; iv) un proceso de estimación numérica. El proceso de estimación permite la determinación simultánea de los parámetros poblacionales, tales como los parámetros de crecimiento de von Bertalanffy, la tasa de mortalidad natural a la edad, tasas de mortalidad por pesca, selectividad, y reclutamientos. Para E. macha se indican síntomas claros de sobreexplotación entre los años 1996 y 2007, con una condición de stock desovante y reclutamientos crítica y una estructura de tamaños y edades en los desembarques que dan cuenta de selectividades inferiores a la talla de primera madurez. Para el caso de T. dombeii, también se detectan algunos síntomas de sobreexplotación, con una condición de stock desovante y reclutamientos más saludable que la observada en el caso de E. macha, pero con una estructura de tamaños y edades en los desembarques que evidencian una alta dependencia de los reclutamientos anuales para el éxito de la actividad. Los stocks parentales de ambas especies muestran tendencias descendentes marcadas, lo cual a su vez estaría afectando de manera importante los reclutamientos a la pesquería. A la luz de los resultados es evidente que en el caso de las pesquerías de huepo y navajuela del Golfo de Arauco es prioritario disminuir el esfuerzo de pesca y mejorar la selectividad en la extracción. En caso que no se realicen cambios en este sentido la sustentabilidad de estas pesquerías puede verse seriamente comprometida. Abstract in english A stock assessment of Ensis macha and Tagelus dombeii for the fishery within the Gulf of Arauco, Chile was conducted from 1996 to 2007. The stock assessment model consisted of: (i) a general model of species-specific population dynamics, ii) models for the observations of annual catches, size compos [...] ition and catch per unit effort; iii) log-likelihood functions for each segment of information and penalties, and iv) a numerical estimation process. The estimation process allows the simultaneous determination of population parameters such as von Bertalanffy growth parameters, rate of natural mortality at age, fishing mortality rates, selectivity, and recruitment. The results for E. macha show clear signs of overfishing between 1996 and 2007, with a critical condition existing in regards to spawning stock and recruitment; the size and age structure in the landings indicates fishing activities are selecting fish that are smaller than the size at first maturity. In the case of T. dombeii, some signs of over exploitation are also detected but with spawning stock and recruitments healthier than that observed in the case of E. macha. Nevertheless, the size and age structure of the landings shows high dependence on the annual recruitment for the success of the fishery. The parental stocks of both species show clear declining trends, which is strongly affecting recruitments to the fishery. Our results demonstrate that it is critical to decrease the amount of fishing and improve the selectivity of the fishery. If changes towards this direction are not carried out, the sustainability of these fisheries is under threat.

  1. South Florida Seagrass Fish and Invertebrate Assessment Network (FIAN)

    U.S. Geological Survey, Department of the Interior — The South Florida Fish and Invertebrate Assessment Network (FIAN) is a monitoring project within the Comprehensive Everglades Restoration Plan (CERP). It is an...

  2. Biodiversity and exploitation of the main fish stocks in the Norwegian - Barents Sea ecosystem

    OpenAIRE

    Hamre, Johannes

    1994-01-01

    Juvenile herring and capelin are the main stocks of plankton feeders in the Barents Sea, the cod is the dominant predator. Warm climate favours recruitment of herring and cod, but large stocks of juvenile herring hamper survival of the capelin fry. Since the early 1970s, the herring stock has been grossly overexploited, which could have led to an imbalance in the state of the predatorprey relationships in the Barents Sea. In the 1970s and early 80s, however, cod could feed on capelin which ha...

  3. International management strategies for a migratory fish stock :a bio-economic simulation model of the Norwegian spring-spawning herring

    OpenAIRE

    Bjørndal, Trond; Gordon, Daniel V.; Lindroos, Marko; Kaitala, Veijo

    2000-01-01

    In this paper, a three-country dynamic bio-economic simulation model is presented for the spring-spawning herring fishery. The international spring-spawning herring fishery, based on potentially one of the most valuable fish stocks in the world, is currently recovering from a severe depletion of the stock and subsequent harvesting moratorium. Management of the herring fishery is complicated by its multi-nation exploitation, due to the highly migratory behaviour of the species moving between s...

  4. Robustness of egg production methods as a fishery independent alternative to assess the Eastern Baltic cod stock (Gadus morhua callarias L.)

    DEFF Research Database (Denmark)

    Kraus, Gerd; Hinrichsen, Hans-Harald

    2012-01-01

    At present, several cod stocks are outside safe biological limits and are managed under recovery plans. For these stocks Total Allowable Catches (TAC's) are generally low and quotas are accompanied by a broad variety of technical measures influencing the fishing patterns. Consequently, the input data to stock assessment models relying on catch statistics from the commercial fisheries is potentially biased and the perception of stock status may be incorrect. Egg production methods (EPM) provide a fishery independent alternative. Additionally, they provide better estimates of stock reproductive potential (SRP). Eastern Baltic cod (Gad us morhua callarias L) has severely declined throughout the 2nd half of the 1980s and 1st half of the 1990s due to climate-driven adverse hydrographic conditions and high fishing intensity. Since 2007 the stock is managed under a long-term management plan and showed signs of recovery in most recent years. Since 1986. egg surveys have been carried! out regularly in the Bornholm Basin, the most important spawning area of Eastern Baltic cod since mid-1980s. In the present paper the robustness of EPM towards simplification of spawning parameters and toward; reduction of the number of egg surveys is tested applying three different methods requiring different numbers of egg surveys. We applied the annual egg production method (AEPM) requiring full egg survey coverage of the spawning season to estimate cod abundances in the Bornholm Basin. In addition, the daily fecundity reduction method (DFRM) and the daily egg production method (DEPM) were tested, the latter two methods requiring only single egg surveys, but require more complex reproduction input parameters. All three methods provided a comparable result, which was also expected as many spawning parameters were derived from the same underlying data sets. In a sensitivity analysis several input parameters were varied simultaneously up to 20% in both directions. EPM were! especially sensitive towards change.; in proportions of matur! e female s at age, whereas changes in the various fecundity parameters and spawning fraction were less influential. EPM results followed the large scale spawning stock trends of the Baltic International Trawl Survey index, whereas the year to year variations of the index were not captured to well. EPM yielded spawning stock sizes in the same order of magnitude as provided by a spatially down-scaled multi-species stock assessment model

  5. Welfare aspects of stocking density in farmed rainbow trout, assessed by behavioural and physiological methods

    DEFF Research Database (Denmark)

    Laursen, Danielle Caroline

    2013-01-01

    There is an increasing amount of interest in the welfare of fish from aquaculture. There are several aquaculture practices that may act as chronic stressors and therefore have the potential to negatively impact welfare. Stocking density has been highlighted as a particular welfare concern, from both an ethical and practical point of view. A quantity of research has been conducted on the relationship between stocking density and indicators of welfare in farmed rainbow trout Oncorhynchus mykiss. The studies to date have revealed that both low and high densities have the potential to detrimentally affect welfare in rainbow trout. Several studies have endeavoured to make specific recommendations for maximum stocking density limits for rainbow trout. However, wide discrepancies exist, highlighting the fact that it has been a challenge to identify density limits that promote optimal welfare and production in rainbow trout. This emphasises the significance of developing alternative methods that provide insight into the potential density limits that are optimal for welfare and performance in rainbow trout. Here, a behavioural method using two-tank systems was developed and applied. The twotank systems consisted of two identical tanks which were attached to each other with a doorway allowing the fish to move freely between the two tanks. By studying the spatial distribution of fish in two-tank systems stocked with different densities and the neuroendocrine stress levels of the fish, a density level was established that showed indications of crowding. The results revealed that a level of aversion to crowding had been reached at an absolute density of approximately 140 kg m–3. Additionally, the influence of the established density limit on physiological indicators of welfare and performance were investigated. At this density of 140 kg m–3, the lower oxygen consumption rates and lower quantity of scale loss collected from the tanks suggested reduced levels of social hierarchy related aggressive encounters. Higher brain serotonergic activity in the brain stem of individuals held at this density indicated elevated stress levels, despite low concentrations of plasma cortisol. The reduced energetic expenditure at 140 kg m–3 resulted in a better utilisation of ingested feed and hence growth performance. Taken together, despite the chronic stress levels at this density, the results showed that at this density the reduced energy expenditure, attributed to reduced aggressive social interactions, resulted in a better growth performance. Therefore, it may be concluded that application of the method using the two-tank systems provided new insight into an optimal stocking density limit for rainbow trout. Furthermore, the method presented here provides a promising tool for investigating stocking density levels in rainbow trout. Further development of the current method would consider it applicable for determining limits for a range of culture situations.

  6. Impact Assessment of the Role of Nigerian Stock Exchange on the Economic Development of Nigeria

    Directory of Open Access Journals (Sweden)

    Okoh, Lucky

    2011-04-01

    Full Text Available The stock exchange is a specialized market for the buying and selling of securities. These securities include stocks and shares which represent ownership interests in business, debentures and government bonds. The study assessed the impact that the Nigerian stock exchange has created on the development of the Nigerian economy. To achieve the objectives, this study reviewed stock exchange, its functions, activities, roles, and legislation. The advantages and disadvantages of listing on the stock market were also x-rayed. Also highlighted were the trading, clearing and settlement process of the Nigerian stock exchange and the short comings. The study concluded that for the Nigerian stock exchange to contribute significantly in the development of the Nigerian economy through mobilization and utilization of funds for expansion of business enterprises in the country, it should intensify efforts in creating public awareness as regards its services to the economy, effective investor education, fostering and stimulating speculation in the market and reforms that would compel investors to take due diligence when funds are to be raised by government to eliminate the buying and selling culture that exists in the market should be carried out.

  7. Fish stomach contents in benthic macroinvertebrate assemblage assessments.

    Science.gov (United States)

    Tupinambás, Th; Pompeu, Ps; Gandini, Cv; Hughes, Rm; Callisto, M

    2015-01-01

    The choice of sampling gears to assess benthic macroinvertebrate communities depends on environmental characteristics, study objectives, and cost effectiveness. Because of the high foraging capacity and diverse habitats and behaviors of benthophagous fishes, their stomach contents may offer a useful sampling tool in studies of benthic macroinvertebrates, especially in large, deep, fast rivers that are difficult to sample with traditional sediment sampling gear. Our objective was to compare the benthic macroinvertebrate communities sampled from sediments with those sampled from fish stomachs. We collected benthic macroinvertebrates and fish from three different habitat types (backwater, beach, riffle) in the wet season, drying season, and dry season along a single reach of the Grande River (Paraná River Basin, southeast Brazil). We sampled sediments through use of a Petersen dredge (total of 216 grabs) and used gill nets to sample fish (total of 36 samples). We analyzed the stomach contents of three commonly occurring benthophagous fish species (Eigenmannia virescens, Iheringichthys labrosus, Leporinus amblyrhynchus). Chironomids dominated in both sampling methods. Macroinvertebrate taxonomic composition and abundances from fish stomachs differed from those from sediment samples, but less so from riffles than from backwater and beach habitats. Macroinvertebrate taxa from E. virescens stomachs were more strongly correlated with sediment samples from all three habitats than were those from the other two species. The species accumulation curves and higher mean dispersion values, compared with with sediment samples suggest that E. virescens is more efficient than sediment samples and the other fish studied at collecting benthic taxa. We conclude that by analyzing the stomach contents of benthophagous fishes it is possible to assess important characteristics of benthic communities (dispersion, taxonomic composition and diversity). This is especially true for studies that only sample fish assemblages to evaluate aquatic ecosystem impacts. Therefore, this approach can be useful to amplify assessments of human impacts, and to incorporate additional bioindicators. PMID:25945633

  8. Hypertrophy in fishponds results in weaker top-down effect of fish stock nad less efficient fish productivity.

    Czech Academy of Sciences Publication Activity Database

    Potužák, J.; H?da, J.; Pechar, Libor

    Olsztyn : European aquaculture society, 2008 - (Kamler, E.; Dabrowski, K.). s. 537-538 ISBN 978-83-60111-30-7 R&D Projects: GA MŠk(CZ) 2B06068 Institutional research plan: CEZ:AV0Z60870520 Keywords : Top-down Effect * plankton * fish production Subject RIV: DA - Hydrology ; Limnology

  9. Potential Conflict between Fishermen and Giant Otter (Pteronura brasiliensis) Populations by Fishermen in Response to Declining Stocks of Arowana Fish (Osteoglossum bicirrhosum) in Northeastern Peru

    OpenAIRE

    Maribel Recharte; Mark Bowler; Richard Bodmer

    2008-01-01

    Giant otter (Pteronura brasiliensis) populations are increasing in many parts of the Peruvian Amazon, and are coming into contact with people more regularly. Giant otters are piscivores and fishermen often see them as potential competitors for fish stocks. We report on giant otter - fisherman conflict on the River Yanayacu. During informal discussions, we found that fishermen considered the giant otter a competitor for fish, and one of their main concerns was for the fisheries of arowana (Ost...

  10. Indirect manifestation of cormorant (Phalacrocorax carbo sinensis (L. predation on pond fish stock

    Directory of Open Access Journals (Sweden)

    Kortan J.

    2008-10-01

    Full Text Available The damage to fisheries caused by cormorant predation pressure consists of losses due to direct predation and subsequent indirect losses elicited by cormorant feeding activities resulting in fish wounding and stress. Healed wounds reduce the commercial value of afflicted fish and stress may impact fish body and health condition. Fulton´s condition coefficient (FCC was calculated for wounded and healthy two-year old carp originating from five South Moravian (Czech Republic fishponds. Significant (P = 0.0011 differences in FCC (mean ± s.d., were found between non-wounded (1.48 ± 0.11, n = 19 and wounded mirror common carp, Cyprinus carpio (1.33 ± 0.14, n = 19. However no differences (P > 0.05 were recorded in scaly common carp between non-wounded (FCC 1.41 ± 0.25, n = 33 and wounded (FCC 1.46 ± 0.47, n = 33 fish of the same age and size category. A computer assisted image analysis was applied to describe the extent of such injuries. In the case of two-year old mirror, scaly and bighead carp (Aristichthys nobilis, signs of serious injuries (necroses were recorded on 1.93, 0.89 and 1.61% of body surface, respectively. Fish with deep wounds and scars, often accompanied with progressive necroses, were subject to parasitological examination. The percentage of wounded fish from total fish harvested was evaluated as ranging between < 1 and 47.4% in five ponds under study.

  11. Empirical Assessment of the Present Value Model of Stock Prices Using the Data from Thailand’s Stock Market

    OpenAIRE

    Jiranyakul, Komain

    2008-01-01

    This study examines whether bubbles are present in the Stock Exchange of Thailand. Three different methods are employed: variance bounds test, equity price bubbles test, and cointegration tests. The results from the variance bounds tests show that stock prices (proxied by the stock market index) diverge from their fundamental values. Speculative bubbles exist using the West’s two-step test. There is no cointegration between stock prices and dividends from the results of both Engle-Granger ...

  12. The Stock Book 2001

    OpenAIRE

    Institute, Marine

    2001-01-01

    The Stock Book is the principal annual publication of the Marine Institute's Fisheries Science Services (FSS). Its purpose is to provide the latest impartial scientific advice on the commercially exploited fish stocks of interest to Ireland.

  13. The Stock Book 2008

    OpenAIRE

    Institute, Marine

    2008-01-01

    The Stock Book is the principal annual publication of the Marine Institute's Fisheries Science Services (FSS). Its purpose is to provide the latest impartial scientific advice on the commercially exploited fish stocks of interest to Ireland.

  14. The Stock Book 2005

    OpenAIRE

    Institute, Marine

    2005-01-01

    The Stock Book is the principal annual publication of the Marine Institute's Fisheries Science Services (FSS). Its purpose is to provide the latest impartial scientific advice on the commercially exploited fish stocks of interest to Ireland.

  15. The Stock Book 2003

    OpenAIRE

    Institute, Marine

    2003-01-01

    The Stock Book is the principal annual publication of the Marine Institute's Fisheries Science Services (FSS). Its purpose is to provide the latest impartial scientific advice on the commercially exploited fish stocks of interest to Ireland.

  16. The Stock Book 2004

    OpenAIRE

    Institute, Marine

    2004-01-01

    The Stock Book is the principal annual publication of the Marine Institute's Fisheries Science Services (FSS). Its purpose is to provide the latest impartial scientific advice on the commercially exploited fish stocks of interest to Ireland.

  17. The Stock Book 2007

    OpenAIRE

    Institute, Marine

    2007-01-01

    The Stock Book is the principal annual publication of the Marine Institute's Fisheries Science Services (FSS). Its purpose is to provide the latest impartial scientific advice on the commercially exploited fish stocks of interest to Ireland.

  18. The Stock Book 2002

    OpenAIRE

    Institute, Marine

    2002-01-01

    The Stock Book is the principal annual publication of the Marine Institute's Fisheries Science Services (FSS). Its purpose is to provide the latest impartial scientific advice on the commercially exploited fish stocks of interest to Ireland.

  19. The Stock Book 2006

    OpenAIRE

    Institute, Marine

    2003-01-01

    The Stock Book is the principal annual publication of the Marine Institute's Fisheries Science Services (FSS). Its purpose is to provide the latest impartial scientific advice on the commercially exploited fish stocks of interest to Ireland.

  20. The Stock Book 2000

    OpenAIRE

    Institute, Marine

    2000-01-01

    The Stock Book is the principal annual publication of the Marine Institute's Fisheries Science Services (FSS). Its purpose is to provide the latest impartial scientific advice on the commercially exploited fish stocks of interest to Ireland.

  1. The Stock Book 2009

    OpenAIRE

    Institute, Marine

    2009-01-01

    The Stock Book is the principal annual publication of the Marine Institute's Fisheries Science Services (FSS). Its purpose is to provide the latest impartial scientific advice on the commercially exploited fish stocks of interest to Ireland.

  2. The Stock Book 2010

    OpenAIRE

    Institute, Marine

    2011-01-01

    The Stock Book is the principal annual publication of the Marine Institute's Fisheries Science Services (FSS). Its purpose is to provide the latest impartial scientific advice on the commercially exploited fish stocks of interest to Ireland.

  3. Mapping of soil organic carbon stocks for spatially explicit assessments of climate change mitigation potential

    International Nuclear Information System (INIS)

    Current methods for assessing soil organic carbon (SOC) stocks are generally not well suited for understanding variations in SOC stocks in landscapes. This is due to the tedious and time-consuming nature of the sampling methods most commonly used to collect bulk density cores, which limits repeatability across large areas, particularly where information is needed on the spatial dynamics of SOC stocks at scales relevant to management and for spatially explicit targeting of climate change mitigation options. In the current study, approaches were explored for (i) field-based estimates of SOC stocks and (ii) mapping of SOC stocks at moderate to high resolution on the basis of data from four widely contrasting ecosystems in East Africa. Estimated SOC stocks for 0–30 cm depth varied both within and between sites, with site averages ranging from 2 to 8 kg m?2. The differences in SOC stocks were determined in part by rainfall, but more importantly by sand content. Results also indicate that managing soil erosion is a key strategy for reducing SOC loss and hence in mitigation of climate change in these landscapes. Further, maps were developed on the basis of satellite image reflectance data with multiple R-squared values of 0.65 for the independent validation data set, showing variations in SOC stocks across these landscapes. These maps allow for spatially explicit targeting of potential climate change mitigation efforts through soil carbon sequestration, which ough soil carbon sequestration, which is one option for climate change mitigation and adaptation. Further, the maps can be used to monitor the impacts of such mitigation efforts over time. (letter)

  4. Estimating Food Consumption by a Heavily Fished Stock of Zooplanktivorous Coregonus lavaretus

    OpenAIRE

    Eckmann, Reiner; Becker, Michael; Schmid, Myriam

    2002-01-01

    The food consumption of adult zooplanktivorous Coregonus lavaretus in Lake Constance, Germany, was estimated monthly from May to October 1989 with a bioenergetics model. To achieve fine temporal resolution of lakewide consumption, we scaled the monthly weight increments of fish during the 6-month growing season by the relative weights of the stomach contents of fish sampled around sunset. As a result, the proportion of maximum consumption varied from month to month. When this proportion was h...

  5. Towards sustainable fisheries of the Öresund cod (Gadus morhua) through sub-stock-specific assessment and management recommendations

    DEFF Research Database (Denmark)

    Lindegren, Martin; Waldo, Staffan

    2013-01-01

    Fisheries management traditionally relies on stock assessments assuming discrete populations within large administrational areas. However, failing to account for sub-stock structuring may result in overestimation of the stocks' true harvest potential and unsustainable exploitation of small stock elements. Atlantic cod (Gadus morhua) frequently occurs in spatially segregated populations, some of which exhibit fine-scaled stock structuring within current management boundaries. Here we use the locally spawning cod stock in the Sound (“Öresund”) as a case study, and perform a sub-stock-specific assessment to evaluate biological and economic effects of managing the Sound cod as a separate stock. Our results indicate that reducing exploitation pressure, particularly through technical regulations i.e. increasing gill-net mesh sizes, would not only enhance the stock age distribution, but yield long-term net benefits to the local gill-net fishery. Furthermore, our study emphasizes the need for developing sub-stock-specific management recommendations in order to ensure the maintenance of fisheries resources in general, and the persistence of sub-stock structuring in particular.

  6. How systematic age underestimation can impede understanding of fish population dynamics: Lessons learned from a Lake Superior cisco stock

    Science.gov (United States)

    Yule, D.L.; Stockwell, J.D.; Black, J.A.; Cullis, K.I.; Cholwek, G.A.; Myers, J.T.

    2008-01-01

    Systematic underestimation of fish age can impede understanding of recruitment variability and adaptive strategies (like longevity) and can bias estimates of survivorship. We suspected that previous estimates of annual survival (S; range = 0.20-0.44) for Lake Superior ciscoes Coregonus artedi developed from scale ages were biased low. To test this hypothesis, we estimated the total instantaneous mortality rate of adult ciscoes from the Thunder Bay, Ontario, stock by use of cohort-based catch curves developed from commercial gill-net catches and otolith-aged fish. Mean S based on otolith ages was greater for adult females (0.80) than for adult males (0.75), but these differences were not significant. Applying the results of a study of agreement between scale and otolith ages, we modeled a scale age for each otolith-aged fish to reconstruct catch curves. Using modeled scale ages, estimates of S (0.42 for females, 0.36 for males) were comparable with those reported in past studies. We conducted a November 2005 acoustic and midwater trawl survey to estimate the abundance of ciscoes when the fish were being harvested for roe. Estimated exploitation rates were 0.085 for females and 0.025 for males, and the instantaneous rates of fishing mortality were 0.089 for females and 0.025 for males. The instantaneous rates of natural mortality were 0.131 and 0.265 for females and males, respectively. Using otolith ages, we found that strong year-classes at large during November 2005 were caught in high numbers as age-1 fish in previous annual bottom trawl surveys, whereas weak or absent year-classes were not. For decades, large-scale fisheries on the Great Lakes were allowed to operate because ciscoes were assumed to be short lived and to have regular recruitment. We postulate that the collapse of these fisheries was linked in part to a misunderstanding of cisco biology driven by scale-ageing error. ?? Copyright by the American Fisheries Society 2008.

  7. Assessment of the North-East Arctic and North Sea Stocks of Saithe Taking Into Account Migration

    OpenAIRE

    Jakobsen, Tore

    1981-01-01

    Tagging experiments have shown that there is a substantial migration of young saithe from the Norwegian coast north of 62°N to the North Sea. Assessments of the North-East Arctic and North Sea Stocks of saithe were made assuming that all 1-4 year old saithe caught between 62° and 64°N would have recruited to the North Sea stock. The new assessments give a decrease in the level of recruitment to the North-East Arctic stock and an increase to the North Sea stock. he exploitation of the Nort...

  8. Kootenai River Resident Fish Assessment, FY2008 KTOI Progress Report.

    Energy Technology Data Exchange (ETDEWEB)

    Holderman, Charles

    2009-06-26

    The overarching goal of project 1994-049-00 is to recover a productive, healthy and biologically diverse Kootenai River ecosystem, with emphasis on native fish species rehabilitation. It is especially designed to aid the recovery of important fish stocks, i.e. white sturgeon, burbot, bull trout, kokanee and several other salmonids important to the Kootenai Tribe of Idaho and regional sport-fisheries. The objectives of the project have been to address factors limiting key fish species within an ecosystem perspective. Major objectives include: establishment of a comprehensive and thorough biomonitoring program, investigate ecosystem--level in-river productivity, test the feasibility of a large-scale Kootenai River nutrient addition experiment (completed), to evaluate and rehabilitate key Kootenai River tributaries important to the health of the lower Kootenai River ecosystem, to provide funding for Canadian implementation of nutrient addition and monitoring in the Kootenai River ecosystem (Kootenay Lake) due to lost system productivity created by construction and operation of Libby Dam, mitigate the cost of monitoring nutrient additions in Arrow Lakes due to lost system productivity created by the Libby-Arrow water swap, provide written summaries of all research and activities of the project, and, hold a yearly workshop to convene with other agencies and institutions to discuss management, research, and monitoring strategies for this project and to provide a forum to coordinate and disseminate data with other projects involved in the Kootenai River basin.

  9. A Stock Assessment of the Blue Swimming Crab Portunus pelagicus (Linnaeus, 1758) for Sustainable Management in Kung Krabaen Bay, Gulf of Thailand

    OpenAIRE

    Kunsook, Chutapa; Gajaseni, Nantana; Paphavasit, Nittharatana

    2014-01-01

    A stock assessment of blue swimming crabs, Portunus pelagicus was conducted with crab gill nets and collapsible crab traps at Kung Krabaen Bay, in the eastern Gulf of Thailand, from 2008 to 2009. Several key indicators show that P. pelagicus population is in crisis. Fishing mortality shows an increase to 4.14. The exploitation rate is 0.71, higher than the optimal value of 0.38. The size of the mature females has also decreased from 8.10±0.39 cm to 7.52±1.14 cm. The average fecundity is 0.5...

  10. Assessing soil carbon stocks under pastures through orbital remote sensing

    Scientific Electronic Library Online (English)

    Gabor Gyula Julius, Szakács; Carlos Clemente, Cerri; Uwe, Herpin; Martial, Bernoux.

    2011-10-01

    Full Text Available The growing demand of world food and energy supply increases the threat of global warming due to higher greenhouse gas emissions by agricultural activity. Therefore, it is widely admitted that agriculture must establish a new paradigm in terms of environmental sustainability that incorporate techniq [...] ues for mitigation of greenhouse gas emissions. This article addresses to the scientific demand to estimate in a fast and inexpensive manner current and potential soil organic carbon (SOC) stocks in degraded pastures, using remote sensing techniques. Four pastures on sandy soils under Brazilian Cerrado vegetation in São Paulo state were chosen due to their SOC sequestration potential, which was characterized for the soil depth 0-50 cm. Subsequently, a linear regression analysis was performed between SOC and Leaf Area Index (LAI) measured in the field (LAIfield) and derived by satellite (LAIsatellite) as well as SOC and pasture reflectance in six spectra from 450 nm - 2350 nm, using the Enhanced Thematic Mapper (ETM+) sensor of satellite Landsat 7. A high correlation between SOC and LAIfield (R² = 0.9804) and LAIsatellite (R² = 0.9812) was verified. The suitability of satellite derived LAI for SOC determination leads to the assumption, that orbital remote sensing is a very promising SOC estimation technique from regional to global scale.

  11. Assessing soil carbon stocks under pastures through orbital remote sensing

    Directory of Open Access Journals (Sweden)

    Gabor Gyula Julius Szakács

    2011-10-01

    Full Text Available The growing demand of world food and energy supply increases the threat of global warming due to higher greenhouse gas emissions by agricultural activity. Therefore, it is widely admitted that agriculture must establish a new paradigm in terms of environmental sustainability that incorporate techniques for mitigation of greenhouse gas emissions. This article addresses to the scientific demand to estimate in a fast and inexpensive manner current and potential soil organic carbon (SOC stocks in degraded pastures, using remote sensing techniques. Four pastures on sandy soils under Brazilian Cerrado vegetation in São Paulo state were chosen due to their SOC sequestration potential, which was characterized for the soil depth 0-50 cm. Subsequently, a linear regression analysis was performed between SOC and Leaf Area Index (LAI measured in the field (LAIfield and derived by satellite (LAIsatellite as well as SOC and pasture reflectance in six spectra from 450 nm - 2350 nm, using the Enhanced Thematic Mapper (ETM+ sensor of satellite Landsat 7. A high correlation between SOC and LAIfield (R² = 0.9804 and LAIsatellite (R² = 0.9812 was verified. The suitability of satellite derived LAI for SOC determination leads to the assumption, that orbital remote sensing is a very promising SOC estimation technique from regional to global scale.

  12. Stakeholder participation in the management of North East Atlantic pelagic fish stocks : The future role of the Pelagic Regional Advisory Council in a reformed CFP

    DEFF Research Database (Denmark)

    Coers, Aukje; Raakjær, Jesper

    2012-01-01

    When the Regional Advisory Councils (RACs) were created during the last reform of the Common Fisheries Policy (CFP) in 2002, it was recognised that in addition to the five geographically orientated stakeholder lead advisory bodies, a separate RAC dedicated exclusively to pelagic fisheries was needed because of it being so distinctly different from other fisheries. Pelagic fishing is different mostly due to the fact that the targeted fish species behave in a unique manner by grouping in schools in mid-water unlike other commercially targeted fishes, which typically reside on or near the ocean floor. For this reason, as well as the fact that they are usually widely distributed, researching and managing this dynamic group of fishes across the borders of many countries requires a unique approach. Fortunately, despite these complexities, policy makers have succeeded to establish a reasonably well functioning management framework, which has lead to the situation that most pelagic fish stocks are harvested biologically sustainable. While a majority of Europe's fish stocks still need rebuilding, and the main aim accordingly is to reduce fishing mortality, the current focus for pelagic fish stocks is to improve the performance of already implemented Long Term Management plans in terms of their biological as well as social and economical objectives. This paper reflects upon experiences of the Pelagic Regional Advisory Council (PRAC) in its role as advisor to the EU institutions. Subsequently, in the context of ideas presented in the European Commission's Green paper, the authors discuss the future of the PRAC and conclude that its main development potential lies not with the current EU's CFP reform, but rather should be sought in a wider international context.

  13. A large-scale field assessment of carbon stocks in human-modified tropical forests.

    Science.gov (United States)

    Berenguer, Erika; Ferreira, Joice; Gardner, Toby Alan; Aragão, Luiz Eduardo Oliveira Cruz; De Camargo, Plínio Barbosa; Cerri, Carlos Eduardo; Durigan, Mariana; Cosme De Oliveira Junior, Raimundo; Vieira, Ima Célia Guimarães; Barlow, Jos

    2014-12-01

    Tropical rainforests store enormous amounts of carbon, the protection of which represents a vital component of efforts to mitigate global climate change. Currently, tropical forest conservation, science, policies, and climate mitigation actions focus predominantly on reducing carbon emissions from deforestation alone. However, every year vast areas of the humid tropics are disturbed by selective logging, understory fires, and habitat fragmentation. There is an urgent need to understand the effect of such disturbances on carbon stocks, and how stocks in disturbed forests compare to those found in undisturbed primary forests as well as in regenerating secondary forests. Here, we present the results of the largest field study to date on the impacts of human disturbances on above and belowground carbon stocks in tropical forests. Live vegetation, the largest carbon pool, was extremely sensitive to disturbance: forests that experienced both selective logging and understory fires stored, on average, 40% less aboveground carbon than undisturbed forests and were structurally similar to secondary forests. Edge effects also played an important role in explaining variability in aboveground carbon stocks of disturbed forests. Results indicate a potential rapid recovery of the dead wood and litter carbon pools, while soil stocks (0-30 cm) appeared to be resistant to the effects of logging and fire. Carbon loss and subsequent emissions due to human disturbances remain largely unaccounted for in greenhouse gas inventories, but by comparing our estimates of depleted carbon stocks in disturbed forests with Brazilian government assessments of the total forest area annually disturbed in the Amazon, we show that these emissions could represent up to 40% of the carbon loss from deforestation in the region. We conclude that conservation programs aiming to ensure the long-term permanence of forest carbon stocks, such as REDD+, will remain limited in their success unless they effectively avoid degradation as well as deforestation. PMID:24865818

  14. Stock prices assessment: proposal of a new index based on volume weighted historical prices through the use of computer modeling

    OpenAIRE

    Colliri, Tiago; Ferreira, Fernando F.

    2012-01-01

    The importance of considering the volumes to analyze stock prices movements can be considered as a well-accepted practice in the financial area. However, when we look at the scientific production in this field, we still cannot find a unified model that includes volume and price variations for stock assessment purposes. In this paper we present a computer model that could fulfill this gap, proposing a new index to evaluate stock prices based on their historical prices and vol...

  15. Effect of Different Stocking Ratio of Pangasid Catfish (Pangasius hypophthalmus) and Silver Carp (Hypophthalmicthys molitrix) on Better Water Quality Maintenance in Cat Fish Farming

    OpenAIRE

    Zannatul Ferdoushiand Farhana Haque

    2006-01-01

    An experiment was conducted in Bangladesh Agricultural University for a period of three and half months from 1st May to 15th August 2002 to observe the effects of different stocking ratio of pangasid catfish and silver carp on better water quality maintenance and impacts of using fence in cat fish farming. Four treatments each with three replicates were used. The fishes were stocked at the rate of 120 fishes/decimal. The stocking ratios were: 100% pangasid catfish in Treatment 1(T1), 0% panga...

  16. Complex dynamics analysis on fish stock harvested by two players with heterogeneous rationality

    International Nuclear Information System (INIS)

    This paper formulates a duopoly game model with heterogeneous expectations assuming that two players with asymmetric information harvest fish from a common fish ground and sell it in an imperfectly competitive market. We study the existence and stability of this system's positive equilibrium characterizing the sustainable use of the renewable resource. Then show the complex dynamics of this system in different parameters though numerical simulation. We finally show the influence of the adjustment speed of the harvesting quantity on the set of initial conditions which give non-negative trajectories converging to an equilibrium (called as a feasible set). When the player accelerates the adjustment speed in order to achieve initial advantage, we discover that it leads to instability of system and makes the system sink into the chaotic state and thus makes the resources exhaust more easily.

  17. Possible economic impact on coastal fish stock resources in Bangladesh in the case of climate change

    OpenAIRE

    Habib, Ahasan

    2010-01-01

    The Bay of Bengal fishery in Bangladesh is the most important and the predominant fishery in the country. Effort data from 1985-1986 to 2007-2008 is standardised to a standard year 2007-2008 (fish trawler) vessel and standardised effort has together with catch data been used to calculate the parameter values for the Gordon-Schafer surplus production model. The parameterised models are used to estimate the biological parameters, maximum sustainable yield, maximum economic yield and open access...

  18. Response of diurnal and nocturnal coral reef fish to protection from fishing: an assessment using baited remote underwater video

    Science.gov (United States)

    Harvey, E. S.; Dorman, S. R.; Fitzpatrick, C.; Newman, S. J.; McLean, D. L.

    2012-12-01

    Diel variation is known to alter the composition and structure of reef fish assemblages. What is unknown is how nocturnal fish assemblages respond to closed fishery area management. Diurnal and nocturnal reef fish assemblages at the Houtman Abrolhos Islands, Western Australia, were studied using baited remote underwater stereo-video systems (stereo-BRUVs). Surveys were conducted during the day and at night (using blue illumination) from three sites inside and three sites outside a closed fishery area (CFA). The relative abundance of 116 fish species from 41 families was recorded. Significant changes were observed in fish assemblage structure from day to night (driven by high dispersion at night) and in areas open versus closed to fishing (driven by increased abundance within the CFA). The effect of protection from fishing was consistent for both diurnal and nocturnal fish assemblages. Closer examination of six targeted fish species showed that their response to diel changes and the absence of fishing pressure varied from species to species. The targeted fishes Pagrus auratus and Glaucosoma hebraicum were sampled during the day and at night with both species responding positively to protection from fishing. Results suggest that the inclusion of diurnal and nocturnal fish assemblage data will provide an improved ability to assess the effectiveness of closed fishery area management.

  19. Assessment of fish freshness with an electronic nose

    Scientific Electronic Library Online (English)

    D.F, Rodríguez; S, Reich; P, Alonso; M, Szudruk; C, Arrieta; H, Lacomi; C, Gillari; A, Boselli; A, Lamagna.

    2005-07-01

    Full Text Available En este trabajo se analiza el desempeño de un prototipo de nariz electrónica, desarrollado en nuestros laboratorios para detectar el grado de conservación de la carne de pescado. El presente estudio es parte de un proyecto en marcha para crear protocolos para el control de calidad en el sector pesqu [...] ero argentino, una creciente demanda debido a razones de exportación y a nuevas regulaciones locales de control vigentes. La calidad de la carne de pescado es un concepto complejo que incluye información y control de todas las etapas, desde la zona de pesca hasta su consumo final. En este trabajo tomamos sólo un aspecto, el deterioro de la calidad de carne de filetes crudos debido a fallas en el almacenamiento refrigerado. Abstract in english In this work the performance of a prototype of electronic nose, developed in our laboratories, to assess fish freshness is analized. The present study is part of an ongoing project to perform quality assurance protocols for the Argentine fish sector, an increasing demand due to export reasons and ne [...] w national food control regulations. Fish quality is a complex concept involving a whole range of factors, freshness being one of the most important. The complete quality assessment of fish meat includes information and control of all the steps, from catching area to final consumption. In this work we address one aspect, quality deterioration of "raw fillets" due to frozen storage defects.

  20. The effect of hydropower on fish stocks: comparison between cascade and non-cascade reservoirs.

    Czech Academy of Sciences Publication Activity Database

    Draštík, Vladislav; Kube?ka, Jan; Tušer, Michal; ?ech, Martin; Frouzová, Jaroslava; Jarolím, Old?ich; Prchalová, Marie

    2008-01-01

    Ro?. 609, ?. 1 (2008), s. 25-36. ISSN 0018-8158. [EIFAC Symposium on hydropower, flood control and water abstraction: implications for fish and fisheries. Mondsee, 14.06.2006-17.06.2006] R&D Projects: GA ?R(CZ) GA206/06/1371; GA ?R(CZ) GA206/02/0520; GA ?R(CZ) GA206/07/1392; GA AV ?R(CZ) 1QS600170504 Institutional research plan: CEZ:AV0Z60170517 Keywords : abundance * biomass * longitudinal gradient * vertical and horizontal distribution * cascade Subject RIV: EH - Ecology, Behaviour Impact factor: 1.449, year: 2008

  1. Influence of climate on recruitment and migration of fish stocks in the North Sea

    OpenAIRE

    Svendsen, Einar; Aglen, Asgeir; Iversen, Svein A.; Skagen, Dankert W.; Smedstad, Odd M.

    1991-01-01

    For several decades one of the prime targets within fishery science has been to be able to understand and explain the great variability in the success of survival from egg to mature fish. One of the reasons why such effort has not lead to any clear and quantifiable conclusions, is probably that the direct and indirect influence of the physical climate has so far been underestimated. 22 years of hydrographic data taken during summer over most of the northern and central North Sea, and meteorol...

  2. ASSESSMENT OF PLASTIC FLOWS AND STOCKS IN SERBIA USING MATERIAL FLOW ANALYSIS

    OpenAIRE

    Goran Vuji?; Jovic?ic?, Nebojs?a M.; Milun Babi?; Stanisavljevic?, Nemanja S.; Batinic?, Bojan J.; Aleksandar Pavlovi?

    2010-01-01

    Material flow analysis (MFA) was used to assess the amounts of plastic materials flows and stocks that are annually produced, consumed, imported, exported, collected, recycled, and disposed in the landfills in Serbia. The analysis revealed that approximatelly 269,000 tons of plastic materials are directly disposed in uncontrolled landfills in Serbia without any preatretment, and that siginificant amounts of these materials have already accumulated in the landfills. The substantial amounts of ...

  3. Potential Conflict between Fishermen and Giant Otter (Pteronura brasiliensis Populations by Fishermen in Response to Declining Stocks of Arowana Fish (Osteoglossum bicirrhosum in Northeastern Peru

    Directory of Open Access Journals (Sweden)

    Maribel Recharte

    2008-10-01

    Full Text Available Giant otter (Pteronura brasiliensis populations are increasing in many parts of the Peruvian Amazon, and are coming into contact with people more regularly. Giant otters are piscivores and fishermen often see them as potential competitors for fish stocks. We report on giant otter - fisherman conflict on the River Yanayacu. During informal discussions, we found that fishermen considered the giant otter a competitor for fish, and one of their main concerns was for the fisheries of arowana (Osteoglossum bicirrhosum. This fishery, for young arowanas for sale to the ornamental fish trade, is very important for the communities in the Pacaya-Samiria National Reserve, and fishermen believe that stocks of this species are declining. Although arowana can be preyed upon by giant otter, smaller fish are preferred and there is no evidence for giant otters impacting on populations of this species. We identify a need for more research into giant otter populations, arowana populations, the exploitation of arowana, and the diet of giant otters in northeastern Peru, to support conservation initiatives aimed at changing the perception of giant otters as competitors for fish.

  4. Impact of hypoxia on consumption of Baltic cod in a multispecies stock assessment context

    DEFF Research Database (Denmark)

    Teschner, E.C.; Kraus, G.

    2010-01-01

    The Baltic Sea is characterised by a heterogeneous oceanographic environment. The deep water layers forming the habitat of Baltic cod (Gadus morhua callarias L.) are subjected to frequently occurring pronounced anoxic conditions. Adverse oxygen conditions result in physiological stress for organisms living under these conditions. For cod e.g. a direct relationship between oxygen availability and food intake with a decreasing ingestion rate at hypoxia could be revealed. In the present study, the effects of oxygen deficiency on consumption rates were investigated and how these translate to stock size estimates in multi-species models. Based on results from laboratory experiments, a model was fitted to evacuation rates at different oxygen levels and integrated into the existing consumption model for Baltic cod. Individual mean oxygen corrected consumption rates were 0.1–10.9% lower than the uncorrected ones. At the currently low predator stock size, however, the effect of oxygen-reduced consumption on the total amount of eaten prey biomass and thus predation mortalities was only marginal. But should successful management lead to higher cod stock sizes in the future, then total predation mortalities will greatly increase and thus improved precision of these estimates would be valuable for the assessment of prey stocks.

  5. Division of Aquatic Resources (DAR), Division of Lands and Natural Resources(DLNR) of the State of Hawaii Fish Stock Surveys from 41 sites on Oahuand Island of Hawaii from 1952-2000

    National Oceanic and Atmospheric Administration, Department of Commerce — Data are from underwater visual surveys of fish stocks from 41 survey siteson the islands of Oahu and Hawaii, conducted by biologists and technicians of Hawaii's...

  6. Assessing the state of pelagic fish communities within an ecosystem approach and the European Marine Strategy Framework Directive

    DEFF Research Database (Denmark)

    Shephard, Samuel; Rindorf, Anna

    2014-01-01

    Pelagic fish are key elements in marine foodwebs and thus comprise an important part of overall ecosystem health. We develop a suite of ecological indicators that track pelagic fish community state and evaluate state of specific objectives against Good Environmental Status (GES) criteria. Indicator time-series are calculated for the EU Marine Strategy Framework Directive “Celtic Seas” (CS) and “Greater North Sea” subregions. Precautionary reference points are proposed for each indicator and a simple decision process is then used to aggregate indicators into a GES assessment for each subregion. The pelagic fish communities of both subregions currently appear to be close to GES, but each remains vulnerable. In the CS subregion, fishing mortality is close to the precautionary reference point, although the unknown dynamics of sandeel, sprat, and sardine in the subregion may reduce the robustness of this evaluation. In the North Sea, sandeel stocks have been in poor state until very recently. Pelagic fish community biomass is slightly below the precautionary reference point in both subregions

  7. Identification and phylogenetic inferences on stocks of sharks affected by the fishing industry off the Northern coast of Brazil

    Scientific Electronic Library Online (English)

    Luis Fernando da Silva, Rodrigues-Filho; Tainá Carreira da, Rocha; Péricles Sena do, Rêgo; Horacio, Schneider; Iracilda, Sampaio; Marcelo, Vallinoto.

    Full Text Available The ongoing decline in abundance and diversity of shark stocks, primarily due to uncontrolled fishery exploitation, is a worldwide problem. An additional problem for the development of conservation and management programmes is the identification of species diversity within a given area, given the mo [...] rphological similarities among shark species, and the typical disembarkation of processed carcasses which are almost impossible to differentiate. The main aim of the present study was to identify those shark species being exploited off northern Brazil, by using the 12S-16S molecular marker. For this, DNA sequences were obtained from 122 specimens collected on the docks and the fish market in Bragança, in the Brazilian state of Pará. We identified at least 11 species. Three-quarters of the specimens collected were either Carcharhinus porosus or Rhizoprionodon sp, while a notable absence was the daggernose shark, Isogomphodon oxyrhyncus, previously one of the most common species in local catches. The study emphasises the value of molecular techniques for the identification of cryptic shark species, and the potential of the 12S-16S marker as a tool for phylogenetic inferences in a study of elasmobranchs.

  8. Identification and phylogenetic inferences on stocks of sharks affected by the fishing industry off the Northern coast of Brazil

    Directory of Open Access Journals (Sweden)

    Luis Fernando da Silva Rodrigues-Filho

    2009-01-01

    Full Text Available The ongoing decline in abundance and diversity of shark stocks, primarily due to uncontrolled fishery exploitation, is a worldwide problem. An additional problem for the development of conservation and management programmes is the identification of species diversity within a given area, given the morphological similarities among shark species, and the typical disembarkation of processed carcasses which are almost impossible to differentiate. The main aim of the present study was to identify those shark species being exploited off northern Brazil, by using the 12S-16S molecular marker. For this, DNA sequences were obtained from 122 specimens collected on the docks and the fish market in Bragança, in the Brazilian state of Pará. We identified at least 11 species. Three-quarters of the specimens collected were either Carcharhinus porosus or Rhizoprionodon sp, while a notable absence was the daggernose shark, Isogomphodon oxyrhyncus, previously one of the most common species in local catches. The study emphasises the value of molecular techniques for the identification of cryptic shark species, and the potential of the 12S-16S marker as a tool for phylogenetic inferences in a study of elasmobranchs.

  9. A cost-efficient method to assess carbon stocks in tropical peat soil

    Directory of Open Access Journals (Sweden)

    M. W. Warren

    2012-06-01

    Full Text Available Estimation of soil carbon stocks in tropical wetlands requires costly laboratory analyses and suitable facilities, which are often lacking in developing nations where most tropical wetlands are found. It is therefore beneficial to develop simple yet robust analytical tools to assess soil carbon stocks where financial and technical limitations are common. Here we use published and original data to describe soil carbon density (gC cm?3; Cd as a function of bulk density (g dry soil cm?3; Bd, which can be used to estimate belowground carbon storage using Bd measurements only. Predicted carbon densities and stocks are compared with those obtained from direct carbon analysis for ten peat swamp forest stands in three national parks of Indonesia. Analysis of soil carbon density and bulk density from the literature indicated a strong linear relationship (Cd = Bd × 0.49 + 4.61, R2 = 0.96, n = 94 for soils with an organic C content >40%. As organic C content decreases, the relationship between Cd and Bd becomes less predictable as soil texture becomes an important determinant of Cd. The equation predicted soil C stocks to within 0.39% to 7.20% of observed values. When original data were included in the analysis, the revised equation: Cd = Bd × 0.48 + 4.28, R2 = 0.96, n = 678 was well within the 95% confidence intervals of the original equation, and tended to decrease Cd estimates slightly. We recommend this last equation for a rapid estimation of soil C stocks for well developed peat soils where C content >40%.

  10. Assessment of the pelagic fish populations using CEN multi-mesh gillnets: consequences for the characterization of the fish communities

    Directory of Open Access Journals (Sweden)

    Deceliere-Vergès C.

    2009-01-01

    Full Text Available The contribution of CEN standard pelagic nets to the assessment of fish communities is tested by comparing three metrics (species composition, species abundance, and size structures measured in accordance with the standard (i.e. using benthic nets only to those calculated from the total effort (i.e. including pelagic nets. Hydroacoustic surveys were used simultaneously to assess fish densities in the pelagic habitat. The results show that in most cases the pelagic nets did not provide any extra information about these three metrics. However, their inclusion in the calculation of CPUE and size structures may affect the picture of the fish communities, especially in lakes containing salmonid populations. This study highlights the need to sample pelagic fish when assessing fish communities in order to determine lake quality.

  11. Assessment of the pelagic fish populations using CEN multi-mesh gillnets: consequences for the characterization of the fish communities

    Directory of Open Access Journals (Sweden)

    C. Deceliere-Vergès

    2008-01-01

    Full Text Available The contribution of CEN standard pelagic nets to the assessment of fish communities is tested by comparing three metrics (species composition, species abundance, and size structures measured in accordance with the standard (i.e. using benthic nets only to those calculated from the total effort (i.e. including pelagic nets. Hydroacoustic surveys were used simultaneously to assess fish densities in the pelagic habitat. The results show that in most cases the pelagic nets did not provide any extra information about these three metrics. However, their inclusion in the calculation of CPUE and size structures may affect the picture of the fish communities, especially in lakes containing salmonid populations. This study highlights the need to sample pelagic fish when assessing fish communities in order to determine lake quality.

  12. Acoustics as a tool for the assessment of Great Lakes forage fishes

    Science.gov (United States)

    Argyle, Ray L.

    1992-01-01

    Sharp reductions in forage fish populations in Lake Michigan have raised concerns about the continued ability of the forage stocks to support large populations of lake trout and other salmonid predators. There was a need for a more comprehensive and accurate estimate of forage fish abundance and distribution to evaluate these concerns. In response, cooperative diel surveys of the Lake Michigan forage species were conducted in late summer 1987 and spring 1989 with acoustics, midwater and bottom trawls.

  13. Fishing for solutions. Environmental and operational assessment of selected Galician fisheries and their products

    OpenAIRE

    Vázquez Rowe, Ian

    2012-01-01

    Fishing is the only hunting activity which is still maintained on an industrial level to sustain worldwide food demand. Currently, worldwide fisheries are suffering a series of hazards linked to overexploitation and increasing human demand for protein, causing a wide range of environmental impacts on marine ecosystems, such as stock depletion or ecosystem disruption. Moreover, the fishing industry has grown to an extent where the environmental burdens associated with on board and on land oper...

  14. Water Resource Inventory and Assessment (WRIA): Erwin National Fish Hatchery, Unicoi County, Tennessee

    US Fish and Wildlife Service, Department of the Interior — The Water Resource Inventory and Assessment WRIA for Erwin National Fish Hatchery NFH summarizes available and relevant information for hatchery water resources and...

  15. Assessment of the Greenland Halibut Stock Component in NAFO Subarea 0 + Division 1A offshore + Division 1D-1F

    DEFF Research Database (Denmark)

    JØrgensen, Ole A; Treble, M.A.

    2014-01-01

    The paper presents the background and the input parameters from research surveys and the commercial fishery to the assessment of the Greenland halibut stock component in NAFO Subarea 0 + Div. 1A offshore + Div. 1B-1F. During 2006-2009 catches have been around 24,000 tons. Catches increased to 26 900 tons in 2010 and has been at that level since. Survey trawlable biomass in Div. 0B decreased between 2011 and 2013 while biomass and recruitment increases in the Greenland shrimp fish survey and the recruitment of the 2012 year class in the entire survey area was the third largest in the time series. A combined standardized CPUE series from Div. 0A + 1AB has been stable since 2002. A combined CPUE series from Div. 1CD+0B decreased between 2011 and 2012 but increased slightly in 2013 and is above the level in 1990-2004. A combined standardized CPUE series from SA0 and 1 combined has been increasing gradually since 1997 and was in 2013 at the third highest level seen since 1990. CPUE series from the gill net in Div.0A and Div. 0B were close to or at the highest level in the time series.

  16. DISPLACE: a dynamic, individual-based model for spatial fishing planning and effort displacement: Integrating underlying fish population models

    DEFF Research Database (Denmark)

    Bastardie, Francois; Nielsen, J. Rasmus

    We previously developed a spatially explicit, individual-based model (IBM) evaluating the bio-economic efficiency of fishing vessel movements between regions according to the catching and targeting of different species based on the most recent high resolution spatial fishery data. The main purpose was to test the effects of alternative fishing effort allocation scenarios related to fuel consumption, energy efficiency (value per litre of fuel), sustainable fish stock harvesting, and profitability of the fisheries. The assumption here was constant underlying resource availability. Now, an advanced version couples the vessel model to selected size-based population models and considers the underlying resource dynamics in the distribution and density patterns of the targeted stocks for the cases of Danish and German vessels harvesting the North Sea and Baltic fish stocks. The stochastic fishing process includes direct and local depletion by stock that is specific to the vessel catching power, which is proportionalto the encountered size-based population on the visited ground and is based on stock assessment and research survey data. The impact of the potential fishing effort displacement by vessels on the fish stocks, with resulting fishing mortality, and the vessels’ economic consequences are evaluated on high spatial and seasonal disaggregation levels by simulating different individual choices of vessel speed, fishing grounds and ports. All tested scenarios led to increased overall energy efficiency, except for the fishing closures that increased fuel consumption and costs for most of the vessels due to increased travel distance. On an individual scale, the simulations led to gains and losses due to either the technical interactions between vessels exploiting the same stocks or to the alteration of individual fishing patterns. We demonstrate that integrating the spatial activity of vessels and local fish stock abundance dynamics allow for interactions and more realistic predictions of fishermen behaviour, revenues and stock abundance

  17. Assessment of current Dutch energy transition policy instruments for the existing housing stock

    International Nuclear Information System (INIS)

    This research assesses to what extent current Dutch energy transition policy instruments for the existing housing stock can fulfil local executive actors' needs and instigate adoption of energy efficiency measures by them. This is done by studying energy policy instruments for the existing housing stock in the Netherlands and in other European countries, and by an empirical research, which analyses barriers and needs of local executive actors. We found that, despite current Dutch energy transition policy instruments for the existing housing stock seem to fulfil local executive actors' needs to a large extent, complementary policy instruments are needed to stimulate and pressure the incumbent renovation regime. A long-term oriented financial rewarding system is needed to build up a structural market for the deployment of renewables, to increase the number of specialist jobs in the building sector, and to stimulate the development of integrated, standardized, building components. Furthermore, a long-term oriented financial rewarding system for energy efficiency investments in housing renovation projects, and a low VAT rate applied to energy efficient renovation measures, are needed. Finally, enforcement possibilities and sanctions (fines) should become an integrative part of Dutch energy certification regulation to make the certificate become part of a value chain.

  18. Combining satellite, aerial and ground measurements to assess forest carbon stocks in Democratic Republic of Congo

    Science.gov (United States)

    Beaumont, Benjamin; Bouvy, Alban; Stephenne, Nathalie; Mathoux, Pierre; Bastin, Jean-François; Baudot, Yves; Akkermans, Tom

    2015-04-01

    Monitoring tropical forest carbon stocks changes has been a rising topic in the recent years as a result of REDD+ mechanisms negotiations. Such monitoring will be mandatory for each project/country willing to benefit from these financial incentives in the future. Aerial and satellite remote sensing technologies offer cost advantages in implementing large scale forest inventories. Despite the recent progress made in the use of airborne LiDAR for carbon stocks estimation, no widely operational and cost effective method has yet been delivered for central Africa forest monitoring. Within the Maï Ndombe region of Democratic Republic of Congo, the EO4REDD project develops a method combining satellite, aerial and ground measurements. This combination is done in three steps: [1] mapping and quantifying forest cover changes using an object-based semi-automatic change detection (deforestation and forest degradation) methodology based on very high resolution satellite imagery (RapidEye), [2] developing an allometric linear model for above ground biomass measurements based on dendrometric parameters (tree crown areas and heights) extracted from airborne stereoscopic image pairs and calibrated using ground measurements of individual trees on a data set of 18 one hectare plots and [3] relating these two products to assess carbon stocks changes at a regional scale. Given the high accuracies obtained in [1] (> 80% for deforestation and 77% for forest degradation) and the suitable, but still to be improved with a larger calibrating sample, model (R² of 0.7) obtained in [2], EO4REDD products can be seen as a valid and replicable option for carbon stocks monitoring in tropical forests. Further improvements are planned to strengthen the cost effectiveness value and the REDD+ suitability in the second phase of EO4REDD. This second phase will include [A] specific model developments per forest type; [B] measurements of afforestation, reforestation and natural regeneration processes and [C] study of Sentinel satellite data series potential use.

  19. Carbon Stock Assessment Using Remote Sensing and Forest Inventory Data in Savannakhet, Lao PDR

    Directory of Open Access Journals (Sweden)

    Phutchard Vicharnakorn

    2014-06-01

    Full Text Available Savannakhet Province, Lao People’s Democratic Republic (PDR, is a small area that is connected to Thailand, other areas of Lao PDR, and Vietnam via road No. 9. This province has been increasingly affected by carbon dioxide (CO2 emitted from the transport corridors that have been developed across the region. To determine the effect of the CO2 increases caused by deforestation and emissions, the total above-ground biomass (AGB and carbon stocks for different land-cover types were assessed. This study estimated the AGB and carbon stocks (t/ha of vegetation and soil using standard sampling techniques and allometric equations. Overall, 81 plots, each measuring 1600 m2, were established to represent samples from dry evergreen forest (DEF, mixed deciduous forest (MDF, dry dipterocarp forest (DDF, disturbed forest (DF, and paddy fields (PFi. In each plot, the diameter at breast height (DBH and height (H of the overstory trees were measured. Soil samples (composite n = 2 were collected at depths of 0–30 cm. Soil carbon was assessed using the soil depth, soil bulk density, and carbon content. Remote sensing (RS; Landsat Thematic Mapper (TM image was used for land-cover classification and development of the AGB estimation model. The relationships between the AGB and RS data (e.g., single TM band, various vegetation indices (VIs, and elevation were investigated using a multiple linear regression analysis. The results of the total carbon stock assessments from the ground data showed that the MDF site had the highest value, followed by the DEF, DDF, DF, and PFi sites. The RS data showed that the MDF site had the highest area coverage, followed by the DDF, PFi, DF, and DEF sites. The results indicated significant relationships between the AGB and RS data. The strongest correlation was found for the PFi site, followed by the MDF, DDF, DEF, and DF sites.

  20. ASSESSMENT OF PLASTIC FLOWS AND STOCKS IN SERBIA USING MATERIAL FLOW ANALYSIS

    Directory of Open Access Journals (Sweden)

    Goran Vuji?

    2010-01-01

    Full Text Available Material flow analysis (MFA was used to assess the amounts of plastic materials flows and stocks that are annually produced, consumed, imported, exported, collected, recycled, and disposed in the landfills in Serbia. The analysis revealed that approximatelly 269,000 tons of plastic materials are directly disposed in uncontrolled landfills in Serbia without any preatretment, and that siginificant amounts of these materials have already accumulated in the landfills. The substantial amounts of landfilled plastics represent not only a loss of valuable recourses, but also pose a seriuos treath to the environment and human health, and if the trend of direct plastic landfilling is continued, Serbia will face with grave consecequnces.

  1. Carbon Stock Assessment Using Remote Sensing and Forest Inventory Data in Savannakhet, Lao PDR

    OpenAIRE

    Phutchard Vicharnakorn; Shrestha, Rajendra P.; Masahiko Nagai; Salam, Abdul P.; Somboon Kiratiprayoon

    2014-01-01

    Savannakhet Province, Lao People’s Democratic Republic (PDR), is a small area that is connected to Thailand, other areas of Lao PDR, and Vietnam via road No. 9. This province has been increasingly affected by carbon dioxide (CO2) emitted from the transport corridors that have been developed across the region. To determine the effect of the CO2 increases caused by deforestation and emissions, the total above-ground biomass (AGB) and carbon stocks for different land-cover types were assessed....

  2. Improving the assessment and management of the plaice stock complex between the North Sea and the Baltic Sea

    DEFF Research Database (Denmark)

    Ulrich, Clara; Boje, Jesper

    2012-01-01

    Plaice in Kattegat and Skagerrak have traditionally been considered as one stock unit. However the collected information on biology and fishery in areas between the North and Baltic Seas suggest changes are needed in assessment units as well as in management areas. Plaice in Skagerrak (Division 20) is now considered to be closely associated with plaice in the North Sea and is proposed to be included in the North Sea plaice stock assessment, although it is recognized that local populations are present in the area. Therefore, specific management of the Skagerrak plaice is suggested. Plaice in Kattegat (Division 21), the Belts (Division 22), and the Sound (Division 23) is considered a stock unit and is proposed to be assessed as such. However, separate management by area is also suggested to assure the preservation of the local populations. Plaice in the Baltic (Divisions 24–32) is considered a stock unit and is proposed to be assessed and managed as such. Pragmatic options are suggested for empirical harvest control rules accounting for the dynamic of local abundance, using a survey?based biomass indicator. For the future, new scientific analyses should be developed to better inform the origin of the catches, provided that additional resources are allocated to the annual monitoring of different stocks and components. Such information would provide on?going quantitative information on the degree of mixing of the various components, potentially allowing a more accurate assessment, management, and conservation of the status of these

  3. Combining Turbine Blade-Strike and Life Cycle Models to Assess Mitigation Strategies for Fish Passing Dams

    Energy Technology Data Exchange (ETDEWEB)

    Ferguson, John W.; Ploskey, Gene R.; Leonardsson, Kjell; Zabel, Richard W.; Lundqvist, Hans

    2008-08-01

    Combining the two models produced a rapid, cost effective tool for assessing dam passage impacts to fish populations and prioritizing among mitigation strategies for conserving fish stocks in regulated rivers. Estimated mortality of juvenile and adult Atlantic salmon (Salmo salar) and sea trout (S. trutta) passing turbines at two dams in northern Sweden was significantly higher for Kaplan turbines compared to Francis turbines, and for adult fish compared to juveniles based on blade strike models. Mean probability of mortality ranged from 6.7% for salmon smolts passing Francis turbines to >100% for adult salmon passing Kaplan turbines. Life cycle modeling allowed benefits to be assessed for three alternatives that mitigated this mortality. Salmon population responses varied considerably among alternatives and rivers: growth rates improved as much as 17.9%, female escapements increased up to 669%, and more than 1,300 additional female salmon were produced in one case. Protecting both smolts and adults provided benefits, and in one river, mitigating turbine mortality alone was estimated to have met the production capacity of the available habitat.

  4. Risk assessment in stock calf transportation from France to Italy: the contribution of road inspections

    Directory of Open Access Journals (Sweden)

    Cesare Zanasi

    2012-01-01

    Full Text Available In order to assess the risk associated with the transport of stock calves imported from France to Italy, information obtained from inspections carried out in Piedmont by competent authorities between 2001 and 2010 was considered. The inspections concerned 246 trucks transporting a total of 13,857 fattening calves. Based on the types of infringements recorded, several hazards related to animal welfare, such as overcrowding, tying by the horns and inappropriate mixing, were identified and characterized. The inspection of vehicles revealed hazards concerning partitions, bedding, decks, lighting, drinking and mechanical ventilation systems. A calculation was made of the incidence of these infringements and the consequent exposure of calves to such hazards and risk characterization was performed. The ranking shows overcrowding and the absence of partitions to be major risks in stock calf transportation from France to Italy. A logistic regression was adopted to evaluate the effect on the exposure to hazards of the only two variables recordable during the inspections: number of calves inside each vehicle and distance of the journey. The results showed a direct relationship between the number of calves per vehicle and exposure to overcrowding or to absence of partitions. The journey distance was found weakly and inversely related to exposure to the absence of partitions. The information obtained from the inspections provides not only a basis for evaluating the welfare of calves during transport but also an objective contribution to the assessment of the risks tied to their transportation.

  5. Diet of stocked and wild trout, Salmo trutta: Is there competition for resources?

    OpenAIRE

    Teixeira, Ami?lcar; Cortes, R.

    2006-01-01

    Stocked and native trout diet was assessed in two north-eastern Portugal headstreams during the summer season of three successive years (2000 to 2002). Significant differences were detected in the diet composition between stocked (age 1+) trout and distinct size-class of native trout. Stocked fish showed preference, almost exclusively, for food items captured near the surface (primarily terrestrial adult insects), emergent pupae and subimagos. In contrast, young-of-year (YOY) native trout fed...

  6. Loss of genetic variability at the transferrin locus in five hatchery stocks of tambaqui (Colossoma macropomum)

    OpenAIRE

    Calcagnotto Daniela; Toledo-Filho Silvio de Almeida

    2000-01-01

    Knowledge and conservation of the genetic variability in stocks maintained as live gene banks have become a high priority task for Brazilian fish culture. The aim of the present survey was to assess the transferrin allelic diversity of five hatchery stocks of tambaqui (Colossoma macropomum). The tambaqui stock from Pentecoste, the oldest maintained in Brazilian hatchery stations, retained three of the six alleles detected in wild populations of tambaqui from the Amazon River. Other hatchery s...

  7. Effect of Different Stocking Ratio of Pangasid Catfish (Pangasius hypophthalmus and Silver Carp (Hypophthalmicthys molitrix on Better Water Quality Maintenance in Cat Fish Farming

    Directory of Open Access Journals (Sweden)

    Zannatul Ferdoushiand Farhana Haque

    2006-01-01

    Full Text Available An experiment was conducted in Bangladesh Agricultural University for a period of three and half months from 1st May to 15th August 2002 to observe the effects of different stocking ratio of pangasid catfish and silver carp on better water quality maintenance and impacts of using fence in cat fish farming. Four treatments each with three replicates were used. The fishes were stocked at the rate of 120 fishes/decimal. The stocking ratios were: 100% pangasid catfish in Treatment 1(T1, 0% pangasid catfish plus 50% silver carp in Treatment 2 (T2, 0% pangasid catfish plus 40% silver carp in Treatment 3 (T3 and 50% pangasid catfish plus 50% silver carp in Treatment 4 (T4. Bamboo made fence were used in treatments 2 and 3 to keep the pangasid catfish and silver carp separately along the breadth wise considering the density of each species. Treatment 4 was set without fence. During the period of study, significant differences were found in dissolved oxygen, N03-N and chlorophyll-a concentrations among different stocking ratios of pangasid catfish and silver carp. The highest concentration of P04-P and NO3-N were found in T1 (2.7 and 3.1 mg L-1, respectively followed by treatments T3, T2 and T4. This higher concentration of NO3-N and PO4-P enhanced the plankton biomass especially Cyanophyceae and Euglenophyceae in ponds of treatment 1 and identified dominant bloom forming cyanophytes were Microcystis and Gloeocapsa, which formed the heavy phytoplankton bloom throughout the culture period and deteriorated the water quality in pangasid catfish monoculture ponds (100% pangasid catfish. Whereas better water quality were found in composite culture. Among different stocking ratios, in composite culture 1:1 without fence (treatment 4 gave the best result in better water quality maintenances than 2:1 and 1:1 (with fence, treatment 3 and 2 ratios. In treatment 4 when the nutrients concentrations enhanced the phytoplankton production then silver carp grazed over phytoplankton throughout water body, which prevented the phytoplankton bloom formation during culture period and maintained a better environmental condition. Some algal bloom occurred in the portion of pangasid catfish in treatment 2 and treatment 3. It might be due to the grazing activity of silver carp over phytoplankton was restricted by the fence in those treatments. Considering the above facts composite culture of pangasid catfish and silver carp with 1:1 ratio and without fence may help in maintaining the good environmental condition of catfish farming through preventing the algal bloom.

  8. Application of system dynamics for assessment of changes of the level of stock after introduction of ERP systems

    Directory of Open Access Journals (Sweden)

    Lebedeva Lyudmyla M.

    2013-03-01

    Full Text Available Application of information management system is an important element of ensuring business effectiveness for any modern enterprise. However, the permanent growth of the cost of such systems requires application of new approaches to assessment of influence of complex information systems upon the level of stock. The article describes a structure of the model and specifically those elements that allow assessment of reduction of delays connected with automation. It offers to assess a change of the stock level with the use of methods of system dynamics. The results are based on imitation experiments of the stock level in the production and sales system with the use of the AnyLogic software system.

  9. Genetic assessment of ornamental fish species from North East India.

    Science.gov (United States)

    Dhar, Bishal; Ghosh, Sankar Kumar

    2015-01-25

    Ornamental fishes are traded with multiple names from various parts around the world, including North East India. Most are collected from the wild, due to lack of species-specific culture or breeding, and therefore, such unmanaged collection of the wild and endemic species could lead to severe threats to biodiversity. Despite many regulatory policies, trade of threatened species, including the IUCN listed species have been largely uncontrolled, due to species identification problems arising from the utilization of multiple trade names. So, the development of species-specific DNA marker is indispensable where DNA Barcoding is proved to be helpful in species identification. Here, we investigated, through DNA Barcoding and morphological assessment, the identification of 128 ornamental fish specimens exported from NE India from different exporters. The generated sequences were subjected to similarity match in BOLD-IDS as well as BLASTN, and analysed using MEGA5.2 for species identification through Neighbour-Joining (NJ) clustering, and K2P distance based approach. The analysis revealed straightforward identification of 84 specimens into 35 species, while 44 specimens were difficult to distinguish based on CO1 barcode alone. However, these cases were resolved through morphology, NJ and distanced based method and found to be belonging to 16 species. Among the 51 identified species, 14 species represented multiple trade names; 17 species belonged to threatened category. Species-level identification through DNA Barcoding along with traditional morphotaxonomy reflects its efficacy in regulating ornamental fish trade and therefore, appeals for their conservation in nature. The use of trade names rather than the zoological name created the passage for trafficking of the threatened species and demands immediate attention for sustaining wildlife conservation. PMID:25447914

  10. Fish Creek Federally Endangered Freshwater Mussel Impact Assessment

    US Fish and Wildlife Service, Department of the Interior — Sediment toxicity was evaluated for one site upstream and three sites downstream of a diesel fuel spill that occurred in Fish Creek OH and IN in September 1993...

  11. Development of a stock-recruitment model and assessment of biological reference points for the Lake Erie walleye fishery

    Science.gov (United States)

    Zhao, Yingming; Kocovsky, Patrick; Madenjian, Charles P.

    2013-01-01

    We developed an updated stock–recruitment relationship for Lake Erie Walleye Sander vitreus using the Akaike information criterion model selection approach. Our best stock–recruitment relationship was a Ricker spawner–recruit function to which spring warming rate was added as an environmental variable, and this regression model explained 39% of the variability in Walleye recruitment over the 1978 through 2006 year-classes. Thus, most of the variability in Lake Erie Walleye recruitment appeared to be attributable to factors other than spawning stock size and spring warming rate. The abundance of age-0 Gizzard Shad Dorosoma cepedianum, which was an important term in previous models, may still be an important factor for Walleye recruitment, but poorer ability to monitor Gizzard Shad since the late 1990s could have led to that term failing to appear in our best model. Secondly, we used numerical simulation to demonstrate how to use the stock recruitment relationship to characterize the population dynamics (such as stable age structure, carrying capacity, and maximum sustainable yield) and some biological reference points (such as fishing rates at different important biomass or harvest levels) for an age-structured population in a deterministic way.

  12. AFSC/REFM: Beaufort Sea Marine Fish Survey, Beaufort Sea, Alaska, August 2008, Fisheries Interaction Team

    National Oceanic and Atmospheric Administration, Department of Commerce — The Alaska Fisheries Science Center's Status of Stocks and Multispecies Assessment (SSMA) Programs Fishery Interaction Team (FIT) conducted a fish survey in the...

  13. Estimation of time-varying selectivity in stock assessments using state-space models

    DEFF Research Database (Denmark)

    Nielsen, Anders; Berg, Casper Willestofte

    2014-01-01

    Time-varying selectivity is one of the main challenges in single species age-based assessment models. In classical deterministic VPA-type models the fishing mortality rates are unfiltered representations of the observed catches. As a consequence the selectivity becomes time-varying, but this representation is too fluctuating, because it includes the observation noise. In parametric statistical catch at age models a common assumption is that the selectivity is constant in all years, although time-varying selectivity can be introduced by splitting the data period in blocks with different selectivities, or by using smoothing splines and penalized time-deviances. However, these methods require subjective choices w.r.t. the degree of time-varying allowed. A simple state-space assessment model is presented as an alternative, which among other benefits offers an objective way of estimating time-varying selectivity pattern. The fishing mortality rates are considered (possibly correlated) stochastic processes, and thecorresponding process variances are estimated within the model. The model is applied to North Sea cod and it is verified from simulations that time-varying selectivity can be estimated

  14. Compression stockings

    Science.gov (United States)

    Compression hose; Pressure stockings; Support stockings; Gradient stockings ... You wear compression stockings to improve blood flow in your legs. Compression stockings gently squeeze your legs to move blood up ...

  15. Assessment of the Marketing of Frozen Fish (Iced Fish in Edo State, Nigeria

    Directory of Open Access Journals (Sweden)

    Ebewore Solomon Okeoghene

    2013-09-01

    Full Text Available The study examines the marketing of frozen fish in Edo State of Nigeria. The primary data used for the study were derived using structured questionnaires administered to 180 randomly selected frozen fish marketers from six markets. Both descriptive and inferential statistics were used in data analysis. From the findings, marketing of fish is mainly carried out by females, most of the respondents are in the economically active age group and are mostly married; they have a lot of experience in the business, majority of them are retailers selling less than four cartons of fish on daily basis and most of them have formal education. From the gross margin analysis and t-test, marketing of frozen fish is profitable in the area. However, it was recommended that major constraints like poor storage/preservation, inadequate capital and marketing costs should be tackled to improve the efficiency of marketing system of frozen fish in the State.

  16. Exposure assessment for trace elements from consumption of marine fish in Southeast Asia

    International Nuclear Information System (INIS)

    Concentrations of 20 trace elements were determined in muscle and liver of 34 species of marine fish collected from coastal areas of Cambodia, Indonesia, Malaysia and Thailand. Large regional difference was observed in the levels of trace elements in liver of one fish family (Carangidae): the highest mean concentration was observed in fish from the Malaysian coastal waters for V, Cr, Zn, Pb and Bi and those from the Java Sea side of Indonesia for Sn and Hg. To assess the health risk to the Southeast Asian populations from consumption of fish, intake rates of trace elements were estimated. Some marine fish showed Hg levels higher than the guideline values by U.S. Environmental Protection Agency and Joint FAO/WHO Expert Committee on Food Additives (JECFA). This suggests that consumption of these fish may be hazardous to the people. -- Intake of mercury through consumption of some marine fish species might be hazardous to the people in Southeast Asia

  17. An assessment of fish mortality at the Rance tidal power barrage, Brittany, France

    International Nuclear Information System (INIS)

    This report describes the results of three weeks field work carried out on the Rance Estuary in August 1991. The objectives were to make a preliminary assessment of the relative frequency with which dead fish accumulate in the Rance barrage lock pit; to assess the likely cause of mortality; and to assess the success with which marine fish migrate across a tidal barrage by tagging a variety of species within the barrage basin. (author)

  18. Unraveling biocomplexity of Northeast Atlantic herring stocks using SNP markers

    DEFF Research Database (Denmark)

    Bekkevold, Dorte; Limborg, Morten

    2012-01-01

    Atlantic herring (Clupea harengus) exhibit biocomplexity, with widespread, geographically explicit populations that perform long?range migration to common feeding and wintering areas, where they are exploited by fisheries. This means that exploited stocks do not describe discrete units, thereby complicating stock assessment and management. It is therefore of management interest to trace individual population migration patterns and contributions to fisheries. To underpin management and to develop a validated tool for traceability of individuals from mixed?stock samples we applied single nucleotide polymorphism (SNP) markers in Northeast Atlantic herring population samples. Marker panels were targeted to include gene?associated loci to maximize statistical resolution. Application of 281 SNP markers to samples representing different levels of stock complexity showed that the regional origin of individual fish and mixed fish samples could be successfully identified at high statistical power. Our results demonstrate the usefulness of genetic stock identification even in fish, such as herring, exhibiting weak neutral genetic structure, and that such methods allow unprecedented insights into temporal and spatial dynamics applicable to stock assessment methods, as well as presenting a traceability tool for certification of herring and herring products

  19. Replacing fish meal by food waste to produce lower trophic level fish containing acceptable levels of polycyclic aromatic hydrocarbons: Health risk assessments.

    Science.gov (United States)

    Cheng, Zhang; Mo, Wing-Yin; Lam, Cheung-Lung; Choi, Wai-Ming; Wong, Ming-Hung

    2015-08-01

    This study aimed at using different types of food wastes (mainly containing cereal [food waste A] and meat meal [food waste B]) as major sources of protein to replace the fish meal used in fish feeds to produce quality fish. The traditional fish farming model used to culture low trophic level fish included: bighead, (Hypophthalmichthys nobilis), grass carp, (Ctenopharyngodon idellus), and mud carp, (Cirrhinus molitorella) of omnivorous chain. The results indicated that grass carp and bighead carp fed with food waste feeds were relatively free of PAHs. The results of health risk assessment showed that the fish fed with food waste feeds were safe for consumption from the PAHs perspective. PMID:25880597

  20. Species diversity, biomass, and carbon stock assessments of a natural mangrove forest in palawan, philippines

    International Nuclear Information System (INIS)

    Philippines claims international recognition for its mangrove-rich ecosystem which play significant functions from the viewpoint of ecosystem services and climate change mitigation. In this study, we assessed the species diversity of the natural mangrove forest of Bahile, Puerto Princesa City, Palawan and evaluated its potential to sequester and store carbon. Sixteen plots with a size of 10 m * 10 m were established using quadrat sampling technique to identify, record, and measure the trees. Diversity index and allometric equations were utilized to determine species diversity, and biomass and carbon stocks. Sediment samples in undisturbed portions using a 30 cm high and 5 cm diameter corer were collected in all plots to determine near-surface sediment carbon. The diversity index (H = 0.9918) was very low having a total of five true mangrove species identified dominated by Rhizophora apiculata Bl. with an importance value index of 148.1%. Among the stands, 74% of the total biomass was attributed to the above-ground (561.2 t ha-1) while 26% was credited to the roots (196.5 t ha-1). The total carbon sequestered and stored in the above-ground and root biomass were 263.8 t C ha-1 (50%) and 92.3 t C ha-1 (17%), respectively. Sediments contained 33% (173.75 t C ha-1) of the mangrove C-stocks. Stored carbon was equivalent to 1944.5 t CO/sub 2/ ha-1. These values suggest that Bahile natural mangrove forest has a potential to sequester and store substantial amounts of atmospheric carbon, hence the need for sustainable management and protection of this important coastal ecosystem. (author)

  1. Assessing Historical Fish Community Composition Using Surveys, Historical Collection Data, and Species Distribution Models

    OpenAIRE

    Labay, Ben; Cohen, Adam E.; Sissel, Blake; Hendrickson, Dean A.; Martin, F. Douglas; Sarkar, Sahotra

    2011-01-01

    Accurate establishment of baseline conditions is critical to successful management and habitat restoration. We demonstrate the ability to robustly estimate historical fish community composition and assess the current status of the urbanized Barton Creek watershed in central Texas, U.S.A. Fish species were surveyed in 2008 and the resulting data compared to three sources of fish occurrence information: (i) historical records from a museum specimen database and literature searches; (ii) a nearl...

  2. Challenges in developing fish-based ecological assessment methods for large foodplain rivers

    OpenAIRE

    Leeuw, J. J.; Buijse, A. D.; Haidvogl, G.; Lapinska, M.

    2007-01-01

    Large European floodplain rivers have a great diversity in habitats and fish fauna, but tend to be heavily modified. The complexity of these river systems and their multiple human impacts pose considerable challenges for assessment of their ecological status. This paper discusses: (1) the application of historical information on fish fauna and habitat availability to describe reference conditions; (2) responses of fish assemblages to human disturbance by comparing various rivers and river seg...

  3. Fish pass assessment by remote control: a novel framework for quantifying the hydraulics at fish pass entrances

    Science.gov (United States)

    Kriechbaumer, Thomas; Blackburn, Kim; Gill, Andrew; Breckon, Toby; Everard, Nick; Wright, Ros; Rivas Casado, Monica

    2014-05-01

    Fragmentation of aquatic habitats can lead to the extinction of migratory fish species with severe negative consequences at the ecosystem level and thus opposes the target of good ecological status of rivers defined in the EU Water Framework Directive (WFD). In the UK, the implementation of the EU WFD requires investments in fish pass facilities of estimated 532 million GBP (i.e. 639 million Euros) until 2027 to ensure fish passage at around 3,000 barriers considered critical. Hundreds of passes have been installed in the past. However, monitoring studies of fish passes around the world indicate that on average less than half of the fish attempting to pass such facilities are actually successful. There is a need for frameworks that allow the rapid identification of facilities that are biologically effective and those that require enhancement. Although there are many environmental characteristics that can affect fish passage success, past research suggests that variations in hydrodynamic conditions, reflected in water velocities, velocity gradients and turbulences, are the major cues that fish use to seek migration pathways in rivers. This paper presents the first steps taken in the development of a framework for the rapid field-based quantification of the hydraulic conditions downstream of fish passes and the assessment of the attractivity of fish passes for salmonids and coarse fish in UK rivers. For this purpose, a small-sized remote control platform carrying an acoustic Doppler current profiler (ADCP), a GPS unit, a stereo camera and an inertial measurement unit has been developed. The large amount of data on water velocities and depths measured by the ADCP within relatively short time is used to quantify the spatial and temporal distribution of water velocities. By matching these hydraulic features with known preferences of migratory fish, it is attempted to identify likely migration routes and aggregation areas at barriers as well as hydraulic features that may distract fish away from fish pass entrances. The initial steps of the framework development have focused on the challenge of precise spatial data referencing in areas with limited sky view to navigation satellites. Platform tracking with a motorised Total Station, various satellite-based positioning solutions and simultaneous localisation and mapping (SLAM) based on stereo images have been tested. The effect of errors in spatial data referencing on ADCP-derived maps of flow features and bathymetry will be quantified through simultaneous deployment of these navigation technologies and the ADCP. This will inform the selection of a cost-effective platform positioning system in practice. Further steps will cover the quantification of uncertainties in ADCP data caused by highly turbulent flows and the identification of suitable ADCP data sampling strategies at fish passes. The final framework for fish pass assessment can contribute to an improved understanding of the interaction of fish and the complex hydraulic river environment.

  4. Application of a Delay-difference model for the stock assessment of southern Atlantic albacore ( Thunnus alalunga)

    Science.gov (United States)

    Zhang, Kui; Liu, Qun; Kalhoro, Muhsan Ali

    2015-06-01

    Delay-difference models are intermediate between simple surplus-production models and complicated age-structured models. Such intermediate models are more efficient and require less data than age-structured models. In this study, a delay-difference model was applied to fit catch and catch per unit effort (CPUE) data (1975-2011) of the southern Atlantic albacore ( Thunnus alalunga) stock. The proposed delay-difference model captures annual fluctuations in predicted CPUE data better than Fox model. In a Monte Carlo simulation, white noises (CVs) were superimposed on the observed CPUE data at four levels. Relative estimate error was then calculated to compare the estimated results with the true values of parameters ? and ? in Ricker stock-recruitment model and the catchability coefficient q. a is more sensitive to CV than ? and q. We also calculated an 80% percentile confidence interval of the maximum sustainable yield (MSY, 21756 t to 23408 t; median 22490 t) with the delay-difference model. The yield of the southern Atlantic albacore stock in 2011 was 24122 t, and the estimated ratios of catch against MSY for the past seven years were approximately 1.0. We suggest that care should be taken to protect the albacore fishery in the southern Atlantic Ocean. The proposed delay-difference model provides a good fit to the data of southern Atlantic albacore stock and may be a useful choice for the assessment of regional albacore stock.

  5. Histological methods in the assessment of different feed effects on liver and intestine of fish

    Directory of Open Access Journals (Sweden)

    Raškovi? Božidar S.

    2011-01-01

    Full Text Available This manuscript describes the importance of using histological methods to assess the effects of feed on the liver and intestine of fish. Due to the constantly increasing world production of fish and other aquatic organisms, it is necessary to replace fishmeal and fish oil in diets with less expensive raw materials of plant origin. Due to the increased fiber content, increased presence of carbohydrates, antinutritional factors, and inappropriate content of amino acids and new compounds can have negative effects on the digestive system of fish and therefore on fitness, health and production characteristics of cultivated fish. The liver and intestines are the most important organs for the digestion and absorption of nutrients from feed. Therefore, monitoring histological structure of fish liver and intestine is the method of choice in assessing the effects of nutrient mixtures that use raw materials of plant origin. For both of these vital organs the normal histological structure and the most important results obtained by research are discussed. This paper presents a critical review of the histological methods used in research on feed effects. Results related to the negative effects of raw soy-based feed on the occurrence of enteritis in carnivorous fish species are discussed. The results point out that use of modern approach in fish pathology such as improved histochemical, stereological, scoring, and other analytical methods could be a beneficial approach in an accurate assessment of new feed effects on fish.

  6. An assessment of the cod stock in NAFO Division 3M

    OpenAIRE

    Vázquez, Antonio; Cerviño, Santiago

    2002-01-01

    The cod stock on Flemish Cap, NAFO Division 3M, remains collapsed. The situation was originally attributed to the severe overfishing of last abundant year-classes, but the recruitment failed since 1995 and the stock did not recovered. Commercial catches are insignificant and two surveys in the area in 2001 did not observed good recruitment. The situation remains steady at a very low level, and it is unlikely a recovery of the stock in a short o medium term

  7. Greenland Halibut in Upernavik: a preliminary study of the importance of the stock for the fishing populace : A study undertaken under the Greenland Climate Research Centre

    DEFF Research Database (Denmark)

    Delaney, Alyne E.; Becker Jakobsen, Rikke

    2012-01-01

    This report presents research undertaken with the belief that a need exists for better understanding of the social and cultural importance of the Greenland Halibut (Reinhardtius hippoglossoides) fishery to Greenlanders. It was decided the research would focus on one of three coastal Greenland Halibut fishery districts: Upernavik. Upernavik was chosen mgiven the critical importance of Greenland halibut for local fishers and area residents. The best method for presenting a combination of social and fishery data takes the form of a fishery profile. Additionally, given that the government of Greenland is currently in the midst of proposing changes to the Halibut management structure, the report focuses specifically on potential social impacts of the fishery management plan to coastal fishers. The degree and consequence of any impact is a function of the characteristics of the fishing community. The critical point is the vulnerability of the community to negative repercussions of the management action and the resilience the community has in being able to absorb these repercussions. Upernavik and Greenlandic fisheries communities are known to be remote and have limited economic opportunities for residents. Consequently, it is important to understand the adaptability and vulnerability of the community in order to successfully anticipate impacts. Greenland halibut is the most important commercial fish stock for Upernavik residents. In 2010 there were more than 385 fishermen with official licenses for Greenland halibut in Upernavik. There are up to an additional 75 who also fish, however, without paying the license fee. This means that almost half of working age men fish for halibut in the Upernavik district. Fishing is extremely important in Upernavik for its role in the local, mixed economy. Fishing often provides the cash needed for materials needed for work (hunting and fishing equipment such as bullets, nets, snowmobiles, etc.) and daily living (housing, transport, television, food, etc). Fishing also supports the important local cultural practice of meeting social obligations and reciprocity such as through kødgaver (gifting of meat), a practice which remains both culturally and economically important in the smaller settlements. Currently, the government of Greenland is proposing changes to the management of Greenland halibut for the coastal fishers, including the closing the fishery to new entrants in 2012. Additional changes include the introduction of ITQs for large boats. With little discussion of where locals will work and live if they can not earn an income from the fishery, or discussion of how the communities may be impacted by the potential consolidation of quota shares into fewer hands (as is seen in all ITQ fisheries), the report suggests that management follows accepted practices of good governance as it introduces its new Greenland halibut plan. Good governance is participatory and is based upon, among other points, social equity, responsiveness, and transparency. It is also responsive to the present and future needs of society. Since the plan has not yet been implemented, however, there is still time to follow good governance practices for the sustainability of not only the Greenland halibut stock, but also for Greenlandic society.

  8. Stock assessment of the red spiny lobster (Panulirus argus) caught in the tropical southwestern Atlantic / Evaluación del stock de la langosta roja (Panulirus argus) en la zona tropical del Atlántico sudoccidental

    Scientific Electronic Library Online (English)

    Humber A, Andrade.

    2015-03-01

    Full Text Available Los stocks de la langosta roja (Panulirus argus) (Latreille, 1804) en el Caribe y en la costa de Brasil son de considerable importancia económica. Hay importantes diferencias genéticas entre las poblaciones del Brasil y del Caribe, que sustentan la evaluación de stocks separados. El presente estudio [...] proporciona una evaluación de la población brasileña de P. argus utilizando un modelo dinámico de biomasa sobre la base de un enfoque bayesiano. Suponiendo que la captura por unidad de esfuerzo es un índice válido de abundancia relativa, los resultados del análisis indican que las poblaciones han sido fuertemente sobreexplotadas desde 1980. El escenario actual es pesimista, y hay evidencia de que la población puede estar al borde del colapso. Abstract in english The stocks of the red spiny lobster (Panulirus argus) (Latreille, 1804) in the Caribbean and in the Brazilian coast are of considerable economic importance. There are important genetic differences between the Brazilian and Caribbean populations, which support separated stock assessment. The present [...] study provides an assessment of the Brazilian stock of P. argus using a biomass dynamic model based on a Bayesian approach. Assuming that the catch per unit effort is a valid index of relative abundance, the results of the analysis indicate that stocks have been heavily overexploited since the 1980s. The present-day scenario is pessimistic, and there is evidence that the stock may be close to collapse.

  9. Loss of genetic variability at the transferrin locus in five hatchery stocks of tambaqui (Colossoma macropomum

    Directory of Open Access Journals (Sweden)

    Calcagnotto Daniela

    2000-01-01

    Full Text Available Knowledge and conservation of the genetic variability in stocks maintained as live gene banks have become a high priority task for Brazilian fish culture. The aim of the present survey was to assess the transferrin allelic diversity of five hatchery stocks of tambaqui (Colossoma macropomum. The tambaqui stock from Pentecoste, the oldest maintained in Brazilian hatchery stations, retained three of the six alleles detected in wild populations of tambaqui from the Amazon River. Other hatchery stocks, directly or indirectly derived from the Pentecoste stock, did not show transferrin allelic variability. Insufficient number of founders and genetic drift due to sampling errors seem to be the main causes leading to loss of genetic diversity in tambaqui hatchery stocks. Appropriate management strategies are required in order to improve the genetic potential of tambaqui stocks in Brazil.

  10. Preliminary assessment of surf-zone and estuarine line-fish species of the Dwesa-Cwebe Marine Protected Area, Eastern Cape, South Africa

    Directory of Open Access Journals (Sweden)

    Jan A. Venter

    2012-09-01

    Full Text Available A preliminary assessment of surf-zone and estuarine line fish was carried out in the DwesaCwebe Marine Protected Area (MPA, on the Wild Coast, South Africa. The purpose was to provide baseline data on inshore line-fish stocks in the MPA. A total of 28 species was recorded, of which 53% have a conservation status reflecting some concern and 43% are endemic to southern Africa. This highlights the value of the MPA for protection of important line-fish species. Within the MPA, localised differences were detected in species diversity, size frequency and catch per unit effort between unexploited and illegally exploited areas. These differences were more prominent in slow growing, long-lived species. It thus appears that illegal exploitation is negatively affecting fish populations within the MPA, which counteract and potentially could eliminate the benefits of fish protection typically associated with no-take MPAs. These results highlight the need for improved law enforcement and better communication with neighbouring communities to increase awareness. It is further recommended that the current no-take status of the MPA should be maintained. In addition, baseline fisheries information was collected on certain fish species that could be used to inform future conservation management of the MPA.Conservation implications: The Dwesa-Cwebe Marine Protected Area is unique and important for the conservation of key surf zone and estuarine fish species. However there is a significant risk to the fish populations due to illegal exploitation. Key interventions should include enhanced law enforcement but, more important, the creation of alternative livelihoods and long term sustainable benefits to local communities.

  11. Preliminary assessment of surf-zone and estuarine line-fish species of the Dwesa-Cwebe Marine Protected Area, Eastern Cape, South Africa

    Scientific Electronic Library Online (English)

    J.A., Venter; B.Q., Mann.

    Full Text Available A preliminary assessment of surf-zone and estuarine line fish was carried out in the Dwesa-Cwebe Marine Protected Area (MPA), on the Wild Coast, South Africa. The purpose was to provide baseline data on inshore line-fish stocks in the MPA. A total of 28 species was recorded, of which 53% have a cons [...] ervation status reflecting some concern and 43% are endemic to southern Africa. This highlights the value of the MPA for protection of important line-fish species. Within the MPA, localised differences were detected in species diversity, size frequency and catch per unit effort between unexploited and illegally exploited areas. These differences were more prominent in slow growing, long-lived species. It thus appears that illegal exploitation is negatively affecting fish populations within the MPA, which counteract and potentially could eliminate the benefits of fish protection typically associated with no-take MPAs. These results highlight the need for improved law enforcement and better communication with neighbouring communities to increase awareness. It is further recommended that the current no-take status of the MPA should be maintained. In addition, baseline fisheries information was collected on certain fish species that could be used to inform future conservation management of the MPA. CONSERVATION IMPLICATIONS: The Dwesa-Cwebe Marine Protected Area is unique and important for the conservation of key surf zone and estuarine fish species. However there is a significant risk to the fish populations due to illegal exploitation. Key interventions should include enhanced law enforcement but, more important, the creation of alternative livelihoods and long term sustainable benefits to local communities.

  12. Environmental assessment, K Pool fish rearing, Hanford Site, Richland, Washington

    International Nuclear Information System (INIS)

    The US Department of Energy (DOE) has a need to respond to a request to lease facilities at the Hanford Site 100-KE and 100-KW filter plant pools (K Pools) for fish rearing activities. These fish rearing activities would be: (1) business ventures with public and private funds and (2) long-term enhancement and supplementation programs for game fish populations in the Columbia River Basin. The proposed action is to enter into a use permit or lease agreement with the YIN or other parties who would rear fish in the 100-K Area Pools. The proposed action would include necessary piping, pump, and electrical upgrades of the facility; cleaning and preparation of the pools; water withdrawal from the Columbia River, and any necessary water or wastewater treatment; and introduction, rearing and release of fish. Future commercial operations may be included

  13. Assessment of fetal status in multiple gestation pregnancies using interphase FISH.

    Science.gov (United States)

    Fiddler, M; Frederickson, M C; Chen, P X; Pergament, E

    2001-03-01

    The use of fluorescence in situ hybridization (FISH) for women with multiple gestation pregnancies has been evaluated. Women were referred for chromosome analysis because of advanced maternal age, abnormal ultrasound findings or a positive family history and/or prior to fetal reduction. FISH was successfully applied to all specimens obtained by amniocentesis or chorionic villus sampling (CVS). Based on FISH results, fetal-fetal contamination of specimens following CVS was 11.5% in twin pregnancies and 16% in triplet or higher multiples. FISH detected trisomy 21 in three cases with no false negatives or positives. Whereas FISH may provide rapid and useful assessment of fetal status in decision-making regarding fetal reduction, the present study also highlighted the obstetrical difficulty of ensuring a sample representative of each fetus following CVS in addition to the possibility of not identifying clinically significant chromosome aberrations using currently available FISH probes. PMID:11260607

  14. The spectre of uncertainty in management of exploited fish stocks: The illustrative case of Atlantic bluefin tuna

    OpenAIRE

    Fromentin, Jean-marc; Bonhommeau, Sylvain; Arrizabalaga, Haritz; Kell, Laurence T.

    2014-01-01

    The recent overexploitation of East Atlantic and Mediterranean bluefin tuna stock has been well documented in the media where it has become the archetype of overfishing and general mis-management. Beyond the public debate, the crisis also highlighted how the interactions between science and management can change through time according to the awareness of the public opinion. To reflect these issues, the history of Atlantic bluefin tuna overfishing is first described. Then, the major uncertaint...

  15. A cross-ecosystem comparison of spatial and temporal patterns of covariation in the recruitment of functionally analogous fish stocks

    Science.gov (United States)

    Megrey, Bernard A.; Hare, Jonathan A.; Stockhausen, William T.; Dommasnes, Are; Gjøsæter, Harald; Overholtz, William; Gaichas, Sarah; Skaret, Georg; Falk-Petersen, Jannike; Link, Jason S.; Friedland, Kevin D.

    2009-04-01

    Temporal and spatial patterns of recruitment ( R) and spawning stock biomass ( S) variability were compared among functionally analogous species and similar feeding guilds from six marine ecosystems. Data were aggregated into four regions including the Gulf of Maine/Georges Bank, the Norwegian/Barents Seas, the eastern Bering Sea, and the Gulf of Alaska. Variability was characterized by calculating coefficients of variation and anomalies for three response variables: ln( R), ln( R/ S), and stock-recruit model residuals. Patterns of synchrony and asynchrony in the response variables were examined among and between ecosystems, between- and within-ocean basins and among functionally analogous species groups using pair-wise correlation analysis corrected for within-time series autocorrelation, multivariate cross-correlation analyses and regime shift detectors. Time series trends in response variables showed consistent within basin similarities and consistent and coherent differences between the Atlantic and Pacific basin ecosystems. Regime shift detection algorithms identified two broad-scale regime shift time periods for the pelagic feeding guild (1972-1976 and 1999-2002) and possibly one for the benthic feeding guild (1999-2002). No spatial patterns in response variable coefficients of variation were observed. Results from multivariate cross-correlation analysis showed similar trends. The data suggest common external factors act in synchrony on stocks within ocean basins but temporal stock patterns, often of the same species or functional group, between basins change in opposition to each other. Basin-scale results (similar within but different between) suggest that the two geographically broad areas are connected by unknown mechanisms that, depending on the year, may influence the two basins in opposite ways. This work demonstrates that commonalities and synchronies in recruitment fluctuations can be found across geographically distant ecosystems but biophysical causes of the fluctuations remain difficult to identify.

  16. Identification and phylogenetic inferences on stocks of sharks affected by the fishing industry off the Northern coast of Brazil

    OpenAIRE

    Luis Fernando da Silva Rodrigues-Filho; Tainá Carreira da Rocha; Péricles Sena do Rêgo; Horacio Schneider; Iracilda Sampaio; Marcelo Vallinoto

    2009-01-01

    The ongoing decline in abundance and diversity of shark stocks, primarily due to uncontrolled fishery exploitation, is a worldwide problem. An additional problem for the development of conservation and management programmes is the identification of species diversity within a given area, given the morphological similarities among shark species, and the typical disembarkation of processed carcasses which are almost impossible to differentiate. The main aim of the present study was to identify t...

  17. Ecological predictions and risk assessment for alien fishes in North America.

    Science.gov (United States)

    Kolar, Cynthia S; Lodge, David M

    2002-11-01

    Methods of risk assessment for alien species, especially for nonagricultural systems, are largely qualitative. Using a generalizable risk assessment approach and statistical models of fish introductions into the Great Lakes, North America, we developed a quantitative approach to target prevention efforts on species most likely to cause damage. Models correctly categorized established, quickly spreading, and nuisance fishes with 87 to 94% accuracy. We then identified fishes that pose a high risk to the Great Lakes if introduced from unintentional (ballast water) or intentional pathways (sport, pet, bait, and aquaculture industries). PMID:12424378

  18. Challenges in using fish communities for assessing the ecological integrity of non-perennial rivers

    Scientific Electronic Library Online (English)

    MF, Avenant.

    2010-07-01

    Full Text Available Environmental Water Assessments (EWAs) aim to protect the ecological integrity of rivers amidst increasing anthropogenic pressures on freshwater resources, and fish communities are the ecosystem component most commonly included. The Fish Response Assessment Index (FRAI) was developed to assess the i [...] ntegrity of fish communities in South African rivers and is commonly applied in EWA studies. This paper reports on the suitability of the FRAI for the non-perennial Seekoei River and discusses some of the challenges faced. Our relatively long and thorough study on the Seekoei River confirmed the concerns that earlier, snapshot, fish integrity assessments in the Orange River system raised: that the existing fish indices are not ideally suited for these rivers with their naturally low species richness and hardy, generalist fish communities. Other difficulties with the use of a score-based method include prediction of the expected species, calculation of a frequency of occurrence rating, selection of the right sampling times for comparative purposes, loss of habitats and sampling points under different flow conditions, and problems experienced when using accumulated data to try to correct for a situation of having too few sampling points. At this stage a more generalised approach is suggested for the Seekoei River, and ultimately other similar non-perennial systems. This could include a number of community characteristics, such as abundance, species richness, species diversity and evenness, recruitment, fish health and the presence/absence of exotic species.

  19. Peat Depth Assessment Using Airborne Geophysical Data for Carbon Stock Modelling

    Science.gov (United States)

    Keaney, Antoinette; McKinley, Jennifer; Ruffell, Alastair; Robinson, Martin; Graham, Conor; Hodgson, Jim; Desissa, Mohammednur

    2013-04-01

    The Kyoto Agreement demands that all signatory countries have an inventory of their carbon stock, plus possible future changes to this store. This is particularly important for Ireland, where some 16% of the surface is covered by peat bog. Estimates of soil carbon stores are a key component of the required annual returns made by the Irish and UK governments to the Intergovernmental Panel on Climate Change. Saturated peat attenuates gamma-radiation from underlying rocks. This effect can be used to estimate the thickness of peat, within certain limits. This project examines this relationship between peat depth and gamma-radiation using airborne geophysical data generated by the Tellus Survey and newly acquired data collected as part of the EU-funded Tellus Border project, together encompassing Northern Ireland and the border area of the Republic of Ireland. Selected peat bog sites are used to ground truth and evaluate the use of airborne geophysical (radiometric and electromagnetic) data and validate modelled estimates of soil carbon, peat volume and depth to bedrock. Data from two test line sites are presented: one in Bundoran, County Donegal and a second line in Sliabh Beagh, County Monaghan. The plane flew over these areas at different times of the year and at a series of different elevations allowing the data to be assessed temporally with different soil/peat saturation levels. On the ground these flight test lines cover varying surface land use zones allowing future extrapolation of data from the sites. This research applies spatial statistical techniques, including uncertainty estimation in geostatistical prediction and simulation, to investigate and model the use of airborne geophysical data to examine the relationship between reduced radioactivity and peat depth. Ground truthing at test line locations and selected peat bog sites involves use of ground penetrating radar, terrestrial LiDAR, peat depth probing, magnetometry, resistivity, handheld gamma-ray spectrometry, moisture content and rainfall monitoring combined with a real-time Differential Global Positioning System (DGPS) to monitor temporal and spatial variability of bog elevations. This research will assist in determining the accuracy and limitations of modelling soil carbon and changes in peat stocks by investigating the attenuation of gamma-radiation from underlying rocks. Tellus Border is supported by the EU INTERREG IVA programme, which is managed by the Special EU Programmes Body in Northern Ireland, the border Region of Ireland and western Scotland. The Tellus project was funded by the Northern Ireland Development of Enterprise Trade and Investment and by the Rural Development Programme through the Northern Ireland Programme for Building Sustainable Prosperity.

  20. Life Cycle Assessment on Icelandic seafood product based on two different fishing methods. Environmental impacts from fisheries

    OpenAIRE

    Aðalbjörg Birna Guttormsdóttir 1978

    2009-01-01

    Human population is ever increasing. Population in 2009 is currently approaching 7 billion people and is expected to become 9.7 billion in 2050. Seafood is an important protein income for humans. According to FAO, more than 80% of all fish stock on Earth are either fully exploited or over exploited. Fisheries have considerable environmental impacts such as effects on seafloor caused by fishing gear, effects on biodiversity, use of fossil fuels and other chemicals that contribute to climate ch...

  1. Environmental Assessment: Land Exchange between the City of Virginia Beach and the U.S. Fish and Wildlife Service

    US Fish and Wildlife Service, Department of the Interior — This Environmental Assessment EA will identify and evaluate the environmental and socioeconomic impacts of the United States Fish and Wildlife Services Service...

  2. Baseline assessment of fish communities of the Flower Garden Banks

    National Oceanic and Atmospheric Administration, Department of Commerce — The work developed baseline information on fish and benthic communities within the Flower Garden Banks National Marine Sanctuary (FGBNMS). Surveys employed diving,...

  3. St. John, USVI Fish Assessment and Monitoring Data (2002 - Present)

    National Oceanic and Atmospheric Administration, Department of Commerce — This fish and benthic composition database is the result of a multifaceted effort described below.The intent of this work is five fold: 1) To spatially characterize...

  4. St. Croix, USVI Fish Assessment and Monitoring Data (2002 - Present)

    National Oceanic and Atmospheric Administration, Department of Commerce — This fish and benthic composition database is the result of a multifaceted effort described below. The intent of this work is five fold: 1) To spatially...

  5. On the modeling of electric railway lines for the assessment of infrastructure impact in radiated emission tests of rolling stock

    OpenAIRE

    Cozza, Andrea; Demoulin, Bernard

    2008-01-01

    In this paper, we address the problem of testing radiated emissions generated by rolling stock, when carried out on actual railway sites, as prescribed by the standard EN 50121. The idea of assessing infrastructure impact on test results is presented here by means of an electromagnetic model of railway sites. In the first part,modeling tools are introduced together with some results from the experimental validation. These tools are then applied to actual railway lines proving the importance o...

  6. Performance Assessment of the Food Industry of Tehran Stock Exchange Based on Balanced Score Card (BSC) Technique

    OpenAIRE

    Morteza Asadi; Javad Mehrabi; Saharnaz Mohseni; Mohammad Hasan Tanhaei

    2013-01-01

    Major objective of the present paper was to study the role of balanced score card regarding performance assessment of companies listed in food and beverage industry in the stock exchange. This survey is descriptive and is regarded as a quasi-experimental research plan (Ex-Post design). The statistical population included 200 managers and research sample consisted of 99 persons based on Cochran formula. Questionnaire was used for data collection. Frequency tables and appropriate diagrams were ...

  7. Qualitative assessment of imported frozen fish fillets in Sulaimani markets

    OpenAIRE

    Khidhir, Z. K.; Murad, H. O. M.; Arif, E. D.

    2013-01-01

    This study aims to determine the quality of frozen fish fillets sold in Sulaimani city markets a total number of (64) sample of frozen fish fillets belonged to 4 foreign trademarks were collected from different parts of Sulaimani markets. The samples were subjected to physical and chemical tests to determine their quality and suitability for human consumption. The proximate chemical analysis referred to presence of significant differences in moisture, fat and protein content among the four tr...

  8. Qualitative assessment of imported frozen fish fillets in Sulaimani markets

    Directory of Open Access Journals (Sweden)

    Z.K. Khidhir

    2013-06-01

    Full Text Available This study aims to determine the quality of frozen fish fillets sold in Sulaimani city markets a total number of (64 sample of frozen fish fillets belonged to 4 foreign trademarks were collected from different parts of Sulaimani markets. The samples were subjected to physical and chemical tests to determine their quality and suitability for human consumption. The proximate chemical analysis referred to presence of significant differences in moisture, fat and protein content among the four trademarks except for ash content. While the physical indices showed that White fish fillets recorded the lowest thawing and cooking loss which in return recorded the highest WHC. Chemical indices showed that the pH mean values of Myanmar and Flander mark were significantly differed (P<0.05 than Hasson and White fish fillet, Although, the results of FFA recorded no significant differences among the trademarks, and Flander mark recorded the highest PV and TBA among the other which made it significantly differed than them and White fish fillet recorded the lowest, still, they were within the international standard limits. Where, the results of TVN values recorded no significant differences ( among the inspected marks. All obtained results referred to the validity of these fish fillets for human consumption.

  9. Proposal of a method for assessing the quality of stock photography websites

    OpenAIRE

    Garcia, Sandra Maria Gonzalez

    2012-01-01

    The advent of the Internet, the advent of digital photography and the chance of digitalizing large volumes of photographs, negatives, slides or daguerreotypes revolutionized the field of commercial stock photography. This new digital environment forced stock photography to adapt to the changing needs of its users. One of the main measures that these agencies were faced with these new needs of users was to create their own websites through which to offer their products to their customers. Pap...

  10. A stochastic length-based assessment model for the Pandalus stock in Skagerrak and the Norwegian Deep

    DEFF Research Database (Denmark)

    Nielsen, Anders; Munch-Petersen, Sten

    2013-01-01

    This working document describes a length based stochastic assessment model of Pandalus in ICES areas IIIA and IVA. The model describing stock development is age based, but the model also estimates the relation between age and length assuming a von Bertalany growth curve. The model presented in this paper is based on the assessment data presented at the 2012 NIPAG meeting, but with updated survey information. Also the estimates shown here are based on equal standard deviations for survey and catch L = (c) L , which is the natural assumption, as this parameter describes the standard deviation of the length distribution in the population

  11. Empirical assessment of the Hellenic non-residential building stock, energy consumption, emissions and potential energy savings

    International Nuclear Information System (INIS)

    Comprehensive information and detailed data for the non-residential (NR) building stock is rather limited, although it is the fastest growing energy demand sector. This paper elaborates the approach used to determine the potential energy conservation in the Hellenic NR building stock. A major obstacle that had to be overcome was the need to make suitable assumptions for missing detailed primary data. A qualitative and quantitative assessment of scattered national data resulted in a realistic assessment of the existing NR building stock and energy consumption. Different energy conservation scenarios and their impact on the reduction of CO2 emissions were evaluated. Accordingly, the most effective energy conservation measures are: addition of thermal insulation of exposed external walls, primarily in hotels and hospitals; installation of energy efficient lamps; installation of solar collectors for sanitary hot water production, primarily in hotels and health care; installation of building management systems in office/commercial and hotel buildings; replacement of old inefficient boilers; and regular maintenance of central heating boilers

  12. The Use of Per Recruit Models for Stock Assessment and Management of Greasy Grouper Epinephelus tauvina in The Arabian Gulf Waters off Qatar.

    Science.gov (United States)

    Abdel Barr, Mehdat A; El-Sayed, Abdel Fattaqh M; Osman, Amany M

    2010-08-01

    Per recruit models were applied to assess greasy grouper, Epinephelus tauvina, stock in the gulf waters off Qatar. Yield per recruit (Y/R) increased rapidly at low values of fishing mortality (F). At present natural mortality (M = 0.17 per year) and age at first capture (Tc = 7.6 years), the Y/R increased with increasing F to reach a maximum value of 1067.8 g per recruit at F = 0.65 per year. Above this level of F, Y/R was constant or slightly decreased. The current level of F is higher than the biological reference points F0.1 (0.15 per year), FSB40% (0.13 per year), FSB50% (0.08 per year) and FSB25% (0.24 per year). Increasing the Tc by one year resulted in a slight increase in the Y/R, while additional increases in Tc led to a decrease in Y/R values. At constant M, the increase in Tc caused an increase in F required to obtain the maximum Y/R until reaching a non-maximum state at the oldest Tc. At the current level of F, increasing the Tc by one year would result in a small increase in biomass per recruit (B/R), while further increases would lead to a decrease in B/R. At higher levels of F, any increase in Tc would cause a gradual increase in B/R, followed by a decline after a certain value of Tc. These results provide evidence of recruitment over-fishing at all optimum fishing levels, F0.1, FSB40%, FSB50% and at the threshold level, FSB25%. Therefore, sustainable management and conservation of greasy grouper in Qatari waters would require a decrease in F to levels less than F0.1 and FSB40%, which can be achieved through a reduction in fishing effort but not through an increase in Tc. PMID:24575192

  13. Chemical and biochemical tools to assess pollution exposure in cultured fish

    International Nuclear Information System (INIS)

    There is little information regarding pollutant levels in farmed fish, and the risks associated to consumption. This study was designed to assess levels of exposure to metals, organochlorinated compounds, polycyclic aromatic hydrocarbons (PAHs) and alkylphenols (APEs) in farmed sea bass Dicentrarchus labrax from five aquacultures located in Southern Europe. Additionally, several biochemical responses (metallothionein, 7-ethoxyresorufin O-deethylase, vitellogenin) were determined as complementary tools. The obtained data indicate that pollutants exposure in farmed fish is similar to the levels reported in wild specimens from the area. Nonetheless, some biochemical responses were observed in the studied organisms, viz. metallothionein induction in Cu exposed organisms, and 7-ethoxyresorufin O-deethylase (EROD) and vitellogenin induction in PAHs and APEs exposed ones. The study further supports the usefulness of the biomarker approach as a first screening method to discriminate between basal and high levels of exposure in cultured fish. - Pollution assessment in cultured fish: chemical and biochemical tools

  14. Assessment of fishing the valuable hydrobionts in the Sivash bay

    Directory of Open Access Journals (Sweden)

    Kireeva Irina Yurievna

    2013-09-01

    Full Text Available The perennial analysis of the production of the main industrial objects by private entrepreneurs in the Sivash bay is presented. The prohibition of the plaice-Glossa’s catch is saved. There is the reduction in net catches of haarder due to the decrease of the livestock herd, the poaching fishing, the water pollution of spawning places and graziery, and the lack of control by the fish inspection. The introduction of the serious control of mullet’s catch and good graziery conditions for this spe-cies facilitates to the restoration of their natural population. The pigfish are the additional objects of the catch with a slight annual increase in their number in catches, but they don’t have the significant influence on the formation of the overall productivity of fish in the Sivash bay. The larvae of hironomus takes the first place of the production on the territory of the East Sivash. There is a gradual advance of the whole productivity of fish in the east part of the Sivash bay, at the expense catching mullet, haarder and hironomus larvae.

  15. Ecological traits of fish assemblages from Mediterranean Europe and its implications when assessing human pressure

    OpenAIRE

    Martinez-Capel, Francisco; Ferrerira, T; Oliveira, J; De Sostoa, A.; Caiola, N.; Casals, F.; Cortés, R.; Zogaris, S.; Economou, A.; García-Jalon, D.; Ilheú, M.; Pont, D.; Rogers, C.; Prenda, J.

    2007-01-01

    [EN] Mediterranean river systems are characterised by more diverse fish assemblages and regional ecological processes compared with the rest of Europe. A data set from Mediterranean France, Iberia and Greece ( 2000 sites) was used to describe the characteristics of fish assemblages, explore their responses to anthropogenic disturbance and analyse the implications for river quality assessment. There was a southwards decline in species richness per site, but endemicity and proportio...

  16. Ecological traits of fish assemblages from Mediterranean Europe and its implications when assessing human pressure

    OpenAIRE

    Ferreira, M. T.; Caiola, N.; Casals, F.; Cortes, R.; Economous, A.; Garcia-jalon, D.; Ilhe?u, M.; Martinez-capel, F.; Oliveira, J.; Pont, D.; Prenda, J.; Rogers, C.; Sostoa, A.; Zogaris, S.

    2007-01-01

    Mediterranean river systems are characterised by more diverse fish assemblages and regional ecological processes compared with the rest of Europe. A data set from Mediterranean France, Iberia and Greece ( 2000 sites) was used to describe the characteristics of fish assemblages, explore their responses to anthropogenic disturbance and analyse the implications for river quality assessment. There was a southwards decline in species richness per site, but endemicity and proportion of alien spe...

  17. Temporal changes in European eel, Anguilla anguilla, stocks in a small catchment after installation of fish passes

    OpenAIRE

    Laffaille, Pascal; Acou, Anthony; Guilloue?t, Je?ro?me; Legault, Antoine

    2005-01-01

    Changes in the abundance of European eel, Anguilla anguilla L., in the River Fre'mur, France, were examined over an 8-year period. Natural connectivity of the river was disturbed by three high dams that inhibited eel upstream migration and reduced recruitment by elvers and yellow eels. After eel passes were installed, fish became more abundant upstream (mean density 0.5 eel m)2). Moreover, except in the more upstream areas, no decline in eel numbers and biomass was found, in contrast to the g...

  18. Life Cycle Assessment of Fish Culture in Thailand: Case Study of Nile Tilapia and Striped Catfish

    Directory of Open Access Journals (Sweden)

    Patcharaporn Pongpat

    2013-10-01

    Full Text Available This study was aimed to assess environmental impacts of fish culturing in Thailand using life cycle assessment (LCA method. The scope was a cradle-to-gate study of red nile tilapia (Oreochromis niloticus and striped catfish (Pangasianodon hypophthalmus. The impact assessment method of CML Baseline 2000 was applied to evaluate the impacts in the categories of abiotic depletion, acidification and global warming. The impacts of red nile tilapia were 3-4 times higher than those of striped catfish. The global warming potential of red nile tilapia was 2.96 kg CO2 eq, where as that of striped catfish was 1.01 kg CO2 eq. The feeds, especially fish meal, were the main impact contributors. Small replacement of fish meal with soybean meal while maintaining the growth rate of the fish was possible. This leaded to slightly decrease in the environmental impacts. The environmental performance of fish meal itself should be improved in order to reduce the impacts from fish culture.

  19. Business risk assessment of the companies on the Mexican Stock Exchange’s sustainable index

    Directory of Open Access Journals (Sweden)

    José Antonio Morales Castro

    2014-12-01

    Full Text Available (Received: 2014/10/27 - Accepted: 2014/12/15This work evaluated the business risk change of 20 companies included on the sustainable index of the Mexican Stock Exchange (BMV. The unlevered beta coefficient was used for this analysis. Two periods were compared: the one before, and the one after including the companies on the index. For each of the 20 companies it was used financial information, stocks closing prices and the stock market index value, over a period of 234 weeks. Then, considering the two periods, the statistical difference between the unlevered beta coefficient averages was calculated. Finally, a hypothesis proof was made to evaluate the business risk change. It was found that for 12 out of the 20 companies, the unlevered beta coefficient suffered a reduction. The findings suggest that it is not enough for the companies to certify as sustainable in order to reduce its business risk.

  20. Growing stock and woody biomass assessment in Asola-Bhatti Wildlife Sanctuary, Delhi, India.

    Science.gov (United States)

    Kushwaha, S P S; Nandy, S; Gupta, Mohini

    2014-09-01

    Biomass is an important entity to understand the capacity of an ecosystem to sequester and accumulate carbon over time. The present study, done in collaboration with the Delhi Forest Department, focused on the estimation of growing stock and the woody biomass in the so-called lungs of Delhi--the Asola-Bhatti Wildlife Sanctuary in northern Aravalli hills. The satellite-derived vegetation strata were field-inventoried using stratified random sampling procedure. Growing stock was calculated for the individual sample plots using field data and species-specific volume equations. Biomass was estimated from the growing stock and the specific gravity of the wood. Among the four vegetation types, viz. Prosopis juliflora, Anogeissus pendula, forest plantation and the scrub, the P. juliflora was found to be the dominant vegetation in the area, covering 23.43 km(2) of the total area. The study revealed that P. juliflora forest with moderate density had the highest (10.7 m(3)/ha) while A. pendula forest with moderate density had the lowest (3.6 m(3)/ha) mean volume. The mean woody biomass was also found to be maximum in P. juliflora forest with moderate density (10.3 t/ha) and lowest in A. pendula forest with moderate density (3.48 t/ha). The total growing stock was estimated to be 20,772.95 m(3) while total biomass worked out to be 19,366.83 t. A strong correlation was noticed between the normalized difference vegetation index (NDVI) and the growing stock (R(2)?=?0.84)/biomass (R(2)?=?0.88). The study demonstrated that growing stock and the biomass of the woody vegetation in Asola-Bhatti Wildlife Sanctuary could be estimated with high accuracy using optical remote sensing data. PMID:24859859

  1. Bio-economic management strategy evaluation of deepwater stocks using the FLBEIA model

    OpenAIRE

    Garcia, Dorleta; Urtizberea, Agurtzane; Diez, Guzman; Gil, Juan; Marchal, Paul

    2013-01-01

    Deepwater fish are characterized by long lifespans, late maturity and low productivity. This implies slow recovery from low biomass levels and it is, therefore, important to manage these stocks correctly to avoid overfishing. However, these stocks are generally data poor, which it makes difficult to apply quantitative assessment models on which to base their management. The management strategy evaluation (MSE) approach consists in evaluating the performance of management strategies by simulat...

  2. A Stock Assessment of the Blue Swimming Crab Portunus pelagicus (Linnaeus, 1758) for Sustainable Management in Kung Krabaen Bay, Gulf of Thailand.

    Science.gov (United States)

    Kunsook, Chutapa; Gajaseni, Nantana; Paphavasit, Nittharatana

    2014-08-01

    A stock assessment of blue swimming crabs, Portunus pelagicus was conducted with crab gill nets and collapsible crab traps at Kung Krabaen Bay, in the eastern Gulf of Thailand, from 2008 to 2009. Several key indicators show that P. pelagicus population is in crisis. Fishing mortality shows an increase to 4.14. The exploitation rate is 0.71, higher than the optimal value of 0.38. The size of the mature females has also decreased from 8.10±0.39 cm to 7.52±1.14 cm. The average fecundity is 0.572×10(6)±0.261×10(6) eggs per batch, and the sex ratio (male:female) is 1:0.92. Based on these results, a sustainable management program for P. pelagicus was proposed as follows: (i) closing the bay during the spawning season, (ii) restoration of the Enhalus acoroides seagrass beds, (iii) restocking crab larvae in the bay and (iv) educating and networking all stakeholders to develop a better understanding of the ecology of the crab to support sustainable fishery management in Kung Krabaen Bay. PMID:25210587

  3. Human health risk assessment of organochlorines associated with fish consumption in a coastal city in China

    International Nuclear Information System (INIS)

    Food consumption is an important route of human exposure to organochlorines (OCs). In order to assess the potential health risks associated with these contaminants due to fish consumption, five species of fish were collected from a local market in Zhoushan City, an island in the East China Sea. Dioxin-like compounds, such as polychlorinated dibenzo-p-dioxins/ dibenzofurans, in the fish samples were screened by H4IIE-luc cell bioassay, and the concentrations of specific organochlorines were measured by gas chromatograph-electron capture detector (GC-ECD). The bioassay results indicated that concentrations of dioxin-like compounds in the fish samples were below detection limit (0.64 pg/mL). The concentrations of OC pesticides and PCBs ranged from 0.67 to 13 and 0.24 to 1.4 ng/g wet wt., respectively. Significantly, concentrations of p,p'-DDE in fish meat were comparatively high (average 3.9 ng/g wet wt.) compared with the other OC pesticides. The daily fish consumption, based on a dietary survey conducted among 160 local healthy residents, was determined to be 105 g/person. The relevant cancer benchmark concentrations of HCB, dieldrin, chlordane, DDTs and PCBs were 0.36, 0.04, 1.6, 1.7, and 0.29 ng/kg per day, respectively, based on the local diet. The hazard ratios (HRs), based on non-cancer endpoints were all less than 1.0, while the HRs based on cancer were greater than 1.0 for certain contaminants based on the 95th centile concentration in fish tissue. - Health riskoncentration in fish tissue. - Health risk assessment of organochlorines associated with fish consumption reveals potential cancer risks for some contaminants in a coastal population in China

  4. Mercury contamination in human hair and fish from Cambodia: levels, specific accumulation and risk assessment

    International Nuclear Information System (INIS)

    Mercury (Hg) concentrations in human hair and fish samples from Phnom Penh, Kien Svay, Tomnup Rolork and Batrong, Cambodia, collected in November 1999 and December 2000 were determined to understand the status of contamination, and age- and sex-dependent accumulation in humans and to assess the intake of mercury via fish consumption. Mercury concentrations in human hair ranged from 0.54 to 190 ?g/g dry wt. About 3% of the samples contained Hg levels exceeding the no observed adverse effects level (NOAEL) of WHO (50 ?g/g) and the levels in some hair samples of women also exceeded the NOAEL (10 ?g/g) associated with fetus neurotoxicity. A weak but significant positive correlation was observed between age and Hg levels in hair of residents. Mercury concentrations in muscle of marine and freshwater fish from Cambodia ranged from <0.01 to 0.96 ?g/g wet wt. Mercury intake rates were estimated on the basis of the Hg content in fish and daily fish consumption. Three samples of marine fish including sharp-tooth snapper and obtuse barracuda, and one sample of sharp-tooth snapper exceeded the guidelines by US EPA and by Joint FAO/WHO Expert Committee on Food Additives (JECFA), respectively, which indicates that some fish specimens examined (9% and 3% for US EPA and JECFA guidelines, respectively) were hazardous for consumption at the ingestion rate of Cambodian people (32.6 g/day). It is suggested that fish is probably the main source of Hg for Cambodian people. However, ext Hg for Cambodian people. However, extremely high Hg concentrations were observed in some individuals and could not be explained by Hg intake from fish consumption, indicating some other contamination sources of Hg in Cambodia. - A source other than fish may be responsible for high Hg in some Cambodians

  5. A scoring system approach for the parasite predictive assessment of fish lots: a proof of concept with anisakids

    OpenAIRE

    Llarena-reino, M.; Abollo, Elvira; Pascual, Santiago

    2013-01-01

    A total of 982 individuals distributed in 11 lots belonging to 10 fish species from three Atlantic FAO fishing areas were sampled and examined to detect the presence of anisakid larvae in fish muscle. After hazard identification by genetic sequencing and exposure assessment by anatomic extent and demographic characterization of infection, all data were fitted for each fish species to a new proposed scoring schema of parasite prediction. In the absence of a criterion standard method for inspec...

  6. Risk assessment and stock market volatility in the Eurozone: 1986-2014

    Science.gov (United States)

    Menezes, Rui; Oliveira, Álvaro

    2015-04-01

    This paper studies the stock market return's volatility in the Eurozone as an input for evaluating the market risk. Stock market returns are endogenously determined by long-term interest rate changes and so is the return's conditional variance. The conditional variance is the time-dependent variance of the underlying variable. In other words, it is the variance of the returns measured at each moment t, so it changes through time depending on the specific market structure at each time observation. Thus, a multivariate EGARCH model is proposed to capture the complex nature of this network. By network, in this context, we mean the chain of stock exchanges that co-move and interact in such a way that a shock in one of them propagates up to the other ones (contagion). Previous studies provide evidence that the Eurozone stock exchanges are deeply integrated. The results indicate that asymmetry and leverage effects exist along with fat tails and endogeneity. In-sample and out-of-sample forecasting tests provide clear evidence that the multivariate EGARCH model performs better than the univariate counterpart to predict the behavior of returns both before and after the 2008 crisis.

  7. Establishment of Chydorus sphaericus (O.F. Muller, 1785 (Crustacea: Cladocera in Australia: consequences of mass fish stocking from Northern Europe?

    Directory of Open Access Journals (Sweden)

    Pranay Sharma

    2014-02-01

    Full Text Available There are 11 species of genus Chydorus Leach, 1816 (Cladocera: Chydoridae in Australia, including populations of Chydorus sphaericus (O.F. Müller, 1785 morphologically undistinguishable from European ones. Our genetic study of C. sphaericus from two large artificial water bodies in the Adelaide region of South Australia led us to conclude the taxon was introduced to Australia from Europe by human activity, at least in the two studied water bodies. To provide a comprehensive sister-taxa coverage and survey of intraspecific variation, our data were complemented by sequences on Chydorus sphaericus-group from GenBank and Barcode of Life Data Systems website. We speculate that it was related to a mass stocking of introduced species of fishes from Europe. To confirm whether C. sphaericus is an invasive species due to human-mediated introductions, or whether it is a native Australian taxon, further extensive molecular studies (involving nuclear genes and detailed morphological comparisons are needed. This is a first report on the invasion of a non-daphniid species of Cladocera to Australia. Its significance for Australian ecosystems needs special future studies.

  8. Towards Integration of Environmental and Health Impact Assessments for Wild Capture Fishing and Farmed Fish with Particular Reference to Public Health and Occupational Health Dimensions

    Directory of Open Access Journals (Sweden)

    Andrew Watterson

    2008-12-01

    Full Text Available The paper offers a review and commentary, with particular reference to the production of fish from wild capture fisheries and aquaculture, on neglected aspects of health impact assessments which are viewed by a range of international and national health bodies and development agencies as valuable and necessary project tools. Assessments sometimes include environmental health impact assessments but rarely include specific occupational health and safety impact assessments especially integrated into a wider public health assessment. This is in contrast to the extensive application of environmental impact assessments to fishing and the comparatively large body of research now generated on the public health effects of eating fish. The value of expanding and applying the broader assessments would be considerable because in 2004 the United Nations Food and Agriculture Organization reports there were 41,408,000 people in the total ‘fishing’ sector including 11,289,000 in aquaculture. The paper explores some of the complex interactions that occur with regard to fishing activities and proposes the wider adoption of health impact assessment tools in these neglected sectors through an integrated public health impact assessment tool.

  9. Risk-benefit evaluation of fish from Chinese markets: Nutrients and contaminants in 24 fish species from five big cities and related assessment for human health

    Energy Technology Data Exchange (ETDEWEB)

    Du, Zhen-Yu, E-mail: zdu@nifes.no [National Institute of Nutrition and Seafood Research (NIFES), N-5817 Bergen (Norway); Zhang, Jian [National Institute of Nutrition and Seafood Research (NIFES), N-5817 Bergen (Norway); Institute of Nutrition and Food Safety, Chinese Center for Disease Control and Prevention, Beijing, 100050 (China); Department of Biomedicine, University of Bergen (Norway); Wang, Chunrong; Li, Lixiang; Man, Qingqing [Institute of Nutrition and Food Safety, Chinese Center for Disease Control and Prevention, Beijing, 100050 (China); Lundebye, Anne-Katrine; Froyland, Livar [National Institute of Nutrition and Seafood Research (NIFES), N-5817 Bergen (Norway)

    2012-02-01

    The risks and benefits of fish from markets in Chinese cities have not previously been fully evaluated. In the present study, 24 common fish species with more than 400 individual samples were collected from markets from five big Chinese cities in 2007. The main nutrients and contaminants were measured and the risk-benefit was evaluated based on recommended nutrient intakes and risk level criteria set by relevant authorities. The comprehensive effects of nutrients and contaminants in marine oily fish were also evaluated using the data of two related human dietary intervention trials performed in dyslipidemic Chinese men and women in 2008 and 2010, respectively. The results showed that concentrations of contaminants analyzed including DDT, PCB{sub 7}, arsenic and cadmium were much lower than their corresponding maximum limits with the exception of the mercury concentration in common carp. Concentrations of POPs and n-3 LCPUFA, mainly EPA and DHA, were positively associated with the lipid content of the fish. With a daily intake of 80-100 g marine oily fish, the persistent organic pollutants in fish would not counteract the beneficial effects of n-3 LCPUFA in reducing cardiovascular disease (CVD) risk markers. Marine oily fish provided more effective protection against CVD than lean fish, particularly for the dyslipidemic populations. The risk-benefit assessment based on the present daily aquatic product intake in Chinese urban residents (44.9 and 62.3 g for the average values for all cities and big cities, respectively) indicated that fish, particularly marine oily fish, can be regularly consumed to achieve optimal nutritional benefits from n-3 LCPUFA, without causing significant contaminant-related health risks. However, the potential health threat from contaminants in fish should still be emphasized for the populations consuming large quantities of fish, particularly wild fish. - Highlights: Black-Right-Pointing-Pointer We collected 24 fish species with more than 400 individual samples from five big Chinese cities. Black-Right-Pointing-Pointer The health risk-benefit was evaluated based on the nutrients and contaminants content in fish. Black-Right-Pointing-Pointer Two human trials were performed to evaluate the effects of contaminated fish on CVD prevalence. Black-Right-Pointing-Pointer Contaminants in these fish couldn't alleviate the benefits of fish n-3 LCPUFA in CVD prevention. Black-Right-Pointing-Pointer These fish in China can be regularly consumed without causing contaminant-related health risks.

  10. Risk–benefit evaluation of fish from Chinese markets: Nutrients and contaminants in 24 fish species from five big cities and related assessment for human health

    International Nuclear Information System (INIS)

    The risks and benefits of fish from markets in Chinese cities have not previously been fully evaluated. In the present study, 24 common fish species with more than 400 individual samples were collected from markets from five big Chinese cities in 2007. The main nutrients and contaminants were measured and the risk–benefit was evaluated based on recommended nutrient intakes and risk level criteria set by relevant authorities. The comprehensive effects of nutrients and contaminants in marine oily fish were also evaluated using the data of two related human dietary intervention trials performed in dyslipidemic Chinese men and women in 2008 and 2010, respectively. The results showed that concentrations of contaminants analyzed including DDT, PCB7, arsenic and cadmium were much lower than their corresponding maximum limits with the exception of the mercury concentration in common carp. Concentrations of POPs and n-3 LCPUFA, mainly EPA and DHA, were positively associated with the lipid content of the fish. With a daily intake of 80–100 g marine oily fish, the persistent organic pollutants in fish would not counteract the beneficial effects of n-3 LCPUFA in reducing cardiovascular disease (CVD) risk markers. Marine oily fish provided more effective protection against CVD than lean fish, particularly for the dyslipidemic populations. The risk–benefit assessment based on the present daily aquatic product intake in Chinese urban residents (44.9 and 62.3 g for tban residents (44.9 and 62.3 g for the average values for all cities and big cities, respectively) indicated that fish, particularly marine oily fish, can be regularly consumed to achieve optimal nutritional benefits from n-3 LCPUFA, without causing significant contaminant-related health risks. However, the potential health threat from contaminants in fish should still be emphasized for the populations consuming large quantities of fish, particularly wild fish. - Highlights: ? We collected 24 fish species with more than 400 individual samples from five big Chinese cities. ? The health risk–benefit was evaluated based on the nutrients and contaminants content in fish. ? Two human trials were performed to evaluate the effects of contaminated fish on CVD prevalence. ? Contaminants in these fish couldn't alleviate the benefits of fish n-3 LCPUFA in CVD prevention. ? These fish in China can be regularly consumed without causing contaminant-related health risks.

  11. Statistical assessment of fish behavior from split-beam hydro-acoustic sampling

    International Nuclear Information System (INIS)

    Statistical methods are presented for using echo-traces from split-beam hydro-acoustic sampling to assess fish behavior in response to a stimulus. The data presented are from a study designed to assess the response of free-ranging, lake-resident fish, primarily kokanee (Oncorhynchus nerka) and rainbow trout (Oncorhynchus mykiss) to high intensity strobe lights, and was conducted at Grand Coulee Dam on the Columbia River in Northern Washington State. The lights were deployed immediately upstream from the turbine intakes, in a region exposed to daily alternating periods of high and low flows. The study design included five down-looking split-beam transducers positioned in a line at incremental distances upstream from the strobe lights, and treatments applied in randomized pseudo-replicate blocks. Statistical methods included the use of odds-ratios from fitted loglinear models. Fish-track velocity vectors were modeled using circular probability distributions. Both analyses are depicted graphically. Study results suggest large increases of fish activity in the presence of the strobe lights, most notably at night and during periods of low flow. The lights also induced notable bimodality in the angular distributions of the fish track velocity vectors. Statistical/SUMmaries are presented along with interpretations on fish behavior

  12. Heavy metal bioaccumulation and health hazard assessment for three fish species from Nansi Lake, China.

    Science.gov (United States)

    Li, Pengfei; Zhang, Jian; Xie, Huijun; Liu, Cui; Liang, Shuang; Ren, Yangang; Wang, Wenxing

    2015-04-01

    Metal accumulation in fish is a global public health concern, because the consumption of contaminated fish accounts for the primary exposure of humans to toxic metals. In this study, the concentrations of arsenic (As), cadmium (Cd), lead (Pb), and mercury (Hg) in Crucian carp (Carassius auratus),Yellow catfish (Pelteobagrus fulvidraco), and Bighead carp (Hypophthalmichthys nobilis) from Nansi Lake of China were evaluated, and compared with the corresponding historical values in 2001 when the government started to govern water environment effectively. Bioaccumulation of heavy metal was highest in P.fulvidraco, followed by C.auratus and H.nobilis. The concentrations of Pb, As, Cd were much lower than the historical values, but Hg concentration was higher, suggesting that heavy metal pollution problem in fish from Nansi Lake still exists. Health hazard assessment showed no health risk from exposure to Pb, As, Cd, and Hg by consuming fish from this lake. PMID:25636438

  13. Assessing the Financial Failure Using Z-Score and Current Ratio: A Case of Sugar Sector Listed Companies of Karachi Stock Exchange

    OpenAIRE

    Ijaz, Muhammad Shahzad; Hunjra, Ahmed Imran; Hameed, Zahid; Maqbool, Adnan; Azam, Rauf I.

    2013-01-01

    Since 1968, after the development of multivariate model, financial health of the corporate sector to predict their financial failure is heavily studied. Altman Z-Score is the most efficient model to judge the financial failure of the companies. This study uses Altman’s Z-Score and current ratio to assess the financial status of sugar sector companies listed at Karachi stock exchange. Sugar sector is the second largest slice among all sectors listed at Karachi stock exchange. Total pop...

  14. Soil organic carbon stocks under native vegetation - revised estimates for use with the simple assessment option of the Carbon Benefits Project system

    OpenAIRE

    Batjes, N. H.

    2011-01-01

    The Carbon Benefits Project (CBP) is developing a standardized system for sustainable land management projects to measure, model and report changes in carbon stocks and greenhouse gas (GHG) emissions for use at varying scales. A global framework of soil organic carbon (SOC) stocks under native vegetation for application in data poor regions, using the simple assessment option of the CBP system, is presented. It considers default classes for climate and mineral soils as required for IPCC Tier ...

  15. A second assessment of the stock of megrim Lepiodorhombus whiffiagonis in Divisions Vll b, c, j and k

    OpenAIRE

    Fahy, E.; Gleeson, P.

    1992-01-01

    An assessment of megrim captured by Irish and joint venture (Spanish) vessels in Divisions Vll b, c, j, k is based on landings from both fleets and discards from Irish vessels targeting whitefish and Nephrops. Fishing activity by the joint venture fleet is centred on the 200m depth contour. Megrim CPUE has declined since 1985. Lepidorhombus whiffiagonis constitutes the majority of the landings by joint venture vessels; L. boscii amounts up to 2% by weight of the landings from deeper wat...

  16. An assessment of the DNA barcodes of Indian freshwater fishes.

    Science.gov (United States)

    Chakraborty, Mohua; Ghosh, Sankar Kumar

    2014-03-01

    Freshwater fishes in India are poorly known and plagued by many unresolved cryptic species complexes that masks some latent and endemic species. Limitations in traditional taxonomy have resulted in this crypticism. Hence, molecular approaches like DNA barcoding, are needed to diagnose these latent species. We have analyzed 1383 barcode sequences of 175 Indian freshwater fish species available in the databases, of which 172 sequences of 70 species were generated. The congeneric and conspecific genetic divergences were calculated using Kimura's 2 parameter distance model followed by the construction of a Neighbor Joining tree using the MEGA 5.1. DNA barcoding principle at its first hand approach, led to the straightforward identification of 82% of the studied species with 2.9% (S.E=0.2) divergence between the nearest congeners. However, after validating some cases of synonymy and mislabeled sequences, 5% more species were found to be valid. Sequences submitted to the database under different names were found to represent single species. On the other hand, some sequences of the species like Barilius barna, Barilius bendelisis and Labeo bata were submitted to the database under a single name but were found to represent either some unexplored species or latent species. Overall, 87% of the available Indian freshwater fish barcodes were diagnosed as true species in parity with the existing checklist and can act as reference barcode for the particular taxa. For the remaining 13% (21 species) the correct species name was difficult to assign as they depicted some erroneous identification and cryptic species complex. Thus, these barcodes will need further assay and inclusion of barcodes of more specimens from same and sister species. PMID:24378233

  17. Fish Health Study Ashtabula River Natural Resource Damage Assessment

    Science.gov (United States)

    Blazer, V.S.; Iwanowicz, L.R.; Baumann, P.C.

    2006-01-01

    INTRODUCTION The Ashtabula River is located in northeast Ohio, flowing into Lake Erie at Ashtabula, Ohio. Tributaries include Fields Brook, Hubbard Run, Strong Brook, and Ashtabula Creek. The bottom sediments, bank soils and biota of Fields Brook have been severely contaminated by unregulated discharges of hazardous substances. Hazardous substances have migrated downstream from Fields Brook to the Ashtabula River and Harbor, contaminating bottom sediments, fish and wildlife. There are presently more than 1,000,000 cubic yards of contaminated sediment in the Ashtabula River and Harbor, much of which originated from Fields Brook. Contaminants include polychlorinated biphenyls (PCBs), chlorinated benzenes, chlorinated ethenes, hexachlorobutadiene, polyaromatic hydrocarbons (PAHs), other organic chemicals, heavy metals and low level radionuclides. A Preassessment Screen, using existing data, was completed for the Ashtabula River and Harbor on May 18, 2001. Among the findings was that the fish community at Ashtabula contained approximately 45 percent fewer species and 52 percent fewer individuals than the Ohio EPA designated reference area, Conneaut Creek. The Ashtabula River and Conneaut Creek are similar in many respects, with the exception of the presence of contamination at Ashtabula. The difference in the fish communities between the two sites is believed to be at least partially a result of the hazardous substance contamination at Ashtabula. In order to investigate this matter further, the Trustees elected to conduct a study of the status and health of the aquatic biological communities of the Ashtabula River and Conneaut Creek in 2002-2004. The following document contains brief method descriptions (more detail available in attached Appendix A) and a summary of the data used to evaluate the health status of brown bullheads (Ameiurus nebulosus) and largemouth bass (Micropterus salmoides) collected from the above sites.

  18. Recruitment variability and environment: issues related to stock assessments of Atlantic tunas

    OpenAIRE

    Fromentin, Jean-marc; Restrepo, Victor

    2001-01-01

    Las variaciones en el reclutamiento y la fuerza de la clase anual de las poblaciones de peces son características bien conocidas que pueden estar relacionadas con tres principales factores: 1) la actividad humana, principalmente la sobreexplotación del stock reproductor, y también la contaminación de las zonas de desove y cría; 2) los procesos biológicos, como la depredación, canibalismo y competencia, y 3) fenómenos del medio ambiente. Las características del ciclo vital de los t...

  19. Species and global change-assessing the extinction point of albacore stocks

    OpenAIRE

    Shyh-Bin Wang; Chien-Hsiung Wang

    2012-01-01

    Global change determines the environmental condition and leads to decide the carrying capacity. While carrying capacity determines the extinction of the species, it is an important issue to estimate the extinction point of the species, the minimal carrying capacity, or the tolerant limitation of the species. If it is possible to estimate the tolerant limitation of the species, it will be possible to control the global change. Applied the above idea to the albacore stocks, it revealed that ext...

  20. Fish orientation along the longitudinal profile of the ?ímov reservoir during daytime: Consequences for horizontal acoustic surveys.

    Czech Academy of Sciences Publication Activity Database

    Tušer, Michal; Kube?ka, Jan; Frouzová, Jaroslava; Jarolím, Old?ich

    2009-01-01

    Ro?. 96, ?. 1 (2009), s. 23-29. ISSN 0165-7836. [Fish Stock Assessment Methods for Lakes and Reservoirs: Towards the true picture of fish stock. ?eské Bud?jovice, 11.09.2007-15.09.2007] R&D Projects: GA ?R(CZ) GA206/07/1392; GA AV ?R(CZ) IAA600170502 Institutional research plan: CEZ:AV0Z60170517 Keywords : acoustics * fish orientation * fish aspect * freshwater * canyon-shaped reservoir * daytime Subject RIV: EH - Ecology, Behaviour Impact factor: 1.531, year: 2009

  1. A cost-efficient method to assess carbon stocks in tropical peat soil

    Directory of Open Access Journals (Sweden)

    M. W. Warren

    2012-11-01

    Full Text Available Estimation of belowground carbon stocks in tropical wetland forests requires funding for laboratory analyses and suitable facilities, which are often lacking in developing nations where most tropical wetlands are found. It is therefore beneficial to develop simple analytical tools to assist belowground carbon estimation where financial and technical limitations are common. Here we use published and original data to describe soil carbon density (kgC m?3; Cd as a function of bulk density (gC cm?3; Bd, which can be used to rapidly estimate belowground carbon storage using Bd measurements only. Predicted carbon densities and stocks are compared with those obtained from direct carbon analysis for ten peat swamp forest stands in three national parks of Indonesia. Analysis of soil carbon density and bulk density from the literature indicated a strong linear relationship (Cd = Bd × 495.14 + 5.41, R2 = 0.93, n = 151 for soils with organic C content > 40%. As organic C content decreases, the relationship between Cd and Bd becomes less predictable as soil texture becomes an important determinant of Cd. The equation predicted belowground C stocks to within 0.92% to 9.57% of observed values. Average bulk density of collected peat samples was 0.127 g cm?3, which is in the upper range of previous reports for Southeast Asian peatlands. When original data were included, the revised equation Cd = Bd × 468.76 + 5.82, with R2 = 0.95 and n = 712, was slightly below the lower 95% confidence interval of the original equation, and tended to decrease Cd estimates. We recommend this last equation for a rapid estimation of soil C stocks for well-developed peat soils where C content > 40%.

  2. Taking Stock and Taking Steps: The Case for an Adolescent Version of the Short-Assessment of Risk and Treatability

    Science.gov (United States)

    Viljoen, Jodi L.; Cruise, Keith R.; Nicholls, Tonia L.; Desmarais, Sarah L.; Webster, Christopher

    2012-01-01

    The field of violence risk assessment has matured considerably, possibly advancing beyond its own adolescence. At this point in the field’s evolution, it is more important than ever for the development of any new device to be accompanied by a strong rationale and the capacity to provide a unique contribution. With this issue in mind, we first take stock of the field of adolescent risk assessment in order to describe the rapid progress that this field has made, as well as the gaps that led us to adapt the Short-Term Assessment of Risk and Treatability (START; Webster, Martin, Brink, Nicholls, & Desmarais, 2009) for use with adolescents. We view the Short-Term Assessment of Risk and Treatability: Adolescent Version (START:AV; Nicholls, Viljoen, Cruise, Desmarais, & Webster, 2010; Viljoen, Cruise, Nicholls, Desmarais, & Webster, in progress) as complementing other risk measures in four primary ways: 1) rather than focusing solely on violence risk, it examines broader adverse outcomes to which some adolescents are vulnerable (including self-harm, suicide, victimization, substance abuse, unauthorized leave, self-neglect, general offending); 2) it places a balanced emphasis on adolescents’ strengths; 3) it focuses on dynamic factors that are relevant to short-term assessment, risk management, and treatment planning; and 4) it is designed for both mental health and justice populations. We describe the developmentally-informed approach we took in the adaptation of the START for adolescents, and outline future steps for the continuing validation and refinement of the START:AV. PMID:23436982

  3. Datos recientes de la distribución de la siembra de especies exóticas como base de la producción pesquera en aguas interiores mexicanas Recent data on the distribution of the exotic species used in Mexican freshwater fisheries based on fish stocking

    Directory of Open Access Journals (Sweden)

    Ana L. Ibáñez

    2011-09-01

    Full Text Available Durante los años 2001-2009, el gobierno federal produjo 780 millones de crías pertenecientes a 22 taxa que se sembraron en cuerpos de agua interiores. El principal propósito de esta siembra fue la repoblación con fines pesqueros. Mediante información del mismo gobierno, se analiza la relación producción-siembra de crías de los Centros Piscícolas federales y su efecto en la producción pesquera estatal en aguas interiores mexicanas. Se plantea que esta producción está relacionada con la siembra de crías que llevó a cabo la Comisión Nacional de Acuacultura y Pesca (CONAPESCA, organismo desconcentrado del gobierno federal. Lo anterior fue revisado al analizar la correspondencia entre la densidad de crías sembradas y los rendimientos pesqueros estatales. De los 22 taxa, 19 son especies de peces (7 nativas y 2 son subespecies, 2 son anfibios nativos y 1 es un crustáceo malayo. En promedio, en el lapso, se sembraron anualmente 86.7 ± 37.9 millones de crías, de las que el 90% son tilapias y carpas, y sólo el 3% son especies nativas. La relación siembra/ha vs producción/ha muestra que a mayor densidad de siembra, se obtiene mayor rendimiento pesquero hasta alcanzar un valor asintótico. Si bien, el gobierno federal tiene actualmente por política no sembrar en cuerpos de agua naturales especies exóticas, éstas permanecen de siembras anteriores, o las siembran los gobiernos estatales o son de cultivos privados.Federal government produced around 780 millions of fry belonging to 22 taxa during 2001-2009 which were stocked in Mexican reservoirs basically to enhance fisheries. With official information from the federal fisheries agency CONAPESCA stocking-production analysis for the fish farms from the federal government was studied at state level. We review stocking-yield relationship at state level. From the 22 taxa: 19 are fish (7 native species and 2 subspecies; 2 native amphibious and 1 Malay crustacean. Production mean for nine-year period was 86.7 ± 37.9 millions of fry, 90% of which were tilapias and carps while only 3% were native species. Stocking/ha vs Yield/ha were clearly related, thus at more stocking rate more production was obtained arriving to an asintotic value. At present, federal government policy don’t allow to stock exotic species in natural water bodies, nevertheless they stay there because of previous or local stocking events.

  4. Datos recientes de la distribución de la siembra de especies exóticas como base de la producción pesquera en aguas interiores mexicanas / Recent data on the distribution of the exotic species used in Mexican freshwater fisheries based on fish stocking

    Scientific Electronic Library Online (English)

    Ana L., Ibáñez; Héctor, Espinosa-Pérez; José L., García-Calderón.

    2011-09-01

    Full Text Available Durante los años 2001-2009, el gobierno federal produjo 780 millones de crías pertenecientes a 22 taxa que se sembraron en cuerpos de agua interiores. El principal propósito de esta siembra fue la repoblación con fines pesqueros. Mediante información del mismo gobierno, se analiza la relación produc [...] ción-siembra de crías de los Centros Piscícolas federales y su efecto en la producción pesquera estatal en aguas interiores mexicanas. Se plantea que esta producción está relacionada con la siembra de crías que llevó a cabo la Comisión Nacional de Acuacultura y Pesca (CONAPESCA), organismo desconcentrado del gobierno federal. Lo anterior fue revisado al analizar la correspondencia entre la densidad de crías sembradas y los rendimientos pesqueros estatales. De los 22 taxa, 19 son especies de peces (7 nativas) y 2 son subespecies, 2 son anfibios nativos y 1 es un crustáceo malayo. En promedio, en el lapso, se sembraron anualmente 86.7 ± 37.9 millones de crías, de las que el 90% son tilapias y carpas, y sólo el 3% son especies nativas. La relación siembra/ha vs producción/ha muestra que a mayor densidad de siembra, se obtiene mayor rendimiento pesquero hasta alcanzar un valor asintótico. Si bien, el gobierno federal tiene actualmente por política no sembrar en cuerpos de agua naturales especies exóticas, éstas permanecen de siembras anteriores, o las siembran los gobiernos estatales o son de cultivos privados. Abstract in english Federal government produced around 780 millions of fry belonging to 22 taxa during 2001-2009 which were stocked in Mexican reservoirs basically to enhance fisheries. With official information from the federal fisheries agency CONAPESCA stocking-production analysis for the fish farms from the federal [...] government was studied at state level. We review stocking-yield relationship at state level. From the 22 taxa: 19 are fish (7 native species) and 2 subspecies; 2 native amphibious and 1 Malay crustacean. Production mean for nine-year period was 86.7 ± 37.9 millions of fry, 90% of which were tilapias and carps while only 3% were native species. Stocking/ha vs Yield/ha were clearly related, thus at more stocking rate more production was obtained arriving to an asintotic value. At present, federal government policy don’t allow to stock exotic species in natural water bodies, nevertheless they stay there because of previous or local stocking events.

  5. EFFECTS OF STOCK SPLIT ON STOCK LIQUIDITY AND STOCK PRICE OPTIMALITY OF COMPANIES QUOTED AT NAIROBI STOCK EXCHANGE

    Directory of Open Access Journals (Sweden)

    MR. SIMON KAMAU GATEI

    2012-11-01

    Full Text Available A number of researchers have found a stock split is normally followed by either positive abnormal returns or increased stock liquidity or both. However other researchers such as Murray (1985 and Bley (2002 found results that are contrary to this. The objective of this paper was to assess the consequence of stock splits on stock liquidity of Kenyan firms quoted at the NSE.The research was a causal study with a trend analytical design aimed at determining the relationship between the stock liquidity positions as a result of the stock split event. The population consisted of all companies quoted in the NSE that had undertaken a stock split between the years of 2005 and 2011. The data used was secondary data on daily volumes of stock traded and daily closing stock prices that was retrieved from the NSE website. The model used for data analysis was the Amivest liquidity ratio which was developed by cooper Groth and Avera (1985. This model measured the shillings volume traded for each 1% change in stock price. The data analysis package used was Excel spread sheet.The results from the study found out that generally the liquidity of stock, as measured by the Amivest liquidity ratio, is relatively higher in the days before the stock split than in the days after the stock split. It was also observed that liquidity tends to be lowest in the days around the stock split. Generally the aggregate liquidity position in the month before the stock split was found to be higher than in the month after the stock split.It was also observed that after the stock split, stock price showed optimality by trading at a relatively constant stock price in almost all the companies.

  6. Assessing risks to fish populations near a proposed disposal facility for used nuclear fuel

    International Nuclear Information System (INIS)

    The concept of used nuclear fuel disposal in the Canadian Shield is currently undergoing a federal environmental assessment review process. As part of this review, potential risks to brook trout populations in the vicinity of such an underground repository were considered. Chemical fate, transport and exposure models have been utilized to estimate the dose rates from released radionuclides and other fuel constituents, and these likely will not be sufficient to harm fish in nearby streams. However, other stressors such as habitat alteration (e.g., loss of upwelling) and/or fishing pressure associated with increased public access could have significant population impacts if the site is located in a pristine northern region. Population models are utilized to explore the risks of local population reduction for different combinations of fishing pressure and habitat degradation

  7. Risk assessment of heavy metals in water and two fish species from golf course ponds in Beijing, China.

    Science.gov (United States)

    PuYang, Xuehua; Gao, Chenhao; Han, Liebao

    2015-04-01

    To assess the situation of heavy metals contamination, the concentrations of Cu, Zn, Pb, Cd, Cr, As and Hg in water and two fish species (crucian carp and grass carp) from six golf course ponds of Beijing were measured. Differences in metals concentrations in water and fish samples were observed among different sites, but below the relevant standards and safety values. Significant positive correlations were found between metals concentrations in water and fish samples, except for As in grass carp. Health risks to human via dietary intake of fish were then assessed based on the target hazard quotient and hazard index (HI). The HI in all fish samples were lower than 1, indicating the absence of health risks through consuming these fish. PMID:25636439

  8. Impact of entrainment and impingement on fish populations in the Hudson River Estuary. Volume II. Impingement impact analyses, evaluations of alternative screening devices, and critiques of utility testimony relating to density-dependent growth, the age-composition of the striped bass spawning stock, and the LMS real-time life cycle model

    International Nuclear Information System (INIS)

    This volume includes a series of four exhibits relating to impacts of impingement on fish populations, together with a collection of critical evaluations of testimony prepared for the utilities by their consultants. The first exhibit is a quantitative evaluation of four sources of bias (collection efficiency, reimpingement, impingement on inoperative screens, and impingement survival) affecting estimates of the number of fish killed at Hudson River power plants. The two following exhibits contain, respectively, a detailed assessment of the impact of impingement on the Hudson River white perch population and estimates of conditional impingement mortality rates for seven Hudson River fish populations. The fourth exhibit is an evaluation of the engineering feasibility and potential biological effectiveness of several types of modified intake structures proposed as alternatives to cooling towers for reducing impingement impacts. The remainder of Volume II consists of critical evaluations of the utilities' empirical evidence for the existence of density-dependent growth in young-of-the-year striped bass and white perch, of their estimate of the age-composition of the striped bass spawning stock in the Hudson River, and of their use of the Lawler, Matusky, and Skelly (LMS) Real-Time Life Cycle Model to estimate the impact of entrainment and impingement on the Hudson River striped bass population

  9. Impact of entrainment and impingement on fish populations in the Hudson River Estuary. Volume II. Impingement impact analyses, evaluations of alternative screening devices, and critiques of utility testimony relating to density-dependent growth, the age-composition of the striped bass spawning stock, and the LMS real-time life cycle model

    Energy Technology Data Exchange (ETDEWEB)

    Barnthouse, L. W.; Van Winkle, W.; Golumbek, J.; Cada, G. F.; Goodyear, C. P.; Christensen, S. W.; Cannon, J. B.; Lee, D. W.

    1982-04-01

    This volume includes a series of four exhibits relating to impacts of impingement on fish populations, together with a collection of critical evaluations of testimony prepared for the utilities by their consultants. The first exhibit is a quantitative evaluation of four sources of bias (collection efficiency, reimpingement, impingement on inoperative screens, and impingement survival) affecting estimates of the number of fish killed at Hudson River power plants. The two following exhibits contain, respectively, a detailed assessment of the impact of impingement on the Hudson River white perch population and estimates of conditional impingement mortality rates for seven Hudson River fish populations. The fourth exhibit is an evaluation of the engineering feasibility and potential biological effectiveness of several types of modified intake structures proposed as alternatives to cooling towers for reducing impingement impacts. The remainder of Volume II consists of critical evaluations of the utilities' empirical evidence for the existence of density-dependent growth in young-of-the-year striped bass and white perch, of their estimate of the age-composition of the striped bass spawning stock in the Hudson River, and of their use of the Lawler, Matusky, and Skelly (LMS) Real-Time Life Cycle Model to estimate the impact of entrainment and impingement on the Hudson River striped bass population.

  10. Diel variation in gillnet catches and vertical distribution of pelagic fishes in a stratified European reservoir.

    Czech Academy of Sciences Publication Activity Database

    Vašek, Mojmír; Kube?ka, Jan; ?ech, Martin; Draštík, Vladislav; Mat?na, Josef; Mrkvi?ka, T.; Peterka, Ji?í; Prchalová, Marie

    2009-01-01

    Ro?. 96, ?. 1 (2009), s. 64-69. ISSN 0165-7836. [Fish Stock Assessment Methods for Lakes and Reservoirs: Towards the true picture of fish stock. ?eské Bud?jovice, 11.09.2007-15.09.2007] R&D Projects: GA AV ?R(CZ) 1QS600170504; GA AV ?R(CZ) IAA600170502; GA ?R(CZ) GP206/06/P418 Institutional research plan: CEZ:AV0Z60170517 Keywords : gillnet * diel catchability * distribution * epilimnetic fishes * CPUE * man-made lake Subject RIV: DA - Hydrology ; Limnology Impact factor: 1.531, year: 2009

  11. A trait-based assessment of the Barents Sea fish community:implications for vulnerability under environmental change

    OpenAIRE

    Wiedmann, Magnus Aune

    2014-01-01

    SUMMARY This is a study of the fish community in the Barents Sea and its vulnerability to disturbance such as fishing and climate change. The vulnerability of the fish community depends on its sensitivity to, and adaptability under, stress. To assess these two components of vulnerability, I have combined survey data from the Barents Sea with information about the species properties (i.e., traits), following three approaches. 1) To study the adaptability under disturbance, I ...

  12. Integrated ecosystem assessment of Vieques, Puerto Rico Fish Assessment and Monitoring Data

    National Oceanic and Atmospheric Administration, Department of Commerce — This fish and benthic composition database is the result of a multifaceted effort described below.The National Oceanic and Atmospheric Administration's (NOAA)...

  13. Fish-based groups for ecological assessment in rivers: the importance of environmental drivers on taxonomic and functional traits of fish assemblages

    Directory of Open Access Journals (Sweden)

    Matono P.

    2012-06-01

    Full Text Available The use of river-types is of practical value, serving as groups for which assessment procedures can be developed and applied. An abiotic typology was set by the Portuguese Water Agency, mainly based on 6 major morphoclimatic regions. However, to be biologically meaningful, this typology should fit the distribution patterns of the biological quality elements communities proposed in Water Framework Directive under the lowest possible human pressure. This study aimed to identify and characterize fish-based geographical groups for continental Portugal and their environmental and geographical discriptors, using taxonomic and functional traits. Sampling took place between 2004 and 2006 during Spring. Fish fauna from 155 reference sites was analysed using a multivariate approach. Cluster Analysis on fish composition identified 10 fish-groups, expressing a clear correspondence to the river basin level, due to the restrict basin distribution of many species. Groups showed a wider aggregation in 4 regions with a larger geographical correspondence, statistically supported by Similarity Analysis, both on fish composition and mostly on fish metrics/guilds. Principal Components Analysis revealed major environmental drivers associated to fish-groups and fish-regions. Fish-groups were hierarchically grouped over major and local regions, expressing a large-scale response to a North-South environmental gradient defined by temperature, precipitation, mineralization and altitude, and a regional scale response mainly to drainage area and flow discharge. From North to South, fish-regions were related to the morphoclimatic regions. Results contributed to reduce redundance in abiotic river-types and set the final typology for Portuguese rivers, constituting a fundamental tool for planning and managing water resources.

  14. Assessment of end-use electricity consumption and peak demand by Townsville's housing stock

    International Nuclear Information System (INIS)

    We have developed a comprehensive model to estimate annual end-use electricity consumption and peak demand of housing stock, considering occupants' use of air conditioning systems and major appliances. The model was applied to analyse private dwellings in Townsville, Australia's largest tropical city. For the financial year (FY) 2010–11 the predicted results agreed with the actual electricity consumption with an error less than 10% for cooling thermostat settings at the standard setting temperature of 26.5 °C and at 1.0 °C higher than the standard setting. The greatest difference in monthly electricity consumption in the summer season between the model and the actual data decreased from 21% to 2% when the thermostat setting was changed from 26.5 °C to 27.5 °C. Our findings also showed that installation of solar panels in Townville houses could reduce electricity demand from the grid and would have a minor impact on the yearly peak demand. A key new feature of the model is that it can be used to predict probability distribution of energy demand considering (a) that appliances may be used randomly and (b) the way people use thermostats. The peak demand for the FY estimated from the probability distribution tracked the actual peak demand at 97% confidence level. - Highlights: • We developed a model to estimate housing stock energy consumption and peak demand. • Appliances used randomly and thermostat settings for space cooling were considered. • On-site installation of solar panels was also considered. • Its' results agree well with the actual electricity consumption and peak demand. • It shows the model could provide the probability distribution of electricity demand

  15. Ecological risk assessment in a large river-reservoir. 2: Fish community

    International Nuclear Information System (INIS)

    This paper summarizes the assessment of risks to fishes in the Clinch River Operable Unit due to contaminants released by the US Department of Energy's activities on its Oak Ridge Reservation in Tennessee. This paper focuses on the most contaminated area, the Poplar Creek (PC) embayment. The assessment is of interest because of its use of five distinct lines of evidence: fish community surveys, fish body burdens, toxicity tests of ambient waters, suborganismal bioindicators, and single chemical toxicity tests. None of these lines of evidence provided unambiguous evidence of a significant risk, but the surveys indicated that the fish community in PC was depauperate, polychlorinated biphenyl body burdens may have been at toxic levels in catfish, one of the three tests of ambient water showed clear toxicity, some of the indicators were indicative of toxic effects, and concentrations that have been toxic in the laboratory were detected periodically. Interpretation was further complicated by upstream contamination of both the Clinch River and PC. The risk characterization was performed by evaluating each line of evidence separately and then weighing the evidence using an ecoepidemiological approach

  16. DDT in fishes from four different Amazon sites: exposure assessment for breast feeding infants

    Energy Technology Data Exchange (ETDEWEB)

    D' Amato, C.; Torres, J.P.; Malm, O. [Lab. de Radioisotopos Eduardo Penna Franca, Inst. de Biofisica, UFRJ, RJ (Brazil); Bastos, W. [Lab. de Biogeoquimica, UNIR, Porto Velho (Brazil); Claudio, L.; Markowitz, S. [International Training Program on Environmental and Occupational Health, Mount Sinai School of Medicine, Queens Coll., NY (United States)

    2004-09-15

    Concerning DDT in food, based on clinical observations as well as experimental animals, the annual Joint FAO/WHO Meetings on Pesticide Residues held in 2000 estimated a Provisional Tolerable Daily Intake (PTDI) for DDT in 0.01 mg/kg/day. Marien and Laflamme have proposed a Tolerable Daily Intake (TDI) for breast feedings infants of 5 x 10{sup -3} mg/kg/day, and conducted an assessment to evaluate the public health significance of eating {sigma}ODDT contaminated fish, accomplished by establishing a daily intake level of DDT for the population of greatest concern, like breastfeeding infants. Their results indicated that mothers who frequently consume contaminated fish could have breast milk DDT concentrations highly enough to expose their infants to levels above the TDI. The aim of this study was to evaluate the ODDT (o,p'-DDT + p,p'-DDT + o,p'-DDE + p,p'-DDE + o,p'-DDD) levels in commercial fish samples from distinct Brazilian Amazon sites, which are consumed by the riverine populations, and to assess the potential health impacts from eating these fishes, especially for breastfeeding infants.

  17. Stream fishes and desirable fish stocks

    DEFF Research Database (Denmark)

    Dieperink, C.; Sand-Jensen, K.

    2006-01-01

    Freshwater fi sh communities have always been valuable resources for society, particularly the species that migrate between freshwater and the sea. Historically, eel, salmon and trout were so abundant that good fi shing luck could turn a capable fi sherman into a wealthy person. Unfortunately, migrating fi sh became threatened by over-fi shing quite early in human history. The more recent construction of dams and other habitat destruction associated with development of towns, industries and intensive agriculture have reduced populations further. The largest Danish river, the River Gudenå, illustrates this historical decline and also the diffi culty of re-establishing healthy fi sh communities once the original populations have deteriorated or, in the case of salmon, become extinct. Efforts are currently needed to be made to effectively restore and manage fi sh communities in streams.

  18. Blood chemistry profile of Surubim hybrid fish (Pseudoplatystoma reticulatum X P. corruscans raised in different stocking densities Perfil bioquímico do híbrido de Surubim (Pseudoplatystoma reticulatum X P. corruscans criado em diferentes densidades

    Directory of Open Access Journals (Sweden)

    Carla Rosa Labarrère

    2013-06-01

    Full Text Available Massive production, such as fish growing in water recirculation system, imposes challenges to animals capable of altering their homeostatic balance, and is able to affect their physiological performance. Therefore, the levels of ions and serum enzymes can be used as indicators of fish health. This study aimed to analyze the blood biochemistry profile of hybrid surubim (P. reticulatum X P. corruscans submitted to different stocking densities in water recirculation system, in two distinct stages of production, from 150 to 400 g (first trial, and 400 to 1000 g (second trial. In the first trial, the five stocking rates were: 27.5, 47.5, 67.5, 87.5 and 107.5 fish/m³ of water. To obtain these densities, it was used 11, 19, 27, 35 and 43 fish per tank, respectively. In the second trial, five stocking rates were: 10, 20, 30, 40 and 50 fish/m³ of water. To obtain these densities we used 4, 8, 12, 16 and 20 fish per tank, respectively. The concentrations of glucose, cholesterol, triglycerides, urea, creatinine, alkaline phosphatase (ALP, aspartate aminotransferase (AST, lactate dehydrogenase (LDH, calcium, phosphorus, potassium and magnesium were obtained. Only urea concentrations in first trial and ALP and AST concentrations in second trial were influenced by stocking density, presenting a significant difference between groups. Thus, in both trials the hybrid fish studied maintained homeostasis when reared in different stocking densities.Dentre os sistemas de produção, o de recirculação de água impõe desafios para os animais que podem ser capazes de alterar o seu equilíbrio homeostático, afetando o índice de desempenho. Por conseguinte, os níveis de ions e enzimas séricas podem ser utilizados como indicadores de saúde dos peixes. Neste estudo, objetivo-se analisar o perfil de bioquímico do sangue do híbrido de Surubim (P. reticulatum X P. corruscans, submetido a diferentes densidades de estocagem em sistema de recirculação de água, em duas fases distintas de produção, de 150 a 400 g (primeiro ensaio e, 400 a 1000 g (segundo ensaio. No primeiro ensaio, as cinco densidades de estocagem estudadas foram: 27,5, 47,5, 67,5, 87,5 e 107,5 peixes/m³ de água. Para a obtenção dessas densidades foram utilizados 11, 19, 27, 35 e 43 peixes por tanque, respectivamente. No segundo ensaio, as cinco densidades de estocagem estudadas foram: 10, 20, 30, 40 e 50 peixes/m³ de água. Para a obtenção dessas densidades foram utilizados 4, 8, 12, 16 e 20 peixes por tanque, respectivamente. As concentrações de glicose, colesterol, triglicérides, ureia, creatinina, fosfatase alcalina (FA, aspartato aminotransferase (AST, desidrogenase lática (LDH, cálcio, fósforo, potássio e magnésio foram avaliadas. Apenas as concentrações de ureia no primeiro ensaio e FA e AST no segundo ensaio foram influenciadas pela densidade de estocagem, apresentando uma diferença significativa entre os grupos. Assim, em ambos os ensaios, o Surubim híbrido manteve a homeostase do sangue em diferentes densidades.

  19. Blood chemistry profile of Surubim hybrid fish (Pseudoplatystoma reticulatum X P. corruscans) raised in different stocking densities / Perfil bioquímico do híbrido de Surubim (Pseudoplatystoma reticulatum X P. corruscans) criado em diferentes densidades

    Scientific Electronic Library Online (English)

    Carla Rosa, Labarrère; Paulo Mário Carvalho de, Faria; Edgar de Alencar, Teixeira; Marília Martins, Melo.

    2013-06-01

    Full Text Available Dentre os sistemas de produção, o de recirculação de água impõe desafios para os animais que podem ser capazes de alterar o seu equilíbrio homeostático, afetando o índice de desempenho. Por conseguinte, os níveis de ions e enzimas séricas podem ser utilizados como indicadores de saúde dos peixes. Ne [...] ste estudo, objetivo-se analisar o perfil de bioquímico do sangue do híbrido de Surubim (P. reticulatum X P. corruscans), submetido a diferentes densidades de estocagem em sistema de recirculação de água, em duas fases distintas de produção, de 150 a 400 g (primeiro ensaio) e, 400 a 1000 g (segundo ensaio). No primeiro ensaio, as cinco densidades de estocagem estudadas foram: 27,5, 47,5, 67,5, 87,5 e 107,5 peixes/m³ de água. Para a obtenção dessas densidades foram utilizados 11, 19, 27, 35 e 43 peixes por tanque, respectivamente. No segundo ensaio, as cinco densidades de estocagem estudadas foram: 10, 20, 30, 40 e 50 peixes/m³ de água. Para a obtenção dessas densidades foram utilizados 4, 8, 12, 16 e 20 peixes por tanque, respectivamente. As concentrações de glicose, colesterol, triglicérides, ureia, creatinina, fosfatase alcalina (FA), aspartato aminotransferase (AST), desidrogenase lática (LDH), cálcio, fósforo, potássio e magnésio foram avaliadas. Apenas as concentrações de ureia no primeiro ensaio e FA e AST no segundo ensaio foram influenciadas pela densidade de estocagem, apresentando uma diferença significativa entre os grupos. Assim, em ambos os ensaios, o Surubim híbrido manteve a homeostase do sangue em diferentes densidades. Abstract in english Massive production, such as fish growing in water recirculation system, imposes challenges to animals capable of altering their homeostatic balance, and is able to affect their physiological performance. Therefore, the levels of ions and serum enzymes can be used as indicators of fish health. This s [...] tudy aimed to analyze the blood biochemistry profile of hybrid surubim (P. reticulatum X P. corruscans) submitted to different stocking densities in water recirculation system, in two distinct stages of production, from 150 to 400 g (first trial), and 400 to 1000 g (second trial). In the first trial, the five stocking rates were: 27.5, 47.5, 67.5, 87.5 and 107.5 fish/m³ of water. To obtain these densities, it was used 11, 19, 27, 35 and 43 fish per tank, respectively. In the second trial, five stocking rates were: 10, 20, 30, 40 and 50 fish/m³ of water. To obtain these densities we used 4, 8, 12, 16 and 20 fish per tank, respectively. The concentrations of glucose, cholesterol, triglycerides, urea, creatinine, alkaline phosphatase (ALP), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), calcium, phosphorus, potassium and magnesium were obtained. Only urea concentrations in first trial and ALP and AST concentrations in second trial were influenced by stocking density, presenting a significant difference between groups. Thus, in both trials the hybrid fish studied maintained homeostasis when reared in different stocking densities.

  20. Radiological assessment of fish samples due to natural radionuclides in river Yobe, Northern Nigeria

    International Nuclear Information System (INIS)

    Assessment of natural radioactivity of some fish samples in river Yobe was conducted, using gamma spectroscopy method with NaI(TI) detector. Radioactivity is phenomenon that leads to production of radiations, whereas radiation is known to trigger or induce cancer. The fish were analyzed to estimate the radioactivity (activity) concentrations due to natural radionuclides 226Ra, 232Th and 40K. The obtained result show that the activity concentration for (226Ra), in all the fish samples collected ranges from 15.23±2.45BqKg-1 to 67.39±2.13BqKg-1 with an average value of 34.13±1.34BqKg-1. That of 232Th, ranges from 42.66±0.81BqKg-1 to 201.18±3.82BqKg-1, and the average value stands at 96.01±3.82BqKg-1. The activity concentration for 40K, ranges between 243.3±1.56 BqKg-1 to 618.2±2.81 BqKg-1 and the average is 413.92±1.7 BqKg-1. This study indicated that average daily intake due to natural activity from the fish is valued at 0.913 Bq/day, 2.577Bq/day and 11.088 Bq/day for 226Ra, 232Th and 40K respectively. This shows that the activity concentration values for fish, shows a promising result with most of the fish activity concentrations been within the acceptable limits. However locations (F02, F07 and F12), fish became outliers with significant values of 112.53?Svy-1, 121.11?Svy-1 and 114.32?Svy-1 effective dose. This could be attributed to variation in geological formations within the river as well as the feeding habits of these fish. The work shows that consumers of fish from River Yobe have no risk of radioactivity ingestion, even though no amount of radiation is assumed to be totally safe.

  1. Assessing ecological risks to the fish community from residual coal fly ash in Watts Bar Reservoir, Tennessee.

    Science.gov (United States)

    Rigg, David K; Wacksman, Mitch N; Iannuzzi, Jacqueline; Baker, Tyler F; Adams, Marshall; Greeley, Mark S

    2015-01-01

    Extensive site-specific biological and environmental data were collected to support an evaluation of risks to the fish community in Watts Bar Reservoir from residual ash from the December 2008 Tennessee Valley Authority (TVA) Kingston ash release. This article describes the approach used and results of the risk assessment for the fish community, which consists of multiple measurement endpoints (measures of exposure and effects) for fish. The lines of evidence included 1) comparing postspill annual fish community assessments with nearby prespill data and data from other TVA reservoirs, 2) evaluating possible effects of exposures of fish eggs and larval fish to ash in controlled laboratory toxicity tests, 3) evaluating reproductive competence of field-exposed fish, 4) assessing individual fish health through physical examination, histopathology, and blood chemistry, 5) comparing fish tissue concentrations with literature-based critical body residues, and 6) comparing concentrations of ash-related contaminants in surface waters with US Environmental Protection Agency's (USEPA) Ambient Water Quality Standards for Fish and Aquatic Life. These measurement endpoints were treated as independent lines of evidence that were integrated into an overall weight-of-evidence estimate of risk to the fish community. Collectively, the data and analysis presented here indicate that ash and ash-related constituents pose negligible risks to the fish communities in Watts Bar Reservoir. This conclusion contradicts the predictions by some researchers immediately following the ash release of devastating effects on the aquatic ecology of Watts Bar Reservoir. The information presented in this article reaffirms the wisdom of carefully evaluating the evidence before predicting probable ecological effects of a major event such as the TVA Kingston ash release. This study demonstrates that a thorough and detailed investigation using multiple measurement endpoints is needed to properly evaluate ecological effects. PMID:25346112

  2. Using Tournament Angler Data to Rapidly Assess the Invasion Status of Alien Sport Fishes (Micropterus spp.) in Southern Africa

    Science.gov (United States)

    Hargrove, John S.; Weyl, Olaf L. F.; Allen, Micheal S.; Deacon, Neil R.

    2015-01-01

    Fishes are one of the most commonly introduced aquatic taxa worldwide, and invasive fish species pose threats to biodiversity and ecosystem function in recipient waters. Considerable research efforts have focused on predicting the invasibility of different fish taxa; however, accurate records detailing the establishment and spread of invasive fishes are lacking for large numbers of fish around the globe. In response to these data limitations, a low-cost method of cataloging and quantifying the temporal and spatial status of fish invasions was explored. Specifically, angler catch data derived from competitive bass angling tournaments was used to document the distribution of 66 non-native populations of black bass (Micropterus spp.) in southern Africa. Additionally, catch data from standardized tournament events were used to assess the abundance and growth of non-native bass populations in southern Africa relative to their native distribution (southern and eastern United States). Differences in metrics of catch per unit effort (average number of fish retained per angler per day), daily bag weights (the average weight of fish retained per angler), and average fish weight were assessed using catch data from 14,890 angler days of tournament fishing (11,045 days from South Africa and Zimbabwe; 3,845 days from the United States). No significant differences were found between catch rates, average daily bag weight, or the average fish weight between countries, suggesting that bass populations in southern Africa reach comparable sizes and numbers relative to waters in their native distribution. Given the minimal cost associated with data collection (i.e. records are collected by tournament organizers), the standardized nature of the events, and consistent bias (i.e. selection for the biggest fish in a population), the use of angler catch data represents a novel approach to infer the status and distribution of invasive sport fish. PMID:26047487

  3. Impact of climate change on a risk assessment for intersex in fish due to steroid estrogens

    OpenAIRE

    V.D.J. Keller; Lloyd, P; WILLIAMS, R. J.

    2013-01-01

    The impact of climate on the natural environment has been a reason for concern for many scientists across the globe. Although water quantity and water resources have been the focus of many studies over the past years, water quality raised less attention. In England and Wales, steroid estrogens, namely estrone (E1), estradiol (E2) and ethinylestradiol (EE2) were identified as being the main chemicals causing intersex in male fish. A national risk assessment is already available for intersex in...

  4. Designing and validating the methodology for the Internet assessment of fish consumption at a university setting

    Scientific Electronic Library Online (English)

    Erika da Silva, Maciel; Julia Santos, Vasconcelos; Luciana Kimie Savay da, Silva; Jaqueline Girnos, Sonati; Juliana, Galvão; Dirceu da, Silva; Marília, Oetterer.

    2014-06-01

    Full Text Available Assessing fish consumption is complex and involves several factors; however, the use of questionnaires in surveys and the use of the Internet as tool to collect data have been considered promising approaches. Therefore, the objective of this research was to design a data collection technique using a [...] questionnaire to assess fish consumption by making it available on a specific home page on the Internet. A bibliographical survey or review was carried out to identify the features of the instrument, and therefore pre-tests were conducted with previous instruments, followed by the Focus Group technique. Specialists then performed an analysis and conducted an online pre-test. Multivariate data analysis was applied using the SmartPLS software. The results indicate that 1.966 participants belonging to the University of São Paulo (USP) community participated in the test, and after the exclusion of some variables, a statistically significant results were obtained. The final constructs comprised consumption, quality, and general characteristics. The instrument consisted of behavioral statements in a 5-point Likert scale and multiple-choice questions. The Cronbach's alpha reliability coefficient was 0.66 for general characteristics, 0.98 for quality, and 0.91 for consumption, which indicate good reliability of the instrument. In conclusion, the results proved that the Internet assessment is efficient. The instrument of analysis allowed us to better understand the process of buying and consuming fish in the country, and it can be used as base for further research.

  5. Assessing the efficacy of single-pass backpack electrofishing to characterize fish community structure

    Science.gov (United States)

    Meador, M.R.; McIntyre, J.P.; Pollock, K.H.

    2003-01-01

    Two-pass backpack electrofishing data collected as part of the U.S. Geological Survey's National Water-Quality Assessment Program were analyzed to assess the efficacy of single-pass backpack electrofishing. A two-capture removal model was used to estimate, within 10 river basins across the United States, proportional fish species richness from one-pass electrofishing and probabilities of detection for individual fish species. Mean estimated species richness from first-pass sampling (p??s1) ranged from 80.7% to 100% of estimated total species richness for each river basin, based on at least seven samples per basin. However, p??s1 values for individual sites ranged from 40% to 100% of estimated total species richness. Additional species unique to the second pass were collected in 50.3% of the samples. Of these, cyprinids and centrarchids were collected most frequently. Proportional fish species richness estimated for the first pass increased significantly with decreasing stream width for 1 of the 10 river basins. When used to calculate probabilities of detection of individual fish species, the removal model failed 48% of the time because the number of individuals of a species was greater in the second pass than in the first pass. Single-pass backpack electrofishing data alone may make it difficult to determine whether characterized fish community structure data are real or spurious. The two-pass removal model can be used to assess the effectiveness of sampling species richness with a single electrofishing pass. However, the two-pass removal model may have limited utility to determine probabilities of detection of individual species and, thus, limit the ability to assess the effectiveness of single-pass sampling to characterize species relative abundances. Multiple-pass (at least three passes) backpack electrofishing at a large number of sites may not be cost-effective as part of a standardized sampling protocol for large-geographic-scale studies. However, multiple-pass electrofishing at some sites may be necessary to better evaluate the adequacy of single-pass electrofishing and to help make meaningful interpretations of fish community structure.

  6. A scoring system approach for the parasite predictive assessment of fish lots: a proof of concept with anisakids.

    Science.gov (United States)

    Llarena-Reino, María; Abollo, Elvira; Pascual, Santiago

    2013-12-01

    A total of 982 individuals distributed in 11 lots belonging to 10 fish species from three Atlantic FAO fishing areas were sampled and examined to detect the presence of anisakid larvae in fish muscle. After hazard identification by genetic sequencing and exposure assessment by anatomic extent and demographic characterization of infection, all data were fitted for each fish species to a new proposed scoring schema of parasite prediction. In the absence of a criterion standard method for inspection and precise definition of the quantum satis for parasites in contaminated fish lots, the inspection rating scheme called SADE (Site of infection, Assurance of quality, Demography, Epidemiology) may help fish industries to precisely handle and to evaluate the likely outcome of infected fish lots after being diagnosed. For this purpose, a supporting flow diagram for decision was defined and suggested. This new performance assessment tool has the aim of staging fish lots, thus helping in planning manufacture, commercial, and research decisions during self-management programs. This novel scoring system provides an improved inspection format by implementing the occurrence stratification for parasites to guide Hazard Analysis and Critical Control Points (HACCP) programs for the uniform exchange of information among fish industries, administration and researchers, thus facilitating standardization and communication. In the future, this scoring version could be validated (in terms of classification and wording) for similar overall predictive purposes in other muscular parasites infecting seafood products. PMID:24147656

  7. An evaluation of multi-annual management strategies for ICES roundfish stocks

    DEFF Research Database (Denmark)

    Kell, L.T.; Pilling, G.M.

    2006-01-01

    Current scientific management objectives for ICES roundfish stocks are to ensure conservation of the biological resource and do not explicitly consider economic or social objectives. For example, there are currently no objectives to maximize the sustainable yield or to reduce variability in total allowable catches (TACs). This is despite the fact that the current system can result in wide annual fluctuations in TAC, limiting the ability of the fishing industry to plan for the future. Therefore, this study evaluated management strategies that stabilized catches by setting bounds on the interannual variability in TACs. An integrated modelling framework was used, which simulated both the real and observed systems and the interactions between system components. This allowed the evaluation of candidate management strategies with respect to the intrinsic properties of the systems, as well as our ability to observe, monitor, assess, and control them. Strategies were evaluated in terms of risk (measured as the probability of spawning-stock biomass falling below a biomass threshold for the stock) and cumulative yield. In general, bounds on interannual TAC change of 10% and 20% affected the ability to achieve management targets, although the outcome of applying TAC bounds could not have been pre-judged because results were highly dependent on the specific biology of the stock, current status, and the interaction with assessment and management. For example, for North Sea haddock, management became less responsive to fluctuations resulting from large recruitment events. Simulated target fishing mortality levels were rarely achieved, regardless of the TAC bound applied, and actual fishing mortality rates oscillated around the target. In the longer term, more restrictive bounds resulted in oscillations of greater amplitude and wavelength in yield and SSB. Bounds had less effect when a stock was close to the biomass corresponding to the target F. Risk for stocks that are declining or currently at low abundance may be greater, because if bounds restrict the extent to which TACs can be reduced each year, they could lead to collapse of the stock and the loss of all future revenue. However, for a recovered stock or one at high abundance, the loss of yield as a result of bounds would be smaller than that caused by the total collapse of the fishery. At low stock size or if the stock was declining, catches should be changed more rapidly than when the stock was increasing or at a high level, especially high stock sizes acting as an insurance against uncertainty. Therefore, rebuilding strategies, and strategies aimed at maintaining the stock above prescribed limits, should be considered separately. (c) 2005 International Council for the Exploration of the Sea. Published by Elsevier Ltd. All rights reserved.

  8. Carbon stock assessment of two agroforestry systems in a tropical forest reserve in the Philippines

    Energy Technology Data Exchange (ETDEWEB)

    Lasco, R.D.; Sales, R.F.; Estrella, R.; Saplaco, S.R.; Castillo, A.S.A.; Cruz, R.V.O.; Pulhin, F.B. [University of Philippines Los Banos, Laguna (Philippines). College of Forestry & Natural Resources Environmental Forestry Programme

    2001-07-01

    Carbon dioxide is the most abundant greenhouse gas (GHG) that causes global warming. Thus, land uses such as an agroforestry system have a significant role in moderating climate change since they can be sources and sinks of carbon. The aim of the study was to generate data on the carbon stocks of two agroforestry systems, specifically a Gmelina arborea-Theobroma cacao multistorey system and an alley cropping system with Gliricidia sepium hedges at the agroforestry research and demonstration area inside a forest reserve in Southern Luzon, Philippines. The multistorey system had a mean biomass of 258 Mg C ha{sup -1} and a carbon density of 185 Mg C ha{sup -1}. Carbon was stored in the various pools in the following order of magnitude: soil > tree biomass (above-ground) > necromass > understorey vegetation > roots. The Gliricidia hedgerow had a biomass density of 3.8 Mg C ha{sup -1}; total carbon density was 93 Mg C ha{sup -1}, of which 92 Mg C ha{sup -1} was in the soil.

  9. Carbon stock assessment of three selected agroforestry systems in Bukidnon, Philippines

    Directory of Open Access Journals (Sweden)

    Mildred M. Labata

    2012-06-01

    Full Text Available Climate change, caused by global warming, is a phenomenon partly resulting from abundance of carbon dioxide in the atmosphere.It is the most pressing environmental problem of the world today. It persists, and it cannot be stopped. Rather, it can be mitigated. Agroforestrysystems as land use can reduce the atmospheric concentration of carbon dioxide. This study therefore aimed to generate data on the carbonstocks of three selected agroforestry systems located within the Province of Bukidnon. The methodologies used include measurement of treesat diameter breast height (dbh and sampling of herbaceous vegetation, litter, and soil for carbon content determination and farmer interview.Results showed that carbon accumulation of agroforestry systems goes along with the following order: taungya agroforestry system (174 MgCha-1 > mixed multistorey system (162 MgC ha-1 > falcata-coffee multistorey system (92 MgC ha-1. Carbon was stored in the various pools inthe following order of magnitude: soil (77-92% > trees (7-22% > herbaceous vegetation and litter (1%. Compared with natural forests, theseselected agroforestry systems represents 23-44% of the total carbon stock. Policy programs promoting the establishment of agroforestry systemsin idle lands in Bukidnon should be considered.

  10. Population dynamics and stock assessment for Octopus maya (Cephalopoda:Octopodidae fishery in the Campeche Bank, Gulf of Mexico

    Directory of Open Access Journals (Sweden)

    Francisco Arreguín-Sánchez

    2000-06-01

    Full Text Available The octopus (Octopus maya is one of the most important fish resources in the Mexican Gulf of Mexico with a mean annual yield of 9000 ton, and a reasonable number of jobs created; O. maya represents 80% of the total octopus catch, followed by Octopus vulgaris. There are two artisanal fleets based on Octopus maya and a middle-size fleet that covers both species. Catch-at-length structured data from the artisanal fleets, for the 1994 season (August 1st to December 15th were used to analyze the O. maya population dynamics and stock and to estimate the current level of exploitation. Von Bertalanffy growth parameters were: L = 252 mm, mantle length; K=1.4 year -1; oscillation parameters C=1.0, WP=0.6; and tz=0.842 years. A rough estimate of natural mortality was M=2.2, total mortality from catch curve Z=8.77, and exploitation rate F/Z=0.75. This last value suggests an intensive exploitation, even when yield per recruit analysis indicates both fleets may increase the minimum legal size on about 10% to increase yields. The length-based VPA also shows that the stock is being exploited under its maximum acceptable biological limit. These apparently contradictory results are explained by biological and behavioral characteristics of this species. Because most females die after reproduction, a new gross estimation of natural mortality was computed as M=3.3. The new estimate of exploitation rate was F/Z=0.57. This new value coincides with results from the length-VPA and the Thompson and Bell methods, the former suggesting that a reduction of 20% in fishing mortality may provide larger yields. This fishery resource is fully exploited and current management measures must be revised to sustain and probably optimize yields.Octopus maya es uno de los recursos pesqueros más importantes del Golfo de México, con rendimientos anuales promedio de 9 000 t, y constituye el 80% de la captura total, seguido por O. vulgaris. En la pesquería participan dos flotas artesanales sobre O. maya, y una de mediana altura capturando ambas especies. Datos de frecuencia de longitudes de la captura para la temporada de pesca 1994 (Agosto 1° a Diciembre 15 fueron usados para analizar la dinámica poblacional y el estado de explotación de O. maya. Los parámetros del modelo de von Bertalanffy fueron: L° = 252 mm longitud de manto, K = 1.4 años-1, C = 1.0 y WP = 0.6, y tZ = 0.842 años. Una estimación inicial de la mortalidad natural fue M = 2.2, la mortalidad total Z = 8.77, y tasa de explotación F/Z = 0.75, lo cual sugiere una intensa explotación. El análisis de rendimiento por recluta indica que podría aumentarse la talla mínima legal para incrementar los rendimientos. El VPA indica un recurso explotado al límite de su capacidad biológica. Debido a que las hembras mueren después de la reproducción, una nueva estimación de mortalidad natural, M = 3.3, y tasa de explotación, F/Z = 0.57 fueron obtenidas, coincidiendo con los resultados del VPA basado en longitudes y el método de Thompson y Bell.

  11. Population dynamics and stock assessment for Octopus maya (Cephalopoda:Octopodidae) fishery in the Campeche Bank, Gulf of Mexico

    Scientific Electronic Library Online (English)

    Francisco, Arreguín-Sánchez; Manuel J, Solís -Ramírez; María E, González de la Rosa.

    2000-06-01

    Full Text Available Octopus maya es uno de los recursos pesqueros más importantes del Golfo de México, con rendimientos anuales promedio de 9 000 t, y constituye el 80% de la captura total, seguido por O. vulgaris. En la pesquería participan dos flotas artesanales sobre O. maya, y una de mediana altura capturando ambas [...] especies. Datos de frecuencia de longitudes de la captura para la temporada de pesca 1994 (Agosto 1° a Diciembre 15) fueron usados para analizar la dinámica poblacional y el estado de explotación de O. maya. Los parámetros del modelo de von Bertalanffy fueron: L° = 252 mm longitud de manto, K = 1.4 años-1, C = 1.0 y WP = 0.6, y tZ = 0.842 años. Una estimación inicial de la mortalidad natural fue M = 2.2, la mortalidad total Z = 8.77, y tasa de explotación F/Z = 0.75, lo cual sugiere una intensa explotación. El análisis de rendimiento por recluta indica que podría aumentarse la talla mínima legal para incrementar los rendimientos. El VPA indica un recurso explotado al límite de su capacidad biológica. Debido a que las hembras mueren después de la reproducción, una nueva estimación de mortalidad natural, M = 3.3, y tasa de explotación, F/Z = 0.57 fueron obtenidas, coincidiendo con los resultados del VPA basado en longitudes y el método de Thompson y Bell. Abstract in english The octopus (Octopus maya) is one of the most important fish resources in the Mexican Gulf of Mexico with a mean annual yield of 9000 ton, and a reasonable number of jobs created; O. maya represents 80% of the total octopus catch, followed by Octopus vulgaris. There are two artisanal fleets based on [...] Octopus maya and a middle-size fleet that covers both species. Catch-at-length structured data from the artisanal fleets, for the 1994 season (August 1st to December 15th) were used to analyze the O. maya population dynamics and stock and to estimate the current level of exploitation. Von Bertalanffy growth parameters were: L = 252 mm, mantle length; K=1.4 year -1; oscillation parameters C=1.0, WP=0.6; and tz=0.842 years. A rough estimate of natural mortality was M=2.2, total mortality from catch curve Z=8.77, and exploitation rate F/Z=0.75. This last value suggests an intensive exploitation, even when yield per recruit analysis indicates both fleets may increase the minimum legal size on about 10% to increase yields. The length-based VPA also shows that the stock is being exploited under its maximum acceptable biological limit. These apparently contradictory results are explained by biological and behavioral characteristics of this species. Because most females die after reproduction, a new gross estimation of natural mortality was computed as M=3.3. The new estimate of exploitation rate was F/Z=0.57. This new value coincides with results from the length-VPA and the Thompson and Bell methods, the former suggesting that a reduction of 20% in fishing mortality may provide larger yields. This fishery resource is fully exploited and current management measures must be revised to sustain and probably optimize yields.

  12. Public Fishing Plan and Environmental Assessment Prime Hook National Wildlife Refuge 1986

    US Fish and Wildlife Service, Department of the Interior — A new fishing plan has been prepared to update the refuges public fishing program and to provide a legal framework for refuge fishing. This plan is combined with an...

  13. Similarities between Line Fishing and Baited Stereo-Video Estimations of Length-Frequency: Novel Application of Kernel Density Estimates

    OpenAIRE

    Langlois, Timothy J.; Fitzpatrick, Benjamin R.; Fairclough, David V.; Wakefield, Corey B.; Hesp, S. Alex; Mclean, Dianne L.; Harvey, Euan S.; Meeuwig, Jessica J.

    2012-01-01

    Age structure data is essential for single species stock assessments but length-frequency data can provide complementary information. In south-western Australia, the majority of these data for exploited species are derived from line caught fish. However, baited remote underwater stereo-video systems (stereo-BRUVS) surveys have also been found to provide accurate length measurements. Given that line fishing tends to be biased towards larger fish, we predicted that, stereo-BRUVS would yield len...

  14. Exhaustive comparison of colour texture features and classification methods to discriminate cells categories in histological images of fish ovary

    OpenAIRE

    González-Rufino, E.; Carrión, Pilar; Cernadas, Eva; Fernández-Delgado, M.; Domínguez-Petit, Rosario

    2013-01-01

    The estimation of fecundity and reproductive cells (oocytes) development dynamic is essential for an accurate study of biology and population dynamics of fish species. This estimation can be developed using the stereometric method to analyse histological images of fish ovary. However, this method still requires specialised technicians and much time and effort to make routinary fecundity studies commonly used in fish stock assessment, because the available software does not allow an automatic ...

  15. Stereology as a tool to assess reproduction strategy and fecundity of teleost fishes : Integrated studies in Central Baltic herring (Clupea harengus L.)

    DEFF Research Database (Denmark)

    Bucholtz, Rikke HagstrØm

    2013-01-01

    In fish stock assessment, spawning stock biomass (SSB) is used as an index of stock reproductive potential (SRP), and proportionality is assumed between SSB and recruitment, i.e. offspring production. SSB is calculated as the sum of biomass proportions of sexually mature individuals per age group. However, evidence that SSB is not a reliable SRP indicator has accumulated over the past decades. The SSB estimation does not consider individual differences in fecundity, skipped spawning, timing of spawning or differences in reproductive traits between sexes, which may all fluctuate significantly, influenced by individual physiological condition. The Central Baltic herring has experienced a radical decline in SSB over the past decades. This is mainly due to overfishing. However, significant changes in Baltic Sea salinity and temperature have also altered herring prey composition and abundance, while reduction in the number of cod has caused sprat numbers and thereby food competition to increase. Together, this has resulted in a significant drop in Central Baltic herring physiological condition. The influence which this lowered condition may have on herring SRP, in terms of increased down-regulation and thereby lowered fecundity, skipped spawning and timing of spawning, has not been investigated and is not considered in assessment of the stock. The objective of the study was two-fold. Firstly, improve methods for quantification of oocyte recruitment dynamics by adapting and applying modern stereological methods to assess fecundity and reproductive strategies. The strength of the stereological method being that, in combination with conventional histological analysis, quantification of all oocyte categories is possible, as well as registration of qualitative characteristics relating to spawning history of individuals, and further that statistical evaluation of estimates and method is possible. Secondly, apply the stereological methods to fill in gaps in knowledge about Baltic Sea herring reproductive strategy under current environmental conditions, including oocyte recruitment pattern, fecundity determination and down-regulation, skipped spawning and spawning fidelity, and to understand how factors like condition may influence individual decision making and fitness regarding these reproductive traits. The stereological methods applied in this project constituted a powerful set of tools for quantification of oocyte dynamics in fish and were successfully implemented in herring ovaries for quantification of both oocyte numbers and sizes as well as total volume fraction of atretic oocytes, introducing a negligible error to the total variance of estimates. The histological nature of the stereological methods facilitated a ready validation of maturity data, distinguishing first time spawners from repeat spawners, as well as a ready recognition of ongoing oocyte recruitment in early maturity stages, early stage atresia, POFs and residual eggs. Analyzing a sample of females all collected during a short time frame in March 2008 covering various stages of maturation progression, we saw that oocyte recruitment followed the characteristic pattern of an iteroparous total spawner with determinate fecundity and group synchronous oocyte development. However, a significant fecundity down-regulation was apparent, which followed a three-step mechanism, resulting in low potential fecundity, but high relative potential fecundity compared to other herring stocks. Individual maturation progression revealed a substantial number of specimens with early developing ovaries, thereby being skipped or delayed spawners in accordance to the spring spawning season. Individual condition generally did not appear to influence fecundity regulation, but showed a strong correlation with degree of maturation progression, skipped or delayed spawners having significantly poorer condition than specimens expected to spawn during the spring spawning season. Results further indicated, that spawning occurs throughout the year in the Central Baltic herring population and that

  16. Bioaccumulation of trace metals in farmed fish from South China and potential risk assessment.

    Science.gov (United States)

    Qiu, Yao-Wen; Lin, Duan; Liu, Jing-Qin; Zeng, Eddy Y

    2011-03-01

    Concentrations of trace metals were determined in water, sediment, fish feed and two species of farmed fish, pompano and snapper, collected from Daya Bay and Hailing Bay of South China in July 2007 and January 2008. Total average concentrations of Cu, Pb, Zn, Cd, Cr, Hg and As were 1.6, 2.7, 27.3, 0.025, 0.62, 0.18 and 0.59 ?g/g dry wt in pompano and 1.5, 2.6, 23.6, 0.020, 0.55, 0.22 and 0.53 ?g/g dry wt in snapper. In general, the concentrations of all target metals except Hg were positively correlated with lipid contents whereas negative correlations were observed between the metal concentrations and fish body weights. Model calculation indicated that dietary uptake of Zn and Cd predominate their accumulation in snapper, accounting for 99.9% and 98.2% of the total inputs. Risk assessments suggested that potential ecological and human health risk may be present due to elevated Pb concentrations in sediment and farmed fish. PMID:20961617

  17. ASSESSING HEAVY METALS IN THE WATERS, FISH AND MACROINVERTEBRATES IN MANILA BAY, PHILIPPINES

    Directory of Open Access Journals (Sweden)

    ARNOLD HALLARE

    2009-12-01

    Full Text Available This study assessed the heavy metals particularly total cadmium, total lead and total chromium in the waters, fish and macroinvertebrates in Manila Bay, Philippines. The heavy metals monitoring in the waters of Manila Bay were carried out for six consecutive months, September to February of 2007-2008, covering both wet and dry periods. The collection of fishes and macroinvertebrates in this investigation lasted from September to November 2007. Results showed that the heavy metals particularly total chromium, total lead and total cadmium were evident in the waters, fish and macroinvertebrates. Significant differences on the total cadmium and total lead in the waters were noted for both the wet and dry periods. Accumulation of heavy metals in the aquatic organisms was species dependent. Highest heavy metal concentrations among the tissues in the studied fishes were evident in the liver as compared to the muscle. Continuous heavy metals monitoring is encouraged to effectively analyze the risk and impact of heavy metals on the environment and on the general public’s welfare.

  18. Impact of entrainment and impingement on fish populations in the Hudson River estuary. Volume III. An analysis of the validity of the utilities' stock-recruitment curve-fitting exercise and prior estimation of beta technique. Environmental Sciences Division publication No. 1792

    International Nuclear Information System (INIS)

    This report addresses the validity of the utilities' use of the Ricker stock-recruitment model to extrapolate the combined entrainment-impingement losses of young fish to reductions in the equilibrium population size of adult fish. In our testimony, a methodology was developed and applied to address a single fundamental question: if the Ricker model really did apply to the Hudson River striped bass population, could the utilities' estimates, based on curve-fitting, of the parameter alpha (which controls the impact) be considered reliable. In addition, an analysis is included of the efficacy of an alternative means of estimating alpha, termed the technique of prior estimation of beta (used by the utilities in a report prepared for regulatory hearings on the Cornwall Pumped Storage Project). This validation methodology should also be useful in evaluating inferences drawn in the literature from fits of stock-recruitment models to data obtained from other fish stocks

  19. Wavelet Transform-Based Approach for Assess the Relationships between Stock Markets of Developed Countries and MENA Region

    Directory of Open Access Journals (Sweden)

    Amel Abdoullah Ahmed

    2014-01-01

    Full Text Available This study develops an economic tool that investigates the relationship between the two developed stock market indices of the United States and the United Kingdom and the ten stock market indices of the Middle East and North Africa (MENA countries. The work is accomplished through a novel technique of combining wavelet filtering and the VEC model. Discrete wavelet filtering is used to eliminate noise in the daily dataset which covers the period from June 29, 2001 to May 5, 2009. The series generated by the discrete wavelet transform is then analyzed to determine the long-and short-term relationships between the stock markets by using a cointegration test and a VEC model. Results of the comparison between the proposed and traditional models demonstrate that the former (DWT with VEC model outperforms the latter (VEC model in performance and fitting the financial stock market series; furthermore, the former provides real information on the relationships among the stock markets. The cointegration test affirms the existence of cointegration between the studied series and a long-term relationship between the United States and United Kingdom stock markets and the MENA stock markets. The proposed model also shows the existence of a short-term relationship between the stock markets of the United States and the United Kingdom and the three stock markets of MENA region: Istanbul, UAE and Morocco.

  20. Multi-Ecosystem Assessment of Mercury Bioaccumulation in Fishes: Habitat, Landscape, and Biogeochemical Drivers of Fish Mercury

    Science.gov (United States)

    Eagles-Smith, C.; Ackerman, J.; Herring, G.; Willacker, J.; Flanagan, C.

    2014-12-01

    Mercury (Hg) is a globally distributed contaminant that threatens ecosystem health across aquatic environments. The complexity of the Hg cycle and its primary drivers, coupled with dynamic food web processes that govern biomagnification, result in marked spatial variability in Hg bioaccumulation across aquatic ecosystems. However, it is unclear if patterns of bioaccumulation are consistent in magnitude and direction across ecosystem types. We synthesized data from several studies spanning more than 200 individual sites, comprising four distinct ecosystem classifications (estuaries, sub-alpine lakes, rivers, and managed wetlands). Within each ecosystem, we compared fish Hg concentrations among replicated sub-habitats and also evaluated the influence of land use, landscape composition, and biogeochemical drivers on fish Hg concentrations. We found substantial variability in fish Hg concentrations among adjacent sub-habitats within ecosystems. In estuarine environments, fish Hg concentrations were 7.4x higher in seasonal-saline wetlands than adjacent tidal wetland habitats. In riverine alcoves, preliminary data suggest that fish Hg concentrations were 1.5x higher than in fishes from paired mainstem river habitat. Among managed wetland habitats, fish Hg concentrations in rice fields were 2x higher than those in managed seasonal wetlands that were subjected to identical wetting and drying patterns. Across ecosystems, dissolved organic carbon (DOC) concentrations in surface waters were consistently correlated with fish Hg concentrations, highlighting its importance in Hg methylation and transport processes. Yet, the strength and direction of the relationships varied among habitat types. For example, fish Hg concentrations were positively correlated with DOC concentrations in riverine environments, whereas we found a negative correlation in alpine lakes. Instead, the most important determinant of fish Hg concentrations in alpine lakes was conifer tree density within a lake's catchment, resulting in a 4x increase in fish Hg concentration in lakes with the lowest to the highest catchment conifer tree density. Together, this integrated ecosystem analysis highlights the importance of understanding small-scale variation in bioaccumulation processes in order to better predict Hg risk.

  1. FISH AND SHELLFISH PRODUCTS DISTRIBUTED BY "ETHNIC" MINI-MARKET: CONFORMITY ASSESSMENT TO CURRENT LEGISLATION

    Directory of Open Access Journals (Sweden)

    M. Prearo

    2012-01-01

    Full Text Available The purpose of this study was to conduct an assessment on the quality and methods for marketing of fish products sold by ethnic minimarket. Has been inspected 20 supermarkets and buyed 60 fish and shellfish samples. The neatness of the rooms were evaluated during the shopping in the markets. Products purchased in the supermarket (about three samples for each shop were brought in Ichthypathology laboratory of State Veterinary Institute of Piedmont, Liguria and Aosta Valley, in Turin. Were conducted in the laboratory the readings of the labels. The conditions of hygiene were poor, especially in supermarket freezers. Only 16 samples were labelled in accordance with current legislation. According to the results obtained, the products 'ethnic' distributed in the supermarkets visited, may be considered a potential risk to human health.

  2. TOXICITY ASSESSMENT OF PHOSPHONIUM BASED IONIC LIQUIDS TOWARDS FEMALE GUPPY FISH

    Directory of Open Access Journals (Sweden)

    Mohanad El-Harbawi

    2013-01-01

    Full Text Available In this study, two phosphonium based ionic liquids (butyl triphenyl phosphonium chloride and hexyl triphenyl phosphonium bromide have been synthesized using quarternisation process. The toxicities of these Ionic Liquids (ILs are unknown and may be harmful to humans and the environment. Therefore, the toxicity assessment of these ILs was carried out according to the Organization for Economic Cooperation and Development (OECD 203 guideline using female guppy fish (Poecilia reticulata. The median Lethal Concentrations (LC50 have been estimated for butyl triphenyl phosphonium chloride and for hexyl triphenyl phosphonium bromide to be 73.35 and 61.36 mg L-1 respectively. Both LC50 obtained can be identified as slightly toxic ILs based on Acute Toxicity Rating Scale by Fish and Wildlife Service (FWS. The findings from this study can be used for better design of phosphonium-based ILs with consideration of their aquatic toxicities.

  3. Public health assessment of dioxin-contaminated fish at former US airbase, Bien Hoa, Vietnam.

    Science.gov (United States)

    Durant, James T; Boivin, Thomas G; Pohl, Hana R; Sinks, Thomas H

    2015-06-01

    Ponds at the former US airbase at Ben Hoa, Vietnam are contaminated with Agent Orange. The ponds had been used for aquaculture, and in all likelihood, fish from those ponds have been sold to the public. We assessed human exposure to 2,3,7,8-tetrachloro-dibenzo-dioxin (2,3,7,8-TCDD) in fish samples from the ponds. For on-base tilapia, muscle concentrations 2,3,7,8-TCDD ranged from 1.4 to 32.7?pg/g. Fat concentrations ranged from 73.3 to 3990?pg/g. Estimated human exposure doses exceed international guidelines and exceed 2,3,7,8-TCDD's lowest adverse effect levels. The Bien Hoa fishponds are a completed human pathway for TCDD exposure. PMID:25087452

  4. Risk assessment in airlines stocks market / Avaliação do risco no mercado de ações de companhias aéreas

    Scientific Electronic Library Online (English)

    Renato Cesar, Sato.

    2013-04-01

    Full Text Available Neste trabalho foram comparados os resultados entre carteiras de ações de companhias aéreas Norte-americanas e Europeia. O modelo avalia o risco de mercado utilizando a abordagem do Value-at-Risk em ambas às carteiras ao longo de um mês. A análise foi realizada através do uso dos métodos GARCH-EVT e [...] t-Student Copula com simulação de Monte Carlo. Os ativos do mercado financeiro costumam apresentar caudas pesadas em suas distribuições probabilísticas, portanto, um processo de modelagem capaz de lidar com esse aspecto é fundamental para mensurar o risco de perda dos investimentos. Foi analisado o período de meados de 2007 até meados de 2012 para compor uma comparação entre as duas carteiras. A crise financeira deflagrada em 2008 teve um maior impacto nas ações do mercado Norte Americano quando em relação ao mercado Europeu. A participação central dos transportes na economia faz com que estudos de avaliação do risco de investimento nesse setor sejam cruciais no processo de desenvolvimento industrial. A volatilidade do risco nesse mercado ocorre tanto por motivos internos e externos ao setor da aviação e o aprimoramento metodológico das ferramentas financeiras pode oferecer uma importante contribuição devido a dependência dos fluxos de investimentos. Abstract in english In this paper we compared the results between stock portfolios of North American and European airlines. The model accesses the market risk using Value-at-Risk approach in both portfolios over one month period. The analysis was performed through the use of GARCH-EVT methods and Student's-t Copula wit [...] h a Monte Carlo Simulation. The assets in the financial market usually present heavy tails in their probability distributions, so, a process capable to deal with this issue is crucial to measure the risk of loss. We analyzed the period from mid-2007 to mid-2012 to compose comparison between these two portfolios. The financial crisis of 2008 had a great impact in the North America market in relative to the European market. The central role of transport in the economy makes studies dealing with investment risk measure in this sector crucial for the industrial development. The volatility of risk in the airline market happens by internal and external motives and the methodological development of financial tools can offer an important contribution due the investment flux dependency.

  5. Assessing Soil Organic Carbon Stocks in Fire-Affected Pinus Palustris Forests

    Science.gov (United States)

    Butnor, J. R.; Johnsen, K. H.; Jackson, J. A.; Anderson, P. H.; Samuelson, L. J.; Lorenz, K.

    2014-12-01

    This study aimed to quantify the vertical distribution of soil organic carbon (SOC) and its biochemically resistant fraction (SOCR; defined as residual SOC following H2O2 treatment and dilute HNO3 digestion) in managed longleaf pine (LLP) stands located at Fort Benning, Georgia, USA (32.38 N., 84.88 W.). Although it is unclear how to increase SOCR via land management, it is a relatively stable carbon (C) pool that is important for terrestrial C sequestration. SOC concentration declines with soil depth on upland soils without a spodic horizon; however, the portion that is SOCR and the residence time of this fraction on LLP stands is unknown. Soils were collected by depth at five sites with common land use history, present use for active military training and a three-year prescribed fire return cycle. Soils were treated with H2O2 and dilute HNO3 to isolate SOCR. In the upper 1-m of soil SOC stocks averaged 72.1 ± 6.6 Mg C ha-1 and SOCR averaged 25.8 ± 3.2 Mg C ha-1. Depending on the site, the ratio of SOCR:SOC ranged from 0.25 to 0.50 in the upper 1-m of soil. On clayey soils the ratio of SOCR:SOC increased with soil depth. One site containing 33% clay at 50 to 100 cm depth had a SOCR:SOC ratio of 0.68. The radiocarbon age of SOCR increased with soil depth, ranging from approximately 2,000 years before present (YBP) at 0 to 10 cm to over 5,500 YBP at 50 to 100 cm depth. Across all sites, SOCR makes up a considerable portion of SOC. What isn't clear is the proportion of SOCR that is of pyrogenic origin (black carbon), versus SOCR that is stabilized by association with the mineral phase. Ongoing analysis with 13C nuclear magnetic resonance spectroscopy will provide data on the degree of aromaticity of the SOCR and some indication of the nature of its biochemical stability.

  6. Contamination of fish in UK fresh water systems: risk assessment for human consumption.

    Science.gov (United States)

    Rose, Martin; Fernandes, Alwyn; Mortimer, David; Baskaran, Christina

    2015-03-01

    There is growing evidence that more people in the UK are consuming fish taken from inland waterways. This may be partly due to the increased numbers of migrants from Eastern Europe where this is part of traditional culture and partly because of a desire to try new foods encouraged by celebrity chefs. Fish can bioaccumulate environmental contaminants and so could contribute a significant amount to dietary exposure to these chemicals. This study examined the changing habits of anglers and consumers and characterised a range of existing and emerging contaminants in freshwater fish species with a view to determining current levels of occurrence and possible risk from consumption. The project was conducted in two stages. The first stage included (a) a study that identified freshwater systems that are contaminated either by anthropogenic activity or as a result of the geology of the area; and (b) socioeconomic research to assess the consumption habits of the public, particularly anglers, with respect to fish and shellfish from unmanaged inland waterways. Based on the outcome from the first stage, specific rivers and other inland waterways were chosen for investigation, along with the range of contaminants to be included in the analytical programme. Predicted contamination levels and prevalence of anglers were among the factors taken into consideration. The second stage of the project involved sampling and analysis of fish taken from selected locations on the chosen waterways. A range of fish species from a variety of inland water habitats were obtained. These were analysed for the following contaminants: heavy metals, chlorinated dioxins (PCDD/Fs), polybrominated biphenyls (PBBs), polychlorinated biphenyls (PCBs), brominated dioxins (PBDD/Fs), polychlorinated naphthalenes (PCNs), polybrominated diphenylethers (PBDEs), OC pesticides, organotin compounds and organo-fluorine compounds. Legal limits for contaminants apply only to food traded commercially, but some samples were in excess of the regulatory limits for PCDD/Fs and PCBs in such fish. The maximum detected WHO-TEQ (1998) for PCDD/Fs plus PCBs was over 32ngkg(-1) on a whole weight basis for a sample of barbel from the River Don, and 6 other samples were also above the 8ngkg(-1) limit. PMID:25532764

  7. The fish embryo toxicity test as an animal alternative method in hazard and risk assessment and scientific research

    International Nuclear Information System (INIS)

    Animal alternatives research has historically focused on human safety assessments and has only recently been extended to environmental testing. This is particularly for those assays that involve the use of fish. A number of alternatives are being pursued by the scientific community including the fish embryo toxicity (FET) test, a proposed replacement alternative to the acute fish test. Discussion of the FET methodology and its application in environmental assessments on a global level was needed. With this emerging issue in mind, the ILSI Health and Environmental Sciences Institute (HESI) and the European Centre for Ecotoxicology and Toxicology of Chemicals (ECETOC) held an International Workshop on the Application of the Fish Embryo Test as an Animal Alternative Method in Hazard and Risk Assessment and Scientific Research in March, 2008. The workshop included approximately 40 scientists and regulators representing government, industry, academia, and non-governmental organizations from North America, Europe, and Asia. The goal was to review the state of the science regarding the investigation of fish embryonic tests, pain and distress in fish, emerging approaches utilizing fish embryos, and the use of fish embryo toxicity test data in various types of environmental assessments (e.g., hazard, risk, effluent, and classification and labeling of chemicals). Some specific key outcomes included agreement that risk assessors need fish data for decision-making, that extendingh data for decision-making, that extending the FET to include eluethereombryos was desirable, that relevant endpoints are being used, and that additional endpoints could facilitate additional uses beyond acute toxicity testing. The FET was, however, not yet considered validated sensu OECD. An important action step will be to provide guidance on how all fish tests can be used to assess chemical hazard and to harmonize the diverse terminology used in test guidelines adopted over the past decades. Use of the FET in context of effluent assessments was considered and it is not known if fish embryos are sufficiently sensitive for consideration as a surrogate to the sub-chronic 7-day larval fish growth and survival test used in the United States, for example. Addressing these needs by via workshops, research, and additional data reviews were identified for future action by scientists and regulators.

  8. Microbiological assessment along the fish production chain of the Norwegian pelagic fisheries sector - Results from a spot sampling programme.

    Science.gov (United States)

    Svanevik, Cecilie Smith; Roiha, Irja Sunde; Levsen, Arne; Lunestad, Bjørn Tore

    2015-10-01

    Microbes play an important role in the degradation of fish products, thus better knowledge of the microbiological conditions throughout the fish production chain may help to optimise product quality and resource utilisation. This paper presents the results of a ten-year spot sampling programme (2005-2014) of the commercially most important pelagic fish species harvested in Norway. Fish-, surface-, and storage water samples were collected from fishing vessels and processing factories. Totally 1 181 samples were assessed with respect to microbiological quality, hygiene and food safety. We introduce a quality and safety assessment scheme for fresh pelagic fish recommending limits for heterotrophic plate counts (HPC), thermos tolerant coliforms, enterococci and Listeria monocytogenes. According to the scheme, in 25 of 41 samplings, sub-optimal conditions were found with respect to quality, whereas in 21 and 9 samplings, samples were not in compliance concerning hygiene and food safety, respectively. The present study has revealed that the quality of pelagic fish can be optimised by improving the hygiene conditions at some critical points at an early phase of the production chain. Thus, the proposed assessment scheme may provide a useful tool for the industry to optimise quality and maintain consumer safety of pelagic fishery products. PMID:26187839

  9. Mitochondrial membrane potential is a suitable candidate for assessing pollution toxicity in fish

    Energy Technology Data Exchange (ETDEWEB)

    Padmini, Ekambaram, E-mail: dstpadmini@rediffmail.com; Usha Rani, Munuswamy, E-mail: musharani.2007@rediffmail.com

    2011-09-01

    Fish inhabiting polluted estuaries are highly exposed to severe stress characterized by an oxidant-antioxidant imbalance. The aim of the study was to explore the use of stress parameters such as adenosine triphosphate/adenosine diphosphate (ATP/ADP) ratio, mitochondrial membrane potential ({Delta}{psi}m) and total protein expression patterns as biomarkers against oxidant exposures in hepatocytes of Mugil cephalus living in either a contaminated (Test; Ennore) or uncontaminated (Control; Kovalam) estuary. Earlier, the pollutant stress impact was determined through light and electron microscopy studies. The ATP/ADP ratio was measured using high performance liquid chromatography; {Delta}{psi}m by fluorescent probe 5, 5', 6, 6'-tetrachloro-1, 1', 3, 3'-tetraethyl benzimidazolcarbocyanine iodide (JC-1) dye and total protein expression patterns by protein profiling. The preponderance of stress impact was confirmed through microscopy studies that featured cytological alterations, disturbances in the surface morphology and in the cell organelles at the ultrastructural levels. Hepatocytes of test fish demonstrated a decrease in ATP and an increase in ADP and thereby alteration in ATP/ADP ratio (p < 0.05; 20.75%). A significant disturbance (p < 0.05; 26.57%) in {Delta}{psi}m with a ratio of J-aggregates/JC-1 monomer of 1 was observed for test fish hepatocytes compared to control group with a J-aggregates/JC-1 monomer ratio of 1.5. Quantitative assessment of protein expression levels also revealed enhanced induction of both low and high molecular weight proteins in test fish hepatocytes. The findings highlight the use of these parameters as the highly sensitive biomarkers in response to contaminant exposure compared to the routinely used antioxidant and oxidant stress parameters in biomonitoring programs. Among the measured parameters, the determination of {Delta}{psi}m may be suggested as a novel candidate as a biomarker because of its greater specificity and rapid quantitative risk assessment of pollutant exposures. - Highlights: {yields} We confirm the impact of environmental pollutant mediated oxidative stress on hepatocytes structures. {yields} Disturbance in bioenergetic status and {Delta}{psi}m, and induction of different kDa proteins were observed in stressed fish. {yields} Evaluation of stress parameters as biological markers is highly sensitive in comparison with routinely used biomarkers. {yields} {Delta}{psi}m determination provides more immediate, quantitative risk assessment of potentially deleterious environmental exposures. {yields} {Delta}{psi}m could function as a novel candidate as a biomarker and could be exploited among the others in biomonitoring programs.

  10. Mitochondrial membrane potential is a suitable candidate for assessing pollution toxicity in fish

    International Nuclear Information System (INIS)

    Fish inhabiting polluted estuaries are highly exposed to severe stress characterized by an oxidant-antioxidant imbalance. The aim of the study was to explore the use of stress parameters such as adenosine triphosphate/adenosine diphosphate (ATP/ADP) ratio, mitochondrial membrane potential (??m) and total protein expression patterns as biomarkers against oxidant exposures in hepatocytes of Mugil cephalus living in either a contaminated (Test; Ennore) or uncontaminated (Control; Kovalam) estuary. Earlier, the pollutant stress impact was determined through light and electron microscopy studies. The ATP/ADP ratio was measured using high performance liquid chromatography; ??m by fluorescent probe 5, 5', 6, 6'-tetrachloro-1, 1', 3, 3'-tetraethyl benzimidazolcarbocyanine iodide (JC-1) dye and total protein expression patterns by protein profiling. The preponderance of stress impact was confirmed through microscopy studies that featured cytological alterations, disturbances in the surface morphology and in the cell organelles at the ultrastructural levels. Hepatocytes of test fish demonstrated a decrease in ATP and an increase in ADP and thereby alteration in ATP/ADP ratio (p < 0.05; 20.75%). A significant disturbance (p < 0.05; 26.57%) in ??m with a ratio of J-aggregates/JC-1 monomer of 1 was observed for test fish hepatocytes compared to control group with a J-aggregates/JC-1 monomer ratio of 1.5. Quantitative assessment of protein expression levels also revealed enhaexpression levels also revealed enhanced induction of both low and high molecular weight proteins in test fish hepatocytes. The findings highlight the use of these parameters as the highly sensitive biomarkers in response to contaminant exposure compared to the routinely used antioxidant and oxidant stress parameters in biomonitoring programs. Among the measured parameters, the determination of ??m may be suggested as a novel candidate as a biomarker because of its greater specificity and rapid quantitative risk assessment of pollutant exposures. - Highlights: ? We confirm the impact of environmental pollutant mediated oxidative stress on hepatocytes structures. ? Disturbance in bioenergetic status and ??m, and induction of different kDa proteins were observed in stressed fish. ? Evaluation of stress parameters as biological markers is highly sensitive in comparison with routinely used biomarkers. ? ??m determination provides more immediate, quantitative risk assessment of potentially deleterious environmental exposures. ? ??m could function as a novel candidate as a biomarker and could be exploited among the others in biomonitoring programs.

  11. Development of methods for assessing the vulnerability of Australian residential building stock to severe wind

    International Nuclear Information System (INIS)

    Knowledge of the degree of damage to residential structures expected from severe wind is used to study the benefits from adaptation strategies developed in response to expected changes in wind severity due to climate change. This study will inform government, the insurance industry and provide emergency services with estimates of expected damage. A series of heuristic wind vulnerability curves for Australian residential structures has been developed. In order to provide rigor to the heuristic curves and to enable quantitative assessment to be made of adaptation strategies, work has commenced to produce a simulation tool to quantitatively assess damage to buildings from severe wind. The simulation tool accounts for variability in wind profile, shielding, structural strength, pressure coefficients, building orientation, component self weights, debris damage and water ingress via a Monte Carlo approach. The software takes a component-based approach to modelling building vulnerability. It is based on the premise that overall building damage is strongly related to the failure of key components (i.e. connections). If these failures can be ascertained, and associated damage from debris and water penetration reliably estimated, scenarios of complete building damage can be assessed. This approach has been developed with varying degrees of rigor by researchers around the world and is best practice for the insurance industry.

  12. Desarrollo de un marco Bayesiano para la valoración del stock y el análisis de decisión de la pesquería del erizo rojo en Baja California, México / Developing a Bayesian framework for stock assessment and decision analysis of the red sea urchin fishery in Baja California, Mexico

    Scientific Electronic Library Online (English)

    J, Jurado-Molina; JS, Palleiro-Nayar; NL, Gutiérrez.

    2009-06-01

    Full Text Available La pesquería del erizo rojo (Strongylocentrotus franciscanus) es importante para la economía de Baja California (México). Su pesca comercial se inició a principios de los años 70 como resultado de la expansión de su mercado de exportación; sin embargo, se ha detectado una baja sustancial en sus capt [...] uras y abundancia desde 1986. Dada la falta de un índice de abundancia relativa independiente de la pesquería para todas las áreas de captura, se utilizaron datos de CPUE y captura para llevar a cabo una valoración del stock del erizo rojo y realizar un análisis de decisión con relación a su pesquería. La dinámica poblacional fue descrita mediante el modelo de biomasa excedente de Schaefer usando métodos Bayesianos para estimar los parámetros del modelo y para proyectar la dinámica poblacional de la especie bajo diferentes escenarios de manejo, los cuales incluyeron estrategias de tasas de explotación constantes y capturas constantes. Los resultados sugieren que el stock actual es sólo 17% de la bioma virgen y que, para una estrategia de captura constante, un incremento del 10% en el nivel de captura actual podría causar el colapso de la pesquería en 20 años. Los resultados de las simulaciones sugieren que una estrategia de tasa de explotación constante entre 15% y 25% causaría que la población se recuperara y la captura se maximizara en 2024. Mayores niveles de explotación incrementarían la probabilidad de que la biomasa sea menor al 40% de la capacidad de carga de la población. Abstract in english The red sea urchin (Strongylocentrotus franciscanus) fishery is of importance to the economy of Baja California (Mexico). The commercial fishery started in the early 1970s as a result of expanding export markets, but has experienced substantial decline in landings and abundance since 1986. Fishery-i [...] ndependent surveys have not been conducted for all fishing areas, thus CPUE and catch data were used to conduct a stock assessment and decision analysis for the red sea urchin stock. The red sea urchin population dynamics was described with the Schaefer biomass dynamic model. Bayesian approaches were used for the estimation of the model parameters and for projecting the population dynamics of the species under different management scenarios, including constant harvest rate and constant catch strategies. This study suggests that the current stock is only 17% of the virgin stock biomass and that, for a constant catch policy, a 10% increase in the current catch rate could potentially cause the collapse of the fishery in 20 years. Simulation results suggested that a constant harvest rate between 15% and 25% would cause the population to recover and maximize the catch in 2024. Higher harvest rate levels would increase the probability of the biomass being less than 40% of the population carrying capacity.

  13. Performance Assessment of the Food Industry of Tehran Stock Exchange Based on Balanced Score Card (BSC Technique

    Directory of Open Access Journals (Sweden)

    Morteza Asadi

    2013-04-01

    Full Text Available Major objective of the present paper was to study the role of balanced score card regarding performance assessment of companies listed in food and beverage industry in the stock exchange. This survey is descriptive and is regarded as a quasi-experimental research plan (Ex-Post design. The statistical population included 200 managers and research sample consisted of 99 persons based on Cochran formula. Questionnaire was used for data collection. Frequency tables and appropriate diagrams were applied to describe data and inferential statistics methods such as student's t-test were used to confirm or reject hypotheses. Variance analysis and t-test for two independent samples were used to study the impact of personal characteristics on responding to the hypotheses. Ranking of improvement degree of indexes for realization of purposes and determining rank of each factor was studied using Friedman test. Results of testing hypotheses reveal it is necessary for organizations to emphasize internal processes more given that planning and implementing efficient and suitable processes in the organization is led to offering appropriate services. About growth and learning scope it is notable that since employees are major capitals of the organization, special attention must be paid to this sector in order to satisfy employees and provide long-term benefits of the organization.

  14. Assessing the feasibility of native fish reintroductions: a framework applied to threatened bull trout

    Science.gov (United States)

    Dunham, Jason B.; Gallo, Kirsten; Shively, Dan; Allen, Chris; Goehring, Brad

    2011-01-01

    Translocations to recover native fishes have resulted in mixed success. One reason for the failure of these actions is inadequate assessments of their feasibility prior to implementation. Here, we provide a framework developed to assess the feasibility of one type of translocation-reintroduction. The framework was founded on two simple components of feasibility: the potential for recipient habitats to support a reintroduction and the potential of available donor populations to support a reintroduction. Within each component, we developed a series of key questions. The final assessment was based on a scoring system that incorporated consideration of uncertainty in available information. The result was a simple yet transparent system for assessing reintroduction feasibility that can be rapidly applied in practice. We applied this assessment framework to the potential reintroduction of threatened bull trout Salvelinus confluentus into the Clackamas River, Oregon. In this case, the assessment suggested that the degree of feasibility for reintroduction was high based on the potential of recipient habitats and available donor populations. The assessment did not provide a comprehensive treatment of all possible factors that would drive an actual decision to implement a reintroduction,

  15. Assessment of fish health effects resulting from exposure to oil sands wastewater

    International Nuclear Information System (INIS)

    The objective of this study was to determine if oil sands wastewater had an effect on the general health and condition of hatchery raised rainbow trout (200 to 400 g). Effects were assessed based on a battery of physiological and biochemical indices and the physical condition of the fish. The trout were exposed to tailings water in the field and in a flow through system under laboratory conditions. The field tests were conducted in 1992 and 1993 in experimental ponds at Syncrude which contained fine tails covered with surface water, fine tails covered with tailings water, and a surface water control pond. The laboratory treatments included Mildred Lake tailings water, dyke drainage water, fractionated tailings pond water (acid fraction containing naphthenic acids), sodium naphthenate, recycle water from Suncor's tailings pond, and a laboratory control. All body condition factors and blood parameters were normal in the field and laboratory exposed fish and there were no apparent differences between the fish exposed to the tailings water and controls

  16. Linking hydrologic, physical and chemical habitat environments for the potential assessment of fish community rehabilitation in a developing city

    Science.gov (United States)

    Zhao, C. S.; Yang, S. T.; Liu, C. M.; Dou, T. W.; Yang, Z. L.; Yang, Z. Y.; Liu, X. L.; Xiang, H.; Nie, S. Y.; Zhang, J. L.; Mitrovic, S. M.; Yu, Q.; Lim, R. P.

    2015-04-01

    Aquatic ecological rehabilitation is increasingly attracting considerable public and research attention. An effective method that requires less data and expertise would help in the assessment of rehabilitation potential and in the monitoring of rehabilitation activities as complicated theories and excessive data requirements on assemblage information make many current assessment models expensive and limit their wide use. This paper presents an assessment model for restoration potential which successfully links hydrologic, physical and chemical habitat factors to fish assemblage attributes drawn from monitoring datasets on hydrology, water quality and fish assemblages at a total of 144 sites, where 5084 fish were sampled and tested. In this model three newly developed sub-models, integrated habitat index (IHSI), integrated ecological niche breadth (INB) and integrated ecological niche overlap (INO), are established to study spatial heterogeneity of the restoration potential of fish assemblages based on gradient methods of habitat suitability index and ecological niche models. To reduce uncertainties in the model, as many fish species as possible, including important native fish, were selected as dominant species with monitoring occurring over several seasons to comprehensively select key habitat factors. Furthermore, a detrended correspondence analysis (DCA) was employed prior to a canonical correspondence analysis (CCA) of the data to avoid the "arc effect" in the selection of key habitat factors. Application of the model to data collected at Jinan City, China proved effective reveals that three lower potential regions that should be targeted in future aquatic ecosystem rehabilitation programs. They were well validated by the distribution of two habitat parameters: river width and transparency. River width positively influenced and transparency negatively influenced fish assemblages. The model can be applied for monitoring the effects of fish assemblage restoration. This has large ramifications for the restoration of aquatic ecosystems and spatial heterogeneity of fish assemblages all over the world.

  17. Assessment of Environmental Contaminants in Muddy River Fishes, Clark County, Nevada

    US Fish and Wildlife Service, Department of the Interior — In 2002 the U.S. Fish and Wildlife Service Service Southern Nevada Field Office initiated a study to identify environmental contaminant impacts to native fish of...

  18. Taking stock of two decades of attachment transmission gap: broadening the assessment of maternal behavior.

    Science.gov (United States)

    Bernier, Annie; Matte-Gagné, Célia; Bélanger, Marie-Ève; Whipple, Natasha

    2014-01-01

    This report aimed to investigate the capacity of maternal behaviors tailored to children's attachment and exploration systems to jointly explain the well-known mother-child transmission of attachment. Four home visits were conducted between ages 7 months and 2 years with 130 mother-child dyads to assess maternal attachment state of mind, sensitivity, autonomy support, and mother-child attachment security. Results showed that together, maternal sensitivity and autonomy support fully accounted for the relation between maternal and child attachment, that they each accounted for a unique portion of this relation, and that the magnitude of these mediated pathways was equivalent. These results suggest that the attachment transmission gap can be narrowed by the use of a theory-driven multidimensional approach to maternal behavior. PMID:24611791

  19. Biological assessments of Appalachian streams based on predictive models for fish, macroinvertebrate, and diatom assemblages

    Science.gov (United States)

    Carlisle, D.M.; Hawkins, C.P.; Meador, M.R.; Potapova, M.; Falcone, J.

    2008-01-01

    We developed empirical models for fish, macroinvertebrate, and diatom assemblages to assess the biological condition of 268 streams sampled from 1993 to 2002 in 7 major river basins in the Appalachian region of the USA. These models estimate the expected taxonomic composition at each site based on observed variation in taxonomic composition at reference sites. The index, O/E, is the ratio of the number of predicted taxa that were observed (O) to that expected (E) to occur at a site and is a measure of taxonomic completeness. We compared how O/E for each assemblage varied among major landuse settings and whether impaired assemblages were associated with particular physicochemical conditions. We also examined concordance among assemblages in their response to stress. Biological, chemical, and physical data were collected following consistent protocols. We used land-cover criteria, published data, and topographic maps to classify sites by major landuse setting. Fish, macroinvertebrate, and diatom assemblages had been sampled at 73, 108, and 52, respectively, of the least disturbed sites used to establish reference conditions. The models accounted for a substantial portion of the natural variation in taxonomic composition across sites that was associated with biogeographic, climatic, and basin-scale factors and generally were unbiased across the range of environmental gradients observed in the region. Assessments at nonreference sites showed that impairment of fish and macroinvertebrate assemblages was most strongly associated with agriculture and urban land uses, whereas impairment of diatom assemblages was most strongly associated with mining in the basin. Concordance in assessments among assemblages was not strong. Assessments based on 2 assemblages differed in 28 to 57% of cases, and assessments were never concordant for cases where all 3 assemblages were sampled. Furthermore, only 1/2 of these cases would have been assessed as ecologically impaired had only 1 assemblage been sampled. Differences between observed and predicted frequencies of occurrence for individual taxa were generally consistent with known tolerances to environmental stressors and might aid in identifying causes of biological impairment. ?? 2008 by The North American Benthological Society.

  20. Schoolhouse stock.

    Science.gov (United States)

    Nuzback, Kara

    2014-11-01

    Texas does not require schools to stock epinephrine unless it's prescribed for a specific student. Texas allergists are now fighting to pass legislation that would force schools to stock unassigned epinephrine injectors so that coaches, school nurses, and other trained staff could immediately treat students who suffer a severe and unexpected allergic reaction. PMID:25416833

  1. The fish community of the Berg River estuary and an assessment of the likely effects of reduced freshwater inflows

    OpenAIRE

    B.A. Bennett

    2012-01-01

    ENGLISH ABSTRACT: Data concerning the species composition, abundance and distribution of fishes in habiting the Berg River estuary are presented and used to assess the value of the estuary to fish, and the likely effects of reduced freshwater in flows. A total of 31 species was recorded, eight of which were classified as estuarine residents, 11 as marine estuarine-opportunist, six as marine stragglers and six were freshwater species. Liza richardsonii, an opportunist, was the most abundant (5...

  2. Environmental Assessment for the Transfer of 1100 AREA, Southern Rail Connection and Rolling Stock, Hanford Site, Richland, Washington

    Energy Technology Data Exchange (ETDEWEB)

    N/A

    1998-08-01

    This environmental assessment (EA) has been prepared to assess potential environmental impacts associated with the U.S. Department of Energy's proposed action: the transfer of the 1100 Area, southern rail connection and rolling stock to a non-federal entity. Impact information contained herein will be used by the U.S. Department of Energy, Richland Operations Office Manager, to determine if the proposed action is a major federal action significantly affecting the quality of the human environment. If the proposed action is determined to be major and significant, an environmental impact statement will be prepared. If the proposed action is determined not to be major and significant, a Finding of No Significant Impact (FONSI) will be issued and the action can proceed. Criteria used to evaluate significance can be found in Title 40, Code of Federal Regulations (CFR) 1508.27. This EA was prepared in compliance with the ''National Environmental Policy Act'' (NEPA) of 1969, as amended, the Council on Environmental Quality (CEQ) Regulations for Implementing the Procedural Provisions of NEPA (40 CFR 1500-1508), and the U.S. Department of Energy Implementing Procedures for NEPA (10 CFR 1021). The following is a description of each section of the EA. (1) Purpose and Need for Action. This provides a brief statement concerning the problem or opportunity the U.S. Department of Energy is addressing with the proposed action. As necessary, background information is provided. (2) Description of the Proposed Action. A description with sufficient detail to identify potential environmental impacts is provided. (3) Alternatives to the Proposed Action. Reasonable alternative actions, which would address the Purpose and Need, are described. A no action alternative, as required by 10 CFR 1021, also is described. (4) Affected Environment. This provides a brief description of the locale in which the proposed action takes place, and which may be environmentally impacted. (5) Environmental Impacts. The range of environmental impacts, beneficial and adverse, are described for the proposed action. Impacts of alternatives briefly are discussed. (6) Permits and Regulatory Requirements. A brief description of permits and regulatory requirements for the proposed action is provided. (7) Organizations Consulted. Any outside agencies, groups, or individuals contacted as part of environmental assessment documentation preparation are listed. (8) References. Documents used to provide information or data are listed. The appendices contain additional information necessary to support an understanding of the proposed action, alternatives, and potential impacts is provided. Comments resulting from review of the environmental assessment by states and tribes or other stakeholders and the response to those comments will be included in the appendices.

  3. Assessment of metal contamination in water, sediment, and tissues of Arius thalassinus fish from the Red Sea coast of Yemen and the potential human risk assessment.

    Science.gov (United States)

    Saleh, Yousef S; Marie, Mohamed-Assem S

    2015-04-01

    Heavy metal pollution is one of the most serious environmental issues globally. To evaluate the metal pollution in the Red Sea coast of Hodeida, Yemen Republic, the concentrations of Fe, Cu, Ni, Pb, and Cd in water, sediment, and some vital organs of sea catfish, Arius thalassinus collected from polluted and unpolluted sites, were determined. The risk of these metals to humans through fish consumption was then assessed. The results showed that the concentration order of metals in water, sediment, and fish tissues were Fe?>?Cu?>?Ni?>?Pb?>?Cd. The levels of studied metals in water, sediment, and fish tissues were significantly higher in the polluted site than those of the unpolluted site, with few exceptions. Linear correlation incorporating paired variables (water-sediment, water-fish, and fish-fish) exhibited several significant correlations indicating a common metal pollution. The risk assessment performed revealed that fish consumption was safe for consumers. This field investigation provides a baseline data on metal pollution in this region. PMID:25380631

  4. Comparative assessment of water quality parameters of mariculture for fish production in Hong Kong Waters.

    Science.gov (United States)

    Leung, H M; Leung, S K S; Au, C K; Cheung, K C; Wong, Y K; Leung, A O W; Yung, K K L

    2015-05-15

    The objective of the study is to evaluate the effect of fish cultivation on water quality in fish culture zone (FCZ) and analysed by Principle Component Analysis (PCA). 120 surface water samples were collected from Hong Kong Waters (60 samples in Victoria Harbour and another 60 in Ma Wan FCZ). Significant difference was found in dissolved oxygen (MW: 59.6%; VH: 81.3%), and Escherichia coli (MW: 465CFU/100ml; VH: 162.5CFU/100ml). Three principle components are responsible for water quality variations in the studying sites. The first component included E. coli (0.625) and dissolved oxygen (0.701). The second included E. coli (0.387) and ammonical-nitrogen (0.571). The third included E. coli (0.194) and ammonical-nitrogen (0.287). This framework provides information to assess the relative contribution of eco-aquaculture to nutrient loads and the subsequent risk of eutrophication. To conclude, a rigorous monitoring of water quality is necessary to assess point and nonpoint source pollution. Besides, appropriate remediation techniques should be used to combat water pollution and achieve sustainability. PMID:25697818

  5. Dose assessment of past accidental or chronic exposure using FISH chromosome painting

    Energy Technology Data Exchange (ETDEWEB)

    Lindholm, C.; Salomaa, S

    2000-07-01

    In order to evaluate the practicality of FISH (fluorescence in situ hybridisation) chromosome painting for retrospective biodosimetry, more information on the stability of translocations with time and the control level of translocations is needed. The temporal behaviour of translocation frequency in four accidentally exposed subjects showed that translocations remained relatively stable throughout the first post-accidental years. A decline in translocation yields was, however, observed in one subject exposed to both high dose and partial body irradiation that lead to severe aplasia. This finding implies that FISH biodosimetry may not be informative in cases where the dose has not been uniformly distributed. In our studies, significant age dependence and wide translocation range has been observed. In dose assessment of low dose exposure to a large number of people the age effect has been accounted for by comparing the results with a matched control group. Our data support the use of translocations for retrospective dosimetry for moderately high doses of the order of 1 Gy acute exposure with uniform whole-body exposures. In low dose chronic exposures, reliable assessment of past exposures can be achieved on group level. (author)

  6. Biomarkers as tools in quality assessment of fish contaminated with trace metals

    Directory of Open Access Journals (Sweden)

    Rodolfo dos Santos Coutinho Coimbra

    2013-09-01

    Full Text Available Trace metals that present toxicity to vertebrates are cause of concern in environmental monitoring programs due to impact caused by anthropogenic activity. The distribution of these elements is found in different settings: water, sediment and biota. Metals such as Pb, Cd, Hg, As and Cr are related to significant environmental damage, which can contaminate man, primarily by fish consumption. Some biomarkers can be applied via an impact approach, and risk assessment for populations of species susceptible to exposure and toxic effects of trace metals. Acetylcholinesterase, metallothionein, delta-aminolevulinic acid dehydratase, and the micronucleus test can be used together as biomarkers for aquatic organisms that are exposed or affected by toxic metals. The CONAMA Resolution 357/2005 of the Brazilian Ministry of the Environment and the Ordinance 2914/2011 from  Ministry of Health set limits for these toxic metals in surface and drinking water respectively. However, it still does not require the determination of chemical species, relative to the bioavailability produced in different arrays, neither to sublethal effects, evaluated by biomarkers, of these metals on aquatic organisms. The purpose of this review is to present the biomarkers (genetic and biochemical as tools to aid assessment of the quality of fish.

  7. The Applicability of Oxidative Stress Biomarkers in Assessing Chromium Induced Toxicity in the Fish Labeo rohita

    Science.gov (United States)

    Khare, Ankur; Dange, Swati

    2014-01-01

    The evaluation of metal's toxicity in freshwater is one of the imperative areas of research and there is an emergent concern on the development of techniques for detecting toxic effects in aquatic animals. Oxidative stress biomarkers are very useful in assessing the health of aquatic life and more in depth studies are necessary to establish an exact cause effect relationship. Therefore, to study the effectiveness of this approach, a laboratory study was conducted in the fish Labeo rohita as a function of hexavalent chromium and the toxicity indices using a battery of oxidative stress biomarkers such as catalase (CAT), superoxide dismutase (SOD), and glutathione reductase (GR) in the liver, muscle, gills, and brain have been studied along with biometric parameters, behavioral changes, and Cr bioaccumulation. A significant increased HSI was observed in contrast to CF which reduced significantly. SOD, CAT, and GR activity increased significantly in all the tissues of treated fishes. The bioaccumulation of Cr was highest in liver followed by gills, muscle, and brain. This study highlights the significance of using a set of integrated biomarker and advocate to include these parameters in National Water Quality Monitoring Program in areas potentially polluted with metals to assess the health of the ecosystem. PMID:25302308

  8. Inter-observer reproducibility of HER2 immunohistochemical assessment and concordance with fluorescent in situ hybridization (FISH): pathologist assessment compared to quantitative image analysis

    OpenAIRE

    Carrier Melinda; West Rob; Gilks Blake; Montgomery Kelli; Turbin Dmitry; Leung Samuel; Turashvili Gulisa; Huntsman David; Aparicio Samuel

    2009-01-01

    Abstract Background In breast cancer patients, HER2 overexpression is routinely assessed by immunohistochemistry (IHC) and equivocal cases are subject to fluorescent in situ hybridization (FISH). Our study compares HER2 scoring by histopathologists with automated quantitation of staining, and determines the concordance of IHC scores with FISH results. Methods A tissue microarray was constructed from 1,212 invasive breast carcinoma cases with linked treatment and outcome information. IHC slide...

  9. Application of sensory and microbial analysis to assess quality of fish in Siliguri city of West Bengal, India.

    Science.gov (United States)

    Jha, Prithwiraj; Roy, Rudra Prasad; Barat, S

    2010-09-01

    Sensory and certain microbial analyses were applied to assess the quality of raw fish sold at a market in Siliguri cityof West Bengal, India. In regular surveys undertaken during June to August 2008, a particular fish species was randomly selected, its source was noted and a sensory analysis, the quality index method (QIM) was applied to assess its quality Raw fish samples were also collected and a small quantity (about 1 g) of scales oran upper layer of the skin surface (forscale-less fish samples), gill, liverand a portion of gut with gut-contents were aseptically removed for enumeration of the total aerobic heterotrophic bacteria, Aeromonas spp., Pseudomonas spp., Salmonella spp. and coliform counts. Oreochromis mossambicus and Tenulosa ilisha recorded significantly higher QIM scores, compared to other species (pLabeo rohita, Labeo bata and Cyprinus carpio were very marginal (p<0.05). Aeromonas spp., Salmonella spp. and total coliforms were recorded from all the studied species while Pseudomonas spp. was isolated from only seven species. Among the tissues examined, the lowest counts of total heterotrophic bacteria, Aeromonas spp., Pseudomonas spp., Salmonella spp. and total coliforms were recorded from the skin in every fish species. Highest counts of pathogenic bacteria (except Pseudomonas spp.) were recorded in Tenulosa ilisha for all the tissues except liver. Since fish are properly cooked in Bengali households, the risk of disease from fish consumption is relatively less. However, some tribes residing in the region are known to consume undercooked fish and proper cooking methods should be followed in view of the present findings to avoid health risks. Besides, utmost care should be taken while handling fish. PMID:21387907

  10. Assessing relationships between chemical exposure, parasite infection, fish health, and fish ecological status: a case study using chub (Leuciscus cephalus) in the Bílina River, Czech Republic.

    Czech Academy of Sciences Publication Activity Database

    Wenger, M.; Ondra?ková, Markéta; Machala, M.; Ne?a, J.; Hyršl, P.; Šimková, A.; Jurajda, Pavel; von der Ohe, P.; Segner, H.

    2010-01-01

    Ro?. 29, ?. 2 (2010), s. 453-466. ISSN 0730-7268 R&D Projects: GA MŠk LC522 Grant ostatní: 6th Framework Programme EC(XE) MODELKEY (511237-GOCE) Institutional research plan: CEZ:AV0Z60930519 Keywords : multiple stressors * environmental risk assessment * exposure biomarkers * parasites * fish health Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 3.026, year: 2010

  11. A comparative assessment of contaminants in fish from four resacas of the Texas, USA-Tamaulipas, Mexico border region

    Science.gov (United States)

    Mora, M.A.; Papoulias, D.; Nava, I.; Buckler, D.R.

    2001-01-01

    A recent survey of contaminant information for the Lower Rio Grande Valley (LRGV), Texas, has shown that little is known about contaminants and their impacts on biota of resacas (oxbows) along the US-Mexico border. In 1996, fish were collected from four resacas in the Texas- Tamaulipas border region to assess contaminant loadings and their impacts on fish and birds. Tissue residue concentrations in fish were analyzed and also compared to two histopathological bioindicators of unhealthy environmental conditions. Of the organochlorine insecticides measured, DDE was the most common and was present at relatively high concentrations (10 ??g/g w/w) at some sites. DDE concentrations were nearly 20 times greater in fish from resacas in Texas than from resacas in Tamaulipas, although the limited sample sizes obtained precluded statistical comparisons. DDE concentrations in fish from the two Texas resacas were also greater than those reported in fish from nearby areas during the 1980s and 1990s. Most trace element concentrations were similar among resacas from Texas and Tamaulipas. Arsenic, however, was two to six times greater in fish from a downtown resaca in Matamoros than in fish from other resacas in Tamaulipas and Texas. The bioindicators, pigment accumulation, and macrophage aggregates (MAs), in general, reflected the contamination indicated by the tissue residues for each site. Overall, it appears that some resacas of the US-Mexico border region are contaminant sinks and could pose potential health or reproductive problems for fish and wildlife, and humans that consume fish from those sites. Published by Elsevier Science Ltd.

  12. Environmental and human health risk assessment of organic micro-pollutants occurring in a Spanish marine fish farm

    International Nuclear Information System (INIS)

    In this work the risk posed to seawater organisms, predators and humans is assessed, as a consequence of exposure to 12 organic micro-pollutants, namely metronidazole, trimethoprim, erythromycin, simazine, flumequine, carbaryl, atrazine, diuron, terbutryn, irgarol, diphenyl sulphone (DPS) and 2-thiocyanomethylthiobenzothiazole (TCMTB). The risk assessment study is based on a 1-year monitoring study at a Spanish marine fish farm, involving passive sampling techniques. The results showed that the risk threshold for irgarol concerning seawater organisms is exceeded. On the other hand, the risk to predators and especially humans through consumption of fish is very low, due to the low bioconcentration potential of the substances assessed. - Exposure and effects of twelve organic micro-pollutants are evaluated at a Spanish fish farm.

  13. Environmental and human health risk assessment of organic micro-pollutants occurring in a Spanish marine fish farm

    Energy Technology Data Exchange (ETDEWEB)

    Munoz, Ivan, E-mail: ivanmuno@ual.e [Departamento de Hidrogeologia y Quimica Analitica, Universidad de Almeria, 04120 Almeria (Spain); Martinez Bueno, Maria J., E-mail: mjbueno@ual.e [Departamento de Hidrogeologia y Quimica Analitica, Universidad de Almeria, 04120 Almeria (Spain); Agueera, Ana, E-mail: aaguera@ual.e [Departamento de Hidrogeologia y Quimica Analitica, Universidad de Almeria, 04120 Almeria (Spain); Fernandez-Alba, Amadeo R., E-mail: amadeo@ual.e [Departamento de Hidrogeologia y Quimica Analitica, Universidad de Almeria, 04120 Almeria (Spain)

    2010-05-15

    In this work the risk posed to seawater organisms, predators and humans is assessed, as a consequence of exposure to 12 organic micro-pollutants, namely metronidazole, trimethoprim, erythromycin, simazine, flumequine, carbaryl, atrazine, diuron, terbutryn, irgarol, diphenyl sulphone (DPS) and 2-thiocyanomethylthiobenzothiazole (TCMTB). The risk assessment study is based on a 1-year monitoring study at a Spanish marine fish farm, involving passive sampling techniques. The results showed that the risk threshold for irgarol concerning seawater organisms is exceeded. On the other hand, the risk to predators and especially humans through consumption of fish is very low, due to the low bioconcentration potential of the substances assessed. - Exposure and effects of twelve organic micro-pollutants are evaluated at a Spanish fish farm.

  14. A Multiple Watershed Approach to Assessing the Effects of Habitat Restoration Actions on Anadromous and Resident Fish Populations, Technical Report 2003-2004.

    Energy Technology Data Exchange (ETDEWEB)

    Marmorek, David

    2004-03-01

    Habitat protection and restoration is a cornerstone of current strategies to restore ecosystems, recover endangered fish species, and rebuild fish stocks within the Columbia River Basin. Strategies featuring habitat restoration include the 2000 Biological Opinion on operation of the Federal Columbia River Power System (FCRPS BiOp) developed by the National Marine Fisheries Service (NMFS), the 2000 Biological Opinion on Bull Trout developed by the US Fish and Wildlife Service (USFWS), and Sub-Basin Plans developed under the Fish and Wildlife Program of the Northwest Power and Conservation Council (NWPCC). There is however little quantitative information about the effectiveness of different habitat restoration techniques. Such information is crucial for helping scientists and program managers allocate limited funds towards the greatest benefits for fish populations. Therefore, it is critical to systematically test the hypotheses underlying habitat restoration actions for both anadromous and resident fish populations. This pilot project was developed through a proposal to the Innovative Projects fund of the NWPCC (ESSA 2002). It was funded by the Bonneville Power Administration (BPA) following reviews by the Independent Scientific Review Panel (ISRP 2002), the Columbia Basin Fish and Wildlife Authority (CBFWA 2002), the NWPCC and BPA. The study was designed to respond directly to the above described needs for information on the effectiveness of habitat restoration actions, including legal measures specified in the 2000 FCRPS BiOp (RPA 183, pg. 9-133, NMFS 2000). Due to the urgency of addressing these measures, the timeline of the project was accelerated from a duration of 18 months to 14 months. The purpose of this pilot project was to explore methods for evaluating past habitat restoration actions and their effects on fish populations. By doing so, the project will provide a foundation of retrospective analyses, on which to build prospective, multi-watershed designs for future habitat restoration actions. Such designs are being developed concurrently with this project by several other groups in the Columbia Basin (RME Workgroup 2003, NMFS 2003, Hillman and Paulsen 2002, Hillman 2003). By addressing questions about habitat restoration and monitoring (in coordination with other related efforts), we hope that this project will catalyze a shift in the Basin's paradigm of habitat restoration, moving from implementation of individual watershed projects towards rigorously designed and monitored, multiwatershed, adaptive management experiments. The project involved three phases of work, which were closely integrated with various related and ongoing efforts in the region: (1) Scoping - We met with a Core Group of habitat experts and managers to scope out a set of testable habitat restoration hypotheses, identify candidate watersheds and recommend participants for a data evaluation workshop. (2) Data Assembly - We contacted over 80 scientists and managers to help evaluate the suitability of each candidate watershed's historical data for assessing the effectiveness of past restoration actions. We eventually settled on the Yakima, Wenatchee, Clearwater, and Salmon subbasins, and began gathering relevant data for these watersheds at a workshop with habitat experts and managers. Data assembly continued for several months after the workshop. (3) Data Analysis and Synthesis - We explored statistical approaches towards retrospectively analyzing the effects of restoration 'treatments' at nested spatial scales across multiple watersheds (Chapters 2-5 of this report). These analyses provided a foundation for identifying existing constraints to testing restoration hypotheses, and opportunities to overcome these constraints through improved experimental designs, monitoring protocols and project selection strategies (Chapters 6 and 7 of this report). Finally, we developed a set of recommendations to improve the design, implementation, and monitoring of prospective habitat restoration programs in the Columbia River Basin (Chap

  15. Stock-catch analysis of carp recreational fisheries in Czech reservoirs: Insights into fish survival, water body productivity and impact of extreme events.

    Czech Academy of Sciences Publication Activity Database

    Boukal S., David; Jankovský, Martin; Kube?ka, Jan; Heino, M.

    119-120, 20 MAY (2012), s. 23-32. ISSN 0165-7836 R&D Projects: GA MŠk 7F10070 Grant ostatní: Financial Mechanism of EEA and Norwegian Financial Mechanism(NO) A/CZ0046/2/0029 Institutional support: RVO:60077344 Keywords : management * time series * stocking Subject RIV: EH - Ecology, Behaviour Impact factor: 1.695, year: 2012 http://www.sciencedirect.com/science/article/pii/S0165783611003687

  16. Connected stocks

    OpenAIRE

    Anton, Miguel; Polk, Christopher

    2010-01-01

    By connecting stocks through common active mutual fund ownership, we forecast cross-sectional variation in return covariance, controlling for similarity in style (in- dustry, size, value, and momentum), the extent of common analyst coverage, and other pair characteristics. We argue this covariance is due to contagion based on re- turn decomposition evidence, cross-sectional heterogeneity in the extent of the e¤ect, and the magnitude of average abnormal returns to a cross-stock...

  17. Assessment of Hydroponically Grown Macrophytes for Their Suitability as Fish Feed

    Directory of Open Access Journals (Sweden)

    A. M. Snow

    2008-01-01

    Full Text Available Water hyacinth, water lettuce and parrot's feather plants were examined for their ability to remove nutrients from aquaculture wastewater at two retention times. During the experiment, the aquatic plants grew rapidly in the hydroponics system and appeared healthy with green color. At hydraulic retention times (HRTs of 6 and 12 days, the average water hyacinth, water lettuce and parrot's feather yields were 83, 51 and 51 g (dm m-2 and 49, 29 and 22 g (dm m-2, respectively. The aquatic plants were able to significantly reduce the pollution load of the aquaculture wastewater. The TS, COD, NH4+-N, NO2--N, NO3--N and PO43--P reductions ranged from 21.4 to 48.0%, from 71.1 to 89.5%, from 55.9 to 76.0%, from 49.6 to 90.6%, from 34.5 to 54.4% and from 64.5 to 76.8%, respectively. Generally, the reductions increased with longer retention times and were highest in compartments containing water hyacinth followed by compartments containing water lettuce and parrot's feather. The nutritive value of the three wastewater grown plants was assessed to determine the suitability of using the plants as a component in fish feed. The three wastewater grown plants did not contain sufficient amounts of protein and fat to meet the dietary requirements of fish and shellfish. They also contained high concentrations of K, Cu, Fe, Mn, Se and Zn, which can lead to reduced feed intake, weight gain and growth rates in fish and shellfish.

  18. Residual levels of DDTs and PAHs in freshwater and marine fish from Hong Kong markets and their health risk assessment.

    Science.gov (United States)

    Cheung, K C; Leung, H M; Kong, K Y; Wong, M H

    2007-01-01

    Axial and ventral muscle from 10 each species of freshwater and marine fish purchased from markets in Hong Kong were analyzed for dichlorodiphenyltrichloroethane (total DDTs including DDE, DDD and DDT) and polycyclic aromatic hydrocarbons (PAHs). Among the 10 freshwater fish species, rice field eel (Monopterus albus) showed significantly higher levels of DDTs in both ventral (125 ng/g wet wt) and axial muscle (127 ng/g wet wt) than the other species. The highest concentration of PAHs was detected in catfish (Clarias fuscus), with 24.8 ng/g in ventral muscle and 9.1 ng/g in axial muscle. As to marine fish, snubnose pompano (Trachinotus blochii) showed significantly higher levels of DDT and its metabolites (1018 ng/g in ventral and 409 ng/g wet wt in axial tissues) than all other marine fish species. The overall concentrations of PAHs in marine fish species were 15.5-57.0 ng/g (axial muscle) and 18.1-118 ng/g wet wt (ventral muscle) where yellow seafin (Acanthopeyrus latus) and golden threadfin bream (Nemipterus virgatus) exhibited the highest concentrations of PAHs in the axial and ventral muscles, respectively. In general, results showed that levels of PAHs in Hong Kong market fish was low and do not expect to cause any concern for human consumption. However, the levels of DDTs in fish samples ranged from 1.10 to 1018 ng/g wet wt, and based on a fish consumption rate of 142.2g/day to calculate the screening value of 14.4 ng/g wet wt for human consumption (USEPA, 2000. Guidance for assessing chemical contaminant, data for use in fish advisories, vol. 1: fish sampling and analysis, third ed. EPA 823-R-95-007. Office of Water, Washington, DC), there were 9 out of 20 (45%) muscle samples of freshwater fish species and 14 out of 20 (70%) muscle samples of marine fish species had elevated levels of DDTs exceeded the screening value. It was also suggested to use ventral muscle for detecting concentrations of persistent organic pollutants in fish. PMID:16870232

  19. Flow cytometric assessment of DNA damage in the fish Catla catla (Ham.) exposed to gamma radiation

    International Nuclear Information System (INIS)

    Environmental mutagens such as ionizing radiation and chemicals induce DNA damage in a wide variety of organisms. The International Commission on Radiological Protection (lCRP) has recently emphasized the need to protect non-human biota from the potential effects of ionizing radiation. Radiation exposures to non-humans can occur as a result of low-level radioactive discharges into the environment. Molecular genetic effects at low-level radiation exposures are largely unexplored and systematic studies using sensitive biomarkers are required to assess DNA damage in representative non-human species. The objective of the study was to detect DNA damage in the fish Catla catla exposed to gamma radiation using flow cytometry at different time intervals. Increases in the coefficient of variation (CV) of the G0/G1 peak, indicating abnormal DNA distributions were observed in fish exposed to gamma radiation than in controls. Significant increase in the CV was observed from day 12-90 and thereafter decreased. This increase in CV might be due to DNA damage in the cell populations at G0/G1 phase or deletions and duplications caused by improper repair of chromosomes in the cell-cycle machinery. Ionizing radiation induced cell-cycle perturbations and apoptosis were also observed after gamma radiation exposure. (author)

  20. Fish Breeding in Nigeria

    OpenAIRE

    J. A. Akankali; E.I. Seighabo; J. F.N. Abowei

    2011-01-01

    Fish breeding is a very important activity ensuring availability of fingerlings for the stocking of ponds, pens, tanks and cages. The breeding habits of fishes in nature differ from specie to specie Different species of fish choose different places in the aquatic environment for breeding. Most species do not breed when in captivity due to a number of factors. In Nigeria, induced breeding of African mud catfish through injection of ova prim hormone or pituitary gland is the main practice. This...

  1. About stock markets predictability

    Directory of Open Access Journals (Sweden)

    Hicham Benjelloun

    2011-01-01

    Full Text Available We argue that the financial markets have a predetermined outcome. They behave deterministically but appear to follow random patterns. Stock prices have nothing to do with future expectations; they are a reflection of previous convictions coming from the confident investors. A financial crisis is the result of the lack of confidence that characterizes a market moments before the crisis. Stocks returns are perfectly correlated to each other and it is possible to obtain high gains consistently. Finally we provide a different way of assessing risk and suggest a method to sense future performances.

  2. Anglerfish Lophius piscatorius L. in Faroese waters. Life history, ecological importance and stock status

    OpenAIRE

    Ofstad, Lise Helen

    2013-01-01

    Anglerfish Lophius piscatorius has during the last two decades become a highly exploited resource and is now one of the five most economically important demersal fish species in the Faroese fishery. Despite this, there is at present little information available on the population status of anglerfish in Faroese waters. The main aim of this study is to increase the biological knowledge of anglerfish and to perform an assessment of the stock in order to evaluate the sustainability of the anglerf...

  3. Definition of a directed fishing effort in a mixed-species trawl fishery, and its impact on stock assessments

    OpenAIRE

    Biseau, Alain

    1998-01-01

    Les captures par unité d'effort de pêche (CPUE) sont fréquemment utilisées comme indice d'abondance et servent notamment à la calibration des analyses de cohortes (VPA). Plutôt que le simple rapport entre la production et l'effort total développé sur une zone de pêche, les CPUE calculées à partir de marées ciblant l'espèce considérée semblent plus pertinentes. À partir de l'analyse de la composition des débarquements de chaquemarée , il est possible de déterminer des esp?...

  4. Assessing the impact of non-native freshwater fishes on native species using relative weight

    Directory of Open Access Journals (Sweden)

    Giannetto D.

    2012-01-01

    Full Text Available The aim of the research was to test relative weight (Wr, a condition index which allows evaluation of fish well-being, as a tool to investigate the impact of the presence of non native species (NNS on the condition of the key native species (NS of the Tiber River basin (Italy: Barbustyberinus Bonaparte, Leuciscus cephalus (Linnaeus, Leuciscus lucumonis Bianco, Rutilus rubilio (Bonaparte and Telestes muticellus (Bonaparte. By means of Canonical Correlation Analysis, data from 130 sampling sites, distributed throughout Tiber River basin, were examined. Wr of NS was related to densities of NNS and to environmental variables. Moreover, the correlation between Wr of NS and density of NNS was investigated through linear regression analysis and covariance analysis. Preliminary results encourage the use of Wr as a tool to assess the relationship between NS and ecological factors (such as the presence of NNS and to explain the changes that occur along the longitudinal gradient of a river.

  5. Quality loss assessment in fish-based ready-to-eat foods during refrigerated storage

    Energy Technology Data Exchange (ETDEWEB)

    Pourashouri, P.; Chapela, M. J.; Atanassova, M.; Cabado, A. G.; Vieites, J. M.; Aubourg, S. P.

    2013-05-01

    The present research addresses the quality loss in two different ready-to-eat (RTE) sea foods. With this aim, chemical and microbiological parameters were measured in tuna lasagne (TL) and hake roe foods which were refrigerated (4 degree centigrade) for up to 35 and 71 days, respectively. Both foods showed a significant lipid oxidation (peroxide and interaction compound formation) development with storage time, which was especially marked in the case of the TL product, which also underwent an important lipid hydrolysis development. Both RTE products showed a low microbial development, no matter how much time had elapsed since the expiration dates; thus, low total viable count scores and volatile amine formation were attained while the presence of pathogen microorganisms was not detected. In view of the current increasing consumer demand for high quality refrigerated foods, the assessment of lipid damage related to nutritional and sensory values is recommended when fish-based RTE products are encountered. (Author) 46 refs.

  6. From fish chemical characterisation to the benefit-risk assessment--part A.

    Science.gov (United States)

    Afonso, Cláudia; Lourenço, Helena Maria; Cardoso, Carlos; Bandarra, Narcisa Maria; Carvalho, Maria Luísa; Castro, Matilde; Nunes, Maria Leonor

    2013-04-15

    Proximate composition, fatty acid profile, cholesterol, ?-tocoferol content and essential (K, Na, Cl, S, Mg, Ca, Zn, Cu, Fe, Mn, and Se) and contaminant element (Hg/MeHg, Cd, Pb, and As) levels in silver scabbardfish (Lepidopus caudatus), hake (Merluccius merluccius), and ray (Raja spp.) were investigated. Results showed that these species contain high protein, low cholesterol and energy levels, being its consumption recommended. Polyunsaturated fatty acids (PUFA) were the dominant group of the fatty acids, being 80% of the n-3 family. Attending to the dietary reference intakes (DRIs), these fish species are a good source of Se and the other minerals can give a relevant contribution to the DRIs in a balanced diet. More than one weekly meal of silver scabbardfish has to be avoided due to the organic mercury concentration. More accurate dietary recommendations require a probabilistic assessment, which will be the focus of this study's Part B. PMID:23199996

  7. Fishing amplifies forage fish population collapses.

    Science.gov (United States)

    Essington, Timothy E; Moriarty, Pamela E; Froehlich, Halley E; Hodgson, Emma E; Koehn, Laura E; Oken, Kiva L; Siple, Margaret C; Stawitz, Christine C

    2015-05-26

    Forage fish support the largest fisheries in the world but also play key roles in marine food webs by transferring energy from plankton to upper trophic-level predators, such as large fish, seabirds, and marine mammals. Fishing can, thereby, have far reaching consequences on marine food webs unless safeguards are in place to avoid depleting forage fish to dangerously low levels, where dependent predators are most vulnerable. However, disentangling the contributions of fishing vs. natural processes on population dynamics has been difficult because of the sensitivity of these stocks to environmental conditions. Here, we overcome this difficulty by collating population time series for forage fish populations that account for nearly two-thirds of global catch of forage fish to identify the fingerprint of fisheries on their population dynamics. Forage fish population collapses shared a set of common and unique characteristics: high fishing pressure for several years before collapse, a sharp drop in natural population productivity, and a lagged response to reduce fishing pressure. Lagged response to natural productivity declines can sharply amplify the magnitude of naturally occurring population fluctuations. Finally, we show that the magnitude and frequency of collapses are greater than expected from natural productivity characteristics and therefore, likely attributed to fishing. The durations of collapses, however, were not different from those expected based on natural productivity shifts. A risk-based management scheme that reduces fishing when populations become scarce would protect forage fish and their predators from collapse with little effect on long-term average catches. PMID:25848018

  8. Fishing amplifies forage fish population collapses

    Science.gov (United States)

    Essington, Timothy E.; Moriarty, Pamela E.; Froehlich, Halley E.; Hodgson, Emma E.; Koehn, Laura E.; Oken, Kiva L.; Siple, Margaret C.; Stawitz, Christine C.

    2015-01-01

    Forage fish support the largest fisheries in the world but also play key roles in marine food webs by transferring energy from plankton to upper trophic-level predators, such as large fish, seabirds, and marine mammals. Fishing can, thereby, have far reaching consequences on marine food webs unless safeguards are in place to avoid depleting forage fish to dangerously low levels, where dependent predators are most vulnerable. However, disentangling the contributions of fishing vs. natural processes on population dynamics has been difficult because of the sensitivity of these stocks to environmental conditions. Here, we overcome this difficulty by collating population time series for forage fish populations that account for nearly two-thirds of global catch of forage fish to identify the fingerprint of fisheries on their population dynamics. Forage fish population collapses shared a set of common and unique characteristics: high fishing pressure for several years before collapse, a sharp drop in natural population productivity, and a lagged response to reduce fishing pressure. Lagged response to natural productivity declines can sharply amplify the magnitude of naturally occurring population fluctuations. Finally, we show that the magnitude and frequency of collapses are greater than expected from natural productivity characteristics and therefore, likely attributed to fishing. The durations of collapses, however, were not different from those expected based on natural productivity shifts. A risk-based management scheme that reduces fishing when populations become scarce would protect forage fish and their predators from collapse with little effect on long-term average catches. PMID:25848018

  9. Inclusion of fish and krill meal in extruded diets for Octopus vulgaris (Cuvier, 1797): assessment of acceptance

    OpenAIRE

    Querol Ordoñez, Pablo; Morillo-Velarde, Piedad S.; Cerezo Valverde, Jesús; Martínez Llorens, Silvia; Moñino López, Andrés Vicente; Jover Cerdá, Miguel; Tomás Vidal, Ana

    2012-01-01

    Querol Ordoñez, P.; Morillo-velarde, PS.; Cerezo Valverde, J.; Martínez Llorens, S.; Moñino López, AV.; Jover Cerdá, M.; Tomás Vidal, A. (2012). Inclusion of fish and krill meal in extruded diets for Octopus vulgaris (Cuvier, 1797): assessment of acceptance. Aquaculture Research. 1-9. doi:10.1111/are.12093.

  10. Toxic metal, micro and macronutrient assessment in fish most consumed by Iguape community, Sao Paulo state, Brazil

    International Nuclear Information System (INIS)

    It is well-known that, fish is an important source of protein for populations around the world. As such, fish consumption has increased because it is a healthy and low cholesterol source of protein and other nutrients. The city of Iguape, in the extreme south of the Sao Paulo State coast, is located in a well-preserved Atlantic Forest region. During the last two centuries the city suffered from drastic environmental changes, reinforcing the importance of environmental monitoring in this region. In the present study, 23 samples of the three most consumed fish species by the Iguape city population were analyzed. Fish samples were bought at local markets, conditioned in isothermic boxes in crushed ice (-4 deg C) and then identified before registering the biometric information (total length, total weight and body weight). The following micro and macronutrients As, Br, Ca, Co, Fe, K, Na, Rb, Sc, Se and Zn concentration in muscle from 02 predatory fish species Macrodon ancylodon (King weakfish - Pescada) and Centropomus parallelus (Fat snook - Robalo peba) and one detritivorus species: Anchoviella lepidentostole (Broadband anchovy - Manjuba) were assessed by INAA. Toxic metals Cd, Hg and Pb were also evaluated by AAS. Statistical correlation between element concentrations and fish species were tested. (author)

  11. Toxic metal, micro and macronutrient assessment in fish most consumed by Iguape community, Sao Paulo state, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Favaro, Deborah I.T.; Vieira, Andre S.; Bordon, Isabella C.A.C., E-mail: defavaro@ipen.br, E-mail: isabella.bordon@gmail.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Farias, Luciana A., E-mail: lufarias2@yahoo.com.br [Universidade Federal de Sao Paulo (UNIFESP), Sao Paulo, SP (Brazil); Braga, Elisabete S., E-mail: edsbraga@usp.br [Universidade de Sao Paulo (LABNUT/IO/USP), Sao Paulo, SP (Brazil). Instituto Oceanografico

    2013-07-01

    It is well-known that, fish is an important source of protein for populations around the world. As such, fish consumption has increased because it is a healthy and low cholesterol source of protein and other nutrients. The city of Iguape, in the extreme south of the Sao Paulo State coast, is located in a well-preserved Atlantic Forest region. During the last two centuries the city suffered from drastic environmental changes, reinforcing the importance of environmental monitoring in this region. In the present study, 23 samples of the three most consumed fish species by the Iguape city population were analyzed. Fish samples were bought at local markets, conditioned in isothermic boxes in crushed ice (-4 deg C) and then identified before registering the biometric information (total length, total weight and body weight). The following micro and macronutrients As, Br, Ca, Co, Fe, K, Na, Rb, Sc, Se and Zn concentration in muscle from 02 predatory fish species Macrodon ancylodon (King weakfish - Pescada) and Centropomus parallelus (Fat snook - Robalo peba) and one detritivorus species: Anchoviella lepidentostole (Broadband anchovy - Manjuba) were assessed by INAA. Toxic metals Cd, Hg and Pb were also evaluated by AAS. Statistical correlation between element concentrations and fish species were tested. (author)

  12. Pacific Reef Assessment and Monitoring Program Fish Monitoring Brief: Pacific Remote Island Areas 2012

    US Fish and Wildlife Service, Department of the Interior — Twopage summary outlines reef fish and benthic habitat survey efforts conducted by the NOAA Coral Reef Ecosystem Division CRED at Howland Island, Baker Island,...

  13. Final Environmental Assessment : Continuation of Recreational Fishing on St. Vincent National Wildlife Refuge

    US Fish and Wildlife Service, Department of the Interior — A continuation of the recreational fishing program has been proposed for St. Vincent National Wildlife Refuge to follow the guidelines of the attached fishery...

  14. Assessing the impact of removing reserve status on the Abore Reef fish assemblage in New Caledonia

    OpenAIRE

    Ferraris, Jocelyne; Pelletier, Dominique; Kulbicki, M.; Chauvet, C.

    2005-01-01

    We propose a statistical approach based on multivariate analysis and general linear models to test the consequences of removal of reserve status from the Abore Reef fish assemblage of the Abore Reef reserve, New Caledonia. Consequences on fish density were examined at the level of fish assemblage, accounting for habitat. Fish counts and habitat-related information were collected before and after the removal of reserve status, both inside and outside the reserve. Species groups were constructe...

  15. Field and laboratory investigations to assess impacts to fish health from oil sands wastewater releases (Part 1)

    International Nuclear Information System (INIS)

    A combined field and laboratory investigation was conducted during 1995 to evaluate the health of fish which were exposed to wastewaters from Suncor Inc., Oil Sands Group's operation. This investigation was designed to: assess effects on major trophic components of aquatic ecosystems; assess effects on the general condition and health of fish; and relate chemical characteristics to measured responses. A suite of indicators was examined at several levels of biological organization: biochemical, physiological, whole-organisms, population and community. This comprehensive approach was followed because stress effects on fish cannot be adequately evaluated by measuring a single indicator at a single level of organization. Fish health data for walleye (Stizostedion vitreum), goldeye (Hiodon alosoides) and longnose sucker (Catostomus catostomus) showed that there were no adverse effects on fish health at any level of organization. The laboratory investigations comprised 7 and 28 exposures to wastewater and showed that no observed effect levels (NOELs) and lowest observed effect levels (LOELs) were greater than 10% for biochemical and physiological and whole-organism endpoints

  16. A new fish-based multi-metric assessment index for cyprinid streams in the Iranian Caspian Sea Basin

    Science.gov (United States)

    Mostafavi, Hossein; Schinegger, Rafaela; Melcher, Andreas; Moder, Karl; Mielach, Carina; Schmutz, Stefan

    2015-01-01

    A major issue for water resource management is the assessment of environmental degradation of lotic ecosystems. The overall aim of this study is to develop a multi-metric fish index for the cyprinid streams of the Caspian Sea Basin (MMICS) in Iran. As species diversity and composition as well as population structure in the studied streams are different to other regions, there is a substantial need to develop a new fish index. We sampled fish and environmental data of 102 sites in medium sized streams. We analysed human pressures at different spatial scales and determined applicable fish metrics showing a response to human pressures. In total, five structural and functional types of metrics (i.e. biodiversity, habitat, reproduction, trophic level and water quality sensitivity) were considered. In addition, we used 29 criteria describing major anthropogenic human pressures at sampling sites and generated a regional pressure index (RPI) that accounted for potential effects of multiple human pressures. For the MMICS development, we first defined reference sites (least disturbed) and secondly quantified differences of fish metrics between reference and impaired sites. We used a Generalised Linear Model (GLM) to describe metric responses to natural environmental differences in least disturbed conditions. By including impaired sites, the residual distributions of these models described the response range of each metric to human pressures, independently of natural environmental influence. Finally, seven fish metrics showed the best ability to discriminate between impaired and reference sites. The multi-metric fish index performed well in discriminating human pressure classes, giving a significant negative linear response to a gradient of the RPI. These methods can be used for further development of a standardised monitoring tool to assess the ecological status and trends in biological condition for streams of the whole country, considering its complex and diverse geology and climate.

  17. By-Catch Impacts in Fisheries: Utilizing the IUCN Red List Categories for Enhanced Product Level Assessment in Seafood LCAs

    Science.gov (United States)

    Hornborg, Sara; Svensson, Mikael; Nilsson, Per; Ziegler, Friederike

    2013-11-01

    Overexploitation of fish stocks causes concern not only to fisheries managers and conservation biologists, but also engages seafood consumers; more integrated product perspectives would be useful. This could be provided by life cycle assessment (LCA); however, further complements of present LCA methodology are needed to assess seafood production, one being by-catch impacts. We studied the scientific rationale behind using the IUCN Red List of Threatened Species™ for assessment of impacts relating to fish species’ vulnerability. For this purpose, the current Red List status of marine fish in Sweden was compared to the advice given in fisheries as well as key life history traits known to indicate sensitivity to high fishing pressure. Further, we quantified the amount of threatened fish (vulnerable, endangered, or critically endangered) that was discarded in demersal trawl fisheries on the Swedish west coast. The results showed that not only did the national Red List of marine fish have a high consistency with advice given in fisheries and indices of vulnerability, the different fishing practices studied were also found to have vastly different amounts of threatened fish discarded per kilo landing. The suggested approach is therefore promising as a carrier of aggregated information on the extent to which seafood production interferes with conservation priorities, in particular for species lacking adequate stock assessment. To enable extensive product comparisons, it is important to increase coverage of fish species by the global IUCN Red List, and to reconsider the appropriate assessment unit (species or stocks) in order to avoid false alarms.

  18. TaqMan DNA technology confirms likely overestimation of cod (Gadus morhua L.) egg abundance in the Irish Sea: Implications for the assessment of the cod stock and mapping of spawning areas using egg-based methods

    OpenAIRE

    Fox, C.J.; Taylor, Martin I; Pereyra, R.; Villasana, M.I.; Rico, Ciro

    2005-01-01

    Recent substantial declines in northeastern Atlantic cod stocks necessitate improved biological knowledge and the development of techniques to complement standard stock assessment methods (which largely depend on accurate commercial catch data). In 2003, an ichthyoplankton survey was undertaken in the Irish Sea and subsamples of 'cod-like' eggs were analysed using a TaqMan multiplex, PCR (polymerase chain reaction) assay (with specific probes for cod, haddock and whiting). The TaqMan method w...

  19. A national statistical survey assessment of mercury concentrations in fillets of fish collected in the U.S. EPA national rivers and streams assessment of the continental USA.

    Science.gov (United States)

    Wathen, John B; Lazorchak, James M; Olsen, Anthony R; Batt, Angela

    2015-03-01

    The U.S. EPA conducted a national statistical survey of fish fillet tissue with a sample size of 541 sites on boatable rivers =>5th order in 2008-2009. This is the first such study of mercury (Hg) in fish tissue from river sites focused on potential impacts to human health from fish consumption to also address wildlife impacts. Sample sites were identified as being urban or non-urban. All sample mercury concentrations were above the 3.33ugkg(-1) (ppb) quantitation limit, and an estimated 25.4% (±4.4%) of the 51663 river miles assessed exceeded the U.S. EPA 300ugkg(-1) fish-tissue based water quality criterion for mercury, representing 13144±181.8 river miles. Estimates of river miles exceeding comparable aquatic life thresholds (translated from fillet concentrations to whole fish equivalents) in avian species were similar to the number of river miles exceeding the human health threshold, whereas some mammalian species were more at risk than human from lower mercury concentrations. A comparison of means from the non-urban and urban data and among three ecoregions did not indicate a statistically significant difference in fish tissue Hg concentrations at p<0.05. PMID:25434269

  20. Department of the Interior U.S. Fish and Wildlife Service : Final Environmental Assessment for Recreational Fishing Plan : Cypress Creek National Wildlife Refuge

    US Fish and Wildlife Service, Department of the Interior — The primary purpose of the proposed action is to consider recreational fishing opportunities on Cypress Creek NWR. This EA analyzes four different fishing...

  1. Exposure and effects assessment of persistent organohalogen contaminants in arctic wildlife and fish.

    Science.gov (United States)

    Letcher, Robert J; Bustnes, Jan Ove; Dietz, Rune; Jenssen, Bjørn M; Jørgensen, Even H; Sonne, Christian; Verreault, Jonathan; Vijayan, Mathilakath M; Gabrielsen, Geir W

    2010-07-01

    Persistent organic pollutants (POPs) encompass an array of anthropogenic organic and elemental substances and their degradation and metabolic byproducts that have been found in the tissues of exposed animals, especially POPs categorized as organohalogen contaminants (OHCs). OHCs have been of concern in the circumpolar arctic for decades. For example, as a consequence of bioaccumulation and in some cases biomagnification of legacy (e.g., chlorinated PCBs, DDTs and CHLs) and emerging (e.g., brominated flame retardants (BFRs) and in particular polybrominated diphenyl ethers (PBDEs) and perfluorinated compounds (PFCs) including perfluorooctane sulfonate (PFOS) and perfluorooctanic acid (PFOA) found in Arctic biota and humans. Of high concern are the potential biological effects of these contaminants in exposed Arctic wildlife and fish. As concluded in the last review in 2004 for the Arctic Monitoring and Assessment Program (AMAP) on the effects of POPs in Arctic wildlife, prior to 1997, biological effects data were minimal and insufficient at any level of biological organization. The present review summarizes recent studies on biological effects in relation to OHC exposure, and attempts to assess known tissue/body compartment concentration data in the context of possible threshold levels of effects to evaluate the risks. This review concentrates mainly on post-2002, new OHC effects data in Arctic wildlife and fish, and is largely based on recently available effects data for populations of several top trophic level species, including seabirds (e.g., glaucous gull (Larus hyperboreus)), polar bears (Ursus maritimus), polar (Arctic) fox (Vulpes lagopus), and Arctic charr (Salvelinus alpinus), as well as semi-captive studies on sled dogs (Canis familiaris). Regardless, there remains a dearth of data on true contaminant exposure, cause-effect relationships with respect to these contaminant exposures in Arctic wildlife and fish. Indications of exposure effects are largely based on correlations between biomarker endpoints (e.g., biochemical processes related to the immune and endocrine system, pathological changes in tissues and reproduction and development) and tissue residue levels of OHCs (e.g., PCBs, DDTs, CHLs, PBDEs and in a few cases perfluorinated carboxylic acids (PFCAs) and perfluorinated sulfonates (PFSAs)). Some exceptions include semi-field studies on comparative contaminant effects of control and exposed cohorts of captive Greenland sled dogs, and performance studies mimicking environmentally relevant PCB concentrations in Arctic charr. Recent tissue concentrations in several arctic marine mammal species and populations exceed a general threshold level of concern of 1 part-per-million (ppm), but a clear evidence of a POP/OHC-related stress in these populations remains to be confirmed. There remains minimal evidence that OHCs are having widespread effects on the health of Arctic organisms, with the possible exception of East Greenland and Svalbard polar bears and Svalbard glaucous gulls. However, the true (if any real) effects of POPs in Arctic wildlife have to be put into the context of other environmental, ecological and physiological stressors (both anthropogenic and natural) that render an overall complex picture. For instance, seasonal changes in food intake and corresponding cycles of fattening and emaciation seen in Arctic animals can modify contaminant tissue distribution and toxicokinetics (contaminant deposition, metabolism and depuration). Also, other factors, including impact of climate change (seasonal ice and temperature changes, and connection to food web changes, nutrition, etc. in exposed biota), disease, species invasion and the connection to disease resistance will impact toxicant exposure. Overall, further research and better understanding of POP/OHC impact on animal performance in Arctic biota are recommended. Regardless, it could be argued that Arctic wildlife and fish at the highest potential risk of POP/OHC exposure and mediated effects are East Greenland, Svalbard and (West and South) Hudson Bay

  2. Epizootics of wild fish induced by farm fish

    OpenAIRE

    Krkos?ek, Martin; Lewis, Mark A.; Morton, Alexandra; Frazer, L. Neil; Volpe, John P.

    2006-01-01

    The continuing decline of ocean fisheries and rise of global fish consumption has driven aquaculture growth by 10% annually over the last decade. The association of fish farms with disease emergence in sympatric wild fish stocks remains one of the most controversial and unresolved threats aquaculture poses to coastal ecosystems and fisheries. We report a comprehensive analysis of the spread and impact of farm-origin parasites on the survival of wild fish populations. We mathematically coupled...

  3. Spatially explicit estimation of fish length histograms, with application to anchovy habitats in the Bay of Biscay

    OpenAIRE

    Petitgas, Pierre; Doray, Mathieu; Masse, Jacques; Grellier, Patrick

    2011-01-01

    Fish length frequency histograms from research surveys are of prime importance for identifying habitats of different life stages, as well as for stock assessment. However, no method has thus far been available for mapping these histograms as spatially varying curves. Here, a procedure is applied to map spatially connected curves, and detail is given on how it can be applied to map the length frequency histograms. At each sample location, a fish length frequency histogram is given as a vector ...

  4. Assessing the vulnerability of wild rainbow trout (Oncorhynchus mykiss) stocks to overfishing in the Thompson Nicola Region of British Columbia

    OpenAIRE

    Webb, Stacy Lynn

    2006-01-01

    Overfishing is more commonly associated with commercial fisheries than recreational fisheries, but evidence increasingly suggests recreational fisheries are not immune. In my study, I use a generalized linear model to examine if wild stocks of rainbow trout Oncorhynchus mykiss in British Columbia's Southern Interior lakes are vulnerable to overharvest from recreational anglers. Assuming high angling effort implies high harvest rates, I determined which factors make a lake attractive to angler...

  5. In situ assessment of a neotropical fish to evaluate pollution in a river receiving agricultural and urban wastewater.

    Science.gov (United States)

    Ghisi, Nédia de Castilhos; de Oliveira, Elton Celton; Fávaro, Luís Fernando; Silva de Assis, Helena Cristina; Prioli, Alberto José

    2014-12-01

    We aimed to assess the quality of a midsize river that receives agricultural and urban wastewater. Nuclear abnormalities (NA), comet assays of blood and gills, and gill histopathology were evaluated in fish Astyanax aff. paranae during the summer and winter 2011 at three sites in Paraná State, Brazil: (1) a biological reserve (Rebio-reference area); (2) an agricultural site; (3) a downstream site that accumulates agricultural and urban effluents. We found the highest effects of pollutants in fish at the downstream site during the summer. The agricultural site showed an intermediate damage rate, and fish at Rebio generally had the least damage, with the exception of NA. Despite conflicting results from the biomarkers used, we observed an increase in damage associated with the accumulation of pollutants. Pesticides are probable xenobiotics in the agricultural area. Additionally, metals and substances such as pharmaceuticals and ammonia may be present at the downstream site. PMID:25319198

  6. Distance from a Fishing Community Explains Fish Abundance in a No-Take Zone with Weak Compliance

    Science.gov (United States)

    Alwany, Magdy A.; Bailey, David M.

    2015-01-01

    There are numerous examples of no-take marine reserves effectively conserving fish stocks within their boundaries. However, no-take reserves can be rendered ineffective and turned into ‘paper parks’ through poor compliance and weak enforcement of reserve regulations. Long-term monitoring is thus essential to assess the effectiveness of marine reserves in meeting conservation and management objectives. This study documents the present state of the 15-year old no-take zone (NTZ) of South El Ghargana within the Nabq Managed Resource Protected Area, South Sinai, Egyptian Red Sea. Previous studies credited willing compliance by the local fishing community for the increased abundances of targeted fish within the designated NTZ boundaries compared to adjacent fished or take-zones. We compared benthic habitat and fish abundance within the NTZ and the adjacent take sites open to fishing, but found no significant effect of the reserve. Instead, the strongest evidence was for a simple negative relationship between fishing pressure and distance from the closest fishing village. The abundance of targeted piscivorous fish increased significantly with increasing distance from the village, while herbivorous fish showed the opposite trend. This gradient was supported by a corresponding negative correlation between the amount of discarded fishing gear observed on the reef and increasing distance from the village. Discarded fishing gear within the NTZ suggested decreased compliance with the no-take regulations. Our findings indicate that due to non-compliance the no-take reserve is no longer functioning effectively, despite its apparent initial successes and instead a gradient of fishing pressure exists with distance from the nearest fishing community. PMID:25950815

  7. Winter diet of great cormorant (Phalacrocorax carbo) on the River Vltava: estimate of size and species composition and potential for fish stock losses.

    Czech Academy of Sciences Publication Activity Database

    ?ech, Martin; Vej?ík, Lukáš

    2011-01-01

    Ro?. 60, ?. 2 (2011), 129–142. ISSN 0139-7893. [Czech Ichthyological Conference /XII./. Vod?any, 19.05.2010-20.05.2010] R&D Projects: GA ?R(CZ) GA206/06/1371; GA ?R(CZ) GP206/09/P266; GA AV ?R(CZ) 1QS600170504 Institutional research plan: CEZ:AV0Z60170517 Keywords : diagnostic bones * fish withdrawal * regurgitated pellets * European chub * European perch * grayling * roach * ruffe * Slapy Reservoir * trout spp. Subject RIV: EG - Zoology Impact factor: 0.554, year: 2011

  8. Estimation of sport fish harvest for risk and hazard assessment of environmental contaminants

    International Nuclear Information System (INIS)

    Consumption of contaminated fish flesh can be a significant route of human exposure to hazardous chemicals. Estimation of exposure resulting from the consumption of fish requires knowledge of fish consumption and contaminant levels in the edible portion of fish. Realistic figures of sport fish harvest are needed to estimate consumption. Estimates of freshwater sport fish harvest were developed from a review of 72 articles and reports. Descriptive statistics based on fishing pressure were derived from harvest data for four distinct groups of freshwater sport fish in three water types: streams, lakes, and reservoirs. Regression equations were developed to relate harvest to surface area fished where data bases were sufficiently large. Other aspects of estimating human exposure to contaminants in fish flesh that are discussed include use of bioaccumulation factors for trace metals and organic compounds. Using the bioaccumulation factor and the concentration of contaminants in water as variables in the exposure equation may also lead to less precise estimates of tissue concentration. For instance, muscle levels of contaminants may not increase proportionately with increases in water concentrations, leading to overestimation of risk. In addition, estimates of water concentration may be variable or expressed in a manner that does not truly represent biological availability of the contaminant. These factors are discussed. 45 refs., 1 fig., 7 tabsfig., 7 tabs

  9. Analyses of trawling track and fishing activity based on the data of vessel monitoring system (VMS): A case study of the single otter trawl vessels in the Zhoushan fishing ground

    Science.gov (United States)

    Wang, Yang; Wang, Yingbin; Zheng, Ji

    2015-02-01

    The original purpose of Vessel Monitoring System (VMS) is for enforcement and control of vessel sailing. With the application of VMS in fishing vessels, more and more population dynamic studies have used VMS data to improve the accuracy of fisheries stock assessment. In this paper, we simulated the trawl trajectory under different time intervals using the cubic Hermite spline (cHs) interpolation method based on the VMS data of 8 single otter trawl vessels (totally 36000 data items) fishing in Zhoushan fishing ground from September 2012 to December 2012, and selected the appropriate time interval. We then determined vessels' activities (fishing or non-fishing) by comparing VMS speed data with the corresponding speeds from logbooks. The results showed that the error of simulated trajectory greatly increased with the increase of time intervals of VMS data when they were longer than 30 minutes. Comparing the speeds from VMS with those from the corresponding logbooks, we found that the vessels' speeds were between 2.5 kn and 5.0 kn in fishing. The cHs interpolation method is a new choice for improving the accuracy of estimation of sailing trajectory, and the VMS can be used to determine the vessels' activities with the analysis of their trajectories and speeds. Therefore, when the fishery information is limited, VMS can be one of the important data sources for fisheries stock assessment, and more attention should be paid to its construction and application to fisheries stock assessment and management.

  10. Risk assessment of aflatoxins B1 (AFB1) in corn arepas in Colombia and chemical risk assessment case study mercury in Fish

    International Nuclear Information System (INIS)

    The power point presentation is about: Identify the pair substrate (corn, wheat and rice) - mycotoxin (DON, AFB1) higher risk for the Colombian population, based on the exposure assessment and mercury in freshwater fish from Colombia. This report answer some the following questions: what are the most consumed products in the country, which may create a risk for the Colombian population, what are the prevention and control recommendations to reduce potential contamination of the products selected, what are economic activities and their impact areas that contribute most to the incorporation of of mercury in freshwater fish from Colombia,what are the species that may pose greater accumulation of mercury and methylmercury identified , what is the risk associated with the consumption of the species, what are the preventive measures to minimize exposure from consumption of fish with mercury and methylmercury and possible intervention strategies

  11. Mercury content in commercial pelagic fish and its risk assessment in the Western Indian Ocean

    OpenAIRE

    Kojadinovic, Jessica; Potier, Michel; Le Corre, Matthieu; Cosson, Richard; Bustamante, Paco

    2006-01-01

    As top predators of pelagic food webs, large fish naturally bioaccumulate mercury (Hg). Determining Hg burdens in commercialized fish is essential considering the concern about effects of contaminants on human health and the legal thresholds that are therefore set for local consumption and/or exportation. Total Hg levels were measured in the muscular tissue of 183 fish of five commercially important species from the tropical zone of the Western Indian Ocean. All individuals were measured and ...

  12. Multibiomarker approach in fish to assess the impact of pollution in a large Brazilian river, Paraiba do Sul

    International Nuclear Information System (INIS)

    This article examines the advantages of the use of biomarkers as environmental indicators by applying it to Paraiba do Sul watershed, one of the most important Brazilian water bodies, which is in a critical environmental situation. We use a multibiomarker approach in fish as an integrated strategy to assess the impact of pollution. It comprehends a general biomarker of fish health, the condition factor (CF), and specific biomarkers of contaminant exposure such as metallothionein (MT), acetylcholinesterase (AChE) activity and biliary polycyclic aromatic hydrocarbons (PAH) metabolites. Our results revealed different effects in the fish from diverse locations with varying degrees of pollution. Furthermore, fish located just upstream of the water-treatment plant of the metropolitan area of Rio de Janeiro has shown to be affected by metals. This study indicates the usefulness of integrating a set of biomarkers to define the effects of anthropogenic inputs in aquatic bodies under complex polluted situations. - Integrated approach using biomarkers proofs suitable for environmental assessment of a diversely polluted river

  13. Multibiomarker approach in fish to assess the impact of pollution in a large Brazilian river, Paraiba do Sul

    Energy Technology Data Exchange (ETDEWEB)

    Linde-Arias, Ana Rosa [Laboratorio de Toxicologia, Centro de Estudos da Saude do Trabalhador e Ecologia Humana, Escola Nacional de Saude Publica Sergio Arouca, Fundacao Oswaldo Cruz, Leopoldo Bulhoes, 1480, Rio de Janeiro (Brazil)], E-mail: arlinde@ensp.fiocruz.br; Inacio, Alan F.; Novo, Leonardo A.; Alburquerque, Carla de; Moreira, Josino C. [Laboratorio de Toxicologia, Centro de Estudos da Saude do Trabalhador e Ecologia Humana, Escola Nacional de Saude Publica Sergio Arouca, Fundacao Oswaldo Cruz, Leopoldo Bulhoes, 1480, Rio de Janeiro (Brazil)

    2008-12-15

    This article examines the advantages of the use of biomarkers as environmental indicators by applying it to Paraiba do Sul watershed, one of the most important Brazilian water bodies, which is in a critical environmental situation. We use a multibiomarker approach in fish as an integrated strategy to assess the impact of pollution. It comprehends a general biomarker of fish health, the condition factor (CF), and specific biomarkers of contaminant exposure such as metallothionein (MT), acetylcholinesterase (AChE) activity and biliary polycyclic aromatic hydrocarbons (PAH) metabolites. Our results revealed different effects in the fish from diverse locations with varying degrees of pollution. Furthermore, fish located just upstream of the water-treatment plant of the metropolitan area of Rio de Janeiro has shown to be affected by metals. This study indicates the usefulness of integrating a set of biomarkers to define the effects of anthropogenic inputs in aquatic bodies under complex polluted situations. - Integrated approach using biomarkers proofs suitable for environmental assessment of a diversely polluted river.

  14. Toxicity of melamine, an adulterant in fish feeds: experimental assessment of its effects on tilapia.

    Science.gov (United States)

    Phromkunthong, W; Nuntapong, N; Boonyaratpalin, M; Kiron, V

    2013-06-01

    Unscrupulous inclusion of melamine in fish feeds can be harmful to fish and may be hazardous to human health. An eight-week feeding trial examined the effects of melamine (inclusion levels; 5-30 g kg?¹ feed) on the growth performance, feed efficiency, histopathological changes and melamine residues in sex-reversed red tilapia, Oreochromis niloticus (L.) × O.mossambicus (Peters). Fish which received melamine-containing feeds grew less, utilized feeds less efficiently and performed poorly, besides exhibiting defects such as fin erosion, anorexia, sluggish swimming behaviour, paling/darkening of skin and low survival. Melamine concentration in the fish reflected its inclusion level in the feeds, and the content was higher in the viscera than in the fish fillet or whole fish. Histopathological alterations were evident in the kidney, liver and gills of fish subjected to melamine treatment - the severity of lesions corresponded to its dosage. Enlargement of renal tubules was observed in the kidney of fish fed with ?10 g melamine kg?¹ feed, although, crystals were not deposited. Fish subjected to melamine insult had more prominent lesions in liver than in kidney. Toxic effects on the gills manifested as epithelial hyperplasia of the primary and secondary lamellae. The anomalies were severe at higher intake levels of melamine. PMID:23163521

  15. Global warming and fish migrations

    OpenAIRE

    Hannesson, Rögnvaldur

    2005-01-01

    Ocean temperatures are expected to rise over the next decades. This is likely to affect the distribution of fish stocks between the exclusive economic zones (EEZs) of different countries. Such changes are likely to be triggered as temperatures rise beyond certain threshold levels, and they are likely to be irregular, because temperatures are likely to vary around a rising trend. The paper looks at the case where temperature changes would displace a fish stock out of the EEZ of one country and...

  16. The Application of Traits-Based Assessment Approaches to Estimate the Effects of Hydroelectric Turbine Passage on Fish Populations

    Energy Technology Data Exchange (ETDEWEB)

    Cada, Glenn F [ORNL; Schweizer, Peter E [ORNL

    2012-04-01

    One of the most important environmental issues facing the hydropower industry is the adverse impact of hydroelectric projects on downstream fish passage. Fish that migrate long distances as part of their life cycle include not only important diadromous species (such as salmon, shads, and eels) but also strictly freshwater species. The hydropower reservoirs that downstream-moving fish encounter differ greatly from free-flowing rivers. Many of the environmental changes that occur in a reservoir (altered water temperature and transparency, decreased flow velocities, increased predation) can reduce survival. Upon reaching the dam, downstream-migrating fish may suffer increased mortality as they pass through the turbines, spillways and other bypasses, or turbulent tailraces. Downstream from the dam, insufficient environmental flow releases may slow downstream fish passage rates or decrease survival. There is a need to refine our understanding of the relative importance of causative factors that contribute to turbine passage mortality (e.g., strike, pressure changes, turbulence) so that turbine design efforts can focus on mitigating the most damaging components. Further, present knowledge of the effectiveness of turbine improvements is based on studies of only a few species (mainly salmon and American shad). These data may not be representative of turbine passage effects for the hundreds of other fish species that are susceptible to downstream passage at hydroelectric projects. For example, there are over 900 species of fish in the United States. In Brazil there are an estimated 3,000 freshwater fish species, of which 30% are believed to be migratory (Viana et al. 2011). Worldwide, there are some 14,000 freshwater fish species (Magurran 2009), of which significant numbers are susceptible to hydropower impacts. By comparison, in a compilation of fish entrainment and turbine survival studies from over 100 hydroelectric projects in the United States, Winchell et al. (2000) found useful turbine passage survival data for only 30 species. Tests of advanced hydropower turbines have been limited to seven species - Chinook and coho salmon, rainbow trout, alewife, eel, smallmouth bass, and white sturgeon. We are investigating possible approaches for extending experimental results from the few tested fish species to predict turbine passage survival of other, untested species (Cada and Richmond 2011). In this report, we define the causes of injury and mortality to fish tested in laboratory and field studies, based on fish body shape and size, internal and external morphology, and physiology. We have begun to group the large numbers of unstudied species into a small number of categories, e.g., based on phylogenetic relationships or ecological similarities (guilds), so that subsequent studies of a few representative species (potentially including species-specific Biological Index Testing) would yield useful information about the overall fish community. This initial effort focused on modifying approaches that are used in the environmental toxicology field to estimate the toxicity of substances to untested species. Such techniques as the development of species sensitivity distributions (SSDs) and Interspecies Correlation Estimation (ICE) models rely on a considerable amount of data to establish the species-toxicity relationships that can be extended to other organisms. There are far fewer studies of turbine passage stresses from which to derive the turbine passage equivalent of LC{sub 50} values. Whereas the SSD and ICE approaches are useful analogues to predicting turbine passage injury and mortality, too few data are available to support their application without some form of modification or simplification. In this report we explore the potential application of a newer, related technique, the Traits-Based Assessment (TBA), to the prediction of downstream passage mortality at hydropower projects.

  17. Diet Composition and Selectivity in O+ Perch (Perca fluviatilis L. and its Competition with Adult Fish and Carp (Cyprinus carpio L. Stock in Pond Culture

    Directory of Open Access Journals (Sweden)

    Zden?k Adámek

    2004-03-01

    Full Text Available Food composition and selectivity of 0+ perch (Perca fluviatilis were studied under the experimental pond conditions during the growing season in 2000. The diet of perch fry consisted mainly of chironomid larvae and pupae and zooplankton, mainly cladocerans (Bosmina longirostris, Chydorus sp., Ceriodaphnia sp., Alona sp. and copepods. Both chironomids and cladocerans were consumed with positive selectivity. The food items of lesser importance were water beetles (genera Rhantus, Hydrobius and Hydroporus, water bugs Corixa affinis and mayfly larvae Caenis sp. Chironomid larvae were most important food items also in the diet of both adult perch and 2+ carp. Also 0+ perch contributed considerably to the diet of adult perch and benthic food resources (bryozoans and organic debris including supplied feed cereals were of biggest importance for common carp. The perch competes with parental fish and common carp for approximately one third of available food items, whilst adult perch and carp compete for a half of them.

  18. Assessing juvenile native fish demographic responses to a steady flow experiment in a large regulated river

    Science.gov (United States)

    Finch, Colton G.; Pine, William E., III; Yackulic, Charles B.; Dodrill, Michael J.; Yard, Mike D.; Gerig, Brandon S.; Coggins, Lewis G., Jr.; Korman, Josh

    2015-01-01

    The Colorado River below Glen Canyon Dam, Arizona, is part of an adaptive management programme which optimizes dam operations to improve various resources in the downstream ecosystem within Grand Canyon. Understanding how populations of federally endangered humpback chub Gila cypha respond to these dam operations is a high priority. Here, we test hypotheses concerning temporal variation in juvenile humpback chub apparent survival rates and abundance by comparing estimates between hydropeaking and steady discharge regimes over a 3-year period (July 2009–July 2012). The most supported model ignored flow type (steady vs hydropeaking) and estimated a declining trend in daily apparent survival rate across years (99.90%, 99.79% and 99.67% for 2009, 2010 and 2011, respectively). Corresponding abundance of juvenile humpback chub increased temporally; open population model estimates ranged from 615 to 2802 individuals/km, and closed model estimates ranged from 94 to 1515 individuals/km. These changes in apparent survival and abundance may reflect broader trends, or simply represent inter-annual variation. Important findings include (i) juvenile humpback chub are currently surviving and recruiting in the mainstem Colorado River with increasing abundance; (ii) apparent survival does not benefit from steady fall discharges from Glen Canyon Dam; and (iii) direct assessment of demographic parameters for juvenile endangered fish are possible and can rapidly inform management actions in regulated rivers.

  19. Does size matter? An assessment of quota market evolution and performance in the Great Barrier Reef fin-fish fishery

    OpenAIRE

    James Innes; Olivier Thébaud; Ana Norman-López; L. Richard Little

    2014-01-01

    In fisheries managed using individual transferable quotas (ITQs) it is generally assumed that quota markets are well-functioning, allowing quota to flow on either a temporary or permanent basis to those able to make best use of it. However, despite an increasing number of fisheries being managed under ITQs, empirical assessments of the quota markets that have actually evolved in these fisheries remain scarce. The Queensland Coral Reef Fin-Fish Fishery (CRFFF) on the Great Barrier Reef has bee...

  20. Assessing connectivity in coastal systems as a tool for fish management and conservation

    OpenAIRE

    Santos, Patrick Reis

    2013-01-01

    Connectivity is a critical component of marine fish populations as it drives population replenishment, determines colonization patterns and populations’ resilience to harvest. Knowledge of individual movement patterns is pivotal to ascertain population dynamics and underpins sustainable management. Many marine fish species occupy spatially segregated habitats throughout their life history. Estuarine nursery function and the ecological link between estuaries and the coastal environment were ...

  1. Does predation by grey seals (Halichoerus grypus) affect Bothnian Sea herring stock estimates?

    DEFF Research Database (Denmark)

    Gårdmark, Anna; Östman, Örjan

    2012-01-01

    Mortality of small pelagic fish due to marine mammals is generally considered to be low compared with other sources of mortality. With recent recoveries of marine mammal predators worldwide, this may no longer hold. The grey seal (Halichoerus grypus) population in the Bothnian Sea has increased fivefold since 1985. Its main prey, herring (Clupea harrengus), is a key species for fisheries in the region. Yet, current stock assessments assume constant natural mortality, leading to a risk of biased stock estimates with increasing predation and misleading analyses of herring population dynamics. We estimated grey seal predation from diet data and reanalysed herring spawning stock biomass (SSB) during 1973–2009. Accounting for predation increased the herring SSB 16% (maximum 19%), but this was within the confidence intervals when ignoring predation. Although mortality in older individuals was inflated when accounting for seal predation, this did not change the conclusions about drivers of herring dynamics. Accounting for grey seal predation is important for abundance estimates of old herring, but currently not for SSB estimates, given the great uncertainties in the standard assessment. The grey seal impact on Bothnian Sea herring will need to be reassessed if stock age composition, grey seal feeding preferences, or total stock development change

  2. Assessment of committed effective dose due to consumption of Red Sea coral reef fishes collected from the local market (Sudan)

    International Nuclear Information System (INIS)

    An assessment of committed effective dose (CED) due to consumption of Red Sea fish containing ''2''1''0Po and ''1''3''7Cs was performed for 23 different marine fish samples collected from the local market at Port Sudan. The fish were classified according to their feeding habits into three categories: carnivores, herbivores, and omnivores. Measured activity concentrations of 2''1''0Po were found in the ranges 0.25-6.42 (carnivores), 0.7- 5 (omnivores) and 1.5-3.8 (herbivores) Bq/kg fresh weight. In the same study, activity concentrations of Cs-137 were determined to be in the ranges 0.1-0.46 (carnivores), 0.09-0.35 (omnivores) and 0.09-0.32 (herbivores) Bq/kg fresh weigh, which were several times lower than those of ''2''1''0Po. Appropriate conversion factors were used to derive the CED, which was found to be 0.012, 0.01 and 0.01 (?Sv/Yr) in carnivores, omnivores and herbivores, respectively, for ''1'''3''7Cs. This contributes about 0.4% of the total dose exclusively by ingestion of fish. For ''2''1''0Po, it was found to be 3.47, 4.81and 4.14 (?Sv/Yr) in carnivores, omnivores and herbivores, respectively, which represents 99.6% of the total dose (exclusively by ingestion of fish ). The results of CED calculations suggest that the dose received by the Sudanese population from the consumption of marine fish is rather small and that the contribution of ''1''3''7Cs is negligible compared to ''2''1''0Po.(Author)

  3. Assessment of Committed Effective Dose due to consumption of Red Sea coral reef fishes collected from the local market (Sudan).

    Science.gov (United States)

    Hassona, Rifaat K; Sam, A K; Osman, O I; Sirelkhatim, D A; LaRosa, J

    2008-04-15

    An assessment of Committed Effective Dose (CED) due to consumption of Red Sea fish containing (210)Po and (137)Cs was performed for 23 different marine fish samples collected from the local market at Port Sudan. The fish were classified according to their feeding habits into three categories: carnivores, herbivores, and omnivores. Measured activity concentrations of (210)Po were found in the ranges 0.25-6.42 (carnivores), 0.7-5 (omnivores) and 1.5-3.8 (herbivores) Bq/kg fresh weight. In the same study, activity concentrations of Cs-137 were determined to be in the ranges 0.1-0.46 (carnivores), 0.09-0.35 (omnivores) and 0.09-0.32 (herbivores) Bq/kg fresh weight, which were several times lower than those of (210)Po. Appropriate conversion factors were used to derive the CED, which was found to be 0.012, 0.01 and 0.01 (microSv/yr) in carnivores, omnivores and herbivores, respectively, for (137)Cs. This contributes about 0.4% of the total dose exclusively by ingestion of fish. For (210)Po, it was found to be 3.47, 4.81 and 4.14 (microSv/yr) in carnivores, omnivores and herbivores, respectively, which represents 99.6% of the total dose (exclusively by ingestion of fish). The results of CED calculations suggest that the dose received by the Sudanese population from the consumption of marine fish is rather small and that the contribution of (137)Cs is negligible compared to (210)Po. PMID:18243278

  4. Assessment of Committed Effective Dose due to consumption of Red Sea coral reef fishes collected from the local market (Sudan)

    International Nuclear Information System (INIS)

    An assessment of Committed Effective Dose (CED) due to consumption of Red Sea fish containing 210Po and 137Cs was performed for 23 different marine fish samples collected from the local market at Port Sudan. The fish were classified according to their feeding habits into three categories: carnivores, herbivores, and omnivores. Measured activity concentrations of 210Po were found in the ranges 0.25-6.42 (carnivores), 0.7-5 (omnivores) and 1.5-3.8 (herbivores) Bq/kg fresh weight. In the same study, activity concentrations of Cs-137 were determined to be in the ranges 0.1-0.46 (carnivores), 0.09-0.35 (omnivores) and 0.09-0.32 (herbivores) Bq/kg fresh weight, which were several times lower than those of 210Po. Appropriate conversion factors were used to derive the CED, which was found to be 0.012, 0.01 and 0.01 (?Sv/yr) in carnivores, omnivores and herbivores, respectively, for 137Cs. This contributes about 0.4% of the total dose exclusively by ingestion of fish. For 210Po, it was found to be 3.47, 4.81 and 4.14 (?Sv/yr) in carnivores, omnivores and herbivores, respectively, which represents 99.6% of the total dose (exclusively by ingestion of fish). The results of CED calculations suggest that the dose received by the Sudanese population from the consumption of marine fish is rather small and that the contribution of 137Cs is negligible compared to 210Po210Po

  5. Rapid assessment of visual impairment (RAVI in marine fishing communities in South India - study protocol and main findings

    Directory of Open Access Journals (Sweden)

    Madala Sreenivas R

    2011-09-01

    Full Text Available Abstract Background Reliable data are a pre-requisite for planning eye care services. Though conventional cross sectional studies provide reliable information, they are resource intensive. A novel rapid assessment method was used to investigate the prevalence and causes of visual impairment and presbyopia in subjects aged 40 years and older. This paper describes the detailed methodology and study procedures of Rapid Assessment of Visual Impairment (RAVI project. Methods A population-based cross-sectional study was conducted using cluster random sampling in the coastal region of Prakasam district of Andhra Pradesh in India, predominantly inhabited by fishing communities. Unaided, aided and pinhole visual acuity (VA was assessed using a Snellen chart at a distance of 6 meters. The VA was re-assessed using a pinhole, if VA was Results The data collection was completed in Conclusion There is a high prevalence of visual impairment in marine fishing communities in Prakasam district in India. The data from this rapid assessment survey can now be used as a baseline to start eye care services in this region. The rapid assessment methodology (RAVI reported in this paper is robust, quick and has the potential to be replicated in other areas.

  6. Estuarine fish health assessment: Evidence of wastewater impacts based on nitrogen isotopes and histopathology

    International Nuclear Information System (INIS)

    Sewage effluent is a powerful agent of ecological change in estuaries. While the effects of sewage pollution on water quality are usually well documented, biological responses of exposed organisms are not. We quantified health impacts in the form of pathological tissue changes across multiple organs in estuarine fish exposed to elevated levels of treated wastewater. Structural pathologies were compared in wild populations of four fish species from two subtropical estuaries on the east coast of Australia that differ substantially in the amount of direct wastewater loadings. Uptake of sewage-derived nitrogen by fish was traced with stable nitrogen isotopes. Pathologies were common in the liver, spleen, gill, kidney and muscle tissues, and included granulomas, melanomacrophage aggregates, and multiple deformities of the gill epithelia. Tissue deformities were more frequent in fish exposed directly to wastewater discharges. Mullet (Valamugil georgii) were most affected, with only a single specimen free of pathologies in the sewage-impacted estuary. Similarly, in those fish that had structural abnormalities, more deformities were generally found in individuals from sites receiving sewage. These spatial contrasts in impaired fish health correspond to significantly enriched ?15N values in fish muscle as a consequence of fish assimilating sewage-N. Overall, the pattern of lower health and enriched ?15N values in fish from sewage-impacted areas suggestsfish from sewage-impacted areas suggests that organism health is lowered by sewage inputs to estuaries. Measurements of organism health are required to understand the effects of sewage on estuarine ecosystems, and histopathology of fishes is a powerful tool to achieve this

  7. Estuarine fish health assessment: Evidence of wastewater impacts based on nitrogen isotopes and histopathology

    Energy Technology Data Exchange (ETDEWEB)

    Schlacher, Thomas A. [Faculty of Science, Health and Education, University of the Sunshine Coast, Maroochydore DC, QLD 4558 (Australia)], E-mail: tschlach@usc.edu.au; Mondon, Julie A. [School of Life and Environmental Sciences, Deakin University, Warrnambool (Australia)], E-mail: julie.mondon@deakin.edu.au; Connolly, Rod M. [Australian Rivers Institute - Coast and Estuaries and Griffith School of Environment, Griffith University (Australia)], E-mail: r.connolly@griffith.edu.au

    2007-11-15

    Sewage effluent is a powerful agent of ecological change in estuaries. While the effects of sewage pollution on water quality are usually well documented, biological responses of exposed organisms are not. We quantified health impacts in the form of pathological tissue changes across multiple organs in estuarine fish exposed to elevated levels of treated wastewater. Structural pathologies were compared in wild populations of four fish species from two subtropical estuaries on the east coast of Australia that differ substantially in the amount of direct wastewater loadings. Uptake of sewage-derived nitrogen by fish was traced with stable nitrogen isotopes. Pathologies were common in the liver, spleen, gill, kidney and muscle tissues, and included granulomas, melanomacrophage aggregates, and multiple deformities of the gill epithelia. Tissue deformities were more frequent in fish exposed directly to wastewater discharges. Mullet (Valamugil georgii) were most affected, with only a single specimen free of pathologies in the sewage-impacted estuary. Similarly, in those fish that had structural abnormalities, more deformities were generally found in individuals from sites receiving sewage. These spatial contrasts in impaired fish health correspond to significantly enriched {delta}{sup 15}N values in fish muscle as a consequence of fish assimilating sewage-N. Overall, the pattern of lower health and enriched {delta}{sup 15}N values in fish from sewage-impacted areas suggests that organism health is lowered by sewage inputs to estuaries. Measurements of organism health are required to understand the effects of sewage on estuarine ecosystems, and histopathology of fishes is a powerful tool to achieve this.

  8. Carbon stock assessment for a forest-to-coffee conversion landscape in Sumber-Jaya (Lampung, Indonesia): from allometric equations to land use change analysis

    Energy Technology Data Exchange (ETDEWEB)

    Meine van Noordwijk; Subekti Rahayu; Kurniatun Hairiah; Y.C. Wulan; A. Farida; Bruno Verbist [International Centre for Research in Agroforestry (ICRAF) SE Asia, Bogor (Indonesia)

    2002-07-01

    The change in stored carbon (C) stocks was assessed for a 700 km{sup 2} area where forest cover decreased from 60% to 10% in the last 30 years. At the same time, the area under coffee increased from 7% to 70% with a gradual evolution from open 'sun coffee' systems to multi-strata 'shade coffee' systems that provide a partial compensation for C loss. The use of a generic tropical forest rather than tree-specific allometric equation can lead to substantial (up to 100%) overestimates of aboveground biomass depending on wood density and tree shape. In the 1970 1984 period, while forest cover was reduced from 59.5% to 19.7%, the landscape lost on average 6.8 Mg C ha{sup -1} a{sup -1}. In the 1984 2000 period forest cover was further reduced to 12.6%, but the landscape lost only 0.39 Mg C ha{sup -1} a{sup -1}, as forest loss was partially compensated by an increase in shade coffee systems. Conversion of all current sun coffee to shade coffee systems while protecting the remaining forest, could increase average landscape level C stocks by 10 Mg ha{sup -1} over a time frame of say 20 years, or 0.5 Mg C ha{sup -1} a{sup -1}.

  9. Stock Assessment and Management of the Egyptian Sole Solea aegyptiaca Chabanaud, 1927 (Osteichthyes: Soleidae), in the Southeastern Mediterranean, Egypt

    OpenAIRE

    Mehanna, Sahar Fahmy

    2007-01-01

    Aspects of the population dynamics of the Egyptian sole, Solea aegyptiaca, which is a commercially important endemic and demersal flatfish species in the Egyptian Mediterranean waters, were described based on materials collected monthly between February 2004 and May 2005 from the fishing harbor at Port Said city. Age and growth studies based on sagittal otoliths revealed that this species is relatively fast growing with a maximum age of 4 years. Marginal increment analysis suggested that band...

  10. PREVALENCE OF ESCHERICHIA COLI IN FOOD FISHES ASSESSED FROM DOMESTIC RETAIL FISH MARKET, GUNTUR CITY, ANDHRA PRADESH, INDIA: A CASE STUDY

    Directory of Open Access Journals (Sweden)

    BUJJAMMA POLIMETLA

    2013-07-01

    Full Text Available The prevalence of Escherichia coli in fin fish and shell fish samples collected from domestic retail fish market, Guntur City, Andhra Pradesh, India. Domestic fish markets in India are poorly maintained hygienic conditions and are prone to several microbiological pathogens which in turn lead to spread of food safety illness such asdiarrhea etc. Most of the low income group people access their food fishes from the local fish markets. Studied over a period of one Year (November 2009 - December 2010. Of the different freshwater, brakishwater, marinewater fin fishes and shell fishes were analyzed, the highest incidence of Escherichia coli was seen in freshwater fishes, (79.76% followed by the brakishwater fishes (78.84%. Among the crustaceans (95.2% showed the highest incidence followed by Macrobrachium rosenbargii (54.16%. Both fin fishes and crustaceans the incidence of Escherichia coli was seen in crustaceans. A well marked seasonal variation in the incidence pattern was observed in both fin fishes and crustaceans with higher incidence during monsoon season fallowed by post-monsoon and pre-monsoon. Results were revealed that the E.coli loads remained higher in Macrobrachium rosenbargii than other finfish and shellfishes. The fishes were contaminated with E.coli indicating poor hygiene and sanitary condition in domestic fish market. The percentages of the prevallance of E.coli were compared to seasonal variation highest in monsoon.

  11. Impact of climate change and population growth on a risk assessment for endocrine disruption in fish due to steroid estrogens in England and Wales

    OpenAIRE

    V.D.J. Keller; Lloyd, P; Terry, J. A.; WILLIAMS, R. J.

    2015-01-01

    In England and Wales, steroid estrogens: estrone, estradiol and ethinylestradiol have previously been identified as the main chemicals causing endocrine disruption in male fish. A national risk assessment is already available for intersex in fish arising from estrogens under current flow conditions. This study presents, to our knowledge, the first set of national catchment-based risk assessments for steroid estrogen under future scenarios. The river flows and temperatures were perturbed using...

  12. Public Review Draft: A Method for Assessing Carbon Stocks, Carbon Sequestration, and Greenhouse-Gas Fluxes in Ecosystems of the United States Under Present Conditions and Future Scenarios

    Science.gov (United States)

    Bergamaschi, Brian A.; Bernknopf, Richard; Clow, David; Dye, Dennis; Faulkner, Stephen; Forney, William; Gleason, Robert; Hawbaker, Todd; Liu, Jinxun; Liu, Shuguang; Prisley, Stephen; Reed, Bradley; Reeves, Matthew; Rollins, Matthew; Sleeter, Benjamin; Sohl, Terry; Stackpoole, Sarah; Stehman, Stephen; Striegl, Rob; Wein, Anne; Zhu, Zhi-Liang

    2010-01-01

    The Energy Independence and Security Act of 2007 (EISA), Section 712, authorizes the U.S. Department of the Interior to develop a methodology and conduct an assessment of the Nation's ecosystems focusing on carbon stocks, carbon sequestration, and emissions of three greenhouse gases (GHGs): carbon dioxide, methane, and nitrous oxide. The major requirements include (1) an assessment of all ecosystems (terrestrial systems, such as forests, croplands, wetlands, shrub and grasslands; and aquatic ecosystems, such as rivers, lakes, and estuaries), (2) an estimation of annual potential capacities of ecosystems to increase carbon sequestration and reduce net GHG emissions in the context of mitigation strategies (including management and restoration activities), and (3) an evaluation of the effects of controlling processes, such as climate change, land use and land cover, and wildlfires. The purpose of this draft methodology for public review is to propose a technical plan to conduct the assessment. Within the methodology, the concepts of ecosystems, carbon pools, and GHG fluxes used for the assessment follow conventional definitions in use by major national and international assessment or inventory efforts. In order to estimate current ecosystem carbon stocks and GHG fluxes and to understand the potential capacity and effects of mitigation strategies, the method will use two time periods for the assessment: 2001 through 2010, which establishes a current ecosystem GHG baseline and will be used to validate the models; and 2011 through 2050, which will be used to assess future potential conditions based on a set of projected scenarios. The scenario framework is constructed using storylines of the Intergovernmental Panel on Climate Change (IPCC) Special Report Emission Scenarios (SRES), along with initial reference land-use and land-cover (LULC) and land-management scenarios. An additional three LULC and land-management mitigation scenarios will be constructed for each storyline to enhance carbon sequestration and reduce GHG fluxes in ecosystems. Input from regional experts and stakeholders will be solicited to construct realistic and meaningful scenarios. The methods for mapping the current LULC and ecosystem disturbances will require the extensive use of both remote-sensing data and in-situ (for example, forest inventory data) to capture and characterize landscape-change events. For future potential LULC and ecosystem disturbances, key drivers such as socioeconomic, policy, and climate assumptions will be used in addition to biophysical data. The product of these analyses will be a series of maps for each future year for each scenario. These annual maps will form the basis for estimating carbon storage and GHG emissions. For terrestrial ecosystems, carbon storage, carbon-sequestration capacities, and GHG emissions under the current and projected future conditions will be assessed using the LULC and ecosystem-disturbance estimates in map format with a spatially explicit biogeochemical ensemble modeling system that incorporates properties of management activities (such as tillage or harvesting) and properties of individual ecosystems (such as elevation, vegetation characteristics, and soil attributes). For aquatic ecosystems, carbon burial in sediments and GHG fluxes are functions of the current and projected future stream flow and sediment transports, and therefore will be assessed using empirical modeling methods. Validation and uncertainty analysis methods described in the methodology will follow established guidelines to assess the quality of the assessment results. The U.S. Environmental Protection Agency's Level II ecoregions map (which delineates 24 ecoregions for the Nation) will be the practical instrument for developing and delivering assessment results. Consequently, the ecoregion will be the reporting unit of the assessment because the mitigation scenarios, assessment results, validation, and uncertainty analysis will be

  13. Fish Passage Assessment of an Advanced Hydropower Turbine and Conventional Turbine Using Blade-Strike Modeling

    Directory of Open Access Journals (Sweden)

    Zhiqun Deng

    2011-01-01

    Full Text Available Hydropower is the largest renewable energy source in the world. However, in the Columbia and Snake River basins, several species of Pacific salmon and steelhead have been listed for protection under the Endangered Species Act due to significant declines of fish population. Dam operators and design engineers are thus faced with the task of making hydroelectric facilities more fish friendly through changes in hydro-turbine design and operation. Public Utility District No. 2 of Grant County, Washington, applied for relicensing from the U.S. Federal Energy Regulatory Commission to replace the 10 turbines at Wanapum Dam with advanced hydropower turbines that were designed to increase power generation and improve fish passage conditions. We applied both deterministic and stochastic blade-strike models to compare fish passage performance of the newly installed advanced turbine to an existing turbine. Modeled probabilities were compared to the results of a large-scale live-fish survival study and a Sensor Fish study under the same operational parameters. Overall, injury rates predicted by the deterministic model were higher than experimental rates of injury, while those predicted by the stochastic model were in close agreement with experimental results. Fish orientation at the time of entry into the plane of the leading edges of the turbine runner blades was an important factor contributing to uncertainty in modeled results. The advanced design turbine had slightly higher modeled injury rates than the existing turbine design; however, no statistical evidence suggested significant differences in blade-strike injuries between the two turbines, thus the hypothesis that direct fish survival rate through the advanced hydropower turbine is equal to or higher than that for fish passing through the conventional turbine could not be rejected.

  14. Assessment and exploitation of the pomfret fishery by the industrial fishing fleets in Bangladesh

    OpenAIRE

    Roy Bikram Jit; Nripendra Kumar Singha; S.M. Hasan Ali; Gaziur Haman

    2013-01-01

    In this study, pomfret fishery data were collected from the 93 commercial fishing trawlers from July 2008 to June 2009 in Bangladesh. Total fish production of these fishing trawlers was 30191.071 MetricTons (MT). Among them, the estimated catch of pomfret was 305.466 MT of which caught within total 18651961.05 hours and an average catch per hour of pomfret was 0.016 kilogram (kg). Three species of pomfret were recorded under the family stromateidae and carangidae. The average tow duration of ...

  15. A histology-based fish health assessment of the tigerfish, Hydrocynus vittatus from a DDT-affected area

    Science.gov (United States)

    McHugh, K. J.; Smit, N. J.; Van Vuren, J. H. J.; Van Dyk, J. C.; Bervoets, L.; Covaci, A.; Wepener, V.

    The Pongolapoort Dam (PPD) in the Phongola River, Kwa-Zulu Natal, South Africa and the surrounding area are classified as intermediate to low risk malaria areas and are continually being treated with DDT for malaria vector control. DDT is known as an endocrine disrupting chemical posing estrogenic and anti-androgenic properties and therefore might impact on the health of the 18 freshwater fish species found within this system. Of these species the tigerfish, Hydrocynus vittatus, is targeted by both recreational and local subsistence fishermen and was recently included in the South African threatened or protected species list. Their protected status and importance as a food source therefore emphasises the need for their health status elucidation. Previous research on H. vittatus in the Phongola floodplain highlighted DDT biomagnification in this species. Recent data show that the sum of the DDT levels in February 2009 (5403.9 ng/g lipid) and July 2009 (5537.4 ng/g lipid) is still comparable to the high levels found 30 years earlier. The aim of the current study was thus to determine the health status of H. vittatus in relation to DDT exposure by means of a histology-based fish health assessment protocol. Tigerfish were collected in February 2009 ( n = 30) and July 2009 ( n = 15) and gill, kidney and liver tissue were subjected to histological analyses. Mean Index values showed that the Kidney Index ( IK), Gill Index ( IG) and Fish Index ( IFISH) were higher in fish from the February survey while the Liver Index was higher in those collected during July. Liver alterations identified included intercellular oedema, granular degeneration, vacuolation, nuclear pleomorphism and lymphocyte infiltration. Kidney alterations included dilation of the glomerulus capillaries, vacuolation and hyaline droplet degeneration. Gill alterations identified included telangiectasia and hyperplasia of the secondary lamella, congestion, and rupture of pillar cells. Although histological alterations were observed, the histology based fish health assessment protocol indicated that the H. vittatus population in PPD were in a healthy state. The histological assessment did not reflect the DDT exposure induced effects that were anticipated. However, the biomagnification effects in other tertiary consumers in the PPD such as crocodiles and fish eagles cannot be ruled out.

  16. Influences of large- and regional-scale climate on fish recruitment in the Skagerrak-Kattegat over the last century

    Science.gov (United States)

    Linderholm, Hans W.; Cardinale, Massimiliano; Bartolino, Valerio; Chen, Deliang; Ou, Tinghai; Svedäng, Henrik

    2014-06-01

    Dynamics of commercial fish stocks are generally associated with fishing pressure and climate variability. Due to short time series, past studies of the relationships between fish stock dynamics and climate have mainly been restricted to the last few decades. Here we analyzed a century-long time series of plaice, cod and haddock from the Skagerrak-Kattegat, to assess the long-term influence of climate on recruitment. Recruitment success (RS) was compared against sea-surface temperature (SST) and atmospheric circulation indices on large (North Atlantic) and regional (Skagerrak-Kattegat) scales. Our results show that the influence of climate on RS was more pronounced on longer, than on shorter timescales. Over the century-long period, a shift from low to high climate sensitivity was seen from the early to the late part for plaice and cod, while the opposite was found for haddock. This shift suggests that the increasing fishing pressure and the climate change in the Skagerrak-Kattegat have resulted in an increased sensitivity of RS to climate for plaice and cod. The diminishing of climate sensitivity in haddock RS, on the other hand, may be linked to the early twentieth century collapse of the stock in the region. While no long-term relationship between RS and the Atlantic Multidecadal Oscillation (AMO) could be found, large RS fluctuations during the positive phase of the AMO (1935-1960), relative to the cold phases, suggests a changed pattern in recruitment during warm periods. On the other hand, this could be due to the increased fishing pressure in the area. Thus, reported correlations between climate and fish may be caused by strong trends in climate in the late-twentieth century, and coincident reduction in fish stocks caused by intense fishing, rather than a stable relationship between climate and fish recruitment per se.

  17. Metabolomics as a Powerful Tool for Molecular Quality Assessment of the Fish Sparus aurata

    Directory of Open Access Journals (Sweden)

    Francesco Capozzi

    2011-02-01

    Full Text Available The molecular profiles of perchloric acid solutions extracted from the flesh of Sparus aurata fish specimens, produced according to different aquaculture systems, have been investigated. The 1H-NMR spectra of aqueous extracts are indicative of differences in the metabolite content of fish reared under different conditions that are already distinguishable at their capture, and substantially maintain the same differences in their molecular profiles after sixteen days of storage under ice. The fish metabolic profiles are studied by top-down chemometric analysis. The results of this exploratory investigation show that the fish metabolome accurately reflects the rearing conditions. The level of many metabolites co-vary with the rearing conditions and a few metabolites are quantified including glycogen (stress indicator, histidine, alanine and glycine which all display significant changes dependent on the aquaculture system and on the storage times.

  18. Assessment of metals in fish from Lake Macquarie, New South Wales, Australia.

    Science.gov (United States)

    Roach, A C; Maher, W; Krikowa, F

    2008-02-01

    The concentrations of the metals cadmium, copper, mercury, lead, silver, selenium and zinc were measured in the muscle and gonad tissues of five species of fish, yellowfin bream (Acanthopagrus australis), silverbiddy (Gerres subfasciatus) and trumpeter whiting (Sillago maculata), southern log finned goby (Favonigobious lateralis), and the halfbridled goby (Arenigobius frenatus) from the contaminated Lake Macquarie NSW and three relatively uncontaminated reference estuaries, Wallis Lake, Port Stephens, and St. Georges Basin NSW. Fish from Lake Macquarie were found to have elevated concentrations of selenium, lead, cadmium, and zinc in one or both of these tissues in these species. Increased concentrations relative to background concentrations were most often observed at Cockle Bay, the site with the highest concentrations of these metals in sediments. The degree to which fish accumulated metals appeared to be related to life history characteristics of the species, with sediment-dwelling fish showing the greatest propensity to accumulate metals. PMID:17768590

  19. Health assessment and mercury analyses of fishes of the Atchafalaya National Wildlife Refuge

    US Fish and Wildlife Service, Department of the Interior — Mercury and poor water quality in the Atchafalaya River Basin have been documented by the Louisiana Department of Environmental Qualitys Mercury Monitoring Program....

  20. Baseline assessment of fish communities of the Flower Garden Banks (2010 - present): 2011

    National Oceanic and Atmospheric Administration, Department of Commerce — The proposed work develop baseline information on fish and benthic communities within the Flower Garden Banks National Marine Sanctuary (FGBNMS). Surveys will...

  1. Baseline assessment of fish and benthic communities of the Flower Garden Banks

    National Oceanic and Atmospheric Administration, Department of Commerce — The work developed baseline information on fish and benthic communities within the Flower Garden Banks National Marine Sanctuary (FGBNMS). Surveys employed diving,...

  2. Assessment of fish health around the Terra Nova oil development site on the Grand Banks

    International Nuclear Information System (INIS)

    American plaice are used as an indicator species for environmental effects monitoring (EEM) programs in the Grand Banks area of Newfoundland. This study reported on fish health studies conducted between 2000 to 2006 at the Terra Nova oil development site before and after the release of produced waters. A total of 500 fishes were studied for a 5-year period in order to evaluate health effect indicators including fish condition; visible skin and organ lesions; levels of mixed-function-oxygenase (MFO) enzymes; haematology; and various histopathological indices in the liver and gills. The study demonstrated slight elevations of MFO enzyme activity in fish from the development site in 2002, before the release of produced water. On the basis of the various studied indicators, results suggest that the project is not having a significant impact on the health of American plaice.

  3. Assessment of fish health around the Terra Nova oil development site on the Grand Banks

    Energy Technology Data Exchange (ETDEWEB)

    Mathieu, A.; Hanlon, J.; Melvin, W.; French, B. [Oceans Ltd., St. John' s, NL (Canada); Myers, M. [Northwest Fisheries Science Center, Seattle, WA (United States); Williams, U.; Janes, G. [Petro-Canada, East Coast Operations, St. John' s, NL (Canada); Wight, F. [Husky Oil Operations Ltd., St. John' s, NL (Canada)

    2010-07-01

    American plaice are used as an indicator species for environmental effects monitoring (EEM) programs in the Grand Banks area of Newfoundland. This study reported on fish health studies conducted between 2000 to 2006 at the Terra Nova oil development site before and after the release of produced waters. A total of 500 fishes were studied for a 5-year period in order to evaluate health effect indicators including fish condition; visible skin and organ lesions; levels of mixed-function-oxygenase (MFO) enzymes; haematology; and various histopathological indices in the liver and gills. The study demonstrated slight elevations of MFO enzyme activity in fish from the development site in 2002, before the release of produced water. On the basis of the various studied indicators, results suggest that the project is not having a significant impact on the health of American plaice.

  4. St. John, USVI fish assessment and monitoring data (2001 - Present): 2011

    National Oceanic and Atmospheric Administration, Department of Commerce — This fish and benthic composition database is the result of a multifaceted effort described below. The intent of this work is five fold: 1) To spatially...

  5. La Parguera, Puerto Rico Fish Assessment and Monitoring Data (2002 - Present)

    National Oceanic and Atmospheric Administration, Department of Commerce — This fish and benthic composition database is the result of a multifaceted effort described below. The intent of this work is five fold: 1) To spatially...

  6. Preliminary assessment of contaminants and potential effects to fish of the Truckee River, Nevada

    US Fish and Wildlife Service, Department of the Interior — Previous investigations by U.S. Geological Survey USGS and others reported elevated concentrations of a variety of metals and polycyclic aromatic hydrocarbons PAH...

  7. Contaminant assessment of fish, rangia clams, and sediments in the Lower Pamlico River, North Carolina

    US Fish and Wildlife Service, Department of the Interior — Samples of sediment, rangia clams Rangia cuneata, gizzard shad Dorosoma cepedianum, and longnose gar Lepisosteus osseus were collected from five sites in the lower...

  8. Toxic impact of two organophosphate insecticides on biochemical parameters of a food fish and assessment of recovery response.

    Science.gov (United States)

    Narra, Madhusudan Reddy; Begum, Ghousia; Rajender, Kodimyala; Rao, J Venkateswara

    2012-05-01

    Sublethal effects of chlorpyrifos (CPF) and monocrotophos (MCP) on fish biochemical constituents were investigated along with the assessment of recovery response after cessation of intoxication. The fish, Clarias batrachus were exposed to 1.656 mg(-l) and 2.114 mg(-l) of CPF and MCP for 28 days. After 28 days, they were released in freshwater and allowed to recover for 21 days. The CPF exposure resulted in the decrease of carbohydrate and glycogen content, whereas MCP intoxication caused mixed response. Pyruvate and lactate contents were altered under the stress of CPF and MCP. Recovery of these alterations was observed after the cessation of toxicity. Exposure of C. batrachus to CPF and MCP resulted in decreased activity of lactate dehydrogenase in the kidney, liver and muscle but its activity increased in the gills. The CPF caused inhibition of succinate dehydrogenase enzyme in all tissues. Induction in the activity of malate dehydrogenase was caused by both insecticides. Glycogen phosphorylase a was induced in all tissues, whereas glycogen phosphorylase ab showed both induction and inhibition. Of the two insecticides, CPF was more toxic and the recovery response was less. These results are important in the assessment of the risk caused by organophosphate insecticides on nontarget organisms, especially the food fish. PMID:21983276

  9. 75 FR 68767 - Taking of Threatened or Endangered Marine Mammals Incidental to Commercial Fishing Operations

    Science.gov (United States)

    2010-11-09

    ...Marine Mammals Incidental to Commercial Fishing Operations AGENCY: National Marine Fisheries...that incidental taking from commercial fishing will have a negligible impact on the endangered...these stocks incidental to commercial fishing operations are at insignificant...

  10. Do stock prices drive people crazy?

    Science.gov (United States)

    Lin, Chung-Liang; Chen, Chin-Shyan; Liu, Tsai-Ching

    2015-03-01

    This is the first research to examine a potential relation between stock market volatility and mental disorders. Using data on daily incidences of mental disorders in Taiwan over 4000 days from 1998 through 2009 to assess the time-series relation between stock price movements and mental disorders, we observe that stock price fluctuation clearly affects the hospitalization of mental disorders. We find that during a 12-year follow-up period, a low stock price index, a daily fall in the stock price index and consecutive daily falls in the stock price index are all associated with greater of mental disorders hospitalizations. A 1000-point fall in the TAIEX (Taiwan Stock Exchange Capitalization Weighted Stock Index) increases the number of daily mental disorders hospitalizations by 4.71%. A 1% fall in the TAIEX in one single day increases daily hospitalizations for mental disorders by 0.36%. When the stock price index falls one consecutive day, it causes a daily increase of approximately 0.32% hospitalizations due to mental disorders on that day. Stock price index is found to be significant for both gender and all age groups. In addition, daily change is significant for both gender and middle-age groups, whereas accumulated change is significant for males and people aged 45-64. Stockholdings can help people accumulate wealth, but they can also increase mental disorders hospitalizations. In other words, stock price fluctuations do drive people crazy. PMID:24526705

  11. Fish quality assessment through the application of chemico-physical, sensory and microbiological analyses

    OpenAIRE

    Nik Zad Sangsari, Homa

    2013-01-01

    The quality of fish products is indispensably linked to the freshness of the raw material modulated by appropriate manipulation and storage conditions, specially the storage temperature after catch. The purpose of the research presented in this thesis, which was largely conducted in the context of a research project funded by Italian Ministry of Agricultural, Food and Forestry Policies (MIPAAF), concerned the evaluation of the freshness of farmed and wild fish species, in relation to differen...

  12. Using DNA Barcoding to Assess Caribbean Reef Fish Biodiversity: Expanding Taxonomic and Geographic Coverage

    OpenAIRE

    Weigt, Lee A.; Baldwin, Carole C.; Driskell, Amy; Smith, David G.; Ormos, Andrea; Reyier, Eric A.

    2012-01-01

    This paper represents a DNA barcode data release for 3,400 specimens representing 521 species of fishes from 6 areas across the Caribbean and western central Atlantic regions (FAO Region 31). Merged with our prior published data, the combined efforts result in 3,964 specimens representing 572 species of marine fishes and constitute one of the most comprehensive DNA barcoding “coverages” for a region reported to date. The barcode data are providing new insights into Caribbean shorefish div...

  13. Ecological risk assessment in a large river-reservoir. 6: Bioindicators of fish population health

    International Nuclear Information System (INIS)

    Spatial distribution of contaminants in the sediments and biota of a large reservoir ecosystem were related to a variety of biological responses in fish populations and communities to determine possible relationships between contaminant loading in the environment and fish health. Much of the contaminant inventory in the Clinch River/Watts Bar Reservoir (CR/WBR) system has originated from three US Department of Energy facilities on the Oak Ridge Reservation, which borders this system in its upper reaches. Fish sampled from areas of the CR/WBR system with the highest levels of contaminants in the sediments and biota, primarily mercury and PCBs, had the most dramatic bioindicator responses. The major changes observed were induction of detoxification enzymes, organ dysfunction, increased frequency of histopathological lesions, impaired reproduction, and reduced fish community integrity. Mercury, the dominant contaminant, displayed a decreasing concentration gradient from the upper reaches of Poplar Creek to the lower Clinch River, which was consistent with a downstream gradient in several of the biological responses. A multivariate analysis using all of the individual fish health responses at each site in a discriminant analysis procedure also revealed a downstream gradient in integrated fish health. In Poplar Creek where contaminant concentrations were the highest, statistical correlations were observed between individual bioindicator responses such as contaminant exposucator responses such as contaminant exposure indicators, organ dysfunction, histopathological damage, and reproductive impairment. Relationships between contaminant loading and fish community indices such as species richness and relative abundance, however, were more difficult to establish in Poplar Creek because of the possible dominating influence of food and habitat availability on fish community dynamics. Using a suite of bioindicators that encompass a range of levels of biological organization and response-sensitivity scales improves the probability of identifying cause and effect and helps in distinguishing between natural and anthropogenic sources of stress in aquatic ecosystems

  14. Refugia of marine fish in the Northeast Atlantic during the Last Glacial Maximum: concordant assessment from archaeozoology and palaeotemperature reconstructions

    Directory of Open Access Journals (Sweden)

    A. J. Kettle

    2010-07-01

    Full Text Available Archaeozoological finds of the remains of marine and amphihaline fish from the Last Glacial Maximum (LGM ca. 21 ka ago show evidence of very different species ranges compared to the present. We show how an ecological niche model (ENM based on palaeoclimatic reconstructions of sea surface temperature and bathymetry can be used to effectively predict the spatial range of marine fish during the LGM. The results indicate that the ranges of marine fish species that are now in Northwestern Europe were almost completely displaced southward from the modern distribution. Significantly, there is strong evidence that there was an invasion of fish of current economic importance into the Western Mediterranean through the Straits of Gibraltar, where they were exploited by Palaeolithic human populations. There has been much recent interest in the marine glacial refugia to understand how the ranges of the economically important fish species will be displaced with the future climate warming. Recent ENM studies have suggested that species ranges may not have been displaced far southward during the coldest conditions of the LGM. However, archaeozoological evidence and LGM ocean temperature reconstructions indicate that there were large range changes, and certain marine species were able invade the Western Mediterranean. These findings are important for ongoing studies of molecular ecology that aim to assess marine glacial refugia from the genetic structure of living populations, and they pose questions about the genetic identity of vanished marine populations during the LGM. The research presents a challenge for future archaeozoological work to verify palaeoclimatic reconstructions and delimit the glacial refugia.

  15. Assessment of the effects of cage fish-farming on damselfish-associated food chains using stable-isotope analyses.

    Science.gov (United States)

    Jan, Rong-Quen; Kao, Shuh-Ji; Dai, Chang-Feng; Ho, Cheng-Tze

    2014-09-15

    To assess the effect of cage fish-farming on the coral reef ecosystem off Xiaoliuchiu Island, southern Taiwan, geographical differences in the food chain of each of two damselfishes, Pomacentrus vaiuli and Chromis margaritifer, were examined using a stable-isotope approach. For each damselfish, individuals were found to consume similar foods at all sites. However, specimens collected at sites near the cage farm (as the experimental sites) exhibited lower ?(13)C and higher ?(15)N signatures compared to those from reference sites. Similar trends also occurred in the zooplankton and detritus, two major food sources for both damselfishes. This finding indicates that particulate organic matter released by the farm may have entered the coral reef ecosystem through the pelagic food chain. Artificial reef emplacement is recommended to provide extra habitats under cage farms to support additional pelagic-feeding fish populations, thereby reducing environmental impacts of cage farming on coral reefs. PMID:25103907

  16. Assessment of Dissolved Oxygen Mitigation at Hydropower Dams Using an Integrated Hydrodynamic/Water Quality/Fish Growth Model

    Energy Technology Data Exchange (ETDEWEB)

    Bevelhimer, Mark S [ORNL; Coutant, Charles C [ORNL

    2006-07-01

    Dissolved oxygen (DO) in rivers is a common environmental problem associated with hydropower projects. Approximately 40% of all FERC-licensed projects have requirements to monitor and/or mitigate downstream DO conditions. Most forms of mitigation for increasing DO in dam tailwaters are fairly expensive. One area of research of the Department of Energy's Hydropower Program is the development of advanced turbines that improve downstream water quality and have other environmental benefits. There is great interest in being able to predict the benefits of these modifications prior to committing to the cost of new equipment. In the case of turbine replacement or modification, there is a need for methods that allow us to accurately extrapolate the benefits derived from one or two turbines with better design to the replacement or modification of all turbines at a site. The main objective of our study was to demonstrate a modeling approach that integrates the effects of flow and water quality dynamics with fish bioenergetics to predict DO mitigation effectiveness over long river segments downstream of hydropower dams. We were particularly interested in demonstrating the incremental value of including a fish growth model as a measure of biological response. The models applied are a suite of tools (RMS4 modeling system) originally developed by the Tennessee Valley Authority for simulating hydrodynamics (ADYN model), water quality (RQUAL model), and fish growth (FISH model) as influenced by DO, temperature, and available food base. We parameterized a model for a 26-mile reach of the Caney Fork River (Tennessee) below Center Hill Dam to assess how improvements in DO at the dam discharge would affect water quality and fish growth throughout the river. We simulated different types of mitigation (i.e., at the turbine and in the reservoir forebay) and different levels of improvement. The model application successfully demonstrates how a modeling approach like this one can be used to assess whether a prescribed mitigation is likely to meet intended objectives from both a water quality and a biological resource perspective. These techniques can be used to assess the tradeoffs between hydropower operations, power generation, and environmental quality.

  17. Assessment and exploitation of the pomfret fishery by the industrial fishing fleets in Bangladesh

    Directory of Open Access Journals (Sweden)

    Roy Bikram Jit

    2013-08-01

    Full Text Available In this study, pomfret fishery data were collected from the 93 commercial fishing trawlers from July 2008 to June 2009 in Bangladesh. Total fish production of these fishing trawlers was 30191.071 MetricTons (MT. Among them, the estimated catch of pomfret was 305.466 MT of which caught within total 18651961.05 hours and an average catch per hour of pomfret was 0.016 kilogram (kg. Three species of pomfret were recorded under the family stromateidae and carangidae. The average tow duration of per trawler per day was 16.25 hours. The percentage contribution by weight showed that, the highest catchof percentage was 1.88 and the lowest was 0.38; and the average catch percentage of pomfret was 1.01 of the total fish production in the trawl fishing. The highest landing of pomfret was recorded 65.460 MTin the month of November, 2008 and lowest was 1.146 MT in July, 2008 at the same study period.

  18. Histopathological assessment of liver and gonad pathology in continental slope fish from the northeast Atlantic Ocean.

    Science.gov (United States)

    Feist, S W; Stentiford, G D; Kent, M L; Ribeiro Santos, A; Lorance, P

    2015-05-01

    The deep-sea environment is a sink for a wide variety of contaminants including heavy metals and organic compounds of anthropogenic origin. Life history traits of many deep-water fish species including longevity and high trophic position may predispose them to contaminant exposure and subsequent induction of pathological changes, including tumour formation. The lack of evidence for this hypothesis prompted this investigation in order to provide data on the presence of pathological changes in the liver and gonads of several deep-water fish species. Fish were obtained from the north east region of the Bay of Biscay (north east Atlantic Ocean) by trawling at depths between 700 and 1400 m. Liver and gonad samples were collected on board ship and fixed for histological processing and subsequent examination by light microscopy. Hepatocellular and nuclear pleomorphism and individual cases of ovotestis and foci of cellular alteration (FCA) were detected in black scabbardfish (Aphanopus carbo). Six cases of FCA were observed in orange roughy (Hoplostethus atlanticus) (n = 50) together with a single case of hepatocellular adenoma. A wide variety of inflammatory and degenerative lesions were found in all species examined. Deep-water fish display a range of pathologies similar to those seen in shelf-sea species used for international monitoring programmes including biological effects of contaminants. This study has confirmed the utility of health screening in deep-water fish for detecting evidence of prior exposure to contaminants and has also gained evidence of pathology potentially associated with exposure to algal toxins. PMID:25756900

  19. Assessing the feasibility of native fish reintroductions: a framework and example applied to bull trout in the Clackamas River, Oregon

    Science.gov (United States)

    Dunham, Jason B.; Gallo, Kirsten

    2008-01-01

    In a species conservation context, translocations can be an important tool, but they frequently fail to successfully establish new populations. We consider the case of reintroductions for bull trout (Salvelinus confluentus), a federally-listed threatened species with a widespread but declining distribution in western North America. Our specific objectives in this work were to: 1) develop a general framework for assessing the feasibility of reintroduction for bull trout, 2) provide a detailed example of implementing this framework to assess the feasibility of reintroducing bull trout in the Clackamas River, Oregon, and 3) discuss the implications of this effort in the more general context of fish reintroductions as a conservation tool. Review of several case histories and our assessment of the Clackamas River suggest that an attempt to reintroduce bull trout could be successful, assuming adequate resources are committed to the subsequent stages of implementation, monitoring, and evaluation.

  20. ARTIFICIAL FISH PROPAGATION IN KANEV RESERVOIR

    Directory of Open Access Journals (Sweden)

    Gurbik Olexandr Bogdanovitch

    2014-12-01

    Full Text Available Based on the analysis of the dynamics of structural parameters of fish fauna of the Kanev reservoir, we determined the major measures for artificial fish propagation (stocking, which would allow increasing their commercial stocks and maintain biological diversity. It was found that main biological factors, which defined the conditions of existence of fish at different stages of their life cycle in the Kanev reservoir was as a whole favorable for providing sufficient efficiency of measures for stocking it with juveniles of commercially and environmentally valuable fishes. With current state of fish fauna and possibilities of fish hatcheries, the priority in the part of artificial maintenance of fish populations should be given to pike-perch, wels, and tench. An increase of amounts of commercial catches should be based first of all on full-scale stocking with silver and bighead carps, the created stock of which will be available for effective exploitation at a regime, which is protective for native fish fauna. The current bioproductive potential allows increasing the indices of the stock of commercially valuable species up to 120 kg/ha that is twice more than the actual indices for 2012-2013.

  1. Population structure and stock assessment of Hoplias malabaricus (Characiformes: Erythrinidae) caught by artisanal fishermen in river-reservoir transition area in Brazil.

    Science.gov (United States)

    Novaes, José Luís Costa; Carvalho, Edmir Daniel

    2011-03-01

    Hoplias malabaricus is a viable economic alternative for artisanal fishermen who used to live on the banks of rivers that now are dammed in Brazil. In order to preserve the species' natural stock, the main objectives of this study were to obtain bio-ecological information on this species reproduction, feeding dynamics and the description of the extent of its exploitation in river-reservoir transition area in Brazil. This way, from January to December 2005, different fishery catches were made with gill nets by artisanal fishermen, and a total of 426 individual H. malabaricus were obtained and sampled. From each specimen, the following biometric and biological data were analyzed: standard length, total weight, stomach contents, reproductive data such as sex, weight and gonadal maturation stage; with these data we estimated sex ratio, reproduction period and feeding habits. To assess growth parameters and infer on the degree of exploitation, the standard length frequency data were analysed using the FISAT (ELEFAN I) computer program. Data revealed a sex ratio of 0.8:1 (M:F), that reproduction occurs all year around, being more intense during spring and summer; it also showed that H. malabaricus is piscivorous. The growth parameters and mortality were estimated at: L(infinity) = 35.18 cm, k = 0.32 year, longevity = 9.3 years, Z = 1.25 years, M = 0.63 year and F = 0.62 year. The weight-length relationship was: In Wt = -3.1663+2.7456 In Lp. The yield-per-recruit analysis produced the following values: E = 0.496, E(max) = 0.916, E0.1 = 0.701 and E0.5 = 0.378. Overall, our data suggest that the stock of H. malabaricus is not yet overfished in the studied area. PMID:21513193

  2. Development and validation of fish-based, multimetric indices for assessing the ecological health of Western Australian estuaries

    Science.gov (United States)

    Hallett, Chris S.; Valesini, Fiona J.; Clarke, K. Robert; Hesp, S. Alex; Hoeksema, Steeg D.

    2012-06-01

    We describe the development of the first fish-based, multimetric indices for assessing and monitoring the health of Australian estuaries, and their application to the nearshore (2 m depth) waters of the Swan Estuary, Western Australia. Suites of fish community metrics, including measures of species composition, diversity and abundance, trophic structure and life history function, were selected via a novel weight of evidence approach on the basis of their sensitivity to detect inter-annual change in estuarine condition. For each selected metric, seasonally-adjusted reference conditions were established for each spatial management zone of the Swan Estuary using 30 years of standardised historical fish assemblage data. This extensive data set provided a sound basis for determining the 'best available' standard of biotic integrity recorded over that time period and thus a reliable benchmark against which the current and future health of the estuary may be assessed and compared. The nearshore and offshore indices were robust to the effects of natural, intra-seasonal variability in environmental conditions, and so provide reliable tools for quantifying and classifying the ecological health of the Swan Estuary and its constituent management zones. The response of the nearshore index to an algal bloom confirmed that it is sufficiently sensitive to quantify ecological health responses to local-scale environmental perturbations and to track the subsequent recovery of the system following their removal. The indices provide managers with a reliable, quantitative method for assessing and communicating the health of the Swan Estuary and, similarly, of other estuaries across south-western Australia.

  3. Mercury content in commercial pelagic fish and its risk assessment in the Western Indian Ocean.

    Science.gov (United States)

    Kojadinovic, Jessica; Potier, Michel; Le Corre, Matthieu; Cosson, Richard P; Bustamante, Paco

    2006-08-01

    As top predators of pelagic food webs, large fish naturally bioaccumulate mercury (Hg). Determining Hg burdens in commercialized fish is essential considering the concern about effects of contaminants on human health and the legal thresholds that are therefore set for local consumption and/or exportation. Total Hg levels were measured in the muscular tissue of 183 fish of five commercially important species from the tropical zone of the Western Indian Ocean. All individuals were measured and sexed in order to study the impregnation of Hg with size and sex within each species. Values of Hg found in this part of the Indian Ocean were comparable to Hg in muscular tissue of the same species studied in other areas. The highest Hg levels were noted in Swordfish (Xiphias gladius) caught in waters surrounding Reunion Island (3.97+/-2.67 microg g(-1) dry weight). Following the Swordfish, in decreasing order of Hg content, were the Yellowfin Tuna (Thunnus albacares) and the Skipjack (Katsuwonus pelamis), then the Common Dolphinfish (Coryphaena hippurus) and the Wahoo (Acanthocybium solandri). In the North of the Mozambique Channel, Swordfish had higher Hg levels than Yellowfin Tunas, and Dolphinfish exhibited intermediate Hg levels. The size of a fish was a determining factor of its Hg burden, as was the species. Differences in size-normalized Hg levels were observed between the two study zones for Swordfish and Common Dolphinfish. Sex, in contrast, did not influence Hg levels suggesting that females and males have similar feeding habits. The muscular Hg levels presented here suggest that consumers of fish originating from the Western Indian Ocean should limit themselves to one Swordfish based meal per week, or one fish meal a day if they choose to eat tuna or Common Dolphinfish. PMID:16580709

  4. Quality Index Method (QIM) to assess the freshness and shelf life of fish

    Scientific Electronic Library Online (English)

    Daniella Cristina, Bernardi; Eliane Teixeira, Mársico; Mônica Queiroz de, Freitas.

    2013-08-01

    Full Text Available The aim of this work was to develop a sensory method as the objective measure of quality of the fishes at all the key stages of fishery chain, from catch to consumer. The Quality Index Method (QIM) is based on a structured scaling for quality measurements and provides accurate and precise informatio [...] n concerning the freshness and a prediction of the remaining shelf-life for specie-specific fishes. The method is discussed and some future outlooks and need are pointed in order to stimulate the implementation of QIM in the relevant parts of the fishery chain giving unique information of the quality.

  5. FRESHWATER FISH AND DECAPOD CRUSTACEAN POPULATIONS ON RÉUNION ISLAND, WITH AN ASSESSMENT OF SPECIES INTRODUCTIONS.

    Directory of Open Access Journals (Sweden)

    KEITH P.

    2002-01-01

    Full Text Available Streams of Réunion Island shelter with 26 fish species and 11 decapod crustacean species. Some species have been introduced (18%, some other are endemic to the island or to the Madagascar-Mascarenes region (16.2%, are originated from Indo-Pacific area (35.2% or from Indo-African area (27%. Gobiidae and Palaemonidae are the prevailing family in freshwaters, with the highest number of species. 16 species were introduced, mainly fishes, beginning at the turn of the 19th century, but only 4 of those have become acclimatised, while 7 have disappeared and the status of the other is uncertain.

  6. Assessment of micronuclei induction in peripheral blood and gill cells of some fish species from Alia?a Bay Turkey.

    Science.gov (United States)

    Çakal Arslan, Özlem; Boyacio?lu, Meltem; Parlak, Hatice; Katalay, Selma; Karaaslan, Muhammet Ali

    2015-05-15

    The aim of this paper was to assess the biological damages in fish caused by various mutagenic agents present in polluted waters of Alia?a Bay. For this purpose, micronuclei (MN) test was performed using peripheral erythrocytes and gill cells of different fish specimens caught from both polluted and relatively clean sites from Alia?a Bay (Turkey). Micronuclei tests is a system of mutagenicity testing used for determining changes in DNA fragments such as micronuclei in the cytoplasm of interphase cells caused by the pollution and chemicals in the environment. Thus, it was attempted to determine whether pollution affected the erythrocytes and gills of fish living in Alia?a Bay at the level of DNA by the means of micronuclei (MN) test. According to the results of present study, frequency of MN was found at high level in polluted site. In conclusion, this study indicates that the micronuclei test gives sensitive results in monitoring the pollution, especially the pollution of harbor, and thus it might be used as standard method in regularly monitoring pollution of coastal ecosystem. PMID:25805583

  7. Polycyclic aromatic hydrocarbons in fish. Exposure assessment for Kuwaiti consumers after the gulf oil spill of 1991

    International Nuclear Information System (INIS)

    This investigation involves a preliminary assessment of public health hazards associated with exposure to PAHs in locally consumed fish from oil-impacted areas after the Gulf oil spill in 1991. Based on levels of 10 PAHs determined in edible parts of fish collected during the NOAA-Mt. Mitchell scientific cruise (April-May 1992), two exposure scenarios were hypothesized. The first scenario considers that the extent of exposure to PAHs is influenced by the frequency of occurrence and the mean concentration of individual PAH compounds. In the second scenario, the maximum detected PAH concentrations are considered as potential extremes in exposure based on the likely preference of consumption of highly contaminated fish. The mean concentration of the frequently occurring pyrene (75%) poses 3.8, 2.37, and 5.85 times the carcinogenic equivalency, carcinogenic potency, and mutagenic potency, respectively, posed by the mean B(a)P concentration. The maximum concentration of pyrene poses 5.81, 3.62, 8.94 times the carcinogenic equivalency, carcinogenic potency, and mutagenic potency, respectively, posed by the maximum B(a)P concentration. The mean concentration of anthracene (frequency of occurrence = 10%) poses 8.05 and 1.51 times the carcinogenic potency and mutagenic potency, respectively, posed by the mean B(a)P concentration. 16 refs., 1 fig., 6 tabs

  8. River modeling and multi-level fish health assessment to evaluate impacts from oil sands water releases (Part 2)

    International Nuclear Information System (INIS)

    A multi-level, multi-scale approach was used to assess potential impacts to fish health from oil sands water releases. The method used to arrive at predicted impacts involved assembling experimental data on the effects of chronic exposure to oil sands wastewaters on biochemical, physiological and whole-organism endpoint. This information was used to determine no effect levels (NOELs) and lowest effect levels (LOELs) for the suite of fish health parameters used in laboratory experiments (primarily biochemical and physiological measurement endpoints). LOELs and NOELs were compared to modeled concentrations of wastewater in the Athabasca River for five time snapshots. For each time period, concentrations were predicted based on mean annual flows and 7Q10 flows (low flows). This comparison was used to predict impacts on biochemical/physiological endpoints. Impacts on at the whole-organism and population-level were determined by comparing what the laboratory data would predict with what was observed in the field. This process was used to draw a conclusion regarding the health and sustainability of fish populations

  9. Quantity, quality, and support for research in the U.S. Fish and Wildlife Service: an organizational assessment

    Science.gov (United States)

    Ratz, Joan M.; Ponds, Phaedra D.; Neilson, Jennifer R.; Liverca, Joyce; Lamb, Berton Lee

    2005-01-01

    To develop a clearer picture of the nature, extent and quality of management support available for conducting research within the FWS, we completed investigations to identify organizational units within the U.S. Fish and Wildlife Service (FWS) that conduct research as a significant portion of their mission; identify positions in the FWS that include, in whole or in part, a component of scientific research; and assess the attitudes of employees and managers about the obstacles and opportunities for scientific research existing within the FWS.

  10. Assessment of heavy metal concentrations in water, sediment and biota (fish and crabs) samples from the Densu Delta

    International Nuclear Information System (INIS)

    The aim of the study was assess the concentration of some selected heavy metals in water, sediments and biota (fish and crab) sampled from the Densu Delta. In situ and laboratory based analysis were carried out to measure the following physicochemical properties of surface water from the delta; temperature, pH, electrical conductivity (EC), salinity, total dissolved solids (TDS), alkalinity, sodium ion concentration (Na+), potassium ion concentration (K+), chloride ion concentration (Cl), bicarbonate concentration, phosphate concentration, nitrate concentration, sulphate concentration and biochemical oxygen demand (BOD). Heavy metal (Fe, Zn, Cu, Ni, Cd, Cr, Pb and Hg) concentrations in water, sediments, fish and crab sampled at six sites from the Densu Delta wetland in the month of December, 2009 were analysed using VARIAN Fast Sequential Atomic Absorption Spectrophotometer (AAS) model AA240 FS. Two fish species; Blackchin tilapia (Sarotherodon melanotheron), White mullet (Mugil curema) and one species of crab; Blue swimming crab (Callinectes amnicola) were collected from the Densu Delta wetland and analysed. Heavy metal contents in the fish were higher in gill tissue than muscle tissue while in crabs concentrations were higher in the soft tissue than the shell. Levels of Fe, Zn and Cu in the muscle tissue of S. melanotheron were greater than the levels detected in the muscle tissue of M. curema. Cd, Ni and Hg were detected in gill tissue but not in the muscle tissue gill tissue but not in the muscle tissue of S. melanotheron, M. curema on the other hand contained these metals in both gill and muscle tissue. The maximum level of Fe (34.98 mg/L), Zn (25.08 mg/L) in the muscle of S. melanotheron was observed at Bortianor and Zn (2.70 mg/L) was observed at Tetegu. In the M. curema, the maximum level of Fe (34.66 mg/L), Zn (15.9 mg/L) and Cu (1.43 mg/L) was detected at Aplaku, Tetegu and Faana respectively. Heavy metal concentrations were higher in sediment than water. The presence of elevated levels of Cd and Ni in the muscle tissue of the white mullet fish from Tetegu and Faana, is a potential public health hazard to the inhabitants of these two communities and other neighbouring communities who depend on fish from the delta as their source of protein. (au)

  11. A nutritional-toxicological assessment of Antarctic krill oil versus fish oil dietary supplements.

    Science.gov (United States)

    Bengtson Nash, Susan M; Schlabach, Martin; Nichols, Peter D

    2014-09-01

    Fish oil dietary supplements and complementary medicines are pitched to play a role of increasing strategic importance in meeting daily requirements of essential nutrients, such as long-chain (? C20, LC) omega-3 polyunsaturated fatty acids and vitamin D. Recently a new product category, derived from Antarctic krill, has been launched on the omega-3 nutriceutical market. Antarctic krill oil is marketed as demonstrating a greater ease of absorption due to higher phospholipid content, as being sourced through sustainable fisheries and being free of toxins and pollutants; however, limited data is available on the latter component. Persistent Organic Pollutants (POP) encompass a range of toxic, man-made contaminants that accumulate preferentially in marine ecosystems and in the lipid reserves of organisms. Extraction and concentration of fish oils therefore represents an inherent nutritional-toxicological conflict. This study aimed to provide the first quantitative comparison of the nutritional (EPA and DHA) versus the toxicological profiles of Antarctic krill oil products, relative to various fish oil categories available on the Australian market. Krill oil products were found to adhere closely to EPA and DHA manufacturer specifications and overall were ranked as containing intermediate levels of POP contaminants when compared to the other products analysed. Monitoring of the pollutant content of fish and krill oil products will become increasingly important with expanding regulatory specifications for chemical thresholds. PMID:25170991

  12. A Nutritional-Toxicological Assessment of Antarctic Krill Oil versus Fish Oil Dietary Supplements

    Directory of Open Access Journals (Sweden)

    Susan M. Bengtson Nash

    2014-08-01

    Full Text Available Fish oil dietary supplements and complementary medicines are pitched to play a role of increasing strategic importance in meeting daily requirements of essential nutrients, such as long-chain (?C20, LC omega-3 polyunsaturated fatty acids and vitamin D. Recently a new product category, derived from Antarctic krill, has been launched on the omega-3 nutriceutical market. Antarctic krill oil is marketed as demonstrating a greater ease of absorption due to higher phospholipid content, as being sourced through sustainable fisheries and being free of toxins and pollutants; however, limited data is available on the latter component. Persistent Organic Pollutants (POP encompass a range of toxic, man-made contaminants that accumulate preferentially in marine ecosystems and in the lipid reserves of organisms. Extraction and concentration of fish oils therefore represents an inherent nutritional-toxicological conflict. This study aimed to provide the first quantitative comparison of the nutritional (EPA and DHA versus the toxicological profiles of Antarctic krill oil products, relative to various fish oil categories available on the Australian market. Krill oil products were found to adhere closely to EPA and DHA manufacturer specifications and overall were ranked as containing intermediate levels of POP contaminants when compared to the other products analysed. Monitoring of the pollutant content of fish and krill oil products will become increasingly important with expanding regulatory specifications for chemical thresholds.

  13. What is "fallback"?: Metrics needed to assess telemetry tag effects on anadromous fish behavior

    Science.gov (United States)

    Frank, Holly J.; Mather, M.E.; Smith, Joseph M.; Muth, Robert M.; Finn, John T.; McCormick, S.D.

    2009-01-01

    Telemetry has allowed researchers to document the upstream migrations of anadromous fish in freshwater. In many anadromous alosine telemetry studies, researchers use downstream movements ("fallback") as a behavioral field bioassay for adverse tag effects. However, these downstream movements have not been uniformly reported or interpreted. We quantified movement trajectories of radio-tagged anadromous alewives (Alosa pseudoharengus) in the Ipswich River, Massachusetts (USA) and tested blood chemistry of tagged and untagged fish held 24 h. A diverse repertoire of movements was observed, which could be quantified using (a) direction of initial movements, (b) timing, and (c) characteristics of bouts of coupled upstream and downstream movements (e.g., direction, distance, duration, and speed). Because downstream movements of individual fish were almost always made in combination with upstream movements, these should be examined together. Several of the movement patterns described here could fall under the traditional definition of "fallback" but were not necessarily aberrant. Because superficially similar movements could have quite different interpretations, post-tagging trajectories need more precise definitions. The set of metrics we propose here will help quantify tag effects in the field, and provide the basis for a conceptual framework that helps define the complicated behaviors seen in telemetry studies on alewives and other fish in the field. ?? Springer Science+Business Media B.V. 2009.

  14. Absence of subtelomeric rearrangements in selected patients with mental retardation as assessed by multiprobe T FISH

    Directory of Open Access Journals (Sweden)

    dos Santos Suely Rodrigues

    2012-12-01

    Full Text Available Abstract Background Mental retardation (MR is a heterogeneous condition that affects 2-3% of the general population and is a public health problem in developing countries. Chromosomal abnormalities are an important cause of MR and subtelomeric rearrangements (STR have been reported in 4-35% of individuals with idiopathic MR or an unexplained developmental delay, depending on the screening tests and patient selection criteria used. Clinical checklists such as that suggested by de Vries et al. have been used to improve the predictive value of subtelomeric screening. Findings Fifteen patients (1–20 years old; five females and ten males with moderate to severe MR from a genetics outpatient clinic of the Gaffrée and Guinle Teaching Hospital (HUGG of the Federal University of Rio de Janeiro State (UNIRIO were screened with Multiprobe T FISH after normal high resolution karyotyping. No subtelomeric rearrangements were detected even though the clinical score of the patients ranged from four to seven. Conclusion In developing countries, FISH-based techniques such as Multiprobe T FISH are still expensive. Although Multiprobe T FISH is a good tool for detecting STR, in this study it did not detect STR in patients with unexplained MR/developmental delay even though these patients had a marked chromosomal imbalance. Our findings also show that clinical scores are not reliable predictors of STR.

  15. Assessing the effects of marine protected area (MPA) on a reef fish assemblage in a northwestern Mediterranean marine reserve: Identifying community-based indicators

    OpenAIRE

    Claudet, Joachim; Pelletier, Dominique; Jouvenel, J.y; Bachet, F; Galzin, R.

    2006-01-01

    Marine protected areas (MPAs) are increasingly envisaged as a tool to manage coastal ecosystems and fisheries. Assessment of their performance with respect to management objectives is therefore important. A number of WAS provided conservation benefits for fished species. Observed benefits do not apply to all species at all times, and responses to protection are also highly variable among fish taxa. Among the many empirical studies on marine reserves, only a few designs considered 'before and ...

  16. Loss of genetic variability at the transferrin locus in five hatchery stocks of tambaqui (Colossoma macropomum)

    Scientific Electronic Library Online (English)

    Daniela, Calcagnotto; Silvio de Almeida, Toledo-Filho.

    2000-03-01

    Full Text Available O conhecimento e a conservação da variabilidade genética mantida nos estoques de peixe são prioridades atuais da piscicultura brasileira. A utilização de marcadores genético-bioquímicos como a transferrina constitui uma eficiente ferramenta para a caracterização de estoques cultivados de peixes. O o [...] bjetivo do presente trabalho foi analisar a diversidade alélica no loco da transferrina em tambaquis provenientes de cinco estações de piscicultura. Foram analisados 437 tambaquis através de eletroforese em gel de poliacrilamida. No estoque de Pentecoste, que é o mais antigo cultivado no Brasil, foram detectados três alelos enquanto que em outros quatro estoques, derivados de Pentecoste, só foi detectada a presença de um alelo fixado para a transferrina. O número insuficiente de fundadores e a deriva genética parecem ser os principais fatores envolvidos na perda de variabilidade genética nos estoques cultivados de tambaqui no Brasil. Estratégias de manejo apropriadas se fazem necessárias para tentar aumentar o potencial genético dos estoques de tambaqui utilizados na piscicultura nacional. Abstract in english Knowledge and conservation of the genetic variability in stocks maintained as live gene banks have become a high priority task for Brazilian fish culture. The aim of the present survey was to assess the transferrin allelic diversity of five hatchery stocks of tambaqui (Colossoma macropomum). The tam [...] baqui stock from Pentecoste, the oldest maintained in Brazilian hatchery stations, retained three of the six alleles detected in wild populations of tambaqui from the Amazon River. Other hatchery stocks, directly or indirectly derived from the Pentecoste stock, did not show transferrin allelic variability. Insufficient number of founders and genetic drift due to sampling errors seem to be the main causes leading to loss of genetic diversity in tambaqui hatchery stocks. Appropriate management strategies are required in order to improve the genetic potential of tambaqui stocks in Brazil.

  17. Trusting the Stock Market

    OpenAIRE

    Haliassos, Michael; Reiter, Michael

    2008-01-01

    We provide a new explanation to the limited stock market participation puzzle. In deciding whether to buy stocks, investors factor in the risk of being cheated. The perception of this risk is a function not only of the objective characteristics of the stock, but also of the subjective characteristics of the investor. Less trusting individuals are less likely to buy stock and, conditional on buying stock, they will buy less. The calibration of the model shows that this problem is sufficiently ...

  18. Assessment of heavy metals in seawater and fish tissues at Pulau Indah, Selangor, Malaysia

    Science.gov (United States)

    Md Yunus, Sabarina; Hamzah, Zaini; Wood, Ab. Khalik; Ahmad

    2015-04-01

    This study focuses on the levels of heavy metals in seawater and selected fish tissue at Pulau Indah, Selangor, Malaysia. Pulau Indah primarily contains Westport (Malaysia's major port), and a host of full scales factories. Therefore, it is important to monitor the levels of pollution in this water body and the aquatic organisms in the long term effects, due to the human activities in this area. Water samples in this study were taken from 8 locations along the coastal area. The water samples were collected using water sampler and sampling locations were determined using a Global Positioning system (GPS). Similarly, in situ water quality parameters including temperature, dissolve oxygen (DO), salinity, total suspended solid (TSS), pH and turbidity were measured by using portable multi probes meter. Then, the samples were acidified until pH 2 and filtered. Fish samples were purchased from local fisherman along the Pulau Indah coastal area and samples were digested using concentrated nitric acid in wet digestion method. The levels of selected heavy metals in four species of fish and seawater from Pulau Indah coastal area were determined using Inductive Coupled Plasma Mass Spectrometer (ICPMS) after dilution to the samples. In general, the quality of water at Pulau Indah is lower than Malaysia Marine Water Quality Standard except for few locations were higher than the maximum permissible levels. The concentration of heavy metals which are lead (Pb), copper (Cu), zinc (Zn) and uranium (U) in water samples are in the range of 0.36-5.43 µg/L, 75.20-621.58 µg/L, 11.92-30.52 µg/L, and 4.00-4.65 µg/L respectively. While the results of the four selected fish showed the following order of abundance Zn> U> Cu> Pb. Transfer factor (TF) of heavy metals in fish tissue of selected fish species from the water was discussed. However, the observed metal concentration in the sample tissue did not exceed the allowable limit of Malaysian Food Act (1983) and Regulation (1985). Therefore, it is safe for human consumption. Moreover, the pollution levels of these heavy metals were also compared with other studies. This present study can also be used to evaluate the safety dose uptake level of marine biota as well as to monitor environmental health.

  19. SEASAT economic assessment. Volume 8: Ocean fishing case study. [economic benefits of SEASAT satellites to ocean fishing industries in the United States and Canada

    Science.gov (United States)

    1975-01-01

    The potential application of SEASAT data with regard to ocean fisheries is discussed. Tracking fish populations, indirect assistance in forecasting expected populations and assistance to fishing fleets in avoiding costs incurred due to adverse weather through improved ocean conditions forecasts were investigated. Case studies on fisheries in the United States and Canada are cited.

  20. A review of image-based tools for automatic fish ageing from otolith features

    OpenAIRE

    Carbini, Sebastien; Chessel, Anatole; Benzinou, Abdesslam; Fablet, Ronan; Mahe, Kelig; Pontual, Helene

    2008-01-01

    Most of European fish stocks are assessed using age-based models, and otolith interpretation for age estimations costs several million euros annually. In this context, automated ageing systems would provide a mean to 1) standardize ageing, 2) control ageing consistency within and between ageing laboratories 3) build interpreted image data bases ensuring the information conservation and sharing and 4) improve growth studies while reducing the cost of the acquisition of age data. This paper pre...

  1. Modeling energy flow in a large Neotropical reservoir: a tool do evaluate fishing and stability

    OpenAIRE

    Ronaldo Angelini; Angelo Antonio Agostinho; Luiz Carlos Gomes

    2006-01-01

    Recently, there is an increasing perception that the ecosystem approach gives important insights to support fisheries stock assessment and management. This paper aims to quantify energy flows in the Itaipu Reservoir (Brazil) and to simulate increase of the fishing effort of some species, using Ecopath with Ecosim software, which could allow inferences on stability. Therefore, two steady-state Itaipu models were built (1983-87 and 1988-92). Results showed that: a) there are no differences betw...

  2. Does size matter? An assessment of quota market evolution and performance in the Great Barrier Reef fin-fish fishery

    Directory of Open Access Journals (Sweden)

    James Innes

    2014-09-01

    Full Text Available In fisheries managed using individual transferable quotas (ITQs it is generally assumed that quota markets are well-functioning, allowing quota to flow on either a temporary or permanent basis to those able to make best use of it. However, despite an increasing number of fisheries being managed under ITQs, empirical assessments of the quota markets that have actually evolved in these fisheries remain scarce. The Queensland Coral Reef Fin-Fish Fishery (CRFFF on the Great Barrier Reef has been managed under a system of ITQs since 2004. Data on individual quota holdings and trades for the period 2004-2012 were used to assess the CRFFF quota market and its evolution through time. Network analysis was applied to assess market structure and the nature of lease-trading relationships. An assessment of market participants’ abilities to balance their quota accounts, i.e., gap analysis, provided insights into market functionality and how this may have changed in the period observed. Trends in ownership and trade were determined, and market participants were identified as belonging to one out of a set of seven generalized types. The emergence of groups such as investors and lease-dependent fishers is clear. In 2011-2012, 41% of coral trout quota was owned by participants that did not fish it, and 64% of total coral trout landings were made by fishers that owned only 10% of the quota. Quota brokers emerged whose influence on the market varied with the bioeconomic conditions of the fishery. Throughout the study period some quota was found to remain inactive, implying potential market inefficiencies. Contribution to this inactivity appeared asymmetrical, with most residing in the hands of smaller quota holders. The importance of transaction costs in the operation of the quota market and the inequalities that may result are discussed in light of these findings.

  3. Estimation of the regional stock of residential buildings as a basis for a comparative risk assessment in Germany

    Directory of Open Access Journals (Sweden)

    L. Kleist

    2006-01-01

    Full Text Available One important prerequisite for a comparable quantitative risk assessment for different types of hazards (e.g., earthquakes, windstorms and floods is the use of a common database about and financial appraisal of the assets at risk. For damage assessments it is necessary to represent the values at risk on a regional disaggregated scale and to intersect them with hazard scenarios. This paper presents a methodology and results of a financial appraisal of residential buildings for all communities in Germany. The calculated values are defined as replacement values for the reference year 2000. The resulting average replacement costs for residential buildings per inhabitant amount to EUR 46 600, with considerable differences between communities. The inventory can be used for the calculations of direct losses from various natural disasters within the project 'Risk Map Germany''.

  4. Asymmetric Effects in Emerging Stock Markets - The Case of Iran Stock Market

    OpenAIRE

    Seyyed Ali Paytakhti Oskooe; Ali Shamsavari

    2011-01-01

    In view of the mixed empirical results in the literature, this paper assesses the extent of asymmetric volatility effects in the Iranian stock market as an emerging stock market, using a variety of nonlinear autoregressive conditional heteroskedasticity specifications. Tests based on standardized residuals from a fitted GARCH model suggest a lack of asymmetric effects in the dynamic volatility of the Iranian stock market. Empirical analyses with asymmetric GARCH models also reject the hypothe...

  5. Applying INAA to assess dietary intake of elements through fish from coastal areas near Vishakhapatnam, India

    International Nuclear Information System (INIS)

    Essential and toxic element concentrations were measured in fish from coastal areas of Pudimadaka near Vishakhapatnam by neutron activation analysis. Elemental concentrations were observed to be within guideline values fit for human consumption. Correlation among elements suggests similar biogeochemical properties and possibly similar sources. The daily dietary intake values were comparable with reported literature from India and ICRP reference man. Hazard Quotients for all elements were <1. These data will serve as baseline values of elemental concentrations that can be compared with future elemental levels during the operational and post-operational stages of the nuclear facility to be set up at this location. They can also be useful for further studies to identify the spatial and seasonal variations of elements in fish species and monitor the concentration level of elements in this region. (author)

  6. A Nutritional-Toxicological Assessment of Antarctic Krill Oil versus Fish Oil Dietary Supplements

    OpenAIRE

    Bengtson Nash, Susan M.; Martin Schlabach; Peter D. Nichols

    2014-01-01

    Fish oil dietary supplements and complementary medicines are pitched to play a role of increasing strategic importance in meeting daily requirements of essential nutrients, such as long-chain (?C20, LC) omega-3 polyunsaturated fatty acids and vitamin D. Recently a new product category, derived from Antarctic krill, has been launched on the omega-3 nutriceutical market. Antarctic krill oil is marketed as demonstrating a greater ease of absorption due to higher phospholipid content, as being so...

  7. Baseline assessment of the reef fish assemblage from Cagarras Archipelago, Rio de Janeiro, southeastern Brazil

    Directory of Open Access Journals (Sweden)

    Carlos A. Rangel

    2007-03-01

    Full Text Available The extensive Brazilian coast comprises diverse reef fish communities. Here, we report a pioneer study on the reef fish community composition of the Cagarras Archipelago. This rocky reef system consists of a small group of coastal islands 5 km south off Ipanema Beach, Rio de Janeiro city, Brazil. A relatively diverse and disturbed fish community (99 species from 39 families was found in this archipelago. Two different visual census techniques were utilized and a large difference was observed in the number of species compared to other Brazilian reef sites. Trophic structure and biogeographical affinities are discussed. The absence of some reef fish species, mainly top predators, suggests severe environmental impact in this area and exhorts the Brazilian authorities to create a marine protected area. Results obtained in this study will serve to future environmental studies in Cagarras.A extensa costa brasileira abriga uma grande diversidade de peixes recifais. Este trabalho é um estudo pioneiro no que diz respeito à composição de espécies de peixes recifais do Arquipélago das Cagarras. Este sistema recifal é formado por um grupo de ilhas costeiras, distantes 5 km ao sul da Praia de Ipanema no estado do Rio de Janeiro, Brasil. Uma comunidade relativamente diversa e impactada, com 99 espécies pertencentes a 39 famílias de peixes recifais, foi encontrada. A utilização de duas técnicas de censo visual mostrou uma grande diferença nos dados obtidos, quando comparados a outras regiões recifais brasileiras. São discutidos dados da estrutura trófica e a distribuição biogeográfica da ictiofauna da região. A ausência de algumas espécies, principalmente grandes predadores, sugere que a região está sofrendo grande impacto ambiental, e torna urgente a criação de uma área de proteção marinha pelas autoridades Brasileiras. Os resultados obtidos poderão servir como base para futuros estudos ambientais nas Cagarras.

  8. Baseline assessment of the reef fish assemblage from Cagarras Archipelago, Rio de Janeiro, southeastern Brazil

    Scientific Electronic Library Online (English)

    Carlos A., Rangel; Laís C. T., Chaves; Cassiano, Monteiro-Neto.

    2007-03-01

    Full Text Available A extensa costa brasileira abriga uma grande diversidade de peixes recifais. Este trabalho é um estudo pioneiro no que diz respeito à composição de espécies de peixes recifais do Arquipélago das Cagarras. Este sistema recifal é formado por um grupo de ilhas costeiras, distantes 5 km ao sul da Praia [...] de Ipanema no estado do Rio de Janeiro, Brasil. Uma comunidade relativamente diversa e impactada, com 99 espécies pertencentes a 39 famílias de peixes recifais, foi encontrada. A utilização de duas técnicas de censo visual mostrou uma grande diferença nos dados obtidos, quando comparados a outras regiões recifais brasileiras. São discutidos dados da estrutura trófica e a distribuição biogeográfica da ictiofauna da região. A ausência de algumas espécies, principalmente grandes predadores, sugere que a região está sofrendo grande impacto ambiental, e torna urgente a criação de uma área de proteção marinha pelas autoridades Brasileiras. Os resultados obtidos poderão servir como base para futuros estudos ambientais nas Cagarras. Abstract in english The extensive Brazilian coast comprises diverse reef fish communities. Here, we report a pioneer study on the reef fish community composition of the Cagarras Archipelago. This rocky reef system consists of a small group of coastal islands 5 km south off Ipanema Beach, Rio de Janeiro city, Brazil. A [...] relatively diverse and disturbed fish community (99 species from 39 families) was found in this archipelago. Two different visual census techniques were utilized and a large difference was observed in the number of species compared to other Brazilian reef sites. Trophic structure and biogeographical affinities are discussed. The absence of some reef fish species, mainly top predators, suggests severe environmental impact in this area and exhorts the Brazilian authorities to create a marine protected area. Results obtained in this study will serve to future environmental studies in Cagarras.

  9. Mercury and selenium accumulation assessment in fish most consumed by Cubatao Community, Sao Paulo, Brazil

    International Nuclear Information System (INIS)

    High correlation between mercury (Hg) and selenium (Se) concentrations in fish organs is well known. In the present study, 58 fish samples of five fish species most commonly consumed by the Cubatao city population, Sao Paulo State, Brazil were analyzed. The Cubatao Estuary, located in southeastern Sao Paulo State, is an economically important area suffering severe environmental water quality problems due to industrial wastes, domestic sewage and solid residues. The waters of the bay suffer the impact of the immense industrial complex of Cubatao. In this study, Hg concentration in muscle, liver and kidney tissues and Se concentration in liver tissue from three predatory fish species: Macrodon ancylodon (Pescada), Menticirrhus americanus (Perna de Moca) and Micropogonias furnieri (Corvina) and two planctivorous species: Mugil liza (Tainha) and Sardella braziliensis (Sardinha) were determined. Mercury determination was performed using Cold Vapour Atomic Absorption Spectrometry (CV AAS) and selenium by Instrumental Neutron Activation Analysis (INAA). The muscle-Hg concentration variation (wet weight) was: (8 to 40 ?g kg-1) - Sardinha; (12 to 62 ?g kg-1) - Pescada; (3 to 23 ?g kg-1) - Tainha; (43 to 184 ?g kg-1) - Perna de Moca and (41 to 348 ?g kg-1) - Corvina. The general concentration ranges of the analyzed elements in all species studied were (dry weight): muscle-Hg (13 to 1512 ?g kg-1); liver-Hg (21 to 1804 ?g kg-1); kidney-Hg 47 to 9912 ?g kg-1) and liver-Se (2.10 to 43.00 mg kg-1). Se concentrations were higher than those of Hg in the liver. (author)

  10. Histopathological assessment of liver and gonad pathology in continental slope fish from the northeast Atlantic Ocean

    OpenAIRE

    Feist, S. W.; Stentiford, G. D.; Kent, M. L.; Ribeiro Santos, Ana; Lorance, Pascal

    2015-01-01

    The deep-sea environment is a sink for a wide variety of contaminants including heavy metals and organic compounds of anthropogenic origin. Life history traits of many deep-water fish species including longevity and high trophic position may predispose them to contaminant exposure and subsequent induction of pathological changes, including tumour formation. The lack of evidence for this hypothesis prompted this investigation in order to provide data on the presence of pathological changes in ...

  11. Assessment of Potential Cancer Risk from Consumption of PCBs Bioaccumulated in Fish and Shellfish.

    OpenAIRE

    Barron, MG; Yurk, JJ; Crothers, DB

    1994-01-01

    We evaluated the potential cancer risk to adults from ingesting polychlorinated biphenyls (PCBs) in fish and shellfish using an equilibrium partitioning model of PCB bioaccumulation in the aquatic animal. Estimated potential cancer risk to humans increased exponentially with increasing hydrophobicity of the PCB. However, the addition of food-chain sources of PCBs was necessary to cause potential cancer risk to exceed 10(-6). Environmental degradation of the PCB reduced cancer risk by reducing...

  12. Essays on performance-vested stock options and corporate governance

    OpenAIRE

    Bo Qin,

    2010-01-01

    This doctorate project aims to assess the incentive effect of performance-vested stock option (PVSO) in the context of corporate governance and to examine the role of corpo¬rate governance in determining the presence and the level of PVSO awards. We find that performance-vested stock options, conditioning the vesting of stock options on pre¬determined performance target which are generally set rela¬tive to the industry median or peer group, can outperform traditional stock options by bette...

  13. Assessing the Effects of Water Rights Purchases on Dissolved Oxygen, Stream Temperatures, and Fish Habitat

    Science.gov (United States)

    Mouzon, N. R.; Null, S. E.

    2014-12-01

    Human impacts from land and water development have degraded water quality and altered the physical, chemical, and biological integrity of Nevada's Walker River. Reduced instream flows and increased nutrient concentrations affect native fish populations through warm daily stream temperatures and low nightly dissolved oxygen concentrations. Water rights purchases are being considered to maintain instream flows, improve water quality, and enhance habitat for native fish species, such as Lahontan cutthroat trout. This study uses the River Modeling System (RMSv4), an hourly, physically-based hydrodynamic and water quality model, to estimate streamflows, temperatures, and dissolved oxygen concentrations in the Walker River. We simulate thermal and dissolved oxygen changes from increased streamflow to prioritize the time periods and locations that water purchases most enhance native trout habitat. Stream temperatures and dissolved oxygen concentrations are proxies for trout habitat. Monitoring results indicate stream temperature and dissolved oxygen limitations generally exist in the 115 kilometers upstream of Walker Lake (about 37% of the study area) from approximately May through September, and this reach currently acts as a water quality barrier for fish passage.

  14. Polychlorinated biphenyls (PCBs) in marine fishes from China: levels, distribution and risk assessment.

    Science.gov (United States)

    Xia, Chonghuan; Lam, James C W; Wu, Xiaoguo; Xie, Zhouqing; Lam, Paul K S

    2012-11-01

    Muscle tissues of large yellow croakers (Pseudosciaena crocea) and sliver pomfret (Pampus argenteus) from nine coastal cities of East China including Dalian, Tianjin, Qingdao, Shanghai, Zhoushan, Wenzhou, Fuzhou, Quanzhou and Xiamen were analyzed for polychlorinated biphenyl (PCB) concentrations. Thirty-six PCB congeners were quantified in the fishes, of which 11 congeners were dioxin-like PCBs. The total PCB concentrations of the present study were at the low end of the global range, which may be related to the smaller usage and shorter consumption history of PCBs in China. PCBs 18, 29, 52, 66, 101, 104, 138, 153, 180 and 194 were the major constituents found in the fish samples. Regression analysis showed a strong positive correlation (R(2)=0.800; ppomfrets, which may be attributed to their different feeding and living habits. No significant difference in total PCB concentrations among the cities was observed; principal component analysis (PCA) of PCB profiles indicated that PCB pollution came from similar sources in the sampling areas and that there may be other PCB sources in Dalian and Wenzhou. The calculated carcinogenic risks (CRs) from the two species based on a low consumption group and high consumption group were all greater than 10(-6), suggesting that daily exposure to dioxin-like PCBs via fish consumption results in a lifetime cancer risk of greater than one in one million. In contrast, the hazard quotients (HQs) of noncancer risks were all less than unity. PMID:22863061

  15. Contributions to the assessment of Astacus leptodactylus Eschscholtz, 1823 stocks from the Razim-Sinoie lagoonary area (Danube Delta Biosphere Reserve, Romania

    Directory of Open Access Journals (Sweden)

    TÖRÖK Zsolt Csaba

    2013-12-01

    Full Text Available In August 24th- August 30th, 2012 period there was performed a pilot study to assess the Slender clawded or Turkish crayfish (Astacus leptodactylus Eschscholtz, 1823 populations from Golovi?a Lake and the southern part of the Razim Lake (both of them located in the Danube Delta Biosphere Reserve - DDBR. There were used 10 sets of traps (each set with 10 traps and after 147 – 149 hours of functioning there were captured 45 specimens of A. leptodactylus, the total biomass of the crayfish being 1,768 g, which is a very low if compared with the official crayfish-quotas issued for various other regions of the DDBR. The scarcity in Astacus leptodactylus of the Razim- Sinoie lagoonary area is probably due to the habitat-requirement of this species (although other stressing factors – as plagues affecting the crayfish– could also be considered to explain the phenomenon. In order to harvest the minimum quantity (100 kg of crayfish issued as official quota in case of various other regions of the DDBR, the method involving 10 sets with 10 traps should be continuously used for about 370 days – the costs of activities for such long period (combined with the fact that in case of the exploited crayfish quantities there have to be paid various taxes for the environmental protection authorities makes economically unprofitable the crayfish stock-harvesting (based on the method used in the present study in the Razim and Golovi?a lakes .

  16. Integrated biomarker response index using a Neotropical fish to assess the water quality in agricultural areas

    Scientific Electronic Library Online (English)

    Carlos Eduardo Delfino, Vieira; Mayara da Silva, Almeida; Bruno Ambrssio, Galindo; Lindalva, Pereira; Claudia Bueno dos Reis, Martinez.

    2014-03-01

    Full Text Available Ecossistemas aquaticos inseridos em areas com intensa atividade agrmcola estco susceptmveis ` contaminagco por pesticidas, os quais podem comprometer a sazde dos peixes. A fim de verificar a qualidade da agua e os possmveis efeitos de pesticidas sobre peixes, um mitodo integrando o uso de diferente [...] s biomarcadores, denominado mndice integrado de respostas de biomarcadores (IBR), foi aplicado utilizando-se as alteragues biolsgicas avaliadas em varios srgcos do peixe neotropical Astyanax altiparanae. Os peixes foram confinados in situ em cinco pontos ao longo de um ribeirco localizado em area de produgco agrmcola e em um csrrego dentro de um fragmento florestal, considerado um local de referjncia. Apss sete dias foram observadas as seguintes alteragues nos peixes confinados nos pontos experimentais: aumento da atividade da glutationa-S-transferase (GST) e catalase (CAT) e aumento do contezdo de glutationa-reduzida (GSH) em fmgado e brbnquias, redugco da atividade da acetilcolinesterase (AChE) no mzsculo e cirebro, aumento de quebras no DNA e na frequjncia de micronzcleos (MN) e alteragues nucleares (ENA) em eritrscitos. O IBR destacou trjs dos pontos estudados como os mais afetados pela contaminagco agrmcola, uma vez que foram observados nos animais confinados nestes locais maiores variagues nas respostas biolsgicas. Os biomarcadores mais significativos para os resultados de IBR foram a GST, AChE, quebras no DNA e ENA. Abstract in english Aquatic ecosystems in areas with intense agricultural activity are subject to pesticide contamination, which may compromise the health of the fish. In order to verify the quality of the water and the possible effects of pesticides on fish, a method that combines different biomarker responses into an [...] index named "integrated biomarker response" (IBR) was applied using the biological alterations in the Neotropical fish Astyanax altiparanae. Fish were maintained in situ at five sites along a stream that runs in an agricultural area and in a stream within a forest fragment, considered a reference site. After seven days of exposure the following alterations were observed in fish confined at experimental sites: increased activity of glutathione-S-transferase (GST) and catalase (CAT) and increase in the content of reduced glutathione (GSH) in liver and gills, reduction of acetylcholinesterase (AChE) activity in the brain and muscle, increase in the occurrence of DNA strand breaks and in the frequency of micronuclei (MN) and nuclear abnormalities (ENA) in erythrocytes. The IBR highlighted three sites as the most affected, as the animals confined at these sites showed greater variations in biological responses. The biomarkers most important for the IBR results were GST, AChE, DNA breaks and ENA.

  17. Integrating multiple fish biomarkers and risk assessment as indicators of metal pollution along the Red Sea coast of Hodeida, Yemen Republic.

    Science.gov (United States)

    Omar, Wael A; Saleh, Yousef S; Marie, Mohamed-Assem S

    2014-12-01

    The marine environment of the Red Sea coast of Yemen Republic is subjected to increasing anthropogenic activities. The present field study assesses the impacts of metal pollutants on two common marine fish species; Pomadasys hasta and Lutjanus russellii collected from a reference site in comparison to two polluted sites along the Red Sea coast of Hodeida, Yemen Republic. Concentrations of heavy metals (Fe, Cu, Zn, Cd and Pb) in fish vital organs, metal pollution index (MPI), indicative biochemical parameters of liver functions (alanine aminotransferase [ALT] and aspartate aminotransferase [AST]) and kidney functions (urea and creatinine) as well as histopathological changes in gills, liver and kidney of both fish species are integrated as biomarkers of metal pollution. These biomarkers showed species-specific and/or site-specific response. The hazard index (HI) was used as an indicator of human health risks associated with fish consumption. The detected low HI values in most cases doesn't neglect the fact that the cumulative risk effects for metals together give an alarming sign and that the health of fish consumers is endangered around polluted sites. The levels of ALT, AST and urea in plasma of both fish species collected from the polluted sites showed significant increase in comparison to those of reference site. Histopathological alterations and evident damage were observed in tissues of fish collected from the polluted sites. The investigated set of biomarkers proved to be efficient and reliable in biomonitoring the pollution status along different pollution gradients. PMID:25261609

  18. Dispersal, growth and diet of stocked and wild northern pike fry in a shallow natural lake, with implications for management of stocking programs

    DEFF Research Database (Denmark)

    Skov, Christian; Koed, Anders

    2011-01-01

    Increasing evidence suggests that stocking northern pike Esox lucius has had limited success, especially when age-0 fish are stocked into water bodies where the recruitment of northern pike already occurs. To better understand the ecology of wild and stocked fry, we investigated the dispersal, growth, and food composition of advanced pike fry (?30 mm) stocked at a high density at a common release site in a shallow natural lake that contained wild youngof- the-year (age-0) pike. The stocked pike fry colonized the entire lake shoreline within just a few days. Dispersal was inversely related to size at stocking, suggesting that smaller fish were displaced by competitively superior larger individuals. While the stocked pike were initially larger than the wild age-0 pike, suboptimal growth was evident among the stocked pike and they were smaller than the wild ones at the end of the growing season. Stomach analyses revealed that the stocked pike ingested less diverse prey items and had higher fractions of empty stomachs throughout the study period. Overall, the fraction of stocked pike in samples rapidly declined over the season, which may have been caused by differential survival or immigration into or emigration out of the study system. Our study adds to the existing literature suggesting that the stocking of age-0 northern pike into waters with naturally reproducing pike populations will result in limited success. We propose two potentially complementary explanations for the apparent low fitness of stocked individuals in competition with wild conspecifics: (1) genetic-based local maladaptation among the stocked fish and (2) carryover effects from the hatchery. The latter may be less likely because the fry stocked were the offspring of wild fish and only spent a few weeks in the hatchery

  19. Dispersal, growth, and diet of stocked and wild northern pike fry in a shallow natural lake, with implications for the management of stocking programs

    DEFF Research Database (Denmark)

    Skov, Christian Houlberg; Koed, Anders

    2011-01-01

    Increasing evidence suggests that stocking northern pike Esox lucius has had limited success, especially when age-0 fish are stocked into water bodies where the recruitment of northern pike already occurs. To better understand the ecology of wild and stocked fry, we investigated the dispersal, growth, and food composition of advanced pike fry (similar to 30 mm) stocked at a high density at a common release site in a shallow natural lake that contained wild young-of- the-year (age-0) pike. The stocked pike fry colonized the entire lake shoreline within just a few days. Dispersal was inversely related to size at stocking, suggesting that smaller fish were displaced by competitively superior larger individuals. While the stocked pike were initially larger than the wild age-0 pike, suboptimal growth was evident among the stocked pike and they were smaller than the wild ones at the end of the growing season. Stomach analyses revealed that the stocked pike ingested less diverse prey items and had higher fractions of empty stomachs throughout the study period. Overall, the fraction of stocked pike in samples rapidly declined over the season, which may have been caused by differential survival or immigration into or emigration out of the study system. Our study adds to the existing literature suggesting that the stocking of age-0 northern pike into waters with naturally reproducing pike populations will result in limited success. We propose two potentially complementary explanations for the apparent low fitness of stocked individuals in competition with wild conspecifics: (1) genetic-based local maladaptation among the stocked fish and (2) carryover effects from the hatchery. The latter may be less likely because the fry stocked were the offspring of wild fish and only spent a few weeks in the hatchery.

  20. Advanced Stock Information

    Science.gov (United States)

    The mission of Advanced Stock Information is to help "investors and analysts by offering access to high quality investment research information." Featured on the site is the stock research search tool. Enter a ticker symbol into the search field, and the site will insert that company into a huge collection of outside stock information Websites. The site also contains a helpful list of top stock information sites, as determined by Advanced Stock Information staff editors. The sites are grouped into "Top Ten" lists in categories including Financial Portals, Stock Screening Tools, and IPO Information Sites.

  1. Fish Loss in Austrian Fish-Ponds as a Result Of Otter (Lutra lutra L. Predation

    Directory of Open Access Journals (Sweden)

    Michaela Bodner

    1995-10-01

    Full Text Available This paper summarises work on the relationship between otters and fish farmers in a country where there is a compensation scheme for fish losses attributed to otters. The results show that otters are no threat to fish farming. Otters do forage in fish ponds and some fish are damaged/eaten, but there is more use of large ponds than small ones. Otter predation can cause secondary damage to carp stocks. "Missing" fish are often attributed to otters when no other cause can be found. In the cold winter months when many water bodies are frozen over, fish ponds cdan be an essential food source for otters.

  2. Assessment of Smolt Condition for Travel Time Analysis, 1993-1994 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Schrock, Robin M; Beeman, John W; VanderKooi, Scott P [US Geological Survey, Western Fisheries Research Center, Columbia River Research Laboratory, Cook, WA

    1999-02-01

    The assessment of smolt condition for travel time analysis (ASCTTA) project provided information on the level of smoltification in Columbia River hatchery and wild salmonid stocks to the Fish Passage Center (FPC), for the primary purpose of in-river management of flows.

  3. Dietary Tools To Modulate Glycogen Storage In Fish Muscle: A Proteomic Assessment

    DEFF Research Database (Denmark)

    Silva, Tomé S.; Matos, Elisabete

    Post-mortem flesh deterioration is dependent on the energy reserves present at the time of death. Early depletion of muscle glycogen leads to the buildup of lactate and to the early onset of rigor mortis, resulting in the activation of endogenous proteases and the degradation of myofibrillar proteins, and consequent muscle softening. The purpose of this study was to modulate the energy status of the muscle at the time of death through the use of dietary muscle buffering compounds, namely glycerol and maslinic acid. Four fish groups of gilthead seabream (in duplicate) were fed for three months with four different diets. The four diets were obtained by starting from a commercial diet formulation and applying a 2×2 factorial design, with two levels of glycerol supplementation (0 and 5%) and two levels of maslinic acid supplementation (0 and 0,025%). The diets were formulated to be isonitrogenous and isolipidic. Fish were slaughtered by immersion in ice-salt water slurry and muscle samples were immediately obtained from three fish of each tank, for a total of six muscle samples per treatment. Sarcoplasmic proteins were extracted from each muscle sample, separated/quantified by 2D-DIGE and identified by peptide fragment fingerprinting using MALDI-TOF MS. Preliminary analysis of the results shows an effect of the diets on muscle parameters such as measured pH and onset of rigor mortis. At the proteome level, the addition of glycerol and maslinic acid to the diets seemed to have affected the abundance of proteins related to oxidative stress (HSC70, HSC71, peroxiredoxin, transferrin), aldehyde toxification (ALDH1A2, ALDH6A1, ALDH7A1), energy homeostasis (adenylate kinase, nucleoside-diphosphate kinase), cytoskeleton (cofilin-2) and signalling (phosphohistidine phosphatase).

  4. Assessment of Present Anadromous Fish Production Facilities in the Columbia River Basin, Oregon Department of Fish and Wildlife Hatcheries, Final Report.

    Energy Technology Data Exchange (ETDEWEB)

    Delarm, Michael R.; Smith, Robert Z.

    1990-07-01

    The goal of this report is to document current production practices for hatcheries which rear anadromous fish in the Columbia River Basin and to identify those facilities where production can be increased. A total of 85 hatchery and satellite facilities operated by the Idaho Department of Fish and Game, Oregon Department of Fish and Game, US Fish and Wildlife Service, Washington Department of Wildlife, and Washington Department of Fisheries were evaluated. The years 1985 to 1987 were used in this evaluation. During those years, releases averaged 143,306,596 smolts weighing 7,693,589 pounds. A total of 48 hatchery or satellite facilities were identified as having expansion capability. They were estimated to have the potential for increasing production by an 84,448,000 smolts weighing 4,853,306 pounds. 2 refs, 25 figs.

  5. Environmental monitoring through protist next-generation sequencing metabarcoding: assessing the impact of fish farming on benthic foraminifera communities.

    Science.gov (United States)

    Pawlowski, Jan; Esling, Philippe; Lejzerowicz, Franck; Cedhagen, Tomas; Wilding, Thomas A

    2014-11-01

    The measurement of species diversity represents a powerful tool for assessing the impacts of human activities on marine ecosystems. Traditionally, the impact of fish farming on the coastal environment is evaluated by monitoring the dynamics of macrobenthic infaunal populations. However, taxonomic sorting and morphology-based identification of the macrobenthos demand highly trained specialists and are extremely time-consuming and costly, making it unsuitable for large-scale biomonitoring efforts involving numerous samples. Here, we propose to alleviate this laborious task by developing protist metabarcoding tools based on next-generation sequencing (NGS) of environmental DNA and RNA extracted from sediment samples. In this study, we analysed the response of benthic foraminiferal communities to the variation of environmental gradients associated with salmon farms in Scotland. We investigated the foraminiferal diversity based on ribosomal minibarcode sequences generated by the Illumina NGS technology. We compared the molecular data with morphospecies counts and with environmental gradients, including distance to cages and redox used as a proxy for sediment oxygenation. Our study revealed high variations between foraminiferal communities collected in the vicinity of fish farms and at distant locations. We found evidence for species richness decrease in impacted sites, especially visible in the RNA data. We also detected some candidate bioindicator foraminiferal species. Based on this proof-of-concept study, we conclude that NGS metabarcoding using foraminifera and other protists has potential to become a new tool for surveying the impact of aquaculture and other industrial activities in the marine environment. PMID:24734911

  6. High-speed assessment of fat and water content distribution in fish fillets using online imaging spectroscopy.

    Science.gov (United States)

    ElMasry, Gamal; Wold, Jens Petter

    2008-09-10

    A nondestructive method using online spectral imaging has been developed for quantitative measurements of moisture and fat distribution in six species of fish fillets: Atlantic halibut (Hippoglossus hippoglossus), catfish (Icatalurus punctatus), cod (Gadus morhua), mackerel (Scomber japonicus), herring (Clupea harengus), and saithe (Pollachius virens). A spectral image cube was acquired for each fish fillet, and a subsampling approach for relating spectral and chemical features was applied. Spectral data was first analyzed by partial least-squares regression (PLSR), and then the regression coefficients were applied pixel-wise to convert the pixel spectra to a meaningful distribution map of moisture and fat contents. The resulting images are called "chemical images", which illustrate the distribution of fat and/or water content in the fillets. The pixel-wise prediction models for water and fat content had a correlation value of 0.94 with root-mean-square error estimated by a cross-validation (RMSECV) of 2.73% and a correlation value of 0.91 with RMSECV of 2.99%, respectively. This technique is suitable for high-speed assessment of quality parameters of biomaterials and should thus be implemented in industrial applications. The product could comprehensively be defined not only in terms of its external features such as size, shape, and color but also in terms of its chemical composition and its spatial distribution. PMID:18656933

  7. Temporal Assessment of Natural Radionuclide Bioaccumulation by the Cubera Snapper Fish (Lutjanus Cyanopterus, Cuvier, 1828) from the Brazilian Coast

    International Nuclear Information System (INIS)

    The present study aims to assess the seasonal variation in the accumulation of the isotopes 238U, 235U, 234U, 232Th, 230Th, 228Th, 226Ra, 228Ra and 210Pb in the cubera snapper fish from the coast of the state of Ceara (Brazil). The fish was caught in January (six specimens), June (eight) and September (seven). The uranium and thorium were analysed by electrodeposition, followed by alpha spectrometry. The isotopes of radium and lead were selectively co-precipitated and measured by gross alpha radiometry for 226Ra and gross beta radiometry for 228Ra and 210Pb. No seasonal variations could be observed neither for the uranium and thorium isotopes nor for the 226Ra isotope. For 228Ra, the activity concentration in February was equal to that of September, and both were higher than in June. For 210Pb, the situation was different: the month of February showed a lower activity concentration than in June, which in turn was lower than in September. (author)

  8. Synthesis of Sensor Fish Data for Assessment of Fish Passage Conditions at Turbines, Spillways, and Bypass Facilities – Phase 1: The Dalles Dam Spillway Case Study

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Zhiqun; Serkowski, John A.; Fu, Tao; Carlson, Thomas J.; Richmond, Marshall C.

    2007-12-31

    This report summarizes the characterization of spillway passage conditions at The Dalles Dam in 2006 and the effort to complete a comprehensive database for data sets from The Dalles Dam spillway Sensor Fish and balloon-tagged live fish experiments. Through The Dalles Dam spillway case study, Pacific Northwest National Laboratory (PNNL) researchers evaluated the database as an efficient means for accessing and retrieving system-wide data for the U.S Army Corps of Engineers (USACE).

  9. Linking effort and fishing mortality in a mixed fisheries model : comparing linear versus non-linear assumptions

    OpenAIRE

    Thøgersen, Thomas Talund; Hoff, Ayoe; Frost, Hans Staby

    2012-01-01

    Since the implementation of the Common Fisheries Policy of the European Union in 1983, the management of EU fisheries has been enormously challenging. The abundance of many fish stocks has declined because too much fishing capacity has been utilised on healthy fish stocks. Today, this decline in fish stocks has led to overcapacity in many fisheries, leading to incentives for overfishing. Recent research has shown that the allocation of effort among fleets can play an important role in mitigat...

  10. Reduced growth in hybrid tilapia ( Oreochromis mossambicus ×O. Niloticus) at intermediate stocking density

    Science.gov (United States)

    Wang, Yan; Cui, Yi-Bo; Yang, Yun-Xia; Cai, Fa-Sheng

    2002-12-01

    Hybrid tilapia were reared at densities of 1, 5 or 10 fish per tank for four weeks. Mortality was 0 at 1 and 10 fish per tank, but was 25% at 5 fish per tank. Specific growth rate was highest at 1 fish per tank, and lowest at 5 fish per tank. The lower growth rate at the intermediate stocking density was associated with reduced feed efficiency, but there was no reduction in feed intake or digestibility. The results suggested increased metabolic cost caused by aggressive behaviour at intermediate stocking density, which can be suppressed by a further increase in density.

  11. Experimental assessment of the effects of a Neotropical nocturnal piscivore on juvenile native and invasive fishes

    Scientific Electronic Library Online (English)

    Alejandra F. G. N., Santos; Carles, Alcaraz; Luciano N., Santos; Carmino, Hayashi; Emili, García-Berthou.

    Full Text Available A relação predador-presa entre juvenis de pintado Pseudoplatystoma corruscans (piscívoro nativo) e jovens do ano de espécies nativas e invasoras de peixes da bacia do rio Paraná, Brasil, foi testada experimentalmente. Três espécies de peixe invasoras (o tucunaré Cichla piquiti, a tilápia do Nilo Ore [...] ochromis niloticus e o bagre do canal Ictalurus punctatus) e duas nativas (o lambari do rabo amarelo Astyanax altiparanae e o curimbatá Prochilodus lineatus) foram oferecidas como presa para P. corruscans em microcosmos, com três tratamentos de complexidade de habitat (0%, 50% e 100% de cobertura por estruturas submersas). A sobrevivência de presas variou ao longo do tempo e entre espécies (C. piquiti Abstract in english We experimentally examined the predator-prey relationships between juvenile spotted sorubim Pseudoplastystoma corruscans and young-of-the-year invasive and native fish species of the Paraná River basin, Brazil. Three invasive (peacock bass Cichla piquiti, Nile tilapia Oreochromis niloticus, and chan [...] nel catfish Ictalurus punctatus) and two native (yellowtail tetra Astyanax altiparanae and streaked prochilod Prochilodus lineatus) fish species were offered as prey to P. corruscans in 300 L aquaria with three habitat complexity treatments (0%, 50% and 100% structure-covered). Prey survival was variable through time and among species (C. piquiti

  12. Evaluation of Midwater Trawl Selectivity and its Influence on Acoustic-Based Fish Population Surveys

    Science.gov (United States)

    Williams, Kresimir

    Trawls are used extensively during fisheries abundance surveys to derive estimates of fish density and, in the case of acoustic-based surveys, to identify acoustically sampled fish populations. However, trawls are selective in what fish they retain, resulting in biased estimates of density, species, and size compositions. Selectivity of the midwater trawl used in acoustic-based surveys of walleye pollock (Theragra chalcogramma) was evaluated using multiple methods. The effects of trawl selectivity on the acoustic-based survey abundance estimates and the stock assessment were evaluated for the Gulf of Alaska walleye pollock population. Selectivity was quantified using recapture, or pocket, nets attached to the outside of the trawl. Pocket net catches were modeled using a hierarchical Bayesian model to provide uncertainty in selectivity parameter estimates. Significant under-sampling of juvenile pollock by the midwater trawl was found, with lengths at 50% retention ranging from 14--26 cm over three experiments. Escapement was found to be light dependent, with more fish escaping in dark conditions. Highest escapement rates were observed in the aft of the trawl near to the codend though the bottom panel of the trawl. The behavioral mechanisms involved in the process of herding and escapement were evaluated using stereo-cameras, a DIDSON high frequency imaging sonar, and pocket nets. Fish maintained greater distances from the trawl panel during daylight, suggesting trawl modifications such as increased visibility of netting materials may evoke stronger herding responses and increased retention of fish. Selectivity and catchability of pollock by the midwater trawl was also investigated using acoustic density as an independent estimate of fish abundance to compare with trawl catches. A modeling framework was developed to evaluate potential explanatory factors for selectivity and catchability. Selectivity estimates were dependent on which vessel was used for the survey, and the condition factor of the fish caught. Ambient water temperature, time of day, and the proportion of fish in spawning condition influenced model-derived estimates of catchability. Finally, the effect of trawl selectivity on the acoustic-based survey abundance estimate and Gulf of Alaska pollock assessment was evaluated. Survey biomass estimates were overestimated by up to 40 % as abundance of juvenile fish increased and adult abundance decreased. The increase in uncertainty in survey abundance estimates due to trawl selectivity had a measurable impact on the stock assessment, changing model estimates of fishing mortality, spawning biomass and recruitment by more than 10 %. The studies provide new methods for assessing selectivity, catchability and for observing fish behavior in midwater trawls, which can be used to evaluate midwater trawls used in other surveys.

  13. A study of fish and shellfish consumers near Sellafield: assessment of the critical groups including consideration of children

    International Nuclear Information System (INIS)

    A survey of people's consumption rates in 1981 and 1982, of fish and shellfish caught near the British Nuclear Fuels plc (BNFL) Sellafield site is described. Particular emphasis has been given to mollusc eaters and consumption rates of children because of the potentially higher radiation doses they may receive. Appropriate critical groups have been selected for dose assessment purposes using principles recommended by the International Commission on Radiological Protection (ICRP). Methods for consideration of children in critical groups are suggested and a comparison of these methods using the present data shows similar results. Combination of seafood consumption pathways is also considered, and it is shown that a simple additive approach is not excessively conservative. (author)

  14. Fish stomach contents in benthic macroinvertebrate assemblage assessments / Conteúdo estomacal de peixes em avaliações de comunidades de macroinvertebrados bentônicos

    Scientific Electronic Library Online (English)

    TH., Tupinambás; PS., Pompeu; CV., Gandini; RM., Hughes; M., Callisto.

    2015-03-01

    Full Text Available A escolha da ferramenta adequada para avaliar as comunidades de macroinvertebrados bentônicos depende dos objetivos do estudo, das características ambientais e dos recursos financeiros disponíveis. Devido à alta capacidade de forrageamento apresentada por espécies de peixes bentófagas e seu acesso a [...] diversos tipos de habitats, a análise do conteúdo estomacal destas espécies pode ser uma ferramenta útil em avaliações de assembleias de macroinvertebrados bentônicos, especialmente em rios grandes, profundos e rápidos, que são difíceis de amostrar através de métodos convencionais de coleta de sedimento. Nosso objetivo foi comparar as assembleias de macroinvertebrados bentônicos amostrados no sedimento com as assembleias amostradas nos estômagos de espécies de peixes bentófagas. Foram coletados peixes e sedimento em três diferentes tipos de habitats (remanso, praia, corredeira) nos períodos úmido e seco ao longo de um único trecho do rio Grande (bacia do rio Paraná, sudeste do Brasil). O sedimento foi amostrado através de uma draga Petersen (total de 216 dragas) e os peixes através de redes de emalhar (total de 36 amostras). Foram analisados os conteúdos estomacais de três espécies de peixes (Eigenmannia virescens Gymnotiformes, Iheringichthys labrosus Siluriformes; Leporinus amblyrhynchus Characiformes). Chironomidae foi a família dominante em ambos os métodos. A composição taxonômica de macroinvertebrados bentônicos encontrados nos estômagos foi diferente daquela amostrada no sedimento. Os taxa de macroinvertebrados amostrados nos estômagos de E. virescens foram mais correlacionados com os três tipos de habitats do que os taxa obtidos nos estômagos das outras duas espécies. As inclinações das curvas cumulativas, assim como os maiores valores de dispersão média, demonstram que E. virescens possui potencial como ferramenta ecológica para acessar as assembleias de macroinvertebrados bentônicos, assim como os maiores valores de dispersão observados. A família Philopotamidae foi encontrada apenas no estômago de L. amblyrhynchus. Concluímos que através da análise do conteúdo do estômago de peixes é possível acessar importantes características das assembleias bentônicas (p.ex. dispersão, composição taxonômica e diversidade). Esta abordagem é especialmente verdadeira em estudos que utilizam apenas as assembleias de peixes para avaliar e/ou monitorar ecossistemas aquáticos. Desta maneira, esse enfoque pode ser útil, aumentando o conhecimento acerca dos impactos humanos sobre os ecossistemas aquáticos e contribuindo para a utilização de diferentes grupos de bioindicadores. Abstract in english The choice of sampling gears to assess benthic macroinvertebrate communities depends on environmental characteristics, study objectives, and cost effectiveness. Because of the high foraging capacity and diverse habitats and behaviors of benthophagous fishes, their stomach contents may offer a useful [...] sampling tool in studies of benthic macroinvertebrates, especially in large, deep, fast rivers that are difficult to sample with traditional sediment sampling gear. Our objective was to compare the benthic macroinvertebrate communities sampled from sediments with those sampled from fish stomachs. We collected benthic macroinvertebrates and fish from three different habitat types (backwater, beach, riffle) in the wet season, drying season, and dry season along a single reach of the Grande River (Paraná River Basin, southeast Brazil). We sampled sediments through use of a Petersen dredge (total of 216 grabs) and used gill nets to sample fish (total of 36 samples). We analyzed the stomach contents of three commonly occurring benthophagous fish species (Eigenmannia virescens, Iheringichthys labrosus, Leporinus amblyrhynchus). Chironomids dominated in both sampling methods. Macroinvertebrate taxonomic composition and abundances from fish stomachs differed from those from sediment samples, but less so from riffles than from backwater and beach habitats.

  15. Risk assessment of residual DDTs in freshwater and marine fish cultivated around the Pearl River Delta, China.

    Science.gov (United States)

    Leung, S Y; Kwok, C K; Nie, X P; Cheung, K C; Wong, M H

    2010-02-01

    Six species of freshwater fish collected from 10 fishponds in Shunde and Zhongshan, China, four species of marine fishes collected from different mariculture farms [four in Hong Kong (Tung Lung Chau, Ma Wan, Cheung Chau and Kat O) and two in mainland China (Daya Bay and Shenzhen)] together with feed (both trash fish and commercial pellets) and sediment were analyzed for DDTs. Total DDTs in freshwater fish flesh decreased in the order of: carnivores [1742 microg/kg lipid weight (l.w.)] > herbivores (165 microg/kg, l.w.) > omnivores (42.5 microg/kg, l.w.), with the highest concentration detected in mandarin fish (Siniperca chuatsi) (2641 microg/kg, l.w.). For marine fish, snubnose pompano (Trachinotus blochii) and orange-spotted grouper (Epinephelus coioides) collected in Ma Wan contained elevated levels of total DDTs (2590 and 2034 microg/kg l.w., respectively). Trash fish used in both freshwater and marine fish farms contained significantly higher levels (86.5-641 microg/kg l.w.) (p < 0.05) of DDTs than in commercial pellets, but correlations between DDT levels in fish feed and muscle were not significant. The elevated biota-sediment accumulating factor for tilapia (Tilapia mossambicus) (24.1) indicated that accumulation of DDTs from sediment to the fish was evident. It can be concluded that trash fish should not be used for fish culture in order to lower the level of residual DDTs in fish muscle. PMID:19603131

  16. Natural recruitment, density-dependent juvenile survival, and the potential for additive effects of stock enhancement: an experimental evaluation of stocking northern pike (Esox lucius) fry

    DEFF Research Database (Denmark)

    Hühn, Daniel; Lübke, Kay

    2014-01-01

    Density-dependent mortality in young life stages should strongly limit the potential for additive effects caused by stocking of fish sizes that are smaller than size at recruitment into the fishery. Indeed, stocking models have suggested that stocking of fry should not elevate year class strength in self-sustaining stocks. However, limited data based on replicated and controlled experiments are available to support this prediction. We performed a pond experiment (N = 4 per treatment) to compare the stock enhancing outcome of stocking hatchery-reared northern pike (Esox lucius) fry and the natural production of young in self-recruiting pike populations. We also added a treatment where pike fry were stocked into ponds that otherwise did not have pike to mimic the absence of natural recruitment. Fry stocking into self-reproducing stocks did not elevate year class strength over unstocked controls. However, in the absence of competition, year class strength of juveniles in late summer emerging from fry stocking was similar to the production of natural recruits. Overall, we demonstrated the competitive disadvantage of hatchery-reared fry when released into waters already containing natural recruits, the partial replacement of natural recruits by hatchery-reared fry, and the lack of additive effects of stock enhancement in naturally reproducing stocks. A stock-enhancing effect of pike fry stocking may only be expected in the absence of natural recruitment.

  17. Use of Adverse Outcome Pathways for Assessing Effects of the Fungicide Propiconazole on Fish Reproduction

    Science.gov (United States)

    Adverse outcome pathways (AOP) are used to describe the linkage of biological events from a molecular initiating point, to individual-level-endpoints relevant to risk assessment. This study was done to assess toxicity outcomes for the conazole fungicide propiconazole based on a p...

  18. Spatially explicit estimates of stock size, structure and biomass of North Atlantic albacore Tuna (Thunnus alalunga)

    Science.gov (United States)

    Lehodey, P.; Senina, I.; Dragon, A.-C.; Arrizabalaga, H.

    2014-04-01

    The development of the ecosystem approach and models for the management of ocean marine resources requires easy access to standard validated datasets of historical catch data for the main exploited species. They are used to measure the impact of biomass removal by fisheries and to evaluate the models skills, while the use of standard dataset facilitates models inter-comparison. Unlike standard stock assessment models, new state-of-the-art ecosystem models require geo-referenced fishing data with highest possible spatial resolution. This study presents an application to the north Atlantic albacore tuna stock with a careful definition and validation of a spatially explicit fishing dataset prepared from publically available sources (ICCAT) for its use in a spatial ecosystem and population dynamics model (SEAPODYM) to provide the first spatially explicit estimate of albacore density in the North Atlantic by life stage. Density distributions are provided (target="_blank">http://doi.pangaea.de/10.1594/PANGAEA.831499) together with the fishing data used for these estimates target="_blank">http://doi.pangaea.de/10.1594/PANGAEA.830797, target="_blank">http://doi.pangaea.de/10.15 1594/PANGAEA.828168, target="_blank">http://doi.pangaea.de/10.1594/PANGAEA.828170, and target="_blank">http://doi.pangaea.de/10.1594/PANGAEA.828171 (see section Source Data References).

  19. An assessment of fish communities along a piedmont river receiving organic pollution (Aconquija Mountains, Argentina

    Directory of Open Access Journals (Sweden)

    fernandez luis

    2010-08-01

    Full Text Available

    The relationships between fish assemblage structure and environmental variables along a pollution gradient in the Medina River were analyzed over a year in four sampling sites (S1-S4. The river flows in a mountain-plain transition and is affected by several small town wastewater and sugar cane industries effluents. Environmental variables were divided in two sets, hereafter named “pollution” and “natural”. The first set included water quality variables modified by anthropic activities such as D.O., C.O.D, and dissolved ion concentrations. Natural variables included altitude, position, and time of the year. The upstream site (S1 had the lowest species richness and CPUE; but the number of species and density increased downriver (S2-S3. S1 was inhabited by invertivore species (Trichomycterus corduvensis, having low tolerance to environmental conditions and high D.O. requirements. S4 sustained the most tolerant and abundant species (Otocinclus vittatus, Corydoras paleatus, enduring the lowest D.O. and the highest C.O.D. A significant Canonical Correspondence Analysis for natural variables showed a gradient of species composition related to altitude and discharge. Water quality degradation by sugar cane factories and urban development, coupled with natural climatic, topographic and hydrological factors explained a significant amount of spatial and temporal variation in fish community structure (@48%. Natural and pollution variables shared about 15% of total variance. However, pollution variables were not significant after partialling- out the effects of natural variables, but natural variability remained significant after removal of pollution effects. The results suggest that effects of pollution may be just the result of ordination of fish communities along natural spatial and temporal gradients that are positively correlated to pollution gradients.

  20. Comparison of the Limulus amoebocyte lysate test with plate counts and chemical analyses for assessment of the quality of lean fish.

    OpenAIRE

    Sullivan, J. D.; Ellis, P. C.; Lee, R. G.; Combs, W. S.; Watson, S. W.

    1983-01-01

    The quality of lean fish was assessed simply and rapidly with Limulus amoebocyte lysate. The endotoxin levels agreed with aerobic plate counts and chemical indices of spoilage. Correlation between level of endotoxin and level of total volatile bases was found to be highly significant (r = 0.8579; P less than 0.001).

  1. Turbine related fish mortality

    International Nuclear Information System (INIS)

    A literature review was conducted to assess the factors affecting turbine-related fish mortality. The mechanics of fish passage through a turbine is outlined, and various turbine related stresses are described, including pressure and shear effects, hydraulic head, turbine efficiency, and tailwater level. The methodologies used in determining the effects of fish passage are evaluated. The necessity of adequate controls in each test is noted. It is concluded that mortality is the result of several factors such as hardiness of study fish, fish size, concentrations of dissolved gases, and amounts of cavitation. Comparisons between Francis and Kaplan turbines indicate little difference in percent mortality. 27 refs., 5 figs

  2. EFFECTS OF COMMONLY USED COOKING PRACTICES ON TOTAL MERCURY CONCENTRATION IN FISH AND THEIR IMPACT ON EXPOSURE ASSESSMENTS

    Science.gov (United States)

    The effects of cooking practices commonly used by Native Americans on total mercury concentrations in fish were investigated. A preparation factor relating mercury concentrations in fish as prepared for consumption to mercury concentration data as measured in typical environmenta...

  3. The use of FISH chromosome painting for assessment of old doses of ionising radiation

    Energy Technology Data Exchange (ETDEWEB)

    Moquet, J.E.; Edwards, A.A.; Lloyd, D.C.; Hone, P

    2000-07-01

    This paper critically reviews data obtained at NRPB concerning the use of FISH chromosome painting for biological dosimetry purposes. Most of the work has aimed at investigating how persistent translocations are with time and this has influenced the choice of aberration which should be used to set up calibration curves. Chromosomes 2, 3 and 5 and all centromeres were painted and the observed translocations classified as one-way or two-way. Two-way translocations appear stable with time whereas one-way translocations decrease by possibly a factor of 2. Since two-way translocations outnumber one-way translocation by about 1.5 to 1, total translocation yields reduce by only about 20% with time. To make use of total translocation yield for biological dosimetry purposes, calibration curves should be constructed from the measurement of translocations in stable cells only. (author)

  4. Cytogenetic biomarkers for the assessment of the influence of pollution on natural fish populations.

    Science.gov (United States)

    Pak, I V; Moiseenko, T I; Sergienko, L L; Chitaeva, E A

    2012-11-01

    Cytogenetic analysis methods were used to study the developing embryos of the following four Coregonidae species: Coregonus peled (Gmelin), Coregonus lavaretus (Gmelin), Coregonus nasus (Pallas) and Coregonus muksun (Pallas). Spawners of these species were selected from rivers and lakes of the Tyumen region (Russia) with different levels of pollution. The variability of the chromosomal aberration rate was analyzed during a monitoring period of more than 20 years. The level of chromosomal mutability in the embryonic cells of these fishes was found to have steadily increased during the observation period (1989-2011). The higher frequency of chromosomal mutations at different stages of embryogenesis in broad whitefish, C. nasus (Pallas), was noted in comparison with other species. The possible use of chromosomal mutation frequency as an indicator (biomarker) to characterize the state of a population is discussed. PMID:22995782

  5. Inter-observer reproducibility of HER2 immunohistochemical assessment and concordance with fluorescent in situ hybridization (FISH: pathologist assessment compared to quantitative image analysis

    Directory of Open Access Journals (Sweden)

    Carrier Melinda

    2009-05-01

    Full Text Available Abstract Background In breast cancer patients, HER2 overexpression is routinely assessed by immunohistochemistry (IHC and equivocal cases are subject to fluorescent in situ hybridization (FISH. Our study compares HER2 scoring by histopathologists with automated quantitation of staining, and determines the concordance of IHC scores with FISH results. Methods A tissue microarray was constructed from 1,212 invasive breast carcinoma cases with linked treatment and outcome information. IHC slides were semi-quantitatively scored by two independent pathologists on a range of 0 to 3+, and also analyzed with an Ariol automated system by two operators. 616 cases were scorable by both IHC and FISH. Results Using data from unequivocal positive (3+ or negative (0, 1+ results, both visual and automated scores were highly consistent: there was excellent concordance between two pathologists (kappa = 1.000, 95% CI: 1-1, between two machines (kappa = 1.000, 95% CI: 1-1, and between both visual and both machine scores (kappa = 0.898, 95% CI: 0.775–0.979. Two pathologists successfully distinguished negative, positive and equivocal cases (kappa = 0.929, 95% CI: 0.909–0.946, with excellent agreement with machine 1 scores (kappa = 0.835, 95% CI: 0.806–0.862; kappa = 0.837, 95% CI: 0.81–0.862, and good agreement with machine 2 scores (kappa = 0.698, 95% CI: 0.6723–0.723; kappa = 0.709, 95% CI: 0.684–0.732, whereas the two machines showed good agreement (kappa = 0.806, 95% CI: 0.785–0.826. When comparing categorized IHC scores and FISH results, the agreement was excellent for visual 1 (kappa = 0.814, 95% CI: 0.768–0.856, good for visual 2 (kappa = 0.763, 95% CI: 0.712–0.81 and machine 1 (kappa = 0.665, 95% CI: 0.609–0.718, and moderate for machine 2 (kappa = 0.535, 95% CI: 0.485–0.584. Conclusion A fully automated image analysis system run by an experienced operator can provide results consistent with visual HER2 scoring. Further development of such systems will likely improve the accuracy of detection and categorization of membranous staining, making this technique suitable for use in quality assurance programs and eventually in clinical practice.

  6. An assessment of fish communities along a piedmont river receiving organic pollution (Aconquija Mountains, Argentina)

    International Nuclear Information System (INIS)

    The relationships between fish assemblage structure and environmental variables along a pollution gradient in the Medina River were analyzed over a year in four sampling sites (S1-S4). The river flows in a mountain-plain transition and is affected by several small town waste water and sugar cane industries effluents. Environmental variables were divided in two sets, hereafter named pollution and natural. The first set included water quality variables modified by anthropogenic activities such as D.O. (Dissolved Oxygen), C.O.D. (Chemical Demand Oxygen), and dissolved ion concentrations. Natural variables included altitude, position, and time of the year. The upstream site (S1) had the lowest species richness and C.P.U.E. (Catch per Unit of Effort). The number of species and density increased down river (S2-S3). S1 was inhabited by an invertivore species (Trichomycterus corduvensis) that has low tolerance to adverse environmental conditions, and has high D.O. requirements. S4 sustained the most tolerant and abundant species (Otocinclus vittatus, Corydoras paleatus), which endure the lowest D.O. and the highest C.O.D. a Canonical Correspondence Analysis for natural variables showed a significant gradient of species composition related to altitude and discharge. Water quality degradation by sugar cane factories and urban development, coupled with natural climatic, topographic and hydrological factors explained a significant amount of spatial and temporal variation in fish community structure (48%). natural and pollution variables shared about 15% of total variance. however, pollution variables were not significant after partitioning out the effects of natural variables. Natural variability remained significant after removal of pollution effects.

  7. Assessment of Heavy Metals in Water, Fish and Sediments from UKE Stream, Nasarawa State, Nigeria

    Directory of Open Access Journals (Sweden)

    O. D. Opaluwa

    2012-12-01

    Full Text Available The levels of lead, zinc, copper, iron, manganese, cadmium and mercury were determined in various body parts of two species of catfish; Clarias gariepinus and Synodontis schall, water and sediment samples from Uke stream using atomic absorption spectrophotometer (AAS method. The results obtained showed that iron (Fe had the highest concentration with average of 8.78 mg/g and 7.51 mg/l in sediment and water respectively followed by Zn with 4.79 mg/g (sediment and 3.19 mg/l (water while Cd had the lowest concentration of 0.035 mg/g and 0.023 mg/l in the sediment and water respectively. In the two fish species, zinc (0.17 – 3.25 mg/g was the most highly concentrated in the various matrices while lead (0.011 – 0.031mg/g was the lowest. Metal levels in the various body parts of the two species of fish studied were found to be more concentrated in either, the head, gills or the intestine. In both species zinc had the widest variability while lead was the least. The metal levels determined in water and sediment are all above the tolerable limits recommended by regulatory bodies which is an indication that this ecosystem is contaminated with heavy metals which would eventually end up in the food chain. The metals determined in various body parts of two species of catfish were below deleterious level; however there is the need for regular monitoring of the heavy metal load in this water body and the aquatic organisms in there because of the long term effects.

  8. Application of fuzzy expert system for the evaluation of fish habitat quality and instream flow assessment

    International Nuclear Information System (INIS)

    Fuzzy logic was used to estimate the habitat suitability indices for the spawning and parr rearing stages of Atlantic salmon located in the Romaine River in northeastern Quebec. Fuzzy sets and fuzzy preference rules were developed by experienced fish biologists and technicians. The fuzzy suitability indices were then used to estimate the weighted usable area (WUA) for a range of flows. Fuzzy rule-based approaches allow for the numerical processing of qualitative knowledge of experts about fish habitat, and can consider multivariate effects of variables without the assumption of independence of input parameters. Habitat suitability and inputs were subdivided into different classes. Velocity and substrate diameters were used as input parameters and were defined by 3 linguistic variables and fuzzy sets corresponding to a combination of simple linear functions for a total of 27 rules. Substrates were also measured in the field. A hydraulic model was used to calculate water depth and velocity for different flow values. The fuzzy sets of the input variables were weighted with degrees of fulfilment and combined into a final fuzzy set. The final fuzzy set was transformed back into a standardized crisp number to describe the habitat suitability index. A sensitivity analysis of the rules indicated that the results were highly dependent on the way in which the rules were defined. Results of the study suggested that biologists using the method may wish to revise sensitive rules aethod may wish to revise sensitive rules and investigate the implications of rules in order to define the range of values of the input variables. It was concluded that future research will compare the results of the fuzzy models developed based on contributions from experts in spawning and parr habitats. 19 refs., 1 tab., 4 figs

  9. Accumulation of Heavy Metals in Freshwater Fish-An Assessment of Toxic Interactions with Calcium

    Directory of Open Access Journals (Sweden)

    Lopa Ghosh

    2006-01-01

    Full Text Available The present investigation deals with the interaction between accumulation of waterborne lead, cadmium and chromium with different calcium concentration (1.0, 2.0, 3.0 and 4.0 mM L-1 in Cirrhina mrigala fingerlings in the laboratory. There was no mortality occurred in metal alone and metal treated with calcium. At the beginning there was no significant differences observed between Pb, Cd and Cr alone and combination with calcium in muscle as well as whole body at lower calcium concentration, but with increasing exposure period marked differences were observed. In muscle tissue accumulations was very much lower compared to whole body and significantly lower below human consumption level. In binary mixtures of Pb, Cd and Cr with calcium, the calcium compound was found to consistently reduce the toxic effect as well as accumulation of Pb, Cd and Cr compounds. Increased Ca levels showed lower transfer of Pb, Cd and Cr from water to the gills which resulted slower transfer of metal from the gills to the blood indicated lower accumulation rates in muscle tissue compared to metal without Ca. An increase in calcium concentration of approximately 3 and 4 mM L-1 resulted in a 46 and 54% decrease of Pb uptake, 55 and 58% of Cd and 41 and 53% of Cr uptake in whole fish at 28 days exposure period. There is an inverse relationship between calcium concentration in the water and metal uptake in whole body, muscle as well as gills of the Cirrhina mrigala. Calcium has strong antagonistic effect on Pb, Cd and Cr accumulation and toxicity. Predicted and experimental values of Pb, Cd and Cr concentration in fish body treated with calcium verified in terms of root mean square percent deviation and correlation coefficient which exhibit fair agreement.

  10. Fishing in dangerous waters: Remarks on a controversial appeal to spawner-recruit theory for long-term impact assessment

    International Nuclear Information System (INIS)

    In the Hudson River power plant case, the defending utility companies appealed to the practices of commercial fishery managers as precedent for their own uses of spawner-recruit models in forecasting the effects on stock abundances of long-term water withdrawals by the power plants. In contrast to this perception of spawner-recruit models as commonly accepted instruments of fishery management, the present survey of managers and regulatory agencies revealed instead a universal rejection of such models. The inadequacies of spawner-recruit models were attributed variously to the effects of environmental uncertainty, to imperfect knowledge of population regulation, and to the lack of sufficient biological meaning in the models themselves. In general, impact assessment little resembles fishery regulation because the options and privileges commonly exercised by a fishery manager are closed to impact management. In either case, long-term forecasting remains unreliable due to the problem, as yet unsolved, of predicting reproduction and recruitment in natural populations. 21 refs., 1 fig

  11. Addressing challenges in single species assessments via a simple state-space assessment model.

    DEFF Research Database (Denmark)

    Nielsen, Anders

    Single-species and age-structured fish stock assessments still remains the main tool for managing fish stocks. A simple state-space assessment model is presented as an alternative to (semi) deterministic procedures and the full parametric statistical catch at age models. It offers a solution to some of the key challenges of these models. Compared to the deterministic procedures it solves a list of problems originating from falsely assuming that age classified catches are known without errors and allows quantification of uncertainties of estimated quantities of interest. Compared to full parametric statistical catch at age models the state-space assessment model avoids the problem of fishing mortality being restricted to a parametric structure (e.g. multiplicative), and problems related to having a high number of model parameters compared to the number of observations. The main criticism of state-space assessment models is that they tend to be more conservative (react slower to changes) than the alternatives. A solution to this criticism is offered by introducing a mixture distribution for the transitions steps. The model presented is used for several commercially important stocks at the International Council for the Exploration of the Sea

  12. Elements of stock market analysis

    OpenAIRE

    Suciu, T.

    2013-01-01

    The paper represents a starting point in the presentation of the two types of stock/market analysis: the fundamental analysis and the technical analysis. The fundamental analysis consist in the assessment of the financial and economic status of the company together with the context and macroeconomic environment where it activates. The technical analysis deals with the demand and supply of securities and the evolution of their trend on the market, using a range of graphics and charts to il...

  13. Population structure and stock assessment of Hoplias malabaricus (Characiformes: Erythrinidae caught by artisanal fishermen in river-reservoir transition area in Brazil

    Directory of Open Access Journals (Sweden)

    José Luís Costa Novaes

    2011-03-01

    Full Text Available Hoplias malabaricus is a viable economic alternative for artisanal fishermen who used to live on the banks of rivers that now are dammed in Brazil. In order to preserve the species’ natural stock, the main objectives of this study were to obtain bio-ecological information on this species reproduction, feeding dynamics and the description of the extent of its exploitation in river-reservoir transition area in Brazil. This way, from January to December 2005, different fishery catches were made with gill nets by artisanal fishermen, and a total of 426 individual H. malabaricus were obtained and sampled. From each specimen, the following biometric and biological data were analyzed: standard length, total weight, stomach contents, reproductive data such as sex, weight and gonadal maturation stage; with these data we estimated sex ratio, reproduction period and feeding habits. To assess growth parameters and infer on the degree of exploitation, the standard length frequency data were analysed using the FISAT (ELEFAN I computer program. Data revealed a sex ratio of 0.8:1 (M:F, that reproduction occurs all year around, being more intense during spring and summer; it also showed that H. malabaricus is piscivorous. The growth parameters and mortality were estimated at: L?=35.18cm, k=0.32 year, longevity=9.3 years, Z=1.25 years, M=0.63 year and F=0.62 year. The weight-length relationship was: ln Wt=-3.1663+2.7456 ln Lp. The yield-per-recruit analysis produced the following values: E=0.496, Emax=0.916, E0.1=0.701 and E0.5=0.378. Overall, our data suggest that the stock of H. malabaricus is not yet overfished in the studied area. Rev. Biol. Trop. 59 (1: 71-83. Epub 2011 March 01.Hoplias malabaricus representa una alternativa económica viable para los pescadores artesanales que viven a la orilla de ríos que actualmente cuentan con represas en Brasil. El objeto del presente estudio fue evaluar la dinámica de la reproducción, alimentación, crecimiento y nivel de explotación de la especie nativa Hoplias malabaricus, capturada por pescadores artesanales en la zona de transición entre el río Paranapanema y el Embalse de Jurumirim. En 2005, los especimenes de H. malabaricus se obtuvieron utilizando redes agalleras de forma mensual y se registraron las siguientes características y datos biológicos de cada uno: longitud estándar, peso corporal, sexo, estadio reproductivo, peso de las gónadas y contenido estomacal. Estos datos fueron utilizados para estimar la proporción sexual, el período reproductivo y los hábitos alimenticios. Para evaluar los parámetros de crecimiento y el grado de explotación, los datos de frecuencia de la longitud estándar fueron analizados utilizando el software FISAT a través de la rutina ELEFAN I. Según los resultados obtenidos, la proporción sexual fue de 0.8:1 (macho:hembra; la reproducción fue observada durante todo el año, pero sobre todo en la primavera y el verano. El hábito alimentario fue piscívoro. Los parámetros de crecimiento y mortalidad fueron estimados en: L?=35.18cm, k=0.32/año; longevidad= 9.3, Z=1.25/año, M=0.63/año y F=0.62/año. La relación longitud-peso fue: Wt=-3.1663+2.7456lnLp. El análisis de rendimiento por recluta estimó los siguientes valores: E=0.496, Emax=0.916, E0.1=0.701 y E0.5=0.378. Puede concluirse que la población de H. malabaricus en la región estudiada todavía no está siendo altamente explotada.

  14. Population structure and stock assessment of Hoplias malabaricus (Characiformes: Erythrinidae) caught by artisanal fishermen in river-reservoir transition area in Brazil

    Scientific Electronic Library Online (English)

    José Luís, Costa Novaes; Edmir Daniel, Carvalho.

    2011-03-01

    Full Text Available Hoplias malabaricus representa una alternativa económica viable para los pescadores artesanales que viven a la orilla de ríos que actualmente cuentan con represas en Brasil. El objeto del presente estudio fue evaluar la dinámica de la reproducción, alimentación, crecimiento y nivel de explotación de [...] la especie nativa Hoplias malabaricus, capturada por pescadores artesanales en la zona de transición entre el río Paranapanema y el Embalse de Jurumirim. En 2005, los especimenes de H. malabaricus se obtuvieron utilizando redes agalleras de forma mensual y se registraron las siguientes características y datos biológicos de cada uno: longitud estándar, peso corporal, sexo, estadio reproductivo, peso de las gónadas y contenido estomacal. Estos datos fueron utilizados para estimar la proporción sexual, el período reproductivo y los hábitos alimenticios. Para evaluar los parámetros de crecimiento y el grado de explotación, los datos de frecuencia de la longitud estándar fueron analizados utilizando el software FISAT a través de la rutina ELEFAN I. Según los resultados obtenidos, la proporción sexual fue de 0.8:1 (macho:hembra); la reproducción fue observada durante todo el año, pero sobre todo en la primavera y el verano. El hábito alimentario fue piscívoro. Los parámetros de crecimiento y mortalidad fueron estimados en: L?=35.18cm, k=0.32/año; longevidad= 9.3, Z=1.25/año, M=0.63/año y F=0.62/año. La relación longitud-peso fue: Wt=-3.1663+2.7456lnLp. El análisis de rendimiento por recluta estimó los siguientes valores: E=0.496, Emax=0.916, E0.1=0.701 y E0.5=0.378. Puede concluirse que la población de H. malabaricus en la región estudiada todavía no está siendo altamente explotada. Abstract in english Hoplias malabaricus is a viable economic alternative for artisanal fishermen who used to live on the banks of rivers that now are dammed in Brazil. In order to preserve the species’ natural stock, the main objectives of this study were to obtain bio-ecological information on this species reproductio [...] n, feeding dynamics and the description of the extent of its exploitation in river-reservoir transition area in Brazil. This way, from January to December 2005, different fishery catches were made with gill nets by artisanal fishermen, and a total of 426 individual H. malabaricus were obtained and sampled. From each specimen, the following biometric and biological data were analyzed: standard length, total weight, stomach contents, reproductive data such as sex, weight and gonadal maturation stage; with these data we estimated sex ratio, reproduction period and feeding habits. To assess growth parameters and infer on the degree of exploitation, the standard length frequency data were analysed using the FISAT (ELEFAN I) computer program. Data revealed a sex ratio of 0.8:1 (M:F), that reproduction occurs all year around, being more intense during spring and summer; it also showed that H. malabaricus is piscivorous. The growth parameters and mortality were estimated at: L?=35.18cm, k=0.32 year, longevity=9.3 years, Z=1.25 years, M=0.63 year and F=0.62 year. The weight-length relationship was: ln Wt=-3.1663+2.7456 ln Lp. The yield-per-recruit analysis produced the following values: E=0.496, Emax=0.916, E0.1=0.701 and E0.5=0.378. Overall, our data suggest that the stock of H. malabaricus is not yet overfished in the studied area. Rev. Biol. Trop. 59 (1): 71-83. Epub 2011 March 01.

  15. Biomarkers responses in fish (Atherinella brasiliensis) of paranaguá bay, southern Brazil, for assessment of pollutant effects

    Scientific Electronic Library Online (English)

    Ciro Alberto de Oliveira, Ribeiro; Alberto, Katsumiti; Patrícia, França; Jocieli, Maschio; Eliandra, Zandoná; Marta Margarete, Cestari; Thainá, Vicari; Hélène, Roche; Helena Cristina Silva de, Assis; Francisco, Filipak Neto.

    2013-03-01

    Full Text Available A Baia de Paranaguá é um complexo estuarino localizado no sul do Brasil constituído de três áreas de proteção ambiental listadas pela UNESCO. Historicamente, o estuário tem sido afetado por atividade urbana, industrial, agricultura e portuária, e eventualmente por acidentes. Particularmente a explos [...] ão do navio Chileno Vicuña em dezembro de 2004 derramou metanol, óleo cru e combustível atingindo áreas protegidas e não protegidas. O presente estudo tem por objetivo investigar a poluição em organismos aquáticos. Cento e vinte indivíduos adultos do peixe Atherinella brasiliensis foram coletados em quatro diferentes pontos de coleta no estuário de Paranaguá, partindo do porto até o oceano aberto nos períodos de verão, inverno e primavera de 2005. Os índices somáticos, parâmetros químicos, enzimáticos, genéticos e morfológicos foram considerados. As análises histopatológicas demonstraram expressiva incidência de patologia no fígado e nas brânquias algumas vezes corroboradas pelas alterações bioquímicas. Danos genéticos e anormalidades genéticas também foram observados. As análises químicas na bile mostraram uma contínua biodisponibilidade de hidrocarbonetos policíclicos aromáticos para os organismos aquáticos. Os dados obtidos indicam que a qualidade da água e a saúde dos peixes encontram-se bastante comprometidos no estuário de Paranaguá. Abstract in english Paranaguá bay is a complex estuary located in southern Brazil containing three protected areas listed by UNESCO. Historically, the estuary has been affected by urban, industrial, agricultural and harbor activities, and occasional accidents. Specifically, the explosion of the Chilean ship Vicuña in D [...] ecember 2004 spilled methanol and crude and fuel oils which affected both protected and non-protected areas. The present study sought to investigate the pollution threat to aquatic organisms in order to evaluate the potential effects of pollutants. One hundred and twenty adult fish Atherinella brasiliensis were collected from different sites within Paranaguá estuary, including the harbor and open ocean, during summer, autumn and winter of 2005. Among the biomarkers, the somatic index, chemical analysis of bile, biochemical, genetic and morphological parameters were considered. Chemical analysis of bile showed a continuous bioavailability of polycyclic aromatic hydrocarbons (PAHs) according to proximity to the harbor site. The histopathological findings have demonstrated aconsiderable incidence of severe pathologies in the liver and gills, corroborated by biochemical disturbances and genetic damage. These findings indicate that more studies are necessary to evaluate both water quality and fish health so as to permit a better analysis of the impact of pollution in Paranaguá estuary.

  16. Experimental assessment of the effects of a Neotropical nocturnal piscivore on juvenile native and invasive fishes

    Directory of Open Access Journals (Sweden)

    Alejandra F. G. N. Santos

    2012-01-01

    Full Text Available We experimentally examined the predator-prey relationships between juvenile spotted sorubim Pseudoplastystoma corruscans and young-of-the-year invasive and native fish species of the Paraná River basin, Brazil. Three invasive (peacock bass Cichla piquiti, Nile tilapia Oreochromis niloticus, and channel catfish Ictalurus punctatus and two native (yellowtail tetra Astyanax altiparanae and streaked prochilod Prochilodus lineatus fish species were offered as prey to P. corruscans in 300 L aquaria with three habitat complexity treatments (0%, 50% and 100% structure-covered. Prey survival was variable through time and among species (C. piquiti A relação predador-presa entre juvenis de pintado Pseudoplatystoma corruscans (piscívoro nativo e jovens do ano de espécies nativas e invasoras de peixes da bacia do rio Paraná, Brasil, foi testada experimentalmente. Três espécies de peixe invasoras (o tucunaré Cichla piquiti, a tilápia do Nilo Oreochromis niloticus e o bagre do canal Ictalurus punctatus e duas nativas (o lambari do rabo amarelo Astyanax altiparanae e o curimbatá Prochilodus lineatus foram oferecidas como presa para P. corruscans em microcosmos, com três tratamentos de complexidade de habitat (0%, 50% e 100% de cobertura por estruturas submersas. A sobrevivência de presas variou ao longo do tempo e entre espécies (C. piquiti < O. niloticus < A. altiparanae < P. lineatus < I. punctatus, sendo governada, em grande parte, por diferenças espécies-específicas no comportamento das presas, mas também pelo tamanho e defesas morfológicas das mesmas. A complexidade de habitat não afetou diretamente a piscivoria de P. corruscans, mas, na presença do predador, algumas espécies-presa alteraram seu comportamento quanto ao uso de micro-habitat e grau de agregação entre os níveis de complexidade de habitat. Pseudoplatystoma corruscans predou preferencialmente sobre os indivíduos menores das espécies invasoras que apresentaram estruturas morfológicas defensivas pouco desenvolvidas e que não formavam cardume. Em geral, os resultados obtidos contrastam com os de um experimento análogo, no qual foi usado um piscívoro diurno, sugerindo que piscívoros noturnos predam preferencialmente sobre espécies de peixes diferentes (de hábitos mais diurnos e que são menos afetados pela complexidade estrutural de habitats. Os resultados obtidos sugerem que a recuperação de populações nativas de P. corruscans poderia contribuir para o controle de algumas espécies de peixes introduzidas no rio Paraná, especialmente C. piquiti e O. niloticus, dos quais se espera que o cuidado parental seja reduzido ou nulo à noite.

  17. Biomarkers responses in fish (Atherinella brasiliensis of paranaguá bay, southern Brazil, for assessment of pollutant effects

    Directory of Open Access Journals (Sweden)

    Ciro Alberto de Oliveira Ribeiro

    2013-03-01

    Full Text Available Paranaguá bay is a complex estuary located in southern Brazil containing three protected areas listed by UNESCO. Historically, the estuary has b