WorldWideScience
1

Annual trends in catchability and fish stock assessments  

OpenAIRE

A key assumption of many fish stock assessment models is that catchability is constant over time. We assume here that trends in catchability may occur through fishing power creeping. The tuning fleets, which are prone to fishing power development, may be identified using the "Hybrid" method. A range of catchability trends, including values derived from the "Hybrid" method, is then implemented to standardise the fishing effort of some tuning fleets used in the stock assessments performed by XS...

Marchal, P.; Ulrich, C.; Korsbrekke, K.; Pastoors, M. A.; Rackham, B.

2003-01-01

2

Annual trends in catchability and fish stock assessments  

DEFF Research Database (Denmark)

A key assumption of many fish stock assessment models is that catchability is constant over time. We assume here that trends in catchability may occur through fishing power creeping. The tuning fleets, which are prone to fishing power development, may be identified using the "Hybrid" method. A range of catchability trends, including values derived from the "Hybrid" method, is then implemented to standardise the fishing effort of some tuning fleets used in the stock assessments performed by XSA (eXtended Survivors Analysis). Stocks being assessed are the North Sea cod, saithe, plaice and sole. The performances of the new and traditional XSA assessments are compared using criteria based on the precision of catchability estimates, stationarity of Log-catchability residuals and retrospective patterns relative to fishing mortality, spawning stock biomass and recruitment estimates. The performances of the North Sea cod, plaice and sole assessments could be enhanced by accounting for an overall annual increase in the catchability of some of the tuning fleets. No significant trends could be detected in the catchability of the tuning fleets relative to the assessment of the North Sea saithe. By contrast with the traditional assessment, the spawning biomass of cod is expected not to have increased between 1997 and 1998, while the fishing mortality of sole is expected to have increased over the same period.

Marchal, P.; Ulrich, Clara

2003-01-01

3

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

OpenAIRE

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...

ICES

1988-01-01

4

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

DEFF Research Database (Denmark)

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.

Kjems-Nielsen, Henrik; Larsen, Lena Inger

2006-01-01

5

STANDING STOCK OF DEMERSAL FISH ASSESSMENT IN SOUTHERN PART OF SOUTH CHINA SEA  

OpenAIRE

Demersal fish assessment is prerequisite for optimal fishing. In this paper, standing stock of demersal fish in southern part of South China Sea was determined by swept area method. The research was carried out by research vessel SEAFDEC on 18 – 30 June 2005. The catch of fish was obtained from 18 in-situ station use bottom trawl. There were found 154 species and 38 563 individual, respectively. The Leiognathus bindus was dominant species at fishing operation. Catch per unit area (CPUA) was...

Masrikat, Julius A. N.

2012-01-01

6

Biased stock assessment when using multiple, hardly overlapping, tuning series if fishing trends vary spatially  

OpenAIRE

Fishing-effort distributions are subject to change, for autonomous reasons and in response to management regulations. Ignoring such changes in a stock-assessment procedure may lead to a biased perception. We simulated a stock distributed over two regions with inter-regional migration and different trends in exploitation, and tested the performance of Extended Survivors Analysis (XSA) and a statistical catch-at-age model in terms of bias, when spatially restricted tuning series were applied. I...

Kraak, S. B. M.; Daan, N.; Pastoors, M. A.

2009-01-01

7

FishFrame : Fisheries and stock assessment data framework  

DEFF Research Database (Denmark)

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.

Degel, Henrik; Jansen, Teunis

2006-01-01

8

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

Directory of Open Access Journals (Sweden)

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

Bonar P. Pasaribu

2004-01-01

9

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

Scientific Electronic Library Online (English)

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

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

10

Precisely wrong or vaguely right: simulations of noisy discard data and trends in fishing effort being included in the stock assessment of North Sea plaice  

OpenAIRE

ICES stock assessments of North Sea plaice are routinely carried out with eXtended Survivors Analysis (XSA), based on landings and survey data. Recently, the assessments included data on discarded young fish, sampled with high variance. Fishing effort has been declining since the mid-1990s, so conditioning the estimated fishing mortality (F) on the recent past could introduce bias into the perceived stock size. Simulated populations with North Sea plaice-like characteristics are used to explo...

Dickey-collas, M.; Pastoors, M. A.; Keeken, O. A.

2007-01-01

11

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

DEFF Research Database (Denmark)

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

Möllmann, Christian; Lindegren, Martin

2014-01-01

12

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

OpenAIRE

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...

Vinther, Morten; Eero, Margit

2013-01-01

13

Fisheries resources management of crucian carp based on assessment of fish stock and potential yield in the mid-upper system of Seomjin River  

Directory of Open Access Journals (Sweden)

Full Text Available This study was undertaken to suggest an effective fisheries resources management system by using stock assessment and potential yield analyses of crucian carp population in the mid-upper system of the Seomjin River. Fieldwork was conducted seasonally from 2008 to 2009 in the mid-upper system of the Seomjin River. The stock assessment was carried out by the swept area method and the potential yield was estimated by improved fisheries resource potential estimation system based on the Allowable Biological Catch. Also, the yield-per-recruit analysis was used to review the efficient management implication of the resource, Carassius auratus. As a result, the age at first capture (tc was estimated as 1.468 year, converted body length (BL was 10.8 cm. Meaning the current fishing intensities, the instantaneous coefficient of fishing mortality (F was 0.067 year-1, and the yield-per-recruit analysis showed that the current yield per recruit was estimated to be 15.999 g with F and tc. The instantaneous rate of fishing mortality that provides for Allowable Biological Catch (FABC based on the current tc and F was estimated as 0.618 year-1. Therefore, the optimum fishing intensities could be achieved at the higher fishing intensity for Carassius auratus. The calculated annual stock of C. auratus was estimated as 7,608 kg, and the potential yield was estimated as 343 kg with tc and F at the fixed current level. Using yield-per-recruit analysis, if F and tc were set at 0.618 year-1 and 2 year, the yield per recruit and total allowable catch would be predicted to increase to 62 g and 2,531 kg by about 3.9 times and 7.3 times, respectively.

Hui Seong Ryu

2014-12-01

14

Influence of fish behaviour on fish stock abundance estimations  

OpenAIRE

A new methodolgy is proposed for studying fish school behaviour, allowing to quantify its influence on stock abundance estimations. Observations are collected in open sea or inside a large net set in shallow waters. Preliminary results concerning fish reactions show a modification of the school structure under a research vessel using acoustic devices for abundance measurements. The school structure, even when the fish is not disturbed, shows an irregular density distribution in opposition to ...

Fre?on, Pierre; Gerlotto, Franc?ois

1988-01-01

15

Catch, stock elasticity and an implicit index of fishing effort  

OpenAIRE

Economists are interested in the relationship between fishing effort and stock size, and how these impacts catch levels. The interest lies in the stock elasticity where it is thought that for pelagic fish species it is close to zero and for demersal fish stocks closer to one. We statistically model and estimate the relationship between stock size and catch for two species, Northeast Arctic cod and saithe. In doing so we are able to recover estimates of stock elasticity but also estimates of c...

Ekerhovd, Nils-arne; Gordon, Daniel V.

2013-01-01

16

Intelligent Fish Freshness Assessment  

OpenAIRE

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...

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

2008-01-01

17

Needs assessment: taking stock.  

Science.gov (United States)

In 1994, the Scottish Needs Assessment Programme (SNAP) carried out a stocktaking review of all needs assessment reports in 14 topic areas produced in Scotland on the previous three years. National needs assessment documents from England in the relevant topic areas were also reviewed. The review identified two particular points for comment. First, in respect of content, the definition of need as "the ability to benefit'-while appropriate for NHS purchasing- must be balanced by a greater emphasis on the wider concerns for the public's health. At the same time, relevant economic and costing information should be incorporated. Secondly, the process of information collation for purchasing could be made more efficient. Closer links between clinical experts and public health specialists would ensure assessments based on timely opportunities for change. National reviews should provide generally applicable intelligence and comparative analyses; short local reports can then focus on local quantification and priority setting. PMID:8655295

Kelly, H; Russell, E M; Stewart, S; McEwen, J

1996-03-01

18

Benefits of threshold strategies and age-selective harvesting in a fluctuating fish stock of Norwegian spring spawning herring Clupea harengus  

OpenAIRE

The current state of the world’s fisheries resources requires further investigation into the means and methods for sustainable use of fish stocks. In this study, I assess the performance of different harvesting strategies on a population model developed for Norwegian spring spawning herring Clupea harengus, a stock historically known as one of the largest and most valuable fish stocks in the world. This stock is further characterized by strong long-term fluctuations in stock size, which con...

Enberg, Katja

2005-01-01

19

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)

20

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

Science.gov (United States)

...Fund. CDFG has been rearing and stocking fish...continued that mandate by rearing and stocking both...throughout the State, rearing 6 trout species and 3 salmon species. Trout hatcheries...freshwater angling opportunities and recreation...

2010-02-05

21

Breathing life into fisheries stock assessments with citizen science.  

Science.gov (United States)

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

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

2014-01-01

22

Limits to the reliability of size-based fishing status estimation for data-poor stocks  

DEFF Research Database (Denmark)

For stocks which are considered “data-poor” no knowledge exist about growth, mortality or recruitment. The only available information is from catches. Here we examine the ability to assess the level of exploitation of a data-poor stock based only on information of the size of individuals in catches. The model is a formulation of the classic Beverton–Holt theory in terms of size where stock parameters describing growth, natural mortality, recruitment, etc. are determined from life-history invariants. A simulation study was used to compare the reliability of assessments performed under different information availability scenarios, from data-limited, where none of the parameters are known beforehand, to different degrees of information availability cases where one or more parameters are known. If no parameters are known it is possible to correctly assess whether the fishing mortality is below Fmsy in more than 60% of the cases, and almost always correctly assess whether a stock is subject to overfishing. Adding information about age, i.e., assuming that growth rate and asymptotic size are known, does not improve the estimation. Only knowledge of the ratio between mortality and growth led to a considerable improvement in the assessment. Overall, the simulation study demonstrates that it may be possible to classify a data-poor stock as undergoing over- or under-fishing, while the exact status, i.e., how much the fishing mortality is above or below Fmsy, can only be assessed with a substantial uncertainty. Limitations of the approach are discussed

Kokkalis, Alexandros; Thygesen, Uffe HØgsbro

2014-01-01

23

77 FR 3450 - Guidelines for Assessing Marine Mammal Stocks  

Science.gov (United States)

...Guidelines for Preparing the Stock Assessment Reports (Appendix IV...or serious injury occurs. Assessment of very small stocks: The...very well could be biased. Assessment of small endangered stocks...Apportioning PBR across feeding aggregations,...

2012-01-24

24

SPAM (Sex-Structured Pandalus Assessment Model): a stock assessment model for Pandalus stocks  

OpenAIRE

Despite the economic importance of Pandalus shrimp fisheries, few analytical tools have been developed to assess their stocks, and traditional stock assessment models are not appropriate because of biological specificities of Pandalus species. In this context, we propose SPAM (Sex-Structured Pandalus Assessment Model), a model dedicated to protandric hermaphrodite pandalids stock assessment. Pandalids are difficult to assess because the cues affecting sex change, size at recruitment, and mort...

Drouineau, H.; Savard, L.; Desgagne?s, M.; Duplisea, D.

2012-01-01

25

Intelligent Fish Freshness Assessment  

Directory of Open Access Journals (Sweden)

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%.

Deena Benjamin

2008-04-01

26

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

DEFF Research Database (Denmark)

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.

Cardinale, M.; Dörner, H.

2013-01-01

27

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)

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.

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

28

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

OpenAIRE

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...

Ratna Purwaningsih; Sjarief Widjaja; Sri Gunani Partiwi

2011-01-01

29

An assessment of NAFO roughhead grenadier Subarea 2 and 3 stock  

OpenAIRE

The aim of this paper is to present the status of NAFO roughhead grenadier Subarea 2 and 3 stock based on different assessments models using all the available information. Different assessment methods have been applied based on the data available: Extended Survivors Analysis, a Stock-Production Model Incorporating Covariates (ASPIC) and a qualitative assessment based on survey and fishery information. XSA results are considered uncertainties due to the low Fishing mortality estimated compa...

Gonza?lez Costas, F.

2013-01-01

30

The Requirement to Rebuild U.S. Fish Stocks: Is it Working?  

Science.gov (United States)

The Magnuson-Stevens Fishery Conservation and Management Act (MSA) was amended in 1996 to require that overfished stocks be rebuilt in as short a time period as possible, not to exceed 10 years, with limited exceptions. This comment examines the basic but important question of whether the implementation of rebuilding plans under the 1996 amendments has in fact been associated with biomass recovery. Specifically, for each of 44 stocks, this analysis compares the biomass trend before rebuilding plan implementation to the trend after rebuilding plan implementation using a linear trend-break model. The analysis demonstrates a statistically significant positive association between the implementation of rebuilding plans and standardized biomass in 19 of 44 stocks. None of the 44 stocks examined showed a statistically significant negative association. The analysis showed a strong temporal relationship between the implementation of the policy and rebounds in fish stocks. Figure 1: Standardized biomass (open circles) based on NMFS stock assessment reports, trend prior to policy implementation (solid black line), hypothetical pre-trend continuation (dotted line), and trendbreak model (red line). Figure 2: Trend break coefficient estimates (difference in the slope of the trend before and after policy implementation) by stock.

Lai, K.; Suatoni, L.; Sewell, B.

2013-12-01

31

Duck Valley Resident Fish Stocking Program, 2000 Final Annual Report.  

Energy Technology Data Exchange (ETDEWEB)

The Shoshone-Paiute Tribes fish-stocking program was begun in 1988 and is intended to provide a subsistence fishery for the tribal members. The program stocks catchable and fingerling size trout in Mt. View and Sheep Creek Reservoirs. Rainbow trout are purchased from only certified disease-free facilities to be stocked in our reservoirs. This project will help restore a fishery for tribal members that historically depended on wild salmon and steelhead in the Owyhee and Bruneau Rivers and their tributaries for their culture as well as for subsistence. This project is partial substitution for loss of anadromous fish production due to construction and operation of hydroelectric dams on the Columbia and Snake Rivers. Until anadromous fish can be returned to the Owyhee and Bruneau Rivers this project will continue indefinitely. As part of this project the Shoshone-Paiute Tribes will also receive income in the form of fees from non-tribal members who come to fish these reservoirs. Regular monitoring and evaluation of the fishery will include sampling for length/weight/condition and for signs of disease. A detailed Monitoring and evaluation plan has been put in place for this project. However due to budget limitations on this project only the fishery surveys and limited water quality work can be completed. A creel survey was initiated in 1998 and we are following the monitoring and evaluation schedule for this program (as budget allows) as well as managing the budget and personnel. This program has been very successful in the past decade and has provided enjoyment and sustenance for both tribal and non-tribal members. All biological data and stocking rates will be including in the Annual reports to Bonneville Power Administration (BPA).

Dodson, Guy; Pero, Vincent

2002-01-01

32

Biological reference points for fish stocks in a multispecies context  

DEFF Research Database (Denmark)

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.

Collie, J.S.; Gislason, Henrik

2001-01-01

33

Single and multispecies reference points for Baltic fish stocks  

DEFF Research Database (Denmark)

Single and multispecies models are used to examine the effect of species interaction on biological reference points for cod, herring, and sprat in the Baltic. The results demonstrate that reference points are different in single and multispecies contexts. Reference points for fishing mortality based on single-species yield and SSB calculations are difficult to use when natural mortality depends on the absolute abundance of the predators and their alternative prey. Reference points based on maximizing total yield from the system may lead to impractical results when species interact. Multispecies predictions suggest that the cod stock in the Baltic should be reduced to a very low level of biomass in order to benefit from the higher productivity of herring and sprat, its major prey. Such a result stresses the need for incorporating socio-economic considerations in the definition of target reference points. Management advice based on biomass reference points will also differ. In the single species situation the combinations of cod and pelagic fishing effort for which the equilibrium spawning- stock biomass of the three species is above the biomass reference points forms a rectangular area. When biological interaction is taken into account the limits of this area becomes curved. Reference limits for forage fish cannot be defined without considering changes in the biomass of their natural predators. Likewise, reference limits for predators cannot be defined without considering changes in the biomass of their prey. (C) 1999 International Council for the Exploration of the Sea.

Gislason, Henrik

1999-01-01

34

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)

35

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

DEFF Research Database (Denmark)

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

Kokkalis, Alexandros; Thygesen, Uffe HØgsbro

36

ss3sim: An R Package for Fisheries Stock Assessment Simulation with Stock Synthesis  

OpenAIRE

Simulation testing is an important approach to evaluating fishery stock assessment methods. In the last decade, the fisheries stock assessment modeling framework Stock Synthesis (SS3) has become widely used around the world. However, there lacks a generalized and scriptable framework for SS3 simulation testing. Here, we introduce ss3sim, an R package that facilitates reproducible, flexible, and rapid end-to-end simulation testing with SS3. ss3sim requires an existing SS3 mod...

Anderson, Sean C.; Monnahan, Cole C.; Johnson, Kelli F.; Ono, Kotaro; Valero, Juan L.

2014-01-01

37

Assessing the effects of a chronic stressor, stocking density, on welfare indicators of juvenile African catfish, Clarias gariepinus Burchell.  

OpenAIRE

Fish welfare is an area of increasing interest and stocking densities used in commercial aquaculture have been highlighted as a subject of specific welfare concern. The present study assessed how stocking density affects growth performance (final body weight, SGR, FCR), physiological (plasma cortisol, glucose, lactate) and behavioural (swimming activity, stereotypes, escapes, aggression, airbreathing) responses of farmed African catfish (Clarias gariepinus). We stocked African catfish (10g) i...

Nieuwegiessen, P. G.; Boerlage, A. S.; Verreth, J. A. J.; Schrama, J. W.

2008-01-01

38

Integrating Anisakis spp. parasites data and host genetic structure in the frame of a holistic approach for stock identification of selected Mediterranean Sea fish species.  

Science.gov (United States)

The unique environment of the Mediterranean Sea makes fish stock assessment a major challenge. Stock identification of Mediterranean fisheries has been based mostly from data on biology, morphometrics, artificial tags, otolith shape and fish genetics, with less effort on the use of parasites as biomarkers. Here we use some case studies comparing Mediterranean vs Atlantic fish stocks in a multidisciplinary framework. The generalized Procrustes Rotation (PR) was used to assess the association between host genetics and larval Anisakis spp. datasets on demersal (hake) and pelagic (horse mackerel, swordfish) species. When discordant results emerged, they were due to the different features of the data. While fish population genetics can detect changes over an evolutionary timescale, providing indications on the cohesive action of gene flow, parasites are more suitable biomarkers when considering fish stocks over smaller temporal and spatial scales, hence giving information of fish movements over their lifespan. Future studies on the phylogeographic analysis of parasites suitable as biomarkers, and that of their fish host, performed on the same genes, will represent a further tool to be included in multidisciplinary studies on fish stock structure. PMID:25145788

Mattiucci, S; Cimmaruta, R; Cipriani, P; Abaunza, P; Bellisario, B; Nascetti, G

2015-01-01

39

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)

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

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

2015-01-01

40

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)

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.

Ratna Purwaningsih

2011-08-01

41

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

OpenAIRE

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...

Quaas, Martin F.; Requate, Till

2012-01-01

42

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

OpenAIRE

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 ...

Wudneh, T.

1998-01-01

43

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

DEFF Research Database (Denmark)

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

Pécuchet, Lauréne; Nielsen, J. Rasmus

2014-01-01

44

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

Energy Technology Data Exchange (ETDEWEB)

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).

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

45

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

Energy Technology Data Exchange (ETDEWEB)

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).

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

46

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

Directory of Open Access Journals (Sweden)

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.

J. N. Bhakta

2010-02-01

47

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

OpenAIRE

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...

Dingsør, Gjert Endre

2006-01-01

48

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

Energy Technology Data Exchange (ETDEWEB)

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).

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

49

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

Energy Technology Data Exchange (ETDEWEB)

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).

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

50

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

2009-07-21

51

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

DEFF Research Database (Denmark)

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

Skov, Christian; Perrow, M.R.

2002-01-01

52

Ageing of Fish  

OpenAIRE

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...

Institute, Marine

2006-01-01

53

How can a potential oil pollution affect the recruitment to fish stocks?  

OpenAIRE

Eggs, larvae and the larvae's first search for food are the most critical stages in a fish life, both to threats from natural causes and pollution. Based on experimental studies of several species of fish eggs, larvae and zooplankton, and their in situ abundance, calculations of potential reduction of the affected year class or stock are demonstrated. The organisms exposed to oil concentrations likely to be found in the marine environment show considerably variation from species to species. W...

Føyn, Lars; Serigstad, Bjørn

1989-01-01

54

Stock assessment methods used for cephalopod fisheries  

OpenAIRE

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...

Pierce, Graham J.; Guerra, A?ngel

1994-01-01

55

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

Science.gov (United States)

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

Holmlund, Cecilia M; Hammer, Monica

2004-06-01

56

[Stock assessment and management for Illex argentinus in Southwest Atlantic Ocean based on Bayesian Schaefer model].  

Science.gov (United States)

Abstract: Bayesian Schaefer model was applied to assess the stock of Illex argentinus in the Southwest Atlantic Ocean, with the risk of alternative management strategies for the squid analyzed. Under the scenarios of normal and uniform prior assumptions, the estimated model parameters and reference points were similar, and higher than the values under the scenario of logarithmic normal prior assumption. Under the three proposed scenarios, the fishing mortalities and the total catches in 2001-2010 were lower than the reference point F0.1 and the maximum sustainable yield (MSY), indicating that the I. argentinus was in an expected sustainable exploited level but not in over-fishing and over-fished. The results of decision analysis indicated that at the same harvest rate, the stock of the I. argentinus under the scenario of logarithmic normal prior assumption in 2025 would be the lowest, and the probability of collapse would be the highest. Under the three scenarios, the harvest rate in 2025 would be all 0.6 if the catch was the maximum. However, if the harvest rate was set to 0.6, the stock of the I. argentinus after 2025 would have definite risk, and thus, the harvest rate 0.4 and the catch 550000 t appeared to be the best management regulation or the baseline case. PMID:24175534

Lu, Hua-Jie; Chen, Xin-Jun; Li, Gang; Cao, Jie

2013-07-01

57

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

58

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

DEFF Research Database (Denmark)

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

Bartolino, V.; Margonski, P.

2014-01-01

59

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

DEFF Research Database (Denmark)

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.

Hansen, Michael MØller; Ruzzante, D.E.

2001-01-01

60

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

2009-05-11

61

Trophic structure of the Barents Sea fish assemblage with special reference to the cod stock recoverability  

Science.gov (United States)

The species composition and trophic structure of the Barents Sea fish assemblage is analysed based on data from research survey trawls and diet analyses of various species. Atlantic cod was the dominant fish species encountered, accounting for more than 55% by abundance or biomass. Only five fish species (long rough dab, thorny skate, Greenland halibut, deepwater redfish and saithe) were sufficiently abundant to be considered as possible food competitors with cod in the Barents Sea. However, possible trophic competition is not high, due to low spatial and temporal overlap between cod and these other species. Analyses of fish assemblages and trophic structures of the Barents Sea and other areas (North Sea, Western Greenland, Newfoundland-Labrador shelf) suggest that Barents Sea cod is the only cod stock for which the ability to recover may not be restricted by trophic relations among fishes, due to a lack of other abundant predatory species and low potential for competition caused by spatial-temporal changes.

Dolgov, Andrey V.

2009-04-01

62

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

DEFF Research Database (Denmark)

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.

Jepsen, Niels; Klenke, Reinhard

2010-01-01

63

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

Directory of Open Access Journals (Sweden)

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.

Khodorevskaya Raisa Pavlovna

2013-04-01

64

Climate, competition and the management of shared fish stocks  

OpenAIRE

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...

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

2004-01-01

65

Risk assessment in airlines stocks market  

Directory of Open Access Journals (Sweden)

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.

Renato Cesar Sato

2013-04-01

66

An Individual-based Probabilistic Model for Fish Stock Simulation  

CERN Document Server

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 avai...

Buti, Federico; Merelli, Emanuela; Paschini, Elio; Penna, Pierluigi; Tesei, Luca; 10.4204/EPTCS.33.3

2010-01-01

67

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

2009-02-20

68

76 FR 61092 - Stock Assessment Reports for Dusky, Sandbar, and Blacknose Sharks in the U.S. Atlantic and Gulf...  

Science.gov (United States)

...Atmospheric Administration RIN 0648-XA662 Stock Assessment Reports for Dusky, Sandbar...NMFS announces the availability of final stock assessment reports for dusky, sandbar...describe methodologies used to determine stock statuses, and detail relevant...

2011-10-03

69

Report of the Working Group on the Assessment of Demersal Stocks in the North Sea and Skagerrak (WGNSSK). 24 - 30 April 2013 ICES Headquarters, Copenhagen  

OpenAIRE

The ICES Working Group for the Assessment of Demersal Stocks in the North Sea and Skagerrak (WGNSSK) met at ICES Headquarters in Copenhagen, Denmark, during 24-30 April – 2013. There were 23 participants from 8 countries. The main terms of reference for the Working Group were: to produce a first draft of the advice on the fish stocks and fisheries under considerations, to update, quality check and report relevant data for the working group, to produce an overview of the sampling activities ...

ICES

2013-01-01

70

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

Science.gov (United States)

...the Pacific Walrus and Three Northern Sea Otters AGENCY: Fish and Wildlife Service...each of the following three northern sea otter stocks in Alaska: Southwest...southcentral, or southwest Alaska northern sea otter stock--your comments...

2013-04-18

71

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

Science.gov (United States)

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

Hutchings, J A

2014-12-01

72

Optimal harvesting of fish stocks under a time-varying discount rate.  

Science.gov (United States)

Optimal control theory has been extensively used to determine the optimal harvesting policy for renewable resources such as fish stocks. In such optimisations, it is common to maximise the discounted utility of harvesting over time, employing a constant time discount rate. However, evidence from human and animal behaviour suggests that we have evolved to employ discount rates which fall over time, often referred to as "hyperbolic discounting". This increases the weight on benefits in the distant future, which may appear to provide greater protection of resources for future generations, but also creates challenges of time-inconsistent plans. This paper examines harvesting plans when the discount rate declines over time. With a declining discount rate, the planner reduces stock levels in the early stages (when the discount rate is high) and intends to compensate by allowing the stock level to recover later (when the discount rate will be lower). Such a plan may be feasible and optimal, provided that the planner remains committed throughout. However, in practice there is a danger that such plans will be re-optimized and adjusted in the future. It is shown that repeatedly restarting the optimization can drive the stock level down to the point where the optimal policy is to harvest the stock to extinction. In short, a key contribution of this paper is to identify the surprising severity of the consequences flowing from incorporating a rather trivial, and widely prevalent, "non-rational" aspect of human behaviour into renewable resource management models. These ideas are related to the collapse of the Peruvian anchovy fishery in the 1970's. PMID:20969881

Duncan, Stephen; Hepburn, Cameron; Papachristodoulou, Antonis

2011-01-21

73

A towed body designed for side-scanning hydroacoustic surveying of fish stocks in shallow waters  

OpenAIRE

An aluminum towed body was designed for use in hydroacoustic surveying of fish stocks in shallow (2–10 m depth) inland waters. The design allows applications in deep (>10 m) water bodies as well. Test results showed that the towed body was a stable platform for the hydroacoustic transducer. The towed body features adjustable beam direction, allowing a side-looking as well as a vertical-looking mode. As the design of the towed body is simple, it can be easily constructed by any skilled craft...

Mous, P. J.; Kemper, J.; Schelvis, A.

1999-01-01

74

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

Science.gov (United States)

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.

Guo, Zhenyuan; Zou, Xingfu

2015-02-01

75

Stocking of Offsite Waters for Hungry Horse Dam Mitigation; Creston National Fish Hatchery, 2001-2002 Annual Report.  

Energy Technology Data Exchange (ETDEWEB)

Mitigation Objective 1: Produce Native Westslope Cutthroat Trout at Creston NFH--Task: Acquire eggs and rear up to 100,000 Westslope Cutthroat trout annually for offsite mitigation stocking. Accomplishments: A total of 150,000 westslope cutthroat eggs (M012 strain) were acquired from the State of Montana Washoe Park State Fish Hatchery in July 2001 for this objective. Another 120,000 westslope cutthroat eggs were taken from feral fish at Rogers Lake in May of 2001 by the Creston Hatchery crew. The fish were reared using approved fish culture techniques as defined in the U.S. Department of the Interior Fish Hatchery Management guidelines. Post release survival and angler success is monitored annually by Montana Fish Wildlife and Parks (MFWP) and the Confederated Salish and Kootenai Tribe (CSKT). Stocking numbers and locations may vary yearly based on results of biological monitoring. Mitigation Objective 2: Produce Rainbow Trout at Creston NFH--Task: Acquire and rear up to 100,000 Rainbow trout annually for offsite mitigation in closed basin waters. Accomplishments: A total of 50,500 rainbow trout eggs (Arlee strain) were acquired from the State of Montana Arlee State Fish Hatchery in December 2001 for this objective. The fish were reared using approved fish culture techniques as defined in the U.S. Department of the Interior Fish Hatchery Management guidelines. Arlee rainbow trout are being used for this objective because the stocking locations are terminal basin reservoirs and habitat conditions and returns to creel are unsuitable for native cutthroat. Post release survival and angler success is monitored annually by the Confederated Salish and Kootenai Tribe (CSKT). Stocking numbers and locations may vary yearly based on results of biological monitoring.

Maskill, Mark (US Fish and Wildlife Service, Creston National Fish Hatchery, Kalispell, MT)

2003-03-01

76

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

OpenAIRE

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...

Okoh, Lucky; Ekane, O. R.

2011-01-01

77

Evidence of Segregated Spawning in a Single Marine Fish Stock: Sympatric Divergence of Ecotypes in Icelandic Cod?  

OpenAIRE

There is increasing recognition of intraspecific diversity and population structure within marine fish species, yet there is little direct evidence of the isolating mechanisms that maintain it or documentation of its ecological extent. We analyzed depth and temperature histories collected by electronic data storage tags retrieved from 104 Atlantic cod at liberty ?1 year to evaluate a possible isolating mechanisms maintaining population structure within the Icelandic cod stock. This stock co...

Grabowski, Timothy B.; Thorsteinsson, Vilhja?lmur; Mcadam, Bruce J.; Marteinsdo?ttir, Gu?ru?n

2011-01-01

78

The reliability of fishing statistics as a source for catches and fish stocks in antiquity  

DEFF Research Database (Denmark)

In 1985, T.W. Gallant published an influential essay on the potential productivity of fishing in the ancient world. He concluded that: ”the role of fishing in the diet and economy would have been, on the whole, subordinate and supplementary…” His methodological approach was original in using modern fishery data to estimate the productivity of ancient fisheries. Unfortunately his work suffered from several severe misunderstandings about ecosystems, the nature of a fishery and its biological interaction with its environment. The purpose of this paper is to discuss the statistical background for Gallant’s conclusions about fishery and the usefulness of modern catch data for historical fishery research. In order to do so, the author adopts the viewpoint of marine-environmental history, with some reference to other authors’ work on ancient fisheries.

Jacobsen, A. Lif Lund

2005-01-01

79

Annual Coded Wire Tag Program; Oregon Stock Assessment, Annual Report 2002.  

Energy Technology Data Exchange (ETDEWEB)

This annual report is in fulfillment of contract obligations with Bonneville Power Administration which is the funding source for the Oregon Department of Fish and Wildlife project 'Annual Stock Assessment - Coded Wire Tag Program (ODFW)'. Results for the 2002 contract period: Objective 1 - Over 1 million juvenile salmon were coded-wire by this program (Table 1). This accounted for about 20% of the fish ODFW coded-wire tagged in 2002 for release in the Columbia Basin; Objective 2 - ODFW recovered and processed over 50,000 snouts collected from coded-wire tagged fish (Table 2); Objective 3 - The survival data summarized below includes results for coded-wire groups funded by this program as well as coded-wire groups funded from other sources; Objective 4 - The last returns of experimental groups of coho marked with VIE tags occurred in 2002 at Sandy Hatchery. This sampling showed that 26 of 67 jack coho and 1 of 2,223 adult coho VIE marked as juveniles retained the VIE mark as adults.

Lewis, Mark; Mallette, Christine; Murray, William

2003-03-01

80

75 FR 46912 - Draft 2010 Marine Mammal Stock Assessment Reports  

Science.gov (United States)

...included in the revised pilot whale reports. Similar analyses have...estimate. The short-finned pilot whale stock remains non-strategic, but the status of the long-finned pilot whale stock is now considered...

2010-08-04

81

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)

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.

L. A. de F. MATEUS

2002-02-01

82

Microsatellite assessment of walrus (Odobenus rosmarus rosmarus stocks in Canada  

Directory of Open Access Journals (Sweden)

Full Text Available Walruses in Canada are currently subdivided into seven stocks based on summering areas; Western Jones Sound (WJS, Baffin Bay (BB, Penny Strait-Lancaster Sound (PS-LS, North Foxe Basin (N-FB, Central Foxe Basin (C-FB, Hudson Bay Davis Strait (HB-DS and Southern and Eastern Hudson Bay (SE-HB. In this study, walrus were sampled from six of the seven stocks (SE-HB samples were not available and genotyped at 10 microsatellite loci. All stocks were genetically diverse (average heterozygosity of 0.58 with no evidence of inbreeding (average FIS of 0.03. We detected significant genetic differentiation among the stocks and a pattern of genetic spatial autocorrelation that suggests a moderate effect of geographic distance on gene flow among stocks. Bayesian clustering suggested the six recognized stocks were elements of two larger genetic clusters - a northern Arctic population (containing BB, WJS, and PS-LS stocks and a central Arctic population (containing C-FB, N-FB, and HB-DS stocks. These populations are moderately differentiated (FST = 0.07, but based on evidence of contemporary movement from assignment tests, are not completely isolated. There was support for maintaining the WJS stock and a combined BB+PS-LS stock, although the latter conclusion is based on a small sample size. Similarly, there was some evidence suggesting separation of the Foxe Basin stocks from the HB-DS but not the N-FB from the C-FB stock. However, given that there are morphological and chemical differences between N-FB and C-FB stocks, there is currently insufficient evidence to support a revision of the current stock designations.

Aaron BA Shafer

2013-08-01

83

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

OpenAIRE

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.

Villasante, Sebastian; Sumaila, Rashid

2013-01-01

84

Assessing ecosystem carbon stocks of Indonesia's threatened wetland forests  

Science.gov (United States)

Over millennia, atmospheric carbon dioxide has been sequestered and stored in Indonesia's tropical wetland forests. Waterlogged conditions impede decomposition, allowing the formation of deep organic soils. These globally significant C pools are highly vulnerable to deforestation, degradation and climate change which can potentially switch their function as C sinks to long term sources of greenhouse gas (GHG) emissions. Also at risk are critical ecosystem services which sustain millions of people and the conservation of unique biological communities. The multiple benefits derived from wetland forest conservation makes them attractive for international C offset programs such as the proposed Reduced Emissions from Deforestation and Degradation (REDD+) mechanism. Yet, ecosystem C pools and fluxes in wetland forests remain poorly quantified. Significant knowledge gaps exist regarding how land use changes impact C dynamics in tropical wetlands, and very few studies have simultaneously assessed above- and belowground ecosystem C pools in Indonesia's freshwater peat swamps and mangroves. In addition, most of what is known about Indonesia's tropical wetland forests is derived from few geographic locations where long-standing research has focused, despite their broad spatial distribution. Here we present results from an extensive survey of ecosystem C stocks across several Indonesian wetland forests. Ecosystem C stocks were measured in freshwater peat swamp forests in West Papua, Central Kalimantan, West Kalimantan, and Sumatra. Carbon storage was also measured for mangrove forests in W. Papua, W. Kalimantan, and Sumatra. One overarching goal of this research is to support the development of REDD+ for tropical wetlands by informing technical issues related to carbon measuring, monitoring, and verification (MRV) and providing baseline data about the variation of ecosystem C storage across and within several Indonesian wetland forests.

Warren, M.; Kauffman, B.; Murdiyarso, D.; Kurnianto, S.

2011-12-01

85

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

86

Fish Catch Assessment of Maljhee-Kangsa Floodplain in Bangladesh  

OpenAIRE

A study was conducted to assess fish catch in the Baila beel of Maljhee-Kangsa floodplain in the north-central part of Bangladesh. A total of 7 types of fishing gear were found in use by the fishermen which are: push net, gill net, cast net, lift net, current net, fish traps and hooks. The duration of fishing depends on use of fishing gear, season, habitat type, water depth and abundance of fishes. From the survey it was found that the highest average fishing time was estimated in fish trap (...

Ahmed, N.; Rahman, M. M.

2005-01-01

87

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)

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

Pierre Fréon

1995-01-01

88

Temporal Assessment of Growing Stock, Biomass and Carbon Stock of Indian Forests  

Energy Technology Data Exchange (ETDEWEB)

The dynamics of terrestrial ecosystems depends on interactions between carbon, nutrient and hydrological cycles. Terrestrial ecosystems retain carbon in live biomass (aboveground and belowground), decomposing organic matter, and soil. Carbon is exchanged naturally between these systems and the atmosphere through photosynthesis, respiration, decomposition, and combustion. Human activities change carbon stock in these pools and exchanges between them and the atmosphere through land-use, land-use change, and forestry. In the present study we estimated the wood (stem) biomass, growing stock (GS) and carbon stock of Indian forests for 1984 and 1994. The forest area, wood biomass, GS, and carbon stock were 63.86 Mha, 4327.99 Mm{sup 3}, 2398.19 Mt and 1085.06 Mt respectively in 1984 and with the reduction in forest area, 63.34 Mha, in 1994, wood biomass (2395.12 Mt) and carbon stock (1083.69 Mt) also reduced subsequently. The Conifers, of temperate region, stocked maximum carbon in their woods, 28.88 to 65.21 t C/ha, followed by Mangrove forests, 28.24 t C/ha, Dipterocarp forests, 28.00 t C/ha, and Shorea robusta forests, 24.07 t C/ha. Boswellia serrata, with 0.22 Mha forest area, stocked only 3.91 t C/ha. To have an idea of rate of carbon loss the negative changes (loss of forest area) in forest area occurred during 1984-1994 (10yrs) and 1991-1994 (4yrs) were also estimated. In India, land-use changes and fuelwood requirements are the main cause of negative change. Total 24.75 Mt C was lost during 1984-1994 and 21.35 Mt C during 1991-94 at a rate of 2.48 Mt C/yr and 5.35 Mt C/yr respectively. While in other parts of India negative change is due to multiple reasons like fuelwood, extraction of non-wood forest products (NWFPs), illicit felling etc., but in the northeastern region of the country shifting cultivation is the only reason for deforestation. Decrease in forest area due to shifting cultivation accounts for 23.0% of the total deforestation in India, with an annual loss of 0.93 Mt C/yr.

Manhas, R.K.; Negi, J.D.S.; Chauhan, P.S. [Forest Ecology and Environment Division, Forest Research Institute, Dehradun, 248 006, Uttaranchal (India); Kumar, R. [Forest Survey of India, Dehradun, 248 001, Uttaranchal (India)

2006-01-15

89

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

Science.gov (United States)

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

Watanabe, Hiroyuki

2014-07-01

90

76 FR 52940 - Draft 2011 Marine Mammal Stock Assessment Reports  

Science.gov (United States)

...Of these, seven are ``strategic'' stocks: North Atlantic right whale, humpback whale, fin whale, sei whale, long-finned pilot whale, Atlantic white-sided dolphin (which became strategic because the 2002 abundance estimate is...

2011-08-24

91

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

OpenAIRE

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 ...

Mundt, Matthias

2012-01-01

92

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

DEFF Research Database (Denmark)

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.

MacKenzie, Brian; Myers, R.A.

2003-01-01

93

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)

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.

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

2011-08-01

94

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

Directory of Open Access Journals (Sweden)

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.

György Á.I.

2012-06-01

95

Precision in recruitment estimates and its implications on management of demersal fish stocks  

OpenAIRE

Errors in abundance indices of recruiting year-classes will affect stock predictions. Thecontribution of recruiting year-classes to the predictions of catch and spawning stock biomassfor the stocks of Northeast Arctic cod, haddock and saithe is investigated. The effect variouslevels of error in the recruitment indices would have had on the predictions during the last twodecades is calculated. The error in the index has frequently gone in the same direction forconsecutive year-classes and erro...

Jakobsen, Tore

1995-01-01

96

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)

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.

Amonsak SAWUSDEE

2009-06-01

97

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

DEFF Research Database (Denmark)

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

Laugen, Ane T.; Engelhard, Georg H.

2014-01-01

98

A Framework for Assessing Global Change Risks to Forest Carbon Stocks in the United States  

OpenAIRE

Among terrestrial environments, forests are not only the largest long-term sink of atmospheric carbon (C), but are also susceptible to global change themselves, with potential consequences including alterations of C cycles and potential C emission. To inform global change risk assessment of forest C across large spatial/temporal scales, this study constructed and evaluated a basic risk framework which combined the magnitude of C stocks and their associated probability of stock change in the c...

Woodall, Christopher W.; Domke, Grant M.; Riley, Karin L.; Oswalt, Christopher M.; Crocker, Susan J.; Yohe, Gary W.

2013-01-01

99

Principles of fish welfare assessment in farm rearing conditions  

Directory of Open Access Journals (Sweden)

Full Text Available For several decades fish welfare has been subject of many researches, and the interest for this subject is connected with the fact that fish can feel pain and suffering. In addition to this stressors’ mechanisms of action and their consequences are similar in mammals and fish. Assessment of welfare for farmed fish is based on the same principles as for terrestrial farm animals. However, special methods of collecting data are needed due to morphological characteristics of fish and properties of their environment. In the world and in our country, researches of different ways of fish welfare assessment are being conducted, especially based on non-invasive techniques such as monitoring of behaviour. In this paper a review of basic principles and methods used in assessment of farmed fish welfare is given.

Reli? Renata R.

2010-01-01

100

An assessment of the cod stock in NAFO Division 3M  

OpenAIRE

This paper reviews past analyses of the cod stock in NAFO Division 3M (Flemish Cap) and presents an updated one. An Extended Survivor Analysis (XSA) was carried out for ages 1 to 8+ and years 1973 to 1998. This analysis link past sequential population analysis for the 1972 to 1983 period with the period since 1988. The analysis was tuned with EU survey results. High fishing mortalities are observed throughout the age range of the exploited population during those years, althoug...

Va?zquez, Antonio; Motos, L.; Mahe?, Jean-claude

1999-01-01

101

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)

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

Kraus, Gerd; Hinrichsen, Hans-Harald

2012-01-01

102

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

Directory of Open Access Journals (Sweden)

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.

Obe Bernardine Wuraola

2011-09-01

103

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

DEFF Research Database (Denmark)

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.

Laursen, Danielle Caroline

2013-01-01

104

PIT telemetry as a method to study the habitat requirements of fish populations: application to native and stocked trout movements  

OpenAIRE

Passive integrated transponder (PIT) technology was used to study the behaviour of fishes during the summer season in two headwater streams of northeastern Portugal. A total of 71 PIT tags (12 mm long x 2.1 mm diameter) were surgically implanted in 1+ stocked (39) and native (32) brown trout of two size classes (< 20.0 and ? 20.0 cm). Eight independent antennae, connected to a multi-point decoder (MPD reader) unit, were placed in different microhabitats, selected randomly every three days d...

Teixeira, Ami?lcar; Cortes, R.

2007-01-01

105

Fish sampling with active methods.  

Czech Academy of Sciences Publication Activity Database

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

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

2012-01-01

106

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

OpenAIRE

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-Grange...

Jiranyakul, Komain

2008-01-01

107

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

OpenAIRE

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...

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

2000-01-01

108

An assessment of the relationship between public real estate markets and stock markets at the local, regional, and global levels  

OpenAIRE

The primary contribution of this study is to assess whether public real estate markets and stock markets are linked at the local, regional, and global levels, and to assess the evolution of their dynamic relationship and gradual integration during the last two decades. For individual pairs of real estate and stock markets, our analysis shows that the current levels of local, regional, and global correlation between real estate and stock markets are time-varying and are, at most, moderate at t...

Liow, Kim Hiang; Schindler, Felix

2011-01-01

109

Evidence of segregated spawning in a single marine fish stock: Sympatric divergence of ecotypes in icelandic cod?  

Science.gov (United States)

There is increasing recognition of intraspecific diversity and population structure within marine fish species, yet there is little direct evidence of the isolating mechanisms that maintain it or documentation of its ecological extent. We analyzed depth and temperature histories collected by electronic data storage tags retrieved from 104 Atlantic cod at liberty ???1 year to evaluate a possible isolating mechanisms maintaining population structure within the Icelandic cod stock. This stock consists of two distinct behavioral types, resident coastal cod and migratory frontal cod, each occurring within two geographically distinct populations. Despite being captured together on the same spawning grounds, we show the behavioral types seem reproductively isolated by fine-scale differences in spawning habitat selection, primarily depth. Additionally, the different groups occupied distinct seasonal thermal and bathymetric niches that generally demonstrated low levels of overlap throughout the year. Our results indicate that isolating mechanisms, such as differential habitat selection during spawning, might contribute to maintaining diversity and fine-scale population structure in broadcast-spawning marine fishes.

Grabowski, T.B.; Thorsteinsson, V.; McAdam, B.J.; Marteinsdottir, G.

2011-01-01

110

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)

111

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

Science.gov (United States)

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 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.

Vågen, Tor-Gunnar; Winowiecki, Leigh A.

2013-03-01

112

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

OpenAIRE

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...

Jakobsen, Tore

1981-01-01

113

Assessing soil carbon stocks under pastures through orbital remote sensing  

Scientific Electronic Library Online (English)

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.

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

2011-10-01

114

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

Science.gov (United States)

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

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

115

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

Science.gov (United States)

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

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

2015-01-01

116

Stock size of north-east arctic cod, estimates from survey data 1982/83  

OpenAIRE

Assessments of the total stock and spawning stock sizes of North-East Arctic cod were carried out on the basis of Norwegian survey data and commercial landings. The total stock at 1 January 1983, fish which was 2 years old and older was estimated to about 400 million specimens and the spawning stock estimate was approximately 130 million specimens. The figure for the total stock was considerably lower than the estimate of 615 million specimens of 3 year old and older fish arrived at by the Wo...

Nakken, Odd; Hylen, Arvid

1983-01-01

117

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

Czech Academy of Sciences Publication Activity Database

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

Potužák, J.; H?da, J.; Pechar, Libor

118

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

OpenAIRE

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...

Kunsook, Chutapa; Gajaseni, Nantana; Paphavasit, Nittharatana

2014-01-01

119

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

OpenAIRE

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 ...

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

2010-01-01

120

78 FR 19002 - Marine Mammal Protection Act; Draft Revised Stock Assessment Reports for Two Stocks of West...  

Science.gov (United States)

...may be removed from a marine mammal stock while allowing...for which significant new information is available...defined in the MMPA as a marine mammal stock...Pollution Bulletin, Marine Technology Society Journal...Journal of Zoo and Wildlife Medicine, Molecular...

2013-03-28

121

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)

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.

Coers, Aukje; Raakjær, Jesper

2012-01-01

122

Accurate assessment of Congo basin forest carbon stocks requires forest type specific assessments  

Science.gov (United States)

Due to a limited number of field-based studies estimations of carbon stocks in the Central Congo Basin remain highly uncertain. In particular, more information is needed about the variation in stocks between forest types and on the factors explaining these differences. This study presents results from biomass and soil carbon inventories in 46 0.25ha old-growth forest plots located in three study sites in Tshopo District, Democratic Republic of Congo. Four forest community types were identified using cluster and indicator species analysis based on the plots' large tree (>30cm DBH) species composition. Carbon stocks were calculated using newly established forest type specific tree height-diameter relationships to prevent errors related to the use of inappropriate regional relationships from literature. Using the Akaike criterion it became clear that for one site and a few forest types separate tree height-diameter relationships gave a robust and significant better fit, showing that there was a clear and significant interaction effect between sites and forest type. Mean above-ground carbon stocks were estimated at 165 ±44 Mg ha-1. Significant differences were found between forest types, but not between sites for a given forest type. Largest stocks were found in monodominant Gilbertiodendron dewevrei forests (187 ± 37 Mg C ha-1), which occurred in all sites. Smallest stocks (91 ± 14 Mg C ha-1) were found in the Margaritaria discoidea mixed forest type, which occurred only in one site, while two other mixed forest types showed intermediate stocks (148 ± 28 Mg C ha-1 and 160 ± 36 Mg C ha-1 respectively). The observed differences in aboveground stocks between forest types could be explained by forest structure related variables including number of large trees (DBH>70cm), average wood density and dominant height. When comparing the G. dewevrei monodominant type with mixed forest types within each study site, the former showed equal basal area and sometimes higher carbon stocks despite poorer physical and chemical soil properties. Soil organic carbon stocks (0-100cm) did not significantly differ between forest types and were estimated at 109 ± 35 Mg C ha-1. Our results confirm recent findings of significantly lower carbon stocks in the Central Congo Basin as compared to the outer regions and of the importance of local tree height-diameter relationships for accurate carbon stock estimations.

Moonen, Pieter C. J.; Van Ballaert, Siege; Verbist, Bruno; Boyemba, Faustin; Muys, Bart

2014-05-01

123

Stocks assesment, biomass and fish production in two mediterranean basins (NE Spain)  

OpenAIRE

In order to evaluate the success of the reintroduction of the Eurasian otter (Lutra lutra) in the Empordh wetlands (Parc Natural dels Aiguamolls de I'Empordhà), and the Muga and Fluvih basins, density of fish, biomass and production in the Muga and Fluvia Rivers have been estimated, since fishes represent the principal prey in the otter diet. 12 study sites were selected in order to survey the main flows in both basins. Electrofishing surveys were conducted by blocking off the station with b...

Zamora Herna?ndez, Llui?s; Saavedra, D.; Moreno I Amich, Ramon

1996-01-01

124

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

OpenAIRE

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 chara...

Cesare Zanasi; Savino Di Trani; Mauro Saracco; Giovanni Mattalia; Sergio Pippione; Leonardo Nanni Costa; Mario Sapino

2012-01-01

125

Performance evaluation of chicken, cow and pig manure in the production of natural fish food in aquadams stocked with Oreochromis mossambicus  

Science.gov (United States)

The main objective of this study was to characterize the ecological conditions that prevail after the application of chicken, cow and pig manure. Three treatments, chicken, cow, pig manure and a control were assigned to aquadams in a completely randomized design and each treatment was replicated three times. The aquadams were fertilized 2 weeks before the fish were stocked. One hundred Oreochromis mossambicus (mean weight ±40 g) were stocked in each aquadam. Water physico-chemical parameters (temperature, dissolved oxygen, pH, electrical conductivity, salinity, turbidity, ammonia, nitrite, total alkalinity as calcium carbonate, and phosphorus) were determined once a week for the duration of the experiment. Zooplankton and phytoplankton in the different treatments were enumerated once every 2 weeks. The relationship between phytoplankton communities and the water physico-chemical parameters were evaluated using canonical correspondence analysis (CCA). The CCA indicated that the physico-chemical variables which best explain the distribution of phytoplankton were carbonate alkalinity, pH, phosphate, potassium, nitrogen and dissolved oxygen. Phytoplankton abundance was highest in chicken manure because the optimum nutrient conditions for the growth of phytoplankton were found in this treatment. Zooplankton abundance was also highest in the chicken manure treatment. The control was associated with one phytoplankton taxa, Chlorella. The numerical contribution of the different food items in the stomachs of O. mossambicus was determined. The diet of O. mossambicus was dominated by phytoplankton particularly Microcystis species. Total coliforms and Escherichia coli were used to assess the microbiological quality of the water in the different manure treatments. Chicken manure had the lowest total coliform and E. coli count. However, chicken manure had the highest Bacillus count. The implications of the microbial load in the chicken, cow and pig manure are discussed.

Rapatsa, M. M.; Moyo, N. A. G.

126

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

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...

Zannatul Ferdoushiand Farhana Haque

2006-01-01

127

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

Directory of Open Access Journals (Sweden)

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%.

M. W. Warren

2012-06-01

128

Mercury toxicology as assessed through fish scales.  

Science.gov (United States)

Increasing pollution in water bodies is directly or indirectly related to increasing urbanization and indiscriminate disposal of agrochemical & industrial effluents. Heavy metals are one of the important categories of such pollutants and are causing serious hazards to non target species (Mwachiro and Druve1997). Their salts constitute a serious type of pollution in fresh water and being stable compounds; they are not readily removed by oxidation, precipitation or other processes and affect the activity in recipient animal (Jagadeesan and Vijayalakshmi 1998). Increase in the concentration of heavy metals has been reported in water of Vasai Creek, Maharastra and surface as well as groundwater of Delhi (Lokhande and Kelker 1999; Dixit et al. 2003). Recently, Food and Drug Adminstration (USFDA) and Environmental Protection Agency (USEPA) (2004) in their combined report recommended that pregnant women and lactating mothers should not eat shark, sword fish and king Mackerel as these fishes contain high levels of mercury. PMID:16158848

Dua, A; Gupta, N

2005-06-01

129

Assessing upstream fish passage connectivity with network analysis.  

Science.gov (United States)

Hydrologic connectivity is critical to the structure, function, and dynamic process of river ecosystems. Dams, road crossings, and water diversions impact connectivity by altering flow regimes, behavioral cues, local geomorphology, and nutrient cycling. This longitudinal fragmentation of river ecosystems also increases genetic and reproductive isolation of aquatic biota such as migratory fishes. The cumulative effects on fish passage of many structures along a river are often substantial, even when individual barriers have negligible impact. Habitat connectivity can be improved through dam removal or other means of fish passage improvement (e.g., ladders, bypasses, culvert improvement). Environmental managers require techniques for comparing alternative fish passage restoration actions at alternative or multiple locations. Herein, we examined a graph-theoretic algorithm for assessing upstream habitat connectivity to investigate both basic and applied fish passage connectivity problems. First, we used hypothetical watershed configurations to assess general alterations to upstream fish passage connectivity with changes in watershed network topology (e.g., linear vs. highly dendritic) and the quantity, location, and passability of each barrier. Our hypothetical network modeling indicates that locations of dams with limited passage efficiency near the watershed outlet create a strong fragmentation signal but are not individually sufficient to disconnect the system. Furthermore, there exists a threshold in the number of dams beyond which connectivity declines precipitously, regardless of watershed topology and dam configuration. Watersheds with highly branched configurations are shown to be less susceptible to disconnection as measured by this metric. Second, we applied the model to prioritize barrier improvement in the mainstem of the Truckee River, Nevada, USA. The Truckee River application demonstrates the ability of the algorithm to address conditions common in fish passage projects including incomplete data, parameter uncertainty, and rapid application. This study demonstrates the utility of a graph-theoretic approach for assessing fish passage connectivity in dendritic river networks assuming full basin utilization for a given species, guild, or community of concern. PMID:24147411

McKay, S Kyle; Schramski, John R; Conyngham, Jock N; Fischenich, J Craig

2013-09-01

130

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.

131

Annual dynamics of the fish stock in a backwater of the River Dyje.  

Czech Academy of Sciences Publication Activity Database

Ro?. 17, 4-5 (2001), s. 571-581. ISSN 0886-9375. [International Symposium on Regulated Streams /8./. Toulouse, 17.07.2000-21.07.2000] R&D Projects: GA ?R GA206/99/1519; GA ?R GA206/00/0668; GA AV ?R IBS6093007; GA AV ?R KSK6005114 Institutional research plan: CEZ:AV0Z6093917 Keywords : backwater * fish communities * River Dyje Subject RIV: EF - Botanics Impact factor: 1.169, year: 2001

Lusk, Stanislav; Hala?ka, Karel; Lusková, V?ra; Horák, Václav

2001-01-01

132

Hydroacoustic estimates of fish stocks in temperate reservoirs: day or night surveys?.  

Czech Academy of Sciences Publication Activity Database

Ro?. 22, ?. 1 (2009), s. 69-77. ISSN 0990-7440 R&D Projects: GA ?R(CZ) GA206/06/1371; GA ?R(CZ) GA206/07/1392; GA AV ?R(CZ) 1QS600170504 Institutional research plan: CEZ:AV0Z60170517 Keywords : hydroacoustics * fish biomass * diel migration * man-made lake Subject RIV: EH - Ecology, Behaviour Impact factor: 1.227, year: 2009

Draštík, Vladislav; Kube?ka, Jan; ?ech, Martin; Frouzová, Jaroslava; ?íha, Milan; J?za, Tomáš; Tušer, Michal; Jarolím, Old?ich; Prchalová, Marie; Peterka, Ji?í; Vašek, Mojmír; Kratochvíl, Michal; Mat?na, Josef; Mrkvi?ka, Tomáš

2009-01-01

133

Eco-Label Conveys Reliable Information on Fish Stock Health to Seafood Consumers  

OpenAIRE

Concerns over fishing impacts on marine populations and ecosystems have intensified the need to improve ocean management. One increasingly popular market-based instrument for ecological stewardship is the use of certification and eco-labeling programs to highlight sustainable fisheries with low environmental impacts. The Marine Stewardship Council (MSC) is the most prominent of these programs. Despite widespread discussions about the rigor of the MSC standards, no comprehensive analysis of th...

Gutie?rrez, Nicola?s L.; Valencia, Sarah R.; Branch, Trevor A.; Agnew, David J.; Baum, Julia K.; Bianchi, Patricia L.; Cornejo-donoso, Jorge; Costello, Christopher; Defeo, Omar; Essington, Timothy E.; Hilborn, Ray; Hoggarth, Daniel D.; Larsen, Ashley E.; Ninnes, Chris; Sainsbury, Keith

2012-01-01

134

Kootenai River Resident Fish Assessment, FY2008 KTOI Progress Report.  

Energy Technology Data Exchange (ETDEWEB)

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.

Holderman, Charles

2009-06-26

135

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)

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.

Maribel Recharte

2008-10-01

136

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. (author)

137

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.

138

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english 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.

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

139

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)

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.

Luis Fernando da Silva Rodrigues-Filho

2009-01-01

140

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

DEFF Research Database (Denmark)

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.

JØrgensen, Ole A; Treble, M.A.

2014-01-01

141

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

Directory of Open Access Journals (Sweden)

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.

Phutchard Vicharnakorn

2014-06-01

142

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

OpenAIRE

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....

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

2014-01-01

143

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

DEFF Research Database (Denmark)

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

Ulrich, Clara; Boje, Jesper

2012-01-01

144

Stock size of north-east arctic cod estimated from acoustic survey data 1982  

OpenAIRE

Assessments of the total stock and spawning stock of North East Arctic cod were carried out on the basis of Norwegian survey data and commercial landings. The total stock, i.e. fish which was 3 years old and older at 1 January 1982, was estimated to 580 million specimens; the corresponding spawning stock amounted to approximately 190 million specimens. The estimates for the total stock were in good agreement with those reported by the Working Group on Arctic Fisheries, with exception of the 6...

Nakken, Odd; Hylen, Arvid

1982-01-01

145

Assessment of fish freshness with an electronic nose  

Scientific Electronic Library Online (English)

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.

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

2005-07-01

146

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

DEFF Research Database (Denmark)

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

Shephard, Samuel; Rindorf, Anna

2014-01-01

147

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

Directory of Open Access Journals (Sweden)

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.

Lebedeva Lyudmyla M.

2013-03-01

148

Assessment of the fish resources of southeast Asia, with emphasis of the Banda and Arafura seas  

Science.gov (United States)

Following a brief presentation of marine catch trends in Southeast Asia, some biological peculiarities of the stocks upon which these fisheries rely are discussed. Two empirical log- linear models are presented allowing rough estimation of potential yield of small pelagic fishes fish from primary production, and of demersal fish from mean water depth and primary production. These models are applied to the Banda and Arafura Seas, and the results compared with yield estimates from similar ecological areas, the Sulu Sea (Philippines) and Gulf of Papua. The standing stock and ecological production of mesopelagic fishes in the Banda Sea are also estimated. The implications for management of these findings are discussed, with emphasis on the strong east to west human population gradient of Indonesia.

Dalzell, Paul; Pauly, Daniel

149

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

OpenAIRE

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...

Va?zquez Rowe, Ian

2012-01-01

150

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

DEFF Research Database (Denmark)

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

Bastardie, Francois; Nielsen, J. Rasmus

151

Improving the assessment of instream flow needs for fish populations  

Energy Technology Data Exchange (ETDEWEB)

Instream flow requirements are one of the most frequent and most costly environmental issues that must be addressed in developing hydroelectric projects. Existing assessment methods for determining instream flow requirements have been criticized for not including all the biological response mechanisms that regulate fishery resources. A new project has been initiated to study the biological responses of fish populations to altered stream flows and to develop improved ways of managing instream flows. 21 refs., 3 figs.

Sale, M.J. (Oak Ridge National Lab., TN (USA)); Otto, R.G. (Otto (R.G.) and Associates, Arlington, VA (USA))

1991-01-01

152

Application of the Beck model to stock markets: Value-at-Risk and portfolio risk assessment  

Science.gov (United States)

We apply the Beck model, developed for turbulent systems that exhibit scaling properties, to stock markets. Our study reveals that the Beck model elucidates the properties of stock market returns and is applicable to practical use such as the Value-at-Risk estimation and the portfolio analysis. We perform empirical analysis with daily/intraday data of the S&P500 index return and find that the volatility fluctuation of real markets is well-consistent with the assumptions of the Beck model: The volatility fluctuates at a much larger time scale than the return itself and the inverse of variance, or “inverse temperature”, ? obeys ?-distribution. As predicted by the Beck model, the distribution of returns is well-fitted by q-Gaussian distribution of Tsallis statistics. The evaluation method of Value-at-Risk (VaR), one of the most significant indicators in risk management, is studied for q-Gaussian distribution. Our proposed method enables the VaR evaluation in consideration of tail risk, which is underestimated by the variance-covariance method. A framework of portfolio risk assessment under the existence of tail risk is considered. We propose a multi-asset model with a single volatility fluctuation shared by all assets, named the single ? model, and empirically examine the agreement between the model and an imaginary portfolio with Dow Jones indices. It turns out that the single ? model gives good approximation to portfolios composed of the assets with non-Gaussian and correlated returns.

Kozaki, M.; Sato, A.-H.

2008-02-01

153

Available information for estimating reproductive potential of Northwest Atlantic groundfish stocks  

DEFF Research Database (Denmark)

The availability of data to improve indices of stock reproductive potential was reviewed for 42 Northwest Atlantic groundfish stocks comprising gadoids, flatfishes, redfishes and grenadiers.For many of the stocks, information on population parameters such as stock size and size/age composition estimates exists for three or more decades. Data on fish age, weight, maturity and sex ratios in the population have also been extensively collected, often allowing for establishment of time series of annual data that could be used for assessing spawning stock biomass and female spawning stock. However, possibilities for estimating stock potential egg production are constrained by scarcity of fecundity data. Data on fish condition, which can be useful in developing fecundity models, were seldom collected in earlier times, but have increased in recent decades. A data richness index, combining information about data quantity and quality, ranked most gadoid stocks as "data comprehensive" with a high proportion of stocks possessing some fecundity information. Flatfish stocks generally were "data moderate" owing to slightly shorter time series of data, while redfish and grenadier stocks in general were "data restricted". Published studies linking aspects of reproductive potential with parental characteristics and/or recruitment have become more frequent as "data richness" has improved for many stocks, but generally the prevalence of such studies remains low.

Tomkiewicz, Jonna; Morgan, M.J.

2003-01-01

154

Behavioral assay for assessing effects of pollutants on fish chemoreception  

Energy Technology Data Exchange (ETDEWEB)

Behavioral assays are sensitive to sublethal levels of pollution but they usually require highly trained personnel and long observation periods. We describe a system that combines the sensitivity of a behavioral assay with commercially available automated monitoring equipment. The observation system consists of a special aquarium coupled to a recirculating water system, and an Opto-Varimex-Aqua activity tracking meter (Columbus Instruments, Columbus, Ohio) interfaced to a microcomputer. The tracking meter forms an intersecting, planar grid of light beams which, when interrupted by fish movements, is translated into a digitized signal and fed to the computer. The assay is based on the response of fish to natural chemical stimuli such as food odors or pheromones. When these stimulus solutions are injected into the water circulation the response of the fish is monitored by the computer system, which is capable of discriminating and quantifying changes in eight parameters. Normal responses to stimuli are compared with the response of fish that have been exposed to pollutants. We have successfully used this technique to examine effects of reduced pH on the response of fathead minnows, Pimephales promelas, to chemical feeding stimuli. The system should be easily adapted to any laboratory concerned with testing for effects of toxic substances, and will identify effects of pollution that have thus far been difficult or impossible to assess.

Lemly, A.D.; Smith, R.J.

1986-04-01

155

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)

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.

Zannatul Ferdoushiand Farhana Haque

2006-01-01

156

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)

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.

C. Deceliere-Vergès

2008-01-01

157

Variation in growth for Hecate Strait English sole ( Parophrys vetulus) with implications for stock assessment  

Science.gov (United States)

In this study we analysed length-at-age data to characterise the growth of English sole ( Parophrys vetulus) and to examine the implications of incorporating uncertainty about growth into English sole stock assessment. Unlike previous analyses of English sole that employed Von Bertalanffy growth, we used a flexible parameterisation of growth after Schnute (1981) that better accommodated observed patterns in the length-at-age data. The model parameters always exist, even when the most appropriate growth form does not include a maximum size asymptote, and they have statistically stable properties. Also, the model parameters are expressed as quantities that have direct biological interpretation. Based on examination of annual growth parameter estimates, we concluded that a change in ageing methodology, sample bias and low sample size precluded analysis of the response of growth to environment and density-dependent effects. We also discuss the implications of uncertainty in the growth parameters on a yield per recruit analysis.

Fargo, J.; Kronlund, A. R.

2000-10-01

158

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

Science.gov (United States)

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.

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

2013-01-01

159

Fish Passage Assessment: Big Canyon Creek Watershed, Technical Report 2004.  

Energy Technology Data Exchange (ETDEWEB)

This report presents the results of the fish passage assessment as outlined as part of the Protect and Restore the Big Canyon Creek Watershed project as detailed in the CY2003 Statement of Work (SOW). As part of the Northwest Power Planning Council's Columbia Basin Fish and Wildlife Program (FWP), this project is one of Bonneville Power Administration's (BPA) many efforts at off-site mitigation for damage to salmon and steelhead runs, their migration, and wildlife habitat caused by the construction and operation of federal hydroelectric dams on the Columbia River and its tributaries. The proposed restoration activities within the Big Canyon Creek watershed follow the watershed restoration approach mandated by the Fisheries and Watershed Program. Nez Perce Tribal Fisheries/Watershed Program vision focuses on protecting, restoring, and enhancing watersheds and treaty resources within the ceded territory of the Nez Perce Tribe under the Treaty of 1855 with the United States Federal Government. The program uses a holistic approach, which encompasses entire watersheds, ridge top to ridge top, emphasizing all cultural aspects. We strive toward maximizing historic ecosystem productive health, for the restoration of anadromous and resident fish populations. The Nez Perce Tribal Fisheries/Watershed Program (NPTFWP) sponsors the Protect and Restore the Big Canyon Creek Watershed project. The NPTFWP has the authority to allocate funds under the provisions set forth in their contract with BPA. In the state of Idaho vast numbers of relatively small obstructions, such as road culverts, block thousands of miles of habitat suitable for a variety of fish species. To date, most agencies and land managers have not had sufficient, quantifiable data to adequately address these barrier sites. The ultimate objective of this comprehensive inventory and assessment was to identify all barrier crossings within the watershed. The barriers were then prioritized according to the amount of habitat blocked at each site and the fish life history stages impacted. This assessment protocol will hopefully prove useful to other agencies and become a model for use in other watersheds.

Christian, Richard

2004-02-01

160

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)

161

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

2008-08-01

162

An assessment of the cod stock in NAFO Division 3M  

OpenAIRE

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

Va?zquez, Antonio; Cervin?o, Santiago

2002-01-01

163

Unraveling biocomplexity of Northeast Atlantic herring stocks using SNP markers  

DEFF Research Database (Denmark)

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

Bekkevold, Dorte; Limborg, Morten

2012-01-01

164

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

DEFF Research Database (Denmark)

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

Nielsen, Anders; Berg, Casper Willestofte

2014-01-01

165

fish  

Science.gov (United States)

In this project you will learn about different types of fish. In your science journal write what you know about fish. Draw a picture of a common fish you might see where you live. On the handout record the information you learn during this unit. Click here to see the Angel Fish. Record information on Handout #1. Now go to the Clown Fish. ...

cory jones

2009-09-28

166

Assessing dispersal patterns of fish propagules from an effective mediterranean marine protected area.  

Science.gov (United States)

Successfully enforced marine protected areas (MPAs) have been widely demonstrated to allow, within their boundaries, the recovery of exploited species and beyond their boundaries, the spillover of juvenile and adult fish. Little evidence is available about the so-called 'recruitment subsidy', the augmented production of propagules (i.e. eggs and larvae) due to the increased abundance of large-sized spawners hosted within effective MPAs. Once emitted, propagules can be locally retained and/or exported elsewhere. Patterns of propagule retention and/or export from MPAs have been little investigated, especially in the Mediterranean. This study investigated the potential for propagule production and retention/export from a Mediterranean MPA (Torre Guaceto, SW Adriatic Sea) using the white sea bream, Diplodus sargus sargus, as a model species. A multidisciplinary approach was used combining 1) spatial distribution patterns of individuals (post-settlers and adults) assessed through visual census within Torre Guaceto MPA and in northern and southern unprotected areas, 2) Lagrangian simulations of dispersal based on an oceanographic model of the region and data on early life-history traits of the species (spawning date, pelagic larval duration) and 3) a preliminary genetic study using microsatellite loci. Results show that the MPA hosts higher densities of larger-sized spawners than outside areas, potentially guaranteeing higher propagule production. Model simulations and field observation suggest that larval retention within and long-distance dispersal across MPA boundaries allow the replenishment of the MPA and of exploited populations up to 100 km down-current (southward) from the MPA. This pattern partially agrees with the high genetic homogeneity found in the entire study area (no differences in genetic composition and diversity indices), suggesting a high gene flow. By contributing to a better understanding of propagule dispersal patterns, these findings provide crucial information for the design of MPAs and MPA networks effective to replenish fish stocks and enhance fisheries in unprotected areas. PMID:23284887

Di Franco, Antonio; Coppini, Giovanni; Pujolar, José Martin; De Leo, Giulio A; Gatto, Marino; Lyubartsev, Vladyslav; Melià, Paco; Zane, Lorenzo; Guidetti, Paolo

2012-01-01

167

Fish habitat simulation models and integrated assessment tools  

International Nuclear Information System (INIS)

Because of human development water use increases in importance, and this worldwide trend is leading to an increasing number of user conflicts with a strong need for assessment tools to measure the impacts both on the ecosystem and the different users and user groups. The quantitative tools must allow a comparison of alternatives, different user groups, etc., and the tools must be integrated while impact assessments includes different disciplines. Fish species, especially young ones, are indicators of the environmental state of a riverine system and monitoring them is a way to follow environmental changes. The direct and indirect impacts on the ecosystem itself are measured, and impacts on user groups is not included. Fish habitat simulation models are concentrated on, and methods and examples are considered from Norway. Some ideas on integrated modelling tools for impact assessment studies are included. One dimensional hydraulic models are rapidly calibrated and do not require any expert knowledge in hydraulics. Two and three dimensional models require a bit more skilled users, especially if the topography is very heterogeneous. The advantages of using two and three dimensional models include: they do not need any calibration, just validation; they are predictive; and they can be more cost effective than traditional habitat hydraulic models when combined with modern data acquisition systems and tailored in a multi-disciplinary study. Suitable modelling model choice sh study. Suitable modelling model choice should be based on available data and possible data acquisition, available manpower, computer, and software resources, and needed output and accuracy in the output. 58 refs

168

Genetic assessment of ornamental fish species from North East India.  

Science.gov (United States)

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

Dhar, Bishal; Ghosh, Sankar Kumar

2015-01-25

169

Peat Depth Assessment Using Airborne Geophysical Data for Carbon Stock Modelling  

Science.gov (United States)

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.

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

2013-04-01

170

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

OpenAIRE

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 ...

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

2013-01-01

171

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)

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.

Delaney, Alyne E.; Becker Jakobsen, Rikke

2012-01-01

172

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

OpenAIRE

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...

Garcia, Sandra Maria Gonzalez

2012-01-01

173

Wavelet decomposition and regime shifts. Assessing the effects of crude oil shocks on stock market returns  

International Nuclear Information System (INIS)

While there is a large body of empirical studies on the relationship between crude oil price changes and stock market returns, they have failed to achieve a consensus on this subject. In this paper, we combine wavelet analysis and Markov Switching Vector Autoregressive (MS-VAR) approach to explore the impact of the crude oil (CO) shocks on the stock market returns for UK, France and Japan over the period from January 1989 to December 2007. Our procedure involves the estimation of the extended MS-VAR model in order to investigate the importance of the resultant wavelet filtering series (after removing random components) in determining the behavior of the stock market volatilities. We show that CO shocks do not affect the recession stock market phases (except for Japan). However, they significantly reduce moderate and/or expansion stock market phases temporarily. Moreover, this negative relationship appears to be more pronounced during the pre-1999 period. The empirical findings will prove extremely useful to investors who need to understand the exact effect of international oil changes on certain stocks prices as well as for policy managers who need a more thorough evaluation about the efficiency of hedging policies affected by oil price changes. (author)

174

Wavelet decomposition and regime shifts: Assessing the effects of crude oil shocks on stock market returns  

International Nuclear Information System (INIS)

While there is a large body of empirical studies on the relationship between crude oil price changes and stock market returns, they have failed to achieve a consensus on this subject. In this paper, we combine wavelet analysis and Markov Switching Vector Autoregressive (MS-VAR) approach to explore the impact of the crude oil (CO) shocks on the stock market returns for UK, France and Japan over the period from January 1989 to December 2007. Our procedure involves the estimation of the extended MS-VAR model in order to investigate the importance of the resultant wavelet filtering series (after removing random components) in determining the behavior of the stock market volatilities. We show that CO shocks do not affect the recession stock market phases (except for Japan). However, they significantly reduce moderate and/or expansion stock market phases temporarily. Moreover, this negative relationship appears to be more pronounced during the pre-1999 period. The empirical findings will prove extremely useful to investors who need to understand the exact effect of international oil changes on certain stocks prices as well as for policy managers who need a more thorough evaluation about the efficiency of hedging policies affected by oil price changes.

175

Assessing patterns of fish demographics and habitat in stream networks  

Science.gov (United States)

Effective habitat restoration planning requires correctly anticipating demographic responses to altered habitats. New applications of Passive Integrated Transponder (PIT) tag technology to fish-habitat research have provided critical insights into fish movement, growth, and surv...

176

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

OpenAIRE

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...

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

2009-01-01

177

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

OpenAIRE

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...

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

2014-01-01

178

Exploiting Growing Stock Volume Maps for Large Scale Forest Resource Assessment: Cross-Comparisons of ASAR- and PALSAR-Based GSV Estimates with Forest Inventory in Central Siberia  

OpenAIRE

Growing stock volume is an important biophysical parameter describing the state and dynamics of the Boreal zone. Validation of growing stock volume (GSV) maps based on satellite remote sensing is challenging due to the lack of consistent ground reference data. The monitoring and assessment of the remote Russian forest resources of Siberia can only be done by integrating remote sensing techniques and interdisciplinary collaboration. In this paper, we assess the information content of GSV estim...

Christian Hüttich; Mikhail Korets; Sergey Bartalev; Vasily Zharko; Dmitry Schepaschenko; Anatoly Shvidenko; Christiane Schmullius

2014-01-01

179

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

DEFF Research Database (Denmark)

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

Nielsen, Anders; Munch-Petersen, Sten

2013-01-01

180

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

Energy Technology Data Exchange (ETDEWEB)

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.

Agusa, Tetsuro [Center for Marine Environmental Studies (CMES), Ehime University, Bunkyo-cho 2-5, Matsuyama 790-8577 (Japan); Kunito, Takashi [Department of Environmental Sciences, Faculty of Science, Shinshu University, 3-1-1 Asahi, Matsumoto 390-8621 (Japan); Sudaryanto, Agus [Center for Marine Environmental Studies (CMES), Ehime University, Bunkyo-cho 2-5, Matsuyama 790-8577 (Japan); Monirith, In [Center for Marine Environmental Studies (CMES), Ehime University, Bunkyo-cho 2-5, Matsuyama 790-8577 (Japan); Kan-Atireklap, Supawat [Center for Marine Environmental Studies (CMES), Ehime University, Bunkyo-cho 2-5, Matsuyama 790-8577 (Japan); Iwata, Hisato [Center for Marine Environmental Studies (CMES), Ehime University, Bunkyo-cho 2-5, Matsuyama 790-8577 (Japan); Ismail, Ahmad [Department of Biology, Faculty of Science and Environmental Studies, Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia); Sanguansin, Joompol [Eastern Marine Fisheries Development Center, Ban Phe, Muang, Rayong 21160 (Thailand); Muchtar, Muswerry [Research and Development Center for Oceanology Indonesia Institute of Sciences, Jl. Pasir Putih 1, Ancol Timur, Jakarta 11048 (Indonesia); Tana, Touch Seang [Social and Cultural Observation Unit (OBSES), Office of the Council of Ministers, Phnom Penh (Cambodia); Tanabe, Shinsuke [Center for Marine Environmental Studies (CMES), Ehime University, Bunkyo-cho 2-5, Matsuyama 790-8577 (Japan)]. E-mail: shinsuke@agr.ehime-u.ac.jp

2007-02-15

181

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

182

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)

183

Global assessment of the status of coral reef herbivorous fishes: evidence for fishing effects  

OpenAIRE

On coral reefs, herbivorous fishes consume benthic primary producers and regulate competition between fleshy algae and reef-building corals. Many of these species are also important fishery targets, yet little is known about their global status. Using a large-scale synthesis of peer-reviewed and unpublished data, we examine variability in abundance and biomass of herbivorous reef fishes and explore evidence for fishing impacts globally and within regions. We show that biomass is more than twi...

Edwards, C. B.; Friedlander, A. M.; Green, A. G.; Hardt, M. J.; Sala, E.; Sweatman, H. P.; Williams, I. D.; Zgliczynski, B.; Sandin, S. A.; Smith, J. E.

2014-01-01

184

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

OpenAIRE

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...

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

2007-01-01

185

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

OpenAIRE

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...

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

2011-01-01

186

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

Science.gov (United States)

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.

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

2014-05-01

187

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)

Full Text Available SciELO South Africa | Language: English Abstract in english 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.

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

188

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)

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

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

2010-08-01

189

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

Directory of Open Access Journals (Sweden)

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.

Raškovi? Božidar S.

2011-01-01

190

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

OpenAIRE

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...

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

2013-01-01

191

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)

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

Kunsook, Chutapa; Gajaseni, Nantana; Paphavasit, Nittharatana

2014-08-01

192

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

OpenAIRE

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...

Aðalbjörg Birna Guttormsdóttir 1978

2009-01-01

193

Regulatory impact assessment : future of UK's system for holding stocks of oil for use in the event of disruption  

International Nuclear Information System (INIS)

This consultation document focuses on the adaption of the United Kingdom government's system for holding emergency stocks of oil to ensure the compliance with international obligations and security of energy supply objectives. The background to the study is traced, and the rational for government intervention is discussed along with the current system which bases obligations on company sales into final consumption, and the urgent need for a new system. Consultation within government resulting in agreement that the system should continue to be based on company obligations and public consultations are discussed. Potential options are assessed and problems with continuing with the existing system based on company obligations are highlighted

194

The effect of corporate disclosure policy on risk assessment and market value: Evidence from Tehran Stock Exchange  

Directory of Open Access Journals (Sweden)

Full Text Available This paper investigates the role of corporate disclosure policy on risk assessment and market value on selected firms from Tehran Stock Exchange over the period 2004-2012. The study considers four risk namely; business risk, cash flow risk, financial risk and systemic risk. Using regression analysis with panel data under fixed effect, the study shows that there was a meaningful relationship between two risks, business risk and systematic risk, and market value before and after corporate disclosure. In other words, after corporate disclosure, the relationship between risk and market value becomes stronger.

Raziyeh Masalegooha

2015-05-01

195

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

196

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

Energy Technology Data Exchange (ETDEWEB)

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.

NONE

1996-12-01

197

Commercial fish species of inland waters: a model for sustainability assessment and management.  

Science.gov (United States)

The permanent increase in the exploitation of commercial fish species has led to the need for developing practical and effective tools for the sustainability assessment and management of the target fish populations. The aim of this study was to formulate an ESHIPPOfishing model which would provide a reliable assessment of commercial fish population sustainability and indicate the conservation priorities. The existing ESHIPPO model was modified by introducing a new Index of local sustainability of fish populations (ILSFP) which enables the selection of "keystone populations" and "keystone habitats/ecosystems" within the basin being investigated. We employed a self-organizing map (SOM) in order to visualize the spatial distribution of the keystone populations and keystone habitats/ecosystems for each fish species. Based on the ILSFP values, environmental specialization (ES) of a fish species and local environmental factors (HIPPO factors), the model estimates the degree of sustainability (DS) of commercial fish populations in the freshwater ecosystems of the western Balkan Peninsula. The results indicate a low degree of sustainability for the majority of commercial fish species of the Middle Danube Basin, especially Acipenser ruthenus and Hucho hucho. The ESHIPPOfishing model presents a cost effective conservation approach, formulated to be applicable to any kind of river basin. The application of the ESHIPPOfishing model provides a comprehensive insight into the viability of target fish populations, which would not only further improve the selection of conservation priorities, but also facilitate the management of aquatic ecosystems. PMID:25170830

Simi?, Vladica M; Simi?, Snežana B; Stojkovi? Piperac, Milica; Petrovi?, Ana; Miloševi?, Djuradj

2014-11-01

198

Co-assessment of biomass and soil organic carbon stocks in a future reservoir area located in Southeast Asia.  

Science.gov (United States)

An assessment of the organic carbon stock present in living or dead vegetation and in the soil on the 450 km2 of the future Nam Theun 2 hydroelectric reservoir in Lao People's Democratic Republic was made. Nine land cover types were defined on the studied area: dense, medium, light, degraded, and riparian forests; agricultural soil; swamps; water; and others (roads, construction sites, and so on). Their geographical distribution was assessed by remote sensing using two 2008 SPOT 5 images. The area is mainly covered by dense and light forests (59%), while agricultural soil and swamps account for 11% and 2%, respectively. For each of these cover types, except water, organic carbon density was measured in the five pools defined by the Intergovernmental Panel on Climate Change: aboveground biomass, litter, deadwood, belowground biomass, and soil organic carbon. The area-weighted mean carbon densities for these pools were estimated at 45.4, 2.0, 2.2, 3.4, and 62.2 tC/ha, respectively, i.e., a total of about 115±15 tC/ha for a soil thickness of 30 cm, corresponding to a total flooded organic carbon stock of 5.1±0.7 MtC. This value is much lower than the carbon density for some South American reservoirs for example where total organic carbon stocks range from 251 to 326 tC/ha. It can be mainly explained by (1) the higher biomass density of South American tropical primary rainforest than of forests in this study and (2) the high proportion of areas with low carbon density, such as agricultural or slash-and-burn zones, in the studied area. PMID:20364314

Descloux, Stéphane; Chanudet, Vincent; Poilvé, Hervé; Grégoire, Alain

2011-02-01

199

The Assessment of Social Reporting on behalf of Accepted Corporations Listed in Tehran Stock Exchange  

OpenAIRE

During the recent years that many changes have accomplished in economy and social expectations, typically the accounting world has confronted the society with the socio-environmental effects of industries development. According to these changes in society and environment, accounting also affects from it s environment. In this study the feasibility of social reporting on behalf of accepted corporations listed in Tehran stock exchange has been studied. In this survey we accumulate required ...

Hosseyn Karbasi Yazdi; Kobra Hemmati; Ali Bayat

2012-01-01

200

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

Science.gov (United States)

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%.

Warren, M. W.; Kauffman, J. B.; Murdiyarso, D.; Anshari, G.; Hergoualc'h, K.; Kurnianto, S.; Purbopuspito, J.; Gusmayanti, E.; Afifudin, M.; Rahajoe, J.; Alhamd, L.; Limin, S.; Iswandi, A.

2012-11-01

201

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

OpenAIRE

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...

Fromentin, Jean-marc; Restrepo, Victor

2001-01-01

202

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

Scientific Electronic Library Online (English)

Full Text Available SciELO South Africa | Language: English Abstract in english 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.

MF, Avenant.

2010-07-01

203

Assessment of physiological strain in inland fishing activity  

OpenAIRE

Ten fishermen aged between 19 and 48 years of age, were examined in the field during inland fishing activity, which they perform individually. Physiological strain in terms of heart rate varied between 86 and 115 beats/min with mean net cardiac cost of 32 beats/min. The average relative cardiac cost was 36%. Analysis of physiological responses revealed that the recommended limits of cardiac strain indices were surpassed during the majority of the fishing period. Average energy cost was...

Biswas R*,1; Samanta A

2006-01-01

204

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

OpenAIRE

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...

Fahy, E.; Gleeson, P.

1992-01-01

205

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)

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.

Pranay Sharma

2014-02-01

206

Question of the Day: Regeneration of Fish  

Science.gov (United States)

The two figures shown above are from the The Fishing Game (more info) game. They show the number of new fish per year that are added to the fish "stock," depending on the maximum number of fish that the ...

207

Fish as bioindicators in aquatic environmental pollution assessment: A case study in Lake Victoria wetlands, Uganda  

Science.gov (United States)

Growing human population and industrialization have led to the pollution of most aquatic ecosystems and consequent deterioration in environmental water quality. Indicator organisms are needed to improve assessment programmes on the ecological impacts of anthropogenic activities on the aquatic environment. Fish have been widely documented as useful indicators of environmental water quality because of their differential sensitivity to pollution. This study investigated the environmental water quality of selected wetland ecosystems using fish as biological indicators. Fish community structure in relation to water quality was assessed in five wetlands along the shoreline of Lake Victoria from August 2006 to June 2008. Four urban wetlands were variedly impacted by anthropogenic activities while one rural wetland was less impacted, and served as a reference site. Fish species diversity, abundance and richness were assessed, and canonical correspondence analysis (CCA) was used to evaluate the relationship between the fish communities and environmental variables. Results revealed that urban effluent impacted negatively on water quality and consequently the fish community structure. A total of 29 fish species were recorded throughout the study with the lowest number of 15 species recorded in the most impacted site. Shannon diversity and Margalef species richness indices were highest at the references site and lowest at the most impacted site. Wetland haplochromis species dominated the reference site, while oreochromis species dominated the most impacted site. The inshore locations registered higher species diversity and low species richness than the offshore locations. Low dissolved oxygen, pH, secchi depth and high electrical conductivity, total phosphorous, and total nitrogen were strongly associated with the effluent-impacted sites and greatly influenced the fish community structure. This study recommends the use of fish as valuable biological indicators in aquatic environmental pollution assessment.

Naigaga, I.; Kaiser, H.; Muller, W. J.; Ojok, L.; Mbabazi, D.; Magezi, G.; Muhumuza, E.

208

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

Directory of Open Access Journals (Sweden)

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%.

M. W. Warren

2012-11-01

209

Assessment of the relationship between oil prices and US oil stocks  

International Nuclear Information System (INIS)

This paper qualitatively and quantitatively analyzes the relationship between US monthly ending oil stocks position with that of West Texas Intermediate (WTI) oil prices from February 1995 to July 2004. The paper concludes if other things are held constant, WTI is inversely related to the petroleum products (PPP), combined petroleum products and crude oil (CPPP), crude oil alone (Crude), total oil stocks including petroleum products, crude oil and strategic petroleum reserves SPR (Total), total gasoline (TGO), total distillate (TDO). It could not establish a statistically significant and negative relationship with SPR when run alone. One percent increase (decrease) in CPPP, PPP, Crude, Total, TGO and TDO leads to decrease (increase) in WTI, respectively, by 0.70, 0.43, 0.37, 0.97, 0.26 and 0.21 percent. Oil prices are largely influenced by total crude and Crude and PPP inventories levels while modestly with variations in gasoline and distillate stocks levels. Despite a healthy increase of over 22 percent in SPR from January 2001 to April 2004, it did not result in easing of oil prices. Primarily because SPR are meant for security of supply concern and are only released under extreme conditions by the President of United States, they are neither meant for the purposes of balancing supply-demand gap nor for the stability of oil prices. The aggressive SPR buildup in recent years is related to international terrorism, geopolitical situation in the Middle East, particularl situation in the Middle East, particularly in Iraq, that encourages US government to enhance its SPR to meet any short-term eventuality. The analyst must keep a close eye on CPPP and the total oil stocks variation to forecast WTI in the short run whilst gasoline and distillate influence oil prices modestly in the short run. SPR, on the other hand, are expected to play a pivotal role in balancing oil prices and in providing a critical resource for the economy in case of any major shortfall in the long run

210

Predictive models for fish assemblages in eastern USA streams: implications for assessing biodiversity  

Science.gov (United States)

Management and conservation of aquatic systems require the ability to assess biological conditions and identify changes in biodiversity. Predictive models for fish assemblages were constructed to assess biological condition and changes in biodiversity for streams sampled in the eastern United States as part of the U.S. Geological Survey's National Water Quality Assessment Program. Separate predictive models were developed for northern and southern regions. Reference sites were designated using land cover and local professional judgment. Taxonomic completeness was quantified based on the ratio of the number of observed native fish species expected to occur to the number of expected native fish species. Models for both regions accurately predicted fish species composition at reference sites with relatively high precision and low bias. In general, species that occurred less frequently than expected (decreasers) tended to prefer riffle areas and larger substrates, such as gravel and cobble, whereas increaser species (occurring more frequently than expected) tended to prefer pools, backwater areas, and vegetated and sand substrates. In the north, the percentage of species identified as increasers and the percentage identified as decreasers were equal, whereas in the south nearly two-thirds of the species examined were identified as decreasers. Predictive models of fish species can provide a standardized indicator for consistent assessments of biological condition at varying spatial scales and critical information for an improved understanding of fish species that are potentially at risk of loss with changing water quality conditions.

Meador, Michael R.; Carlisle, Daren M.

2009-01-01

211

Littleneck clam, Protothaca staminea, as a tool for potential oil pollution assessment: density of stock  

Energy Technology Data Exchange (ETDEWEB)

Littleneck clams were sampled on two plots in the north Puget Sound region (a control beach and a beach adjacent to an oil refinery which has been contaminated with crude oil in the past) to evaluate the effects of sampling strategy on costs for measuring plot density in a hypothesis testing framework. The general approach involved sampling of 0.25 sq m quadrats, to a depth of 15 to 30 cm, on permanently marked plots. Detection of differences in density as small as 10% with 80% probability would exceed in cost the economic value of 10% of the stock and decimate > 10% of the stock unless provision were made to allow survival of sampled clams. Restriction of sampling to the marketable cohort or to parts of plots covered by vegetation, increasing the probability for a Type I error, and use of a smaller quadrat size all reduced sampling costs substantially. The projections of sampling requirements were made using estimates of variance obtained from sampling in differing manners and at different seasons. These estimates did not give good uniformity. This has an important ramification for pollutant studies because a common variance for control and polluted means is an assumption central to the use of probability models.

Vanderhorst, J.R.; Wilkinson, P.

1979-07-01

212

Chemical and biochemical tools to assess pollution exposure in cultured fish  

Energy Technology Data Exchange (ETDEWEB)

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.

Fernandes, Denise [C.I.M.A., University of Algarve, F.C.M.A., Campus de Gambelas, 8005-139 Faro (Portugal); Department of Environmental Chemistry, IIQAB-CSIC, Jordi Girona 18, 08034 Barcelona (Spain); Zanuy, Silvia [Department of Fish Reproductive Physiology, IATS-CSIC, 12595 Castellon (Spain); Bebianno, Maria Joao [C.I.M.A., University of Algarve, F.C.M.A., Campus de Gambelas, 8005-139 Faro (Portugal); Porte, Cinta [Department of Environmental Chemistry, IIQAB-CSIC, Jordi Girona 18, 08034 Barcelona (Spain)], E-mail: cpvqam@cid.csic.es

2008-03-15

213

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

214

Assessment of fishing the valuable hydrobionts in the Sivash bay  

Directory of Open Access Journals (Sweden)

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.

Kireeva Irina Yurievna

2013-09-01

215

Combining Telephone Surveys and Fishing Catches Self-Report: The French Sea Bass Recreational Fishery Assessment  

OpenAIRE

Fisheries statistics are known to be underestimated, since they are mainly based on information about commercial fisheries. However, various types of fishing activities exist and evaluating them is necessary for implementing effective management plans. This paper assesses the characteristics and catches of the French European sea bass recreational fishery along the Atlantic coasts, through the combination of large-scale telephone surveys and fishing diaries study. Our results demonstrated tha...

Rocklin, Delphine; Levrel, Harold; Drogou, Mickae?l; Herfaut, Johanna; Veron, Ge?rard

2014-01-01

216

The Assessment of Social Reporting on behalf of Accepted Corporations Listed in Tehran Stock Exchange  

Directory of Open Access Journals (Sweden)

Full Text Available During the recent years that many changes have accomplished in economy and social expectations, typically the accounting world has confronted the society with the socio-environmental effects of industries development. According to these changes in society and environment, accounting also affects from it s environment. In this study the feasibility of social reporting on behalf of accepted corporations listed in Tehran stock exchange has been studied. In this survey we accumulate required data about corporations using a questionnaire and due to the obviousness of statistical population size to estimate the sample size. Conclusions of research indicate that factors such as lack of appropriate accounting information system, lack of awareness of managers about the social cost and nonexistence of legal standards and high social reporting costs causes the avoidance of social reporting on behalf of Iranian corporations.

Hosseyn Karbasi Yazdi

2012-07-01

217

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

218

Assessing Ecological Water Quality with Macroinvertebrates and Fish: A Case Study from a Small Mediterranean River  

Science.gov (United States)

Biological elements, such as benthic macroinvertebrates and fish, have been used in assessing the ecological quality of rivers according to the requirements of the Water Framework Directive. However, the concurrent use of multiple organism groups provides a broader perspective for such evaluations, since each biological element may respond differently to certain environmental variables. In the present study, we assessed the ecological quality of a Greek river (RM4 type), during autumn 2003 and spring 2004 at 10 sites, with benthic macroinvertebrates and fish. Hydromorphological and physicochemical parameters, habitat structure, and riparian vegetation were also considered. Pollution sensitive macroinvertebrate taxa were more abundant at headwaters, which had good/excellent water quality according to the Hellenic Evaluation System (HES). The main river reaches possessed moderate water quality, while downstream sites were mainly characterised as having bad or poor water quality, dominated by pollution-tolerant macroinvertebrate taxa. Macroinvertebrates related strongly to local stressors as chemical degradation (ordination analysis CCA) and riparian quality impairment (bivariate analysis) while fish did not. Fish were absent from the severely impacted lower river reaches. Furthermore, external pathological signs were observed in fish caught at certain sites. A combined use of both macroinvertebrates and fish in biomonitoring programs is proposed for providing a safer assessment of local and regional habitat impairment.

Cheimonopoulou, Maria Th.; Bobori, Dimitra C.; Theocharopoulos, Ioannis; Lazaridou, Maria

2011-02-01

219

Long-term consumption of dried bonito dashi (a traditional Japanese fish stock) reduces anxiety and modifies central amino acid levels in rats.  

Science.gov (United States)

Dried bonito dashi, a traditional Japanese fish stock, enhances palatability of various dishes because of its specific flavor. Daily intake of dashi has also been shown to improve mood status such as tension-anxiety in humans. This study aimed at investigating beneficial effects of dashi ingestion on anxiety/depression-like behaviors and changes in amino acid levels in the brain and plasma in rats. Male Wistar rats were given either dried bonito dashi or water for long-term (29 days; Experiment 1) or single oral administration (Experiment 2). Anxiety and depression-like behaviors were tested using the open field and forced swimming tests, respectively. Concentrations of amino acids were measured in the hippocampus, hypothalamus, cerebellum, and jugular vein. During the long-term (29 days) consumption, rats given 2% dashi frequently entered the center zone and spent more time compared with the water controls in the open field test. However, the dashi was ineffective on depression-like behavior. In the hippocampus, concentrations of hydroxyproline, anserine, and valine were increased by dashi while those of asparagine and phenylalanine were decreased. In the hypothalamus, the methionine concentration was decreased. In a single oral administration experiment, the dashi (1%, 2% or 10%) showed no effects on behaviors. Significance was observed only in the concentrations of ?-aminoadipic acid, cystathionine, and ornithine in the hippocampus. Dried bonito dashi is a functional food having anxiolytic-like effects. Daily ingestion of the dashi, even at lower concentrations found in the cuisine, reduces anxiety and alters amino acid levels in the brain. PMID:24701973

Funatsu, Shoichiro; Kondoh, Takashi; Kawase, Takahiro; Ikeda, Hiromi; Nagasawa, Mao; Michael Denbow, D; Furuse, Mitsuhiro

2014-04-01

220

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

221

Mercury contamination in fish from gold mining areas in Indonesia and human health risk assessment.  

Science.gov (United States)

This study investigates the effects on fish and assesses human health hazards from mercury released in two gold mining areas in Indonesia: Tatelu (North Sulawesi Province) and Galangan (Katingan District, Central Kalimatan Province). In Tatelu, 154 fish specimens of 10 freshwater species were collected, as well as five marine species from the fish market. The mean concentration of total mercury in muscles of freshwater fish from this area was 0.58+/-0.44 microg/g, with more than 45% of fish having Hg levels above the WHO guideline for human consumption of 0.5 microg/g. In Galangan, where 263 fish specimens of 25 species were collected, the total mercury in muscles averaged 0.25+/-0.69 microg/g. Excluding data from flooded open pits in sub-area P4, mean Hg levels in fish from Galangan were 2 to 4 times lower than 0.5 microg/g, while fewer than 10% of fish from Galangan exceeded WHO guidelines. The Hazard Quotient (HQ) was applied to both areas to determine the threat of MeHg exposure for communities in both areas. The HQ is a risk assessment indicator which defines the ratio of exposure level to a single substance in relation to a reference dose. Samples from Tatelu (excluding marine species) had an HQ above one, while those from Galangan resulted in values of 2.4 for the whole area and 9.9 for sub-area P4, pointing to potentially harmful fish consumption for the local population. By using the single-compartment model to estimate mercury levels in blood and hair from daily intake dose, sub-area P4 showed the highest levels, higher than the upper limit guideline for pregnant women, but still lower than threshold levels associated with observed clinical effects. PMID:16600329

Castilhos, Zuleica C; Rodrigues-Filho, Saulo; Rodrigues, Ana Paula C; Villas-Bôas, Roberto C; Siegel, Shefa; Veiga, Marcello M; Beinhoff, Christian

2006-09-01

222

Large-scale assessment of Mediterranean marine protected areas effects on fish assemblages.  

Science.gov (United States)

Marine protected areas (MPAs) were acknowledged globally as effective tools to mitigate the threats to oceans caused by fishing. Several studies assessed the effectiveness of individual MPAs in protecting fish assemblages, but regional assessments of multiple MPAs are scarce. Moreover, empirical evidence on the role of MPAs in contrasting the propagation of non-indigenous-species (NIS) and thermophilic species (ThS) is missing. We simultaneously investigated here the role of MPAs in reversing the effects of overfishing and in limiting the spread of NIS and ThS. The Mediterranean Sea was selected as study area as it is a region where 1) MPAs are numerous, 2) fishing has affected species and ecosystems, and 3) the arrival of NIS and the northward expansion of ThS took place. Fish surveys were done in well-enforced no-take MPAs (HP), partially-protected MPAs (IP) and fished areas (F) at 30 locations across the Mediterranean. Significantly higher fish biomass was found in HP compared to IP MPAs and F. Along a recovery trajectory from F to HP MPAs, IP were similar to F, showing that just well enforced MPAs triggers an effective recovery. Within HP MPAs, trophic structure of fish assemblages resembled a top-heavy biomass pyramid. Although the functional structure of fish assemblages was consistent among HP MPAs, species driving the recovery in HP MPAs differed among locations: this suggests that the recovery trajectories in HP MPAs are likely to be functionally similar (i.e., represented by predictable changes in trophic groups, especially fish predators), but the specific composition of the resulting assemblages may depend on local conditions. Our study did not show any effect of MPAs on NIS and ThS. These results may help provide more robust expectations, at proper regional scale, about the effects of new MPAs that may be established in the Mediterranean Sea and other ecoregions worldwide. PMID:24740479

Guidetti, Paolo; Baiata, Pasquale; Ballesteros, Enric; Di Franco, Antonio; Hereu, Bernat; Macpherson, Enrique; Micheli, Fiorenza; Pais, Antonio; Panzalis, Pieraugusto; Rosenberg, Andrew A; Zabala, Mikel; Sala, Enric

2014-01-01

223

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)

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.

Ana L. Ibáñez

2011-09-01

224

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)

Full Text Available SciELO Mexico | Language: Spanish Abstract in spanish 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.

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

2011-09-01

225

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

Czech Academy of Sciences Publication Activity Database

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

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

2009-01-01

226

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

227

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

Energy Technology Data Exchange (ETDEWEB)

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 {mu}g/g dry wt. About 3% of the samples contained Hg levels exceeding the no observed adverse effects level (NOAEL) of WHO (50 {mu}g/g) and the levels in some hair samples of women also exceeded the NOAEL (10 {mu}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 {mu}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, 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.

Agusa, Tetsuro [Center for Marine Environmental Studies (CMES), Ehime University, Bunkyo-cho 2-5, Matsuyama 790-8577 (Japan); Kunito, Takashi [Department of Environmental Sciences, Faculty of Science, Shinshu University, 3-1-1 Asahi, Matsumoto, Nagano 390-8621 (Japan); Iwata, Hisato [Center for Marine Environmental Studies (CMES), Ehime University, Bunkyo-cho 2-5, Matsuyama 790-8577 (Japan); Monirith, In [Center for Marine Environmental Studies (CMES), Ehime University, Bunkyo-cho 2-5, Matsuyama 790-8577 (Japan); Tana, Touch Seang [Social and Cultural Observation Unit (OBSES) of the Cabinet of the Council of Ministers, Phnom Penh (Cambodia); Subramanian, Annamalai [Center for Marine Environmental Studies (CMES), Ehime University, Bunkyo-cho 2-5, Matsuyama 790-8577 (Japan); Tanabe, Shinsuke [Center for Marine Environmental Studies (CMES), Ehime University, Bunkyo-cho 2-5, Matsuyama 790-8577 (Japan)]. E-mail: shinsuke@agr.ehime-u.ac.jp

2005-03-01

228

Development of a spatially distributed model of fish population density for habitat assessment of rivers  

Science.gov (United States)

Flow conditions play an important role in sustaining biodiversity of river ecosystem. However, their relations to freshwater fishes, especially to fish population density, have not been clearly described. This study, therefore, aimed to propose a new methodology to quantitatively link habitat conditions, including flow conditions and other physical conditions, to population density of fish species. We developed a basin-scale fish distribution model by integrating the concept of habitat suitability assessment with a distributed hydrological model (DHM) in order to estimate fish population density with particular attention to flow conditions. Generalized linear model (GLM) was employed to evaluate the relationship between population density of fish species and major environmental factors. The target basin was Sagami River in central Japan, where the river reach was divided into 10 sections by estuary, confluences of tributaries, and river-crossing structures (dams, weirs). The DHM was employed to simulate river discharge from 1998 to 2005, which was used to calculate 10 flow indices including mean discharge, 25th and 75th percentile discharge, duration of low and high flows, number of floods. In addition, 5 water quality parameters and 13 other physical conditions (such as basin area, river width, mean diameter of riverbed material, and number of river-crossing structures upstream and downstream) of each river section were considered as environmental variables. In case of Sagami River, 10 habitat variables among them were then selected based on their correlations to avoid multicollinearity. Finally, the best GLM was developed for each species based on Akaike's information criterion. As results, population densities of 16 fish species in Sagami River were modelled, and correlation coefficients between observed and calculated population densities for 10 species were more than 0.70. The key habitat factors for population density varied among fish species. Minimum discharge (MID) was found to be positively correlated to 9 among 16 fish species. For duration of high and low flows (DHF and DLF), longer DHF/DLF was corresponded to lower population density for 7/6 fish species, respectively, such as Rhinogobius kurodai and Plecoglossus altivelis altivelis. Among physical habitat conditions, sinuosity index (SI, the ratio between actual river section length and straight line length) seems to be the most important parameter for fish population density in Sagami River basin, since it affects 12 out of 16 fish species, followed by mean longitudinal slope (S) and number of downstream dams (NLD). Above results demonstrated the applicability of fish distribution model to provide quantitative information on flow conditions required to maintain fish population, which enabled us to evaluate and project ecological consequences of water resource management policy, such as flood management and water withdrawal.

Sui, Pengzhe; Iwasaki, Akito; Ryo, Masahiro; Saavedra, Oliver; Yoshimura, Chihiro

2013-04-01

229

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

230

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

Directory of Open Access Journals (Sweden)

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.

Mildred M. Labata

2012-06-01

231

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.

232

Heavy metal bioaccumulation and health hazard assessment for three fish species from nansi lake, china.  

Science.gov (United States)

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

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

2015-04-01

233

An assessment of the DNA barcodes of Indian freshwater fishes.  

Science.gov (United States)

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

Chakraborty, Mohua; Ghosh, Sankar Kumar

2014-03-01

234

Health risk assessment for consumption of fish originating from ponds near Dabaoshan mine, South China.  

Science.gov (United States)

Mining effluents are a potential source of toxic metals in the surrounding aquatic ecosystem and pose a potential health risk to humans from fish consumption. The objective of this paper is to assess the impact of the long-term Dabaoshan mining operation on heavy metal accumulation in different fish species. Heavy metal accumulation (lead (Pb), cadmium (Cd), zinc (Zn), and copper (Cu)) in four tissues (liver, muscle, intestine, and gills) of five carp species (Hypophthalmichthys molitrix, Ctenopharyngodon idellus, Megalobrama amblycephala, Aristichthys nobilis, and Carassius auratus auratus) from two fishponds exposed to effluent waters from Dabaoshan mine, South China. The bioaccumulation factor (BAF) and target hazard quotients were calculated to assess potential health risks to local residents through fish consumption. Levels of heavy metals varied depending on the analyzed tissues. C. auratus auratus accumulated the higher Pb, Cd, Zn, and Cu in the intestine compared with other fish species. Liver of all five species contained high concentrations of Pb, Cd, Zn, and Cu. The BAF for the studied metals showed a descending order of Cd>Zn>Cu>Pb for fishpond 1 and Zn>Cd>Cu>Pb for fishpond 2. Risk assessments suggested that potential human health risk may be present due to high Pb and Cd concentration in the muscle of some fish species exceeding the national and international limits, although the target hazard quotients were less than one. PMID:23508535

Zhuang, Ping; Li, Zhi-an; McBride, Murray B; Zou, Bi; Wang, Gang

2013-08-01

235

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)

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.

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

236

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

237

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

Directory of Open Access Journals (Sweden)

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.

Amel Abdoullah Ahmed

2014-01-01

238

Mercury concentrations in Maine sport fishes  

Energy Technology Data Exchange (ETDEWEB)

To assess mercury contamination of fish in Maine, fish were collected from 120 randomly selected lakes. The collection goal for each lake was five fish of the single most common sport fish species within the size range commonly harvested by anglers. Skinless, boneless fillets of fish from each lake were composited, homogenized, and analyzed for total mercury. The two most abundant species, brook trout Salvelinus fontinalis and smallmouth bass Micropterus dolomieu, were also analyzed individually. The composite fish analyses indicate high concentrations of mercury, particularly in large and long-lived nonsalmonid species. Chain pickerel Esox niger, smallmouth bass, largemouth bass Micropterus salmoides, and white perch Morone americana had the highest average mercury concentrations, and brook trout and yellow perch Perca flavescens had the lowest. The mean species composite mercury concentration was positively correlated with a factor incorporating the average size and age of the fish. Lakes containing fish with high mercury concentrations were not clustered near known industrial or population centers but were commonest in the area within 150 km of the seacoast, reflecting the geographical distribution of species that contained higher mercury concentrations. Stocked and wild brook trout were not different in length or weight, but wild fish were older and had higher mercury concentrations. Fish populations maintained by frequent introductions of hatchery-produced fish and subject to high angler exploitation rates may consist of younger fish with lower exposure to environmental mercury and thus contain lower concentrations than wild populations.

Stafford, C.P. [Univ. of Maine, Orono, ME (United States); Haines, T.A. [Geological Survey, Orono, ME (United States)

1997-01-01

239

Use of artificial substrates to enhance production of fresh water herbivorous fish in pond culture  

OpenAIRE

Two trials were conducted in mud-bottomed concrete tanks to assess the potential of using artificial substrates to enhance fish production in ponds. Three substrate types were tested: bamboo poles, PVC pipes and sugarcane bagasse bundles. In one trial, periphyton was grown on the substrates in the absence of fish. In the second trial, masheer (Tor khudree Sykes) fingerlings were stocked at three densities. Results showed a significant effect of substrate type on fish growth (P 0.001) and on n...

Keshavanath, P.; Gangadhar, B.; Ramesh, T. J.; Rooij, J. M.; Beveridge, M. C. M.; Baird, D.; Verdegem, M. C. J.

2001-01-01

240

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)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese 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.

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

2013-06-01

241

Lock, stock, and barrel: A comprehensive assessment of the determinants of terror  

OpenAIRE

We assess the robustness of previous findings on the determinants of terrorism. Using extreme bound analysis, the three most comprehensive terrorism datasets, and focusing on the three most commonly analyzed aspects of terrorist activity, i.e., location, victim, and perpetrator, we re-assess the effect of 65 proposed correlates. Evaluating around 13.4 million regressions, we find 18 variables to be robustly associated with the number of incidents occurring in a given country-year, 15 variable...

Gassebner, Martin; Luechinger, Simon

2011-01-01

242

Closed recirculating culture of scorpaenid fish and puffer fish. Examination of nitrogen-excretion rate, proper stocking density and optimum temperature, and rearing experiments; Junkan roka hoshiki ni yoru oniokoze oyobi torafugu yogyo gijutsu no kaihatsu. Chisso haishutsuryo, tekisei shuyo mitsudo, koteki suion no kaimei oyobi shiiku shiken  

Energy Technology Data Exchange (ETDEWEB)

Nitrogen excretion rate, proper stocking density, and optimum temperature for growth were examined on scorpaenid fish and puffer fish to establish closed recirculating culture techniques. Nitrogen excretion rate of scorpaenid fish about 5, 10 and 150 g in body weight was 20, 28 and 10 mg-N/100 g/day after feeding, respectively. Necessary volume of net filter medium to produce 1 kg of fish was estimated to be 1 liter. Growth rate and survival rate of fish were not affected by rearing density of 10 to 30 kg/m{sup 2}-bottom area of cage. The optimum temperature for the growth was 27degC regardless of development stage. Nitrogen excretion rate of puffer fish about 23 g in body weight was 60 mg-N/100 g/day after feeding. Necessary volume of net filter medium to produce 1 kg of fish was estimated to be 2 liters. Growth rate of fish was not affected by rearing density of 6 to 50 kg/m{sup 3}-volume of cage. However, a survival rate was slightly decreased as the rearing density increased. For the fish of 3 g in body weight, growth at 18degC was significantly inferior to those at 21, 24 and 27degC. For the fish of 54 g, growth at 25degC was superior to those at 15, 20 and 30degC. Survival rate of both sizes of fish was decreased as the temperature increased. 59 refs., 9 figs., 9 tabs.

Furuta, T.; Kikuchi, K.; Iwata, N.; Honda, H. [Central Research Institute of Electric Power Industry, Tokyo (Japan)

1997-03-01

243

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

Czech Academy of Sciences Publication Activity Database

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

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

2009-01-01

244

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

Scientific Electronic Library Online (English)

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.

Renato Cesar, Sato.

2013-04-01

245

Assessing the potential for fish predation to impact zebra mussels (Dreissena polymorpha): Insight from bioenergetics models  

Science.gov (United States)

Rates of annual food consumption and biomass were modeled for several fish species across representative rivers and lakes in eastern North America. Results were combined to assess the relative potential of fish predation to impact zebra mussels (Dreissena polymorpha). Predicted annual food consumption by fishes in southern waters was over 100% greater than that in northern systems because of warmer annual water temperatures and presumed increases in metabolic demand. Although generally increasing with latitude, biomasses of several key zebra mussel fish predators did not change significantly across latitudes. Biomasses of some less abundant fish predators did increase significantly with latitude, but increases were not of the magnitude to offset predicted decreases in food consumption. Our results generally support the premise that fishes in rivers and lakes of the southern United States (U.S.) have inherently greater potential to impact zebra mussels by predation. Our simulations may provide a partial explanation of why zebra mussel invasions have not been as rapid and widespread in southern U.S. waters compared to the Great Lakes region. ?? Blackwell Munksgaard, 2004.

Eggleton, M.A.; Miranda, L.E.; Kirk, J.P.

2004-01-01

246

Stream fishes and desirable fish stocks  

DEFF Research Database (Denmark)

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.

Dieperink, C.; Sand-Jensen, K.

2006-01-01

247

Stock Assessment of Columbia River Anadromous Salmonids : Final Report, Volume I, Chinook, Coho, Chum and Sockeye Salmon Summaries.  

Energy Technology Data Exchange (ETDEWEB)

The purpose was to identify and characterize the wild and hatchery stocks of salmon and steelhead in the Columbia River Basin on the basis of currently available information. This report provides a comprehensive compilation of data on the status and life histories of Columbia Basin salmonid stocks.

Howell, Philip J.

1986-07-01

248

Reproductive effects assessment of fish in streams on the Oak Ridge Reservation  

International Nuclear Information System (INIS)

The Department of Energy has three large facilities located on the Oak Ridge Reservation Site, the Y-12 Plant, and the Oak Ridge National Laboratory. Several Biological Monitoring and Abatement Programs (BMAP) monitor and assess the effects of these facilities on the aquatic and terrestrial resources of the reservation. One BMAP task concerns the potential role of contaminant-related reproductive dysfunction in shaping the composition of fish communities in creeks draining the facilities. This task addresses specific questions concerning (1) the reproductive competence of adult fish in the streams, and (2) the capacity of fish embryos and fry to survive and develop sequent reproductive cohorts. Evidence for current or potential reproductive impacts in several of the streams include abnormal fecundity at some sites, increased incidences of oocyte atresia, and a marked toxicity of surface water samples from several stream reaches to fish embryos in periodic embryo-larval tests. Recovery of certain of the monitored streams in response to ongoing remedial actions is documented by positive changes over time in many these indicators of reproductive dysfunction. These results suggest that the monitoring of reproductive indicators can be a sensitive tool for assessing the effects of both industrial discharges and remedial activities on the fish resources of receiving streams

249

Assessment on dioxin-like compounds intake from various marine fish from Zhoushan Fishery, China.  

Science.gov (United States)

Sea fish consuming is an important intake source of dioxin-like compounds, especially for the coastal residents. To assess the intake levels of these contaminants from sea fish and to provide risk-based consumption advice, concentrations of 17 polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and 12 dioxin-like polychlorinated biphenyls (dl-PCBs) were measured in 32 commonly consumed fish species from Zhoushan Fishery, China. Due to the different accumulation influenced by fat content, feed habits and living zone in the sea area, the levels of PCDDs, PCDFs and dl-PCBs in different fish species varied significantly ranging from 0.002 to 0.078pg WHO-TEQ/g fresh weight, from 0.002 to 0.553pg WHO-TEQ/g fresh weight and from 0.003 to 2.059pg WHO-TEQ/g fresh weight, respectively. Based on mean fish consuming rate in China, the estimated maximum possible dioxin-like compounds intake through different fish species ranged from 0.26 to 65.61pgTEQkg(-1)bwmonth(-1). Bullet mackerel has the highest monthly intake level which was much higher than other fish species and very close to the provisional tolerable monthly intake (70pgTEQkg(-)(1)bwmonth(-)(1)) proposed by the Joint FAO/WHO Expert Committee on Food Additives. Hence, comparing to other fish species, the consumption of Bullet mackerel from Zhoushan Fishery should be cautious to reduce the potential health risk. PMID:25180652

Wang, Xiangyong; Zhang, Hongxia; Zhang, Lei; Zhong, Kai; Shang, Xiaohong; Zhao, Yunfeng; Tong, Zhendong; Yu, Xinwei; Li, Jingguang; Wu, Yongning

2015-01-01

250

A Comparative Assessment of Hydroponically Grown Cereal Crops for the Purification of Aquaculture Wastewater and the Production of Fish Feed  

Directory of Open Access Journals (Sweden)

Full Text Available Hydroponically grown wheat, barley and oats were examined for their ability to remove nutrients from aquaculture wastewater. Wheat, barley and oats seeds were germinated in water in a hydroponics system. The seedlings then received wastewater from an aquaculture system stocked with Arctic charr. During the experiment, the crops grew rapidly and fairly uniformly and showed no signs of mineral deficiency although fungal growth was evident. The average crop heights and yields at harvest were 19.0, 25.5 and 25.2 cm and 64, 59 and 42 t ha-1 for wheat, barley and oats, respectively. The hydroponically grown wheat, barley and oats 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 53.3 to 57.7%, from 55.7 to 78.7%, from 76.0 to 80.0% from 85.1 to 92.9%, from 62.1 to 79.3% and from 74.1 to 93.0%, respectively. The compartments containing barley produced the highest quality effluent, which was suitable for reuse in aquaculture operations. The average TS, COD, NH4+-N, NO2--N, NO3--N and PO43--P concentrations and pH of the final effluent from the compartments containing barley were 442, 64, 0.50, 0.02, 5.89 and 0.61 mg L-1 and 6.65, respectively. The nutritive value of the three wastewater grown crops was assessed to determine the suitability of using the plants as a component in fish feed. The three terrestrial crops meet the energy, fat, Ca, Mg, P, Na, S and Mn dietary requirements of aquatic animals, exceed the carbohydrate, crude fiber, Cl, K, Cu, Fe, Se and Zn requirements of fish and shellfish and do not contain sufficient amounts of protein to meet the dietary requirements of fish and shellfish. The crops will require supplementation with a high protein source that contains low concentrations of carbohydrates, crude fiber, Cl, K, Cu, Fe, Se and Zn. Common protein sources that could be used for supplementation included fishmeal, bone meal and blood meal.

A. M. Snow

2008-01-01

251

Harvesting Strategies in a Fish Stock Dominated by Low-frequency Variability:The Norwegian Spring-spawning Herring (Clupea harengus)  

OpenAIRE

Heavy positively autocorrelated natural fluctuations in a fisheries stock level are problematic for fisheries management, and collapses in the stock dynamics are difficult to avoid. In this paper, we compare three different harvesting strategies (proportional harvesting, threshold harvesting, and proportional threshold harvesting) in an autocorrelated and heavily fluctuating fishery — the Norwegian spring-spawning herring (Clupea harengus) — in terms of risk of quasi-extinction, average a...

Kaitala, Veijo; Jonze?n, Niclas; Enberg, Katja

2003-01-01

252

Exploratory assessment of fish consumption among Asian-origin sportfishers on the St. Lawrence river in the montreal region.  

Science.gov (United States)

An exploratory survey was undertaken in the fall 1995 open-water fishing season with nine Bangladeshi and nine Vietnamese-origin sportfishers. Survey methodology and techniques of dietary and fish intake assessment were adapted to the cultural values and second language of each community. A 70-item instrument assessing sportfishing practices and fish consumption habits was administered by dietitians in participants' homes. Two 24-h diet recalls (aided by photographs taken by the participants) and a fish consumption calendar permitted the assessment of fish intake in the overall dietary context. A fish frequency item addressed consumption of locally available fish species (both sport and market fish) as well as imported frozen or dried species. Annually, Bangladeshi fishers consumed 46.8+/-25.6 sportfish meals, and Vietnamese fishers ate 40. 7+/-35.1 meals. In contrast, Bangladeshis reported greater annual consumption of imported, frozen nonsportfish (76.0+/-40.9 meals), and the Vietnamese ate more ocean than freshwater fish (45.1+/-34.4 ocean fish meals). Fish constituted approximately 19% of all protein foods eaten among the Bangladeshi fishers and 10% in the Vietnamese sample. Plasma and erythrocyte eicosapentanoic acid (EPA):arachidonic acid (AA) ratios supported findings from the fish frequency question showing that the two groups of Asian-origin fishers eat differing quantities of different fish species and that Asian-origin sportfishers-particularly the Bangladeshis-eat fish overall more frequently and in greater variety and quantity than francophone Quebecers; species selection appears to be both culturally motivated and influenced by the availability of St. Lawrence sportfish. PMID:10092420

Shatenstein, B; Kosatsky, T; Tapia, M; Nadon, S; Leclerc, B S

1999-02-01

253

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

254

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.

255

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)

Full Text Available SciELO Mexico | Language: Spanish Abstract in spanish 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.

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

2009-06-01

256

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

Directory of Open Access Journals (Sweden)

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.

Morteza Asadi

2013-04-01

257

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

258

Risk assessment of heavy metals in water and two fish species from golf course ponds in beijing, china.  

Science.gov (United States)

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

PuYang, Xuehua; Gao, Chenhao; Han, Liebao

2015-04-01

259

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

OpenAIRE

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 (IC...

Sawusdee, Amonsak; Songrak, Apirak

2009-01-01

260

Comparative Environmental Assessment in the Studies of Benthic Diatom, Macroinvertebrate, and Fish Communities  

Science.gov (United States)

Community response to environmental gradients operating at hierarchical scales was assessed in studies of benthic diatoms, macroinvertebrates and fish from 44 stream sites in the New York City watershed. Hierarchical cluster analysis (TWINSPAN) of diatoms and fish partitioned the study sites into four groups, i.e., acid streams, reservoir outlets and wetland streams, large eutrophic streams, and small eutrophic streams; macroinvertebrate TWINSPAN distinguished an additional group of silty eutrophic streams. The correspondence among the three assemblage TWINSPAN groupings was moderate, ranging from 51 to 57%. The similarity across the four major group types was the highest among large eutrophic stream and acid stream assemblages, and the lowest among small eutrophic stream assemblages.Stepwise discriminant function analysis revealed that environmental factors discriminated most effectively the diatom grouping and least effectively the fish grouping. The best environmental predictors for diatom and macroinvertebrate grouping were conductance and percent surface water, while population density was most powerful in separating the fish groups. Carbaryl was the only pesticide that correlated with macroinvertebrate grouping.Partial redundancy analyses suggested a differential dependence of freshwater communities on the scale of the environmental factors to which they respond. The role of small-scale habitat and habitatland cover/land use interaction steadily increased across the diatom, macroinvertebrate, and fish assemblages, whereas the effect of large-scale land cover/land use declined.

Passy, Sophia I.; Bode, Robert W.; Carlson, Douglas M.; Novak, Margaret A.

2004-05-01

261

HABITAT USE BY NATIVE AND STOCKED TROUT (SALMO TRUTTA L. IN TWO NORTHEAST STREAMS, PORTUGAL  

Directory of Open Access Journals (Sweden)

Full Text Available Habitat use by stocked and native brown trout (Salmo trutta L. was assessed in two headwater streams of North-eastern Portugal. Underwater observations were made during the summer season in three successive years to evaluate the effect of supplemental trout stocking. Multivariate analysis techniques applied to data sets on microhabitat use were exploited to identify the focal elevation (distance of fish from the bottom, total depth and cover as the variables that contribute most to the discrimination between stocked and native trout. Preference curves computed for native and stocked trout of the same age (1+, showed a distinct pattern in their ability to explore the available microhabitat resources. Stocked trout tended to occupy deeper pools (total depth > 100 cm vs. 60-100 cm for native trout, holding higher focal elevations (140-160 cm vs. 22.5 cm and cover (combination of boulders and overhanging vegetation or undercut banks. Furthermore, a high poststocking movement of 80% hatchery-reared fish was verified just one month after their release, suggesting that stocking did not contribute to the sustainable populations in either stream, and is far from being an adequate management technique.

TEIXEIRA A.

2006-04-01

262

Rapid Fishery Assessment by Market Survey (RFAMS) – An Improved Rapid-Assessment Approach to Characterising Fish Landings in Developing Countries  

OpenAIRE

The complex multi-gear, multi-species tropical fisheries in developing countries are poorly understood and characterising the landings from these fisheries is often impossible using conventional approaches. A rapid assessment method for characterising landings at fish markets, using an index of abundance and estimated weight within taxonomic groups, is described. This approach was developed for contexts where there are no detailed data collection protocols, and where consistent data collectio...

White, William T.; Last, Peter R.; Dharmadi, ...; Faizah, Ria; Chodrijah, Umi; Buckworth, Rik C.; Dichmont, Catherine M.

2014-01-01

263

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

264

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)

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

Bucholtz, Rikke HagstrØm

2013-01-01

265

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)

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.

Matono P.

2012-06-01

266

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.

267

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

Science.gov (United States)

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

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

2015-01-01

268

Toxicological assessment of biodegraded pentachlorophenol: Microtox and fish embryos.  

Science.gov (United States)

A Gram-negative bacterium, Pseudomonas sp. strain SR3, was isolated from soil at a former wood treatment plant in north central Florida. The ability of this bacterium to degrade pentachlorophenol (PCP) was confirmed by growing cells in a basal salts medium in which PCP was the only source of carbon and energy. Degradation from a measured concentration of 39-40 micrograms PCP/ml to 0.0006 micrograms PCP/ml was observed within 120 h of incubation in the presence of PCP-induced cells of Pseudomonas sp. strain SR3. The initial cell density in these cultures was 6 x 10(6) cfu/ml. Microtox 5 min EC50 toxicity tests revealed that aqueous solutions of PCP, measured concentrations 39-40 micrograms/ml were toxic but that final biodegraded samples, 0.0006 micrograms PCP/ml were nontoxic. However, bioassays with embryonic inland silversides, Menidia beryllina, showed that the biodegraded samples were embryotoxic or teratogenic. Water containing added PCP at concentrations up to 30 times higher than measured in the final biodegraded samples was less toxic/teratogenic. These results indicate that while biodegradation of PCP was nearly complete, intermediate metabolites of the degradation process or undegraded impurities in PCP were toxic or teratogenic. Thus, the M. beryllina bioassay allows extremely sensitive assessment of toxicity associated with biodegraded environmental pollutants and may be a useful criterion for determining whether bioremediated water or soil is safe for discharge back into the environment. PMID:8466298

Middaugh, D P; Resnick, S M; Lantz, S E; Heard, C S; Mueller, J G

1993-02-01

269

Deliverable 3.4-4: Fish indicators for ecological status assessment of lakes affected by eutrophication and hydromorphological pressures  

OpenAIRE

One of the objectives of work package 3.4 of WISER is to develop a fish-based ecological status indicator for European lakes exposed to hydromorphological and eutrophication pressures, including uncertainty assessment.

Pe?dron, S.; Bortoli, J.; Argillier, C.

2009-01-01

270

Stock size of north-east arctic cod, estimates from survey data 1984/85  

OpenAIRE

Both the total and spawning stocks of North-East Arctic cod were assessed using Norwegian survey data and commercial landings. The total stock at 1 January 1985 was estimated to about 5100 million specimens, of which age group 2 and 3 amounted to about 3400 and 1200 million specimens respectively. The total number of fish of age 3 and older (3+) were estimated to 1500 million specimens which is 2.5 times higher than the estimate of about 575 million specimens arrived at by the Working Group o...

Nakken, Odd; Hylen, Arvid

1985-01-01

271

Fish micronucleus assay to assess genotoxic potential of arsenic at its guideline exposure in aquatic environment.  

Science.gov (United States)

The exposure to arsenic, a potential genotoxic carcinogen in humans, via drinking water is a serious worldwide health hazard. The arsenic content of 10 ?g L(-1) in drinking water, however, has been established as its guideline standard (maximum contaminant limit) that has been estimated to pose minimum risk to cancer. Since micronucleus induction in the erythrocytes of fish is a sensitive indicator of genotoxic agents in water, the piscine micronucleus assay was used in the present experiment to assess the genotoxic potential of arsenic at its various exposure levels including the guideline value for drinking water. The experiments were conducted in two different species of fishes, the pond murrel (Channa punctatus) and the goldfish (Carassius auratus). Significant increases in the frequency of micronucleated erythrocytes were documented in a dose-dependent manner in both Channa and Carassius. The fishes, however, exhibited variations in inter-specific sensitivity to micronucleus induction following arsenic exposure. The exposure level of arsenic at its guideline value for drinking water, therefore, exhibited marked genotoxicity in fishes. PMID:23494554

Kumar, Amod; Kesari, Vibudh P; Khan, Parimal K

2013-04-01

272

Trace metal levels in water, fish, and sediment from River Nile, Egypt: potential health risks assessment.  

Science.gov (United States)

The purposes of this study were to describe the impact of metal pollution on the main economic fish species Tilapia nilotica and to assess the potential health risk from consuming this contaminated fish in Egypt. Trace metals, including Ag, Al, Cd, Bo, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, St, V, Zn, and As, were determined in water, Tilapia nilotica, and sediments from the River Nile, Domiate branch, Egypt. Metal concentrations in fish of Al, Cd, Co, Fe, Mn, Pb, V, and Zn (mg/kg dry weight [dw]) and concentrations in sediment of Cd, Co, Cr, Cu, Mn, Ni, Pb, V, and Zn (mg/kg dw) were above the International Atomic Energy Agency (IAEA-407) levels. However, trace metals in river water were still at permissible levels for Egyptian standards. The hazard index (HI) of estimated metal mixtures for intake of Tilapia nilotica (23.37) demonstrated that intake resulted in higher noncarcinogenic risk. In conclusion, the overall problem of metal contamination in fish collected from the River Nile was more serious than postulated to occur in an industrialized and densely populated area. In the light of known risks to public health, environmental protection laws are needed in Egypt. PMID:24283369

Dahshan, Hesham; Abd-Elall, Amr Mohamed Mohamed; Megahed, Ayman Mohamed

2013-01-01

273

A multispecies statistical age-structured model to assess predator-prey balance: application to an intensively managed Lake Michigan pelagic fish community  

Science.gov (United States)

Using a Bayesian model fitting approach, we developed a multispecies statistical catch-at-age model to assess trade-offs between predatory demands and prey productivities, focusing on the Lake Michigan pelagic fish community. We assessed these trade-offs in terms of predation mortalities and productivities of alewife (Alosa pseudoharengus) and rainbow smelt (Osmerus mordax) and functional responses of salmonines. Our predation mortality estimates suggest that salmonine consumption has been a major driver of historical fluctuations in prey abundance, with sharp declines in alewife abundance in the 1980s and 2000s coinciding with estimated increases in predation mortalities. While Chinook salmon (Oncorhynchus tshawytscha) were food limited during periods of low alewife abundance, other salmonines appeared to maintain a (near) maximum per-predator consumption across all observed prey densities, suggesting that feedback mechanisms are unlikely to help maintain a balance between predator consumption and prey productivity in Lake Michigan. This study demonstrates that a multispecies modeling approach that combines stock assessment methods with explicit consideration of predator–prey interactions could provide the basis for tactical decision-making from a broader ecosystem perspective.

Tsehaye, Iyob; Jones, Michael L.; Bence, James R.; Brenden, Travis O.; Madenjian, Charles P.; Warner, David M.

2014-01-01

274

Replacing fish meal by food waste in feed pellets to culture lower trophic level fish containing acceptable levels of organochlorine pesticides: health risk assessments.  

Science.gov (United States)

The present study used food waste (collected from local hotels and restaurants) feed pellets in polyculture of low-trophic level fish [bighead (Aristichtys nobilis), grass carp (Ctenopharyngodon idellus), and mud carp (Cirrhina molitorella)] aiming at producing safe and quality products for local consumption. The results indicated that grass carp (hexachlorocyclohexanes (HCHs) biomagnification of OCPs in the food chains within the ponds. The raw concentrations of OCPs extracted from the fish were not in the bioavailable form, which would ultimately reach bloodstream and exert adverse effects on human body. Health risk assessments based on digestible concentrations are commonly regarded as a more accurate method. The results of health risk assessments based on raw and digestible concentrations showed that the fish fed with food waste feed pellets were safe for consumption from the OCP perspective. PMID:25080070

Cheng, Zhang; Mo, Wing-Yin; Man, Yu-Bon; Nie, Xiang-Ping; Li, Kai-Bing; Wong, Ming-Hung

2014-12-01

275

Assessing the suitability of a partial water reuse system for rearing juvenile Chinook salmon Oncorhynchus tshawytscha for stocking in Washington State  

Science.gov (United States)

Health and welfare of juvenile Chinook salmon Oncorhynchus tshawytsha reared in a pilot circular tank-based partial water reuse system in Washington State were evaluated in comparison to fish from the same spawn reared in a flow-through raceway, in order to assess the suitability of using water reus...

276

Comparability of fish-based ecological quality assessments for geographically distinct Iberian regions.  

Science.gov (United States)

In this work we compare two Iberian and a pan-European fish-based methods to assess ecological quality in rivers: the Fish-based Index of Biotic Integrity for Portuguese Wadeable Streams (F-IBIP), the Mediterranean Index of Biotic Integrity (IBIMED) and the pan-European Fish Index (EFI+). The results presented herein were developed in the context of the 2nd phase of the Intercalibration Exercise (IC), as required by the Water Frame Directive (WFD). The IC is aimed at ensuring comparability of the quality boundaries among the different WFD assessment methods developed by the Member States for each biological quality element. Although the two national assessment methods were developed for very distinct regions of Iberia (Western and Eastern Iberian Peninsula) they share the same methodological background: both are type-specific and guild-based multimetric indices. EFI+ is a multimetric guild-based model, but it is site-specific and uses a predictive modelling approach. The three indices were computed for all sites included in the Iberian Intercalibration database to allow the direct comparison, by means of linear regressions, of the resulting three quality values per site. The quality boundary harmonization between the two Iberian methods was only possible through an indirect comparison between the two indices, using EFI+ as a common metric. The three indices were also shown to be responsive to a common set of human induced pressures. This study highlights the need to develop general assessment methods adapted to wide geographical ranges with high species turnover to help intercalibrating assessment methods tailored for geographically more restricted regions. PMID:24071063

Segurado, P; Caiola, N; Pont, D; Oliveira, J M; Delaigue, O; Ferreira, M T

2014-04-01

277

Assessing lake typologies and indicator fish species for Italian natural lakes using past fish richness and assemblages  

OpenAIRE

In order to establish a fish-based typology of Italian lakes and identify possible reference and indicator fish species for each lake type, we analysed historical data on fish assemblages of all Italian natural lakes[0.5 km2 from the period prior to the major decline in water quality in the 1950s. General linear regression models showed the ecoregion and lake altitude being the best predictors of fish species richness. The number of species was significantly higher in the Alpine than in the M...

Volta, Pietro; Oggioni, Alessandro; Bettinetti, Roberta; Jeppesen, Erik

2011-01-01

278

Do national advisories serve local consumers: an assessment of mercury in economically important North Carolina fish.  

Science.gov (United States)

Consumption of marine fish provides both benefits (lean protein, omega-3 fatty acids and essential nutrients) and risks (main source of mercury (Hg) exposure for humans). Mercury is a potent neurotoxin and the source of more fish advisories nationwide than any other toxicant. Despite the widespread nature of Hg, it is unknown whether local Hg contamination reflects national and regional levels often used as bases to inform consumers of potential fish consumption risk. Thus, the objectives of our study were to examine Hg levels of six commonly consumed marine species harvested locally off the North Carolina coast and to compare our results to published regional (Monterey Bay Aquarium's Seafood Watch List) and national (Environmental Protection Agency, EPA, and Food and Drug Administration, FDA) Hg averages, action levels, and guidelines. We found significant differences in Hg concentrations among collected species, and we identified correlations between Hg concentration and fish length and trophic levels. Collected mahi mahi and triggerfish were below the EPA fish tissue action level (0.3ppm). Wahoo and grouper exceeded the EPA action level but were below the FDA action level (1.0ppm). King mackerel had the highest Hg concentration among targeted species, exceeding both EPA and FDA action levels. Further, our local results were not always consistent with calculated averages from EPA and FDA databases for the same species, and although many of our findings were consistent with Monterey Bay Aquarium's Seafood Watch List (southeast region), recommendations based on Hg levels would conflict with recommendations they provide based on sustainability. We find regional and national averages are not always reflective of local Hg contamination and suggest local data may be needed to accurately assess consumer risk. PMID:22453298

Petre, Sally Jane; Sackett, Dana K; Aday, D Derek

2012-05-01

279

Evaluation of swimming capability and potential velocity barrier problems for fish. Part B: New telemetric approaches to the assessment of fish swimming performance  

International Nuclear Information System (INIS)

This report represents the second part of a study undertaken to develop information related to swimming capability of several important fish species. The study will provide biological design criteria to mitigate potential velocity barrier problems associated with hydroelectric power plants. This part of the report focuses on the development and evaluation of approaches to assessing locomotory activity, swimming performance and energy load costs to fish under naturally occurring conditions and in relation to potential barriers. The study involved implantation of a bio-sensitive radio transmitter (electromyogram (EMG)) tag in the swimming muscle of fish, calibration of locomotory ability and energetic scope, and subsequent use of EMG signals to assess swimming performance and metabolic costs in situ. Digital signal processing (DSP) with antennae switching was also used to study high speed swimming performance, behaviour, and migratory strategy in relation to ascent of an experimental flume. The techniques and technologies developed indicate the complexity of factors that regulate fish swimming energy expenditure that need to be considered in the design and operation of fish passage facilities. 84 refs., 6 tabs., figs., 2 appendices

280

Heavy metals and arsenic concentrations in ten fish species from the Šalek lakes (Slovenia): assessment of potential human health risk due to fish consumption.  

Science.gov (United States)

The study, which measured the concentrations of Hg, Pb, Cd, Zn and As in various fish tissues (muscle, gill and liver) of 10 fish species (Abramis brama danubii, Alburnus alburnus alburnus, Barbus meridionalis petenyi, Carassius auratius gibelio, Cyprinus carpio, Lepomis gibossus, Leuciscius cephalus cephalus, Perca fluviatilis fluviatilis, Rutilus rutilus, Scardinus erythrophtlalmus erythrophtlalmus) collected in the Šalek lakes, is the first survey regarding metal concentrations in fish species with samples originating from Slovene lakes, while only a limited number of such studies have been carried out in southeastern Europe. Since these lakes are situated in the close vicinity of the largest Slovene thermal power plant, the study provides an insight into the potential impact of increased levels of metals in the environment as well as an estimate of the contamination of fish tissues with metals. Furthermore, it was possible to compare the results obtained with those from other studies regarding metal levels in freshwater fish species. The mean metal concentrations of different tissues irrespective of species varied in the following ranges: Zn 4.31-199 mg/kg ww, Pb 0.01-0.48 mg/kg ww, As 0.02-0.44 mg/kg ww, Hg fish revealed that the ecosystems of the Šalek lakes are not polluted with Hg and Pb, slightly loaded with As and Cd and moderately polluted with Zn. In addition, the potential human health risk due to fish consumption was assessed. This showed that the estimated weekly intakes for all metals were far below provisional permissible tolerable weekly intakes determined by WHO/FAO. The consumption of fish from the Šalek lakes, therefore, does not pose a risk to human health. PMID:21713497

Al Sayegh Petkovšek, Samar; Mazej Grudnik, Zdenka; Pokorny, Boštjan

2012-05-01

281

Rapid assessment of toxicity of oil sands process-affected waters using fish cell lines  

International Nuclear Information System (INIS)

Oil-sand process-affected waters (OSPAW) are being evaluated in acute and chronic toxicity tests with various model organisms to assess the safety of reclamation ponds where OSPAWs are being deposited. Classical toxicity assays typically require large volumes of test waters, take time and are costly. They may also require expensive analytical assays to characterize the contaminants present. Cytotoxicity assays using indigenous and model fish cell lines may prove useful for a prompt comparative toxicity assessment of copious samples retrieved at various temporal and spatial sites at a fraction of cost and time compared to in vivo assays. This presentation reported on a study in which a rapid fluorometric assay using several fish cell lines was used to assess the acute toxicity of 20 water samples including OSPAW. The water samples were mixed with media salts and evaluated directly on cells in culture without prior extraction procedures. The evaluation was done in blind and a consistent pattern of toxicity was observed with the tested cell lines. It was concluded that this approach may minimize the need of using whole organisms for toxicity assessment of OSPAW.

282

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

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

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

283

Histopathological biomarkers in estuarine fish species for the assessment of biological effects of contaminants.  

Science.gov (United States)

The increasing emphasis on the assessment and monitoring of estuarine ecosystems has highlighted the need to deploy appropriate biological indices for these locations. Fish diseases and histopathology, with a broad range of causes, are increasingly being used as indicators of environmental stress since they provide a definite biological end-point of historical exposure. This study reports on the histopathological alterations observed in selected organs and tissues of three species of estuarine fish (Platichthys flesus, Pomatoschistus minutus and Zoarces viviparus), captured from four British estuaries (the Tyne, Tees, Mersey and Alde), differently impacted by contaminants, including PAHs. A biannual sampling regime was used to identify the important seasonal variations that occur in terms of the observed biological effects. Inflammatory lesions and hepatocellular fibrillar inclusions attained their highest prevalence in P. flesus captured from the Tyne, Tees and Mersey. The presence of pre-neoplastic and neoplastic toxicopathic lesions was highest in P. flesus captured from these sites, when compared to fish from the Aide reference site. In particular, the prevalence of hepatic foci of cellular alteration (up to 43.3%) and hepatocellular adenoma (up to 10%) were highest in P. flesus captured from the Mersey estuary. Intersex (ovotestis) was only recorded in male P.flesus captured from the Mersey estuary (up to 8.3%) and from male Z. viviparous captured from the Tyne estuary (25%). Pathologies associated with the gill and the kidney were also most prevalent in fish captured from the Tyne, Tees and Mersey estuaries. This study has successfully applied histopathology to an estuarine monitoring program, both for the recording of toxicopathic lesions in the liver and other organs, and for the detection of the endpoint of endocrine disruption, intersex. As such, it provides a powerful integrative tool for the assessment of biological effects of contaminants in these environments. PMID:12502035

Stentiford, G D; Longshaw, M; Lyons, B P; Jones, G; Green, M; Feist, S W

2003-03-01

284

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

Science.gov (United States)

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 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. PMID:20061034

Embry, Michelle R; Belanger, Scott E; Braunbeck, Thomas A; Galay-Burgos, Malyka; Halder, Marlies; Hinton, David E; Léonard, Marc A; Lillicrap, Adam; Norberg-King, Teresa; Whale, Graham

2010-04-15

285

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.

286

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

Energy Technology Data Exchange (ETDEWEB)

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 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.

Embry, Michelle R., E-mail: membry@ilsi.org [ILSI Health and Environmental Sciences Institute, 1156 15th Street, NW, Suite 200, Washington, DC 20005 (United States); Belanger, Scott E., E-mail: belanger.se@pg.com [Procter and Gamble, Central Product Safety, PO Box 538707, Miami Valley Innovation Center, Cincinnati, OH 45253-8707 (United States); Braunbeck, Thomas A., E-mail: braunbeck@zoo.uni-heidelberg.de [University of Heidelberg, Im Neuenheimer Feld 230, Heidelberg D -69120 (Germany); Galay-Burgos, Malyka, E-mail: malyka.galay-burgos@ecetoc.org [European Centre for Ecotoxicology and Toxicology of Chemicals (ECETOC), 4 Avenue E. Van Nieuwenhuyse B-1160, Brussels (Belgium); Halder, Marlies, E-mail: marlies.halder@jrc.ec.europa.eu [European Commission, Joint Research Centre, Institute for Health and Consumer Protection, In-Vitro Methods Unit TP-580 Ispra 21027 (Italy); Hinton, David E., E-mail: dhinton@duke.edu [Duke University, Nicholas School of the Environment, PO Box 90328, Durham, NC 27708, Unites States (United States); Leonard, Marc A., E-mail: mleonard@rd.loreal.com [L' Oreal Recherche Avancee, Unite d' Ecotoxicologie, 1 av. E. Schueller, 93601 Aulnay sous bois (France); Lillicrap, Adam, E-mail: Adam.lillicrap@niva.no [AstraZeneca, Freshwater Quarry, Brixham TQ5 8BA (United Kingdom); Norberg-King, Teresa, E-mail: norberg-king.teresa@epa.gov [U.S. EPA, Mid-Continent Ecology Division, 6201 Congdon Boulevard, Duluth, MN 55804-1636 (United States); Whale, Graham, E-mail: graham.whale@shell.com [Shell Global Solutions, Analytical Technology, P.O. Box 1, Chester CH1 3SH (United Kingdom)

2010-04-15

287

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.

288

Assessing estuarine environmental quality using fish-based indices: performance evaluation under climatic instability.  

Science.gov (United States)

The seasonal variation of five selected multimetric indices for the determination of the Ecological Quality Status (EQS) of transitional waters was evaluated, as well as the indices' responses to an extreme drought event that occurred in 2005. The database used regards the Mondego River estuary, which was sampled from June 2003 to August 2006 on a monthly basis. Among the selected indices (EBI-Deegan et al. [Deegan, L., Finn, J.T., Ayvazlan, S.G., Ryder-Kieffer, C.A., Buonaccoesi, J., 1997. Development and validation of an Estuarine Biotic Integrity Index. Estuaries 30(3), 601-617], EDI-Borja et al. [Borja, A., Franco, J., Valencia, V., Bald, J., Muxika, I., Belzunce, M.J., Solaun, O., 2004. Implementation of the European Water Framework Directive from the Basque Country (northern Spain): a methodological approach. Marine Pollution Bulletin 48(3-4), 209-218], EFCI-Harrison and Whitfield [Harrison, T.D., Whitfield, A.K., 2004. A multi-metric fish index to assess the environmental condition of estuaries. Journal of Fish Biology 65, 683-710], EBI-Breine et al. [Breine, J.J., Maes, J., Quataert, P., Van den Bergh, E., Simoens, I., Van Thuyne, G., Belpaire, C., 2007. A fish-based assessment tool for the ecological quality of the brackish Scheldt estuary in Flanders (Belgium). Hydrobiologia 575, 141-159] and TFCI - Coates et al. [Coates, S., Waugh, A., Anwar, A., Robson, M., 2007. Efficacy of a multi-metric fish index as an analysis tool for the transitional fish component of the Water Framework Directive. Marine Pollution Bulletin 55, 225-240]), the EBI by Breine et al. (2007) was the only that evidenced clear interannual and seasonal variations. The EQS by the several indices ranged from "Low" to "High", depending on the index considered, evidencing the high level of mismatch between indices. The results are discussed in the scope of the EU Water Framework Directive, regarding monitoring strategies, application of indices and EQS assessment. PMID:18790506

Martinho, F; Viegas, I; Dolbeth, M; Leitão, R; Cabral, H N; Pardal, M A

2008-11-01

289

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

2011-09-01

290

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

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...

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

2005-01-01

291

Submission of Danish Coastal Fish data to HELCOM FISH, for the Thematic Assessment : Data from six NOVANA stations 2006  

DEFF Research Database (Denmark)

Coastal fish communities are important components of Baltic Sea ecosystems. Coastal fish experts have been meeting on an annual basis since 2004 under the umbrella of HELCOM. In 2006, the expert group developed a metadatabase on monitoring activities, methods, parameters and species surveyed based on the data contained in the COBRA database. A GIS interactive map was subsequently created by HELCOM to improve access to the information in the metadatabase and to visualise coastal fish monitoring activities in the Baltic Sea. Link: http://www.helcom.fi/GIS/en_GB/coastalfishGIS/

Strand, Jakob

292

Stock Market Liberalization, Stock Market Performance and Economic Growth in Kenya  

Directory of Open Access Journals (Sweden)

Full Text Available The study empirically examined whether stock market liberalization improves the functioning of domestic stock market and accelerates economic growth in Kenya. The study also assessed the kind of relationship between liberalization, stock market performance and economic growth in Kenya. Liberalization was assessed by stock market capitalization while turnover was used to asses stock market performance. The study used quarterly time series data collected through secondary sources and covered a period of 22 years from January, 1991 to December, 2012. The study utilized econometric techniques of Vector autoregressive and Granger Causality Tests to investigate the relationships. The results displayed a one way causality that runs from stock market development to economic growth. The results also show that stock market liberalization indirectly impacts on economic growth through investment. The study found that stock market liberalization has a significant positive impact on the economic growth in Kenya.  

Isaac Kimunio Kinuthia

2014-03-01

293

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

Science.gov (United States)

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. PMID:19932535

Muñoz, Ivan; Martínez Bueno, María J; Agüera, Ana; Fernández-Alba, Amadeo R

2010-05-01

294

Extinction Risk and Overfishing: Reconciling Conservation and Fisheries Perspectives on the Status of Marine Fishes  

OpenAIRE

Anthropogenic disturbances are ubiquitous in the ocean, but their impacts on marine species are hotly debated. We evaluated marine fish statuses using conservation (Red List threatened or not) and fisheries (above or below reference points) metrics, compared their alignment, and diagnosed why discrepancies arise. Whereas only 13.5% of Red Listed marine fishes (n = 2952) are threatened, 40% and 21% of populations with stock assessments (n = 166) currently are below their more conservative and ...

Davies, Trevor D.; Baum, Julia K.

2012-01-01

295

"We Like to Listen to Stories about Fish": Integrating Indigenous Ecological and Scientific Knowledge to Inform Environmental Flow Assessments  

Directory of Open Access Journals (Sweden)

Full Text Available Studies that apply indigenous ecological knowledge to contemporary resource management problems are increasing globally; however, few of these studies have contributed to environmental water management. We interviewed three indigenous landowning groups in a tropical Australian catchment subject to increasing water resource development pressure and trialed tools to integrate indigenous and scientific knowledge of the biology and ecology of freshwater fish to assess their water requirements. The differences, similarities, and complementarities between the knowledge of fish held by indigenous people and scientists are discussed in the context of the changing socioeconomic circumstances experienced by indigenous communities of north Australia. In addition to eliciting indigenous knowledge that confirmed field fish survey results, the approach generated knowledge that was new to both science and indigenous participants, respectively. Indigenous knowledge influenced (1 the conceptual models developed by scientists to understand the flow ecology and (2 the structure of risk assessment tools designed to understand the vulnerability of particular fish to low-flow scenarios.

Sue E. Jackson

2014-03-01

296

Assessment of Present Anadromous Fish Production Facilities in the Columbia River Basin, Washington Department of Fish Hatcheries, Final Report.  

Energy Technology Data Exchange (ETDEWEB)

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.

Delarm, Michael R.; Smith, Robert Z.

1990-07-01

297

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

OpenAIRE

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...

Webb, Stacy Lynn

2006-01-01

298

VIS - A database on the distribution of fishes in inland and estuarine waters in Flanders, Belgium.  

Science.gov (United States)

The Research Institute for Nature and Forest (INBO) has been performing standardized fish stock assessments in Flanders, Belgium. This Flemish Fish Monitoring Network aims to assess fish populations in public waters at regular time intervals in both inland waters and estuaries. This monitoring was set up in support of the Water Framework Directive, the Habitat Directive, the Eel Regulation, the Red List of fishes, fish stock management, biodiversity research, and to assess the colonization and spreading of non-native fish species. The collected data are consolidated in the Fish Information System or VIS. From VIS, the occurrence data are now published at the INBO IPT as two datasets: 'VIS - Fishes in inland waters in Flanders, Belgium' and 'VIS - Fishes in estuarine waters in Flanders, Belgium'. Together these datasets represent a complete overview of the distribution and abundance of fish species pertaining in Flanders from late 1992 to the end of 2012. This data paper discusses both datasets together, as both have a similar methodology and structure. The inland waters dataset contains over 350,000 fish observations, sampled between 1992 and 2012 from over 2,000 locations in inland rivers, streams, canals, and enclosed waters in Flanders. The dataset includes 64 fish species, as well as a number of non-target species (mainly crustaceans). The estuarine waters dataset contains over 44,000 fish observations, sampled between 1995 and 2012 from almost 50 locations in the estuaries of the rivers Yser and Scheldt ("Zeeschelde"), including two sampling sites in the Netherlands. The dataset includes 69 fish species and a number of non-target crustacean species. To foster broad and collaborative use, the data are dedicated to the public domain under a Creative Commons Zero waiver and reference the INBO norms for data use. PMID:25685001

Brosens, Dimitri; Breine, Jan; Van Thuyne, Gerlinde; Belpaire, Claude; Desmet, Peter; Verreycken, Hugo

2015-01-01

299

VIS – A database on the distribution of fishes in inland and estuarine waters in Flanders, Belgium  

Science.gov (United States)

Abstract The Research Institute for Nature and Forest (INBO) has been performing standardized fish stock assessments in Flanders, Belgium. This Flemish Fish Monitoring Network aims to assess fish populations in public waters at regular time intervals in both inland waters and estuaries. This monitoring was set up in support of the Water Framework Directive, the Habitat Directive, the Eel Regulation, the Red List of fishes, fish stock management, biodiversity research, and to assess the colonization and spreading of non-native fish species. The collected data are consolidated in the Fish Information System or VIS. From VIS, the occurrence data are now published at the INBO IPT as two datasets: ‘VIS - Fishes in inland waters in Flanders, Belgium’ and ‘VIS - Fishes in estuarine waters in Flanders, Belgium’. Together these datasets represent a complete overview of the distribution and abundance of fish species pertaining in Flanders from late 1992 to the end of 2012. This data paper discusses both datasets together, as both have a similar methodology and structure. The inland waters dataset contains over 350,000 fish observations, sampled between 1992 and 2012 from over 2,000 locations in inland rivers, streams, canals, and enclosed waters in Flanders. The dataset includes 64 fish species, as well as a number of non-target species (mainly crustaceans). The estuarine waters dataset contains over 44,000 fish observations, sampled between 1995 and 2012 from almost 50 locations in the estuaries of the rivers Yser and Scheldt (“Zeeschelde”), including two sampling sites in the Netherlands. The dataset includes 69 fish species and a number of non-target crustacean species. To foster broad and collaborative use, the data are dedicated to the public domain under a Creative Commons Zero waiver and reference the INBO norms for data use. PMID:25685001

Brosens, Dimitri; Breine, Jan; Van Thuyne, Gerlinde; Belpaire, Claude; Desmet, Peter; Verreycken, Hugo

2015-01-01

300

76 FR 14923 - Endangered and Threatened Species; Take of Anadromous Fish  

Science.gov (United States)

...authority to take listed species is subject to conditions...individuals from all the species covered in this notice...support stock assessment models for commercially and...harvested groundfish species. The survey would collect data on 90+ fish species in the...

2011-03-18

301

Exploiting Growing Stock Volume Maps for Large Scale Forest Resource Assessment: Cross-Comparisons of ASAR- and PALSAR-Based GSV Estimates with Forest Inventory in Central Siberia  

Directory of Open Access Journals (Sweden)

Full Text Available Growing stock volume is an important biophysical parameter describing the state and dynamics of the Boreal zone. Validation of growing stock volume (GSV maps based on satellite remote sensing is challenging due to the lack of consistent ground reference data. The monitoring and assessment of the remote Russian forest resources of Siberia can only be done by integrating remote sensing techniques and interdisciplinary collaboration. In this paper, we assess the information content of GSV estimates in Central Siberian forests obtained at 25 m from ALOS-PALSAR and 1 km from ENVISAT-ASAR backscatter data. The estimates have been cross-compared with respect to forest inventory data showing 34% relative RMSE for the ASAR-based GSV retrievals and 39.4% for the PALSAR-based estimates of GSV. Fragmentation analyses using a MODIS-based land cover dataset revealed an increase of retrieval error with increasing fragmentation of the landscape. Cross-comparisons of multiple SAR-based GSV estimates helped to detect inconsistencies in the forest inventory data and can support an update of outdated forest inventory stands.

Christian Hüttich

2014-07-01

302

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)

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

Saleh, Yousef S; Marie, Mohamed-Assem S

2015-04-01

303

Causes and methods to estimate cryptic sources of fishing mortality.  

Science.gov (United States)

Cryptic, not readily detectable, components of fishing mortality are not routinely accounted for in fisheries management because of a lack of adequate data, and for some components, a lack of accurate estimation methods. Cryptic fishing mortalities can cause adverse ecological effects, are a source of wastage, reduce the sustainability of fishery resources and, when unaccounted for, can cause errors in stock assessments and population models. Sources of cryptic fishing mortality are (1) pre-catch losses, where catch dies from the fishing operation but is not brought onboard when the gear is retrieved, (2) ghost-fishing mortality by fishing gear that was abandoned, lost or discarded, (3) post-release mortality of catch that is retrieved and then released alive but later dies as a result of stress and injury sustained from the fishing interaction, (4) collateral mortalities indirectly caused by various ecological effects of fishing and (5) losses due to synergistic effects of multiple interacting sources of stress and injury from fishing operations, or from cumulative stress and injury caused by repeated sub-lethal interactions with fishing operations. To fill a gap in international guidance on best practices, causes and methods for estimating each component of cryptic fishing mortality are described, and considerations for their effective application are identified. Research priorities to fill gaps in understanding the causes and estimating cryptic mortality are highlighted. PMID:24090548

Gilman, E; Suuronen, P; Hall, M; Kennelly, S

2013-10-01

304

The applicability of oxidative stress biomarkers in assessing chromium induced toxicity in the fish Labeo rohita.  

Science.gov (United States)

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

Kumari, Kanchan; Khare, Ankur; Dange, Swati

2014-01-01

305

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

International Nuclear Information System (INIS)

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)

306

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

Science.gov (United States)

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

Khare, Ankur; Dange, Swati

2014-01-01

307

Arsenic concentration in rice, fish, meat and vegetables in Cambodia: a preliminary risk assessment.  

Science.gov (United States)

To assess arsenic contaminations and its possible adverse health effects, food samples were collected from Kandal, Kratie and Kampong Cham in Cambodia. The highest and the lowest concentrations were observed in fish (mean 2,832 ng g(-1), ww) collected from Kandal province and cattle stomach (1.86 ± 1.10 ng g(-1), ww) collected from Kratie, respectively. The daily intake of arsenic via food consumption was 604, 9.70 and 136 ?g day(-1) in Kandal, Kratie and Kampong Cham, respectively. The arsenic dietary intake in Kandal ranked No. 1 among all the 17 compared countries or regions. Fish consumption contributed the greatest proportion of total arsenic daily intake in Kandal (about 63.0 %) and Kampong Cham (about 69.8 %). It is revealed to be a much more important exposure pathway than drinking water for residents in Kampong Cham. The results of risk assessment suggested that the residents in Cambodia, particularly for people in Kandal province, suffer high public health risks due to consuming arsenic-contaminated food. PMID:23728998

Wang, Hong-Sheng; Sthiannopkao, Suthipong; Chen, Zhuo-Jia; Man, Yu-Bon; Du, Jun; Xing, Guang-Hua; Kim, Kyoung-Woong; Mohamed Yasin, Mohamed Salleh; Hashim, Jamal Hisham; Wong, Ming-Hung

2013-12-01

308

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)

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

Marmorek, David

2004-03-01

309

An approach for quantitative assessment of fluorescence in situ hybridization (FISH) signals for applied human molecular cytogenetics.  

Science.gov (United States)

A number of applied molecular cytogenetic studies require the quantitative assessment of fluorescence in situ hybridization (FISH) signals (for example, interphase FISH analysis of aneuploidy by chromosome enumeration DNA probes; analysis of somatic pairing of homologous chromosomes in interphase nuclei; identification of chromosomal heteromorphism after FISH with satellite DNA probes for differentiation of parental origin of homologous chromosome, etc.). We have performed a pilot study to develop a simple technique for quantitative assessment of FISH signals by means of the digital capturing of microscopic images and the intensity measuring of hybridization signals using Scion Image software, commonly used for quantification of electrophoresis gels. We have tested this approach by quantitative analysis of FISH signals after application of chromosome-specific DNA probes for aneuploidy scoring in interphase nuclei in cells of different human tissues. This approach allowed us to exclude or confirm a low-level mosaic form of aneuploidy by quantification of FISH signals (for example, discrimination of pseudo-monosomy and artifact signals due to over-position of hybridization signals). Quantification of FISH signals was also used for analysis of somatic pairing of homologous chromosomes in nuclei of postmortem brain tissues after FISH with "classical" satellite DNA probes for chromosomes 1, 9, and 16. This approach has shown a relatively high efficiency for the quantitative registration of chromosomal heteromorphism due to variations of centromeric alphoid DNA in homologous parental chromosomes. We propose this approach to be efficient and to be considered as a useful tool in addition to visual FISH signal analysis for applied molecular cytogenetic studies. PMID:15750029

Iourov, Ivan Y; Soloviev, Ilia V; Vorsanova, Svetlana G; Monakhov, Viktor V; Yurov, Yuri B

2005-03-01

310

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

Science.gov (United States)

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 (pCatla catla, Labeo 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

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

2010-09-01

311

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

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 * parasite s * fish health Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 3.026, year: 2010

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

312

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

313

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.

314

Seals, cod and forage fish: A comparative exploration of variations in the theme of stock collapse and ecosystem change in four Northwest Atlantic ecosystems  

Science.gov (United States)

The facts: four Northwest Atlantic ecosystems, three cod stock collapses 15 years ago (plus one severely depleted), seals now top predator in all ecosystems, all had cod as a top predator before collapse, groundfish declines in all areas, forage base increased in most systems. No recovery in any system. Have these ecosystems fundamentally changed? Why? The challenge: compare and contrast these four ecosystems. The answer: using mass balance models, empirical data and a suite of ecosystem indicators, we explore how and why these systems have changed over time. At the ecosystem and community level, we see broad similarities between ecosystems. However, structurally and functionally these systems have shifted to an alternate state, with changes in predator structure, trophic structure and flow.

Bundy, Alida; Heymans, Johanna J.; Morissette, Lyne; Savenkoff, Claude

2009-04-01

315

A survey-based assessment of cod in Division 3M  

OpenAIRE

The cod stock in NAFO division 3M is in fishing moratorium since 1999. Commercial catches have been very low since then, although they were noticeable in 2006. During the last few years a survey-based assessment method has been used to evaluate the stock status in a stochastic way. The method takes into account uncertainties in survey results as well as in catchability estimates. The present document updates the results of the assessment conducted in 2006 (details in Murua et al. ...

Ferna?ndez, Carmen; Cervin?o, Santiago; Va?zquez, Antonio

2004-01-01

316

Determination of toxic elements (mercury, cadmium, lead, tin and arsenic) in fish and shellfish samples. Risk assessment for the consumers.  

Science.gov (United States)

Although fish intake has potential health benefits, the presence of metal contamination in seafood has raised public health concerns. In this study, levels of mercury, cadmium, lead, tin and arsenic have been determined in fresh, canned and frozen fish and shellfish products and compared with the maximum levels currently in force. In a further step, potential human health risks for the consumers were assessed. A total of 485 samples of the 43 most frequently consumed fish and shellfish species in Andalusia (Southern Spain) were analyzed for their toxic elements content. High mercury concentrations were found in some predatory species (blue shark, cat shark, swordfish and tuna), although they were below the regulatory maximum levels. In the case of cadmium, bivalve mollusks such as canned clams and mussels presented higher concentrations than fish, but almost none of the samples analyzed exceeded the maximum levels. Lead concentrations were almost negligible with the exception of frozen common sole, which showed median levels above the legal limit. Tin levels in canned products were far below the maximum regulatory limit, indicating that no significant tin was transferred from the can. Arsenic concentrations were higher in crustaceans such as fresh and frozen shrimps. The risk assessment performed indicated that fish and shellfish products were safe for the average consumer, although a potential risk cannot be dismissed for regular or excessive consumers of particular fish species, such as tuna, swordfish, blue shark and cat shark (for mercury) and common sole (for lead). PMID:23792415

Olmedo, P; Pla, A; Hernández, A F; Barbier, F; Ayouni, L; Gil, F

2013-09-01

317

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

Science.gov (United States)

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. PMID:18524439

Linde-Arias, Ana Rosa; Inácio, Alan F; Novo, Leonardo A; de Alburquerque, Carla; Moreira, Josino C

2008-12-01

318

The variability of fisheries and fish populations prior to industrialized fishing: An appraisal of the historical evidence  

Science.gov (United States)

This paper assesses the potentials of the available time series (50 years+) from historical records of the pre-industrial period until c. 1850-1950. A number of historical records from commercially important fish species are available for examining natural variability of fish stocks. Especially for North Atlantic and Japanese fisheries historical data have been retrieved from archives and museums, which cover time spans of 50-350 years. This makes it possible to examine natural variability of fish stocks over a much longer time span than what is normally possible with modern survey data and commercial catch data. Furthermore, historical evidence from the pre-industrialized period have the benefit of stemming from a period in time, when fishing had an insignificant impact on the abundance of open sea fish stocks. The best material comes from cod and herring fisheries, where it is possible to reconstruct CPUE as accurate as catch per boat per day absent, as well as changing spatial distribution over longer time periods.

Poulsen, Bo

2010-02-01

319

Does predation by grey seals (Halichoerus grypus) affect Bothnian Sea herring stock estimates?  

DEFF Research Database (Denmark)

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

Gårdmark, Anna; Östman, Örjan

2012-01-01

320

Assessment of Hydroponically Grown Macrophytes for Their Suitability as Fish Feed  

Directory of Open Access Journals (Sweden)

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.

A. M. Snow

2008-01-01

321

Fish Breeding in Nigeria  

OpenAIRE

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...

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

2011-01-01

322

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)

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}.

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

323

The fish community of a moderately exposed beach on the southwestern Cape coast of South Africa and an assessment of this habitat as a nursery for juvenile fish  

Science.gov (United States)

The ichthyofauna of a moderately exposed surf-zone habitat on the southwestern Cape coast of South Africa was sampled by seine netting monthly for 13 months. Twenty species of fish, 40 306 individuals weighing a total of 211 kg were captured. The number of species and standing crop varied seasonally with higher values occurring during the summer (January-March). The average summer standing stock of 38·6 g m -2 was considerably higher than any previously recorded from a surf-zone habitat and the annual average (10·1 g m -2 was comparable with that in estuaries. Eighteen of the species sampled occurred almost exclusively as juveniles and only two as adults. Four species were present throughout the year, 11 of them seasonally and the remaining five sporadically. Small juveniles (20-35 mm) typically appeared in the surf-zone 2-4 months after they were spawned. These 0+ juveniles remained there for between three months and one year depending on species, before vacating the surf-zone for their adult habitats. A comparison of the abundance of juveniles in the surf-zone with other inshore marine habitats suggested that five species ( Amblyrhynchotes honckenii, Cheilodonichthys capensis, Diplodus sargus, Lithognathus mormyrus and Pomadasys olivaceum) may be entirely, and three species ( Lichia amia, Liza richardsoni and Rhabdosargus globiceps) largely, dependent on the surf-zone as a nursery area. It was concluded that the surf-zone of sandy beaches may be as important as estuaries as a nursery habitat for juvenile fish.

Bennett, B. A.

1989-03-01

324

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

Science.gov (United States)

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

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

2007-01-01

325

Do stock prices drive people crazy?  

Science.gov (United States)

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

Lin, Chung-Liang; Chen, Chin-Shyan; Liu, Tsai-Ching

2015-03-01

326

Interrenal dysfunction in fish from contaminated sites: In vivo and in vitro assessment  

Energy Technology Data Exchange (ETDEWEB)

Cortisol, synthesized in the interrenal cells of teleost head kidney, has a major role in the physiologic response to physical and chemical stressors. Plasma levels of cortisol increase in physiologically competent fish acutely exposed to stressors such as cadmium or mercury. The effects of chronic low level exposures are less well understood. The author has diagnosed an endocrine impairment characterized by a reduced capacity to elevate plasma cortisol levels in response to an acute standardized capture stress in yellow perch (Perca flavescens) and in northern pike (Esox lucius) sampled at sites contaminated by mixtures of pollutants (heavy metals, polycyclic aromatic hydrocarbons, and polychlorinated biphenyls), by heavy metals, or by bleached kraft mill effluent. The studies with fish, as well as with amphibians at contaminated sites, demonstrated that low level chronic exposures impair secretion of corticosteroids. The author has developed new tests for assessment of the functional integrity of teleost and amphibian interrenal tissue using an adrenocorticotropic hormone (ACTH) challenge, in vivo and in vitro. The reduced ability to respond to ACTH indicates that the normal neuroendocrine response to stressors may be disrupted and that the ability to cope with biotic and abiotic stressors in the environment may be significantly reduced in the impaired animals.

Hontela, A. [Univ. du Quebec, Montreal, Quebec (Canada)

1998-01-01

327

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

Science.gov (United States)

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

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

2013-04-15

328

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

2013-05-01

329

Assessing Cumulative Thermal Stress in Fish During Chronic Exposure to High Temperature  

Energy Technology Data Exchange (ETDEWEB)

As environmental laws become increasingly protective, and with possible future changes in global climate, thermal effects on aquatic resources are likely to receive increasing attention. Lethal temperatures for a variety of species have been determined for situations where temperatures rise rapidly resulting in lethal effects. However, less is known about the effects of chronic exposure to high (but not immediately lethal) temperatures and even less about stress accumulation during periods of fluctuating temperatures. In this paper we present a modeling framework for assessing cumulative thermal stress in fish. The model assumes that stress accumulation occurs above a threshold temperature at a rate depending on the degree to which the threshold is exceeded. The model also includes stress recovery (or alleviation) when temperatures drop below the threshold temperature as in systems with large daily variation. In addition to non-specific physiological stress, the model also simulates thermal effects on growth.

Bevelhimer, M.S.; Bennett, W.R.

1999-11-14

330

Assessing the health condition profile in the freshwater fish Astyanax aeneus in Champoton River, Mexico.  

Science.gov (United States)

The use of biomarkers for monitoring aquatic environmental quality has gained considerable interest worldwide. The effects of the environmental conditions of Río Champotón, México, in the hotspot of Mesoamerica, were assessed in Astyanax aeneus, a native fish of the tropics of southwestern México. Pollution from agrochemical residues is a major problem in Río Champotón. Three study sites along the freshwater portion of the river were monitored in April, July, and November 2007 and February 2008. This study includes a water quality index, a set of biomarkers (hepatic glycogen levels and lipid peroxidation in liver, gills, and muscle) to assess the integrated biomarker response, and population bioindicators (gonadosomatic and hepatosomatic indices and Fulton's condition factor). Although the water quality index suggested low level of contamination in the Río Champotón, biomarkers indicated that A. aeneus is exposed to stressors that impair biological responses. The integrated biomarker response showed stress periods with higher biomarker response and recovery periods with decreasing biomarker values. The somatic indices did not indicate severe effects at the population level. This study illustrates the usefulness of lipid peroxidation evaluation in the assessment of aquatic health conditions and corroborates the suitability of A. aeneus as a sentinel species. PMID:24579529

Trujillo-Jiménez, Patricia; Sedeño-Díaz, Jacinto Elías; López-López, Eugenia

2014-01-01

331

Carbon stocks in the Alaska Yukon River Basin  

Science.gov (United States)

Boreal forest systems in Alaska maybe vulnerable to long-term ecological changes related to climate change and shifting fire regimes. Future projections of boreal forest carbon stocks are improved with more accurate quantification of current baseline soil carbon stocks. Above ground biomass (R2 = 0.66) and soil organic layer thickness (R2 = 0.67, p < 0.01) were quantified using field plots parameters estimated with regression tree techniques using 30 m resolution Landsat and ancillary data as inputs within the Yukon Flats ecoregion of Alaska. Soil organic layer thickness was converted to soil carbon stocks with a regression (R2 = 0.80, p < 0.01). We extended these Landsat-based regression tree mapping techniques with Fish and Wildlife and Natural Resources Conservation Service collaborators and additional collected field observations, airborne electromagnetic surveys, Landsat Web-enabled Landsat Data (WELD), and ancillary data to map carbon stocks at a 30 m spatial resolution for the Alaskan portion of the Yukon River basin. The carbon stocks in non-disturbed and previously burned fire scar areas within the boreal forests of this region were then assessed. Future boreal forest above ground biomass for boreal forests through the entire Yukon River basin was mapped for 2070 using the ecosystem performance modeling approach. Undisturbed boreal forest biomass was expected to increase in the south central areas of the Yukon River basin and decline in portions of the eastern extents. Current to 2070 precent difference in biomass for boreal forest in the Yukon River Basin.

Wylie, B. K.; Pastick, N.; Jorgenson, M. T.; Zhu, Z.; Ji, L.; Rigge, M. B.; Johnson, K. D.

2012-12-01

332

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)

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

Bergamaschi, Brian; 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

333

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)

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.

Zden?k Adámek

2004-03-01

334

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)

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.

Wang, Yang; Wang, Yingbin; Zheng, Ji

2015-02-01

335

Augmented Fish Health Monitoring for Washington Department of Wildlife, 1989 Annual Report.  

Energy Technology Data Exchange (ETDEWEB)

The augmented fish health monitoring project is funded by the Bonneville Power Administration (BPA) with the mandate to collect fish health data on anadromous fish stocks of the BPA Columbia River Basin in a standardized manner. The project began in 1986 and the data reported here was collected in the fourth year. This segment of the project was carried out by the Washington Department of Wildlife and summarizes fish health findings at anadromous game fish hatcheries in Washington State operated by the BPA. Information gathered to data has provided impetus to alter facility design and management practices for improved fish health through prevention. Treatment efficacy can be better assessed due to the monthly monitoring of fish stocks and insight is being gained into disease prevention and control. The ultimate goal, of course, is to improve fish health for better survival in the wild. Tagged returns at index hatcheries within this project area will provide some indication of the impact of improving fish health on providing greater adult returns as well as an improved product for the fishery. 3 refs., 2 figs., 16 tabs.

Kerwin, John L.; Roberts, Steve; Oman, Leni; Bolding, Bruce

1991-04-01

336

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

337

Fish Breeding in Nigeria  

Directory of Open Access Journals (Sweden)

Full Text Available 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 article reviews the wild sources of fish seeds, some cultivable fishes. carp breeding, relationship between the endocrine system and gonad development, function of the Central Nervous System (CNS in propagation, influence of ecological conditions on gonad development, artificial propagation of common carp, natural induced spawning, salmon culture and an innovation in the sea to educate fish breeders, fish genetics and fish culturist in other to facilitate their productivity.

J.A. Akankali

2011-06-01

338

Epizootics of wild fish induced by farm fish  

OpenAIRE

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...

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

2006-01-01

339

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

Science.gov (United States)

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

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

340

Assessment of Heavy Metals in the Fish Collected from the River Ravi, Pakistan  

Directory of Open Access Journals (Sweden)

Full Text Available The toxicity of heavy metals viz. aluminium (Al, arsenic (As, barium (Ba, chromium (Cr, nickel (Ni and zinc (Zn in fish at three main public fishing sites of the river Ravi viz. Shahdara bridge, Baloki headworks and Sidhnai barrage has been studied from June, 2009 to May, 2010. The concentrations of heavy metals in the body organs (gills, liver, kidney, intestine, reproductive organs, skin, muscle, fins, scales, bones, fats of three fish species viz. Catla catla, Labeo rohita and Cirrhina mrigala were determined. The present results reveal that the toxicity of metals fluctuated significantly in fish at all the three sampling stations with season. The fish samples collected from all the three sampling stations had significantly higher aluminium and zinc. However, the fish at Sidhnai barrage showed significantly lower metallic toxicity, followed by that at Baloki headworks and Shahdara bridge. Significantly higher metals were observed in fish liver, followed by that of kidney, gills, intestine, reproductive organs, skin, scales, fins, bones, muscle and fats. The accumulation of metals in carnivorous fish body organs showed significantly direct dependence on the metallic toxicity of herbivorous cyprinids. Fish liver and kidney showed significantly higher abilities for the accumulation of all metals while accumulations were lowest in fish muscle and fats. The health status of river Ravi at three main public fishing sites viz. Shahdara bridge, Baloki headworks and Sidhnai barrage, with respect to eco-toxicity of Al, As, Ba, Cr, Ni and Zn was above the recommended permissible standards.

Ghazala Jabeen*, Muhammad Javed and Hamda Azmat

2012-01-01

341

Fugitive Salmon: Assessing the Risks of Escaped Fish from Net-Pen Aquaculture  

Science.gov (United States)

This peer-reviewed resource from BioScience journal is the risks associated with aquaculture.The farming of salmon and other marine finfish in open net pens continues to increase along the world's coastlines as the aquaculture industry expands to meet human demand. Farm fish are known to escape from pens in all salmon aquaculture areas. Their escape into the wild can result in interbreeding and competition with wild salmon and can facilitate the spread of pathogens, thereby placing more pressure on already dwindling wild populations. Here we assess the ecological, genetic, and socioeconomic impacts of farm salmon escapes, using a risk-assessment framework. We show that risks of damage to wild salmon populations, ecosystems, and society are large when salmon are farmed in their native range, when large numbers of salmon are farmed relative to the size of wild populations, and when exotic pathogens are introduced. We then evaluate the policy and management options for reducing risks and discuss the implications for farming other types of marine finfish.

ROSAMOND NAYLOR, KJETIL HINDAR, IAN A. FLEMING, REBECCA GOLDBURG, SUSAN WILLIAMS, JOHN VOLPE, FRED WHORISKEY, JOSH EAGLE, DENNIS KELSO, and MARC MANGEL (; )

2005-05-01

342

Global warming and fish migrations  

OpenAIRE

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...

Hannesson, Ro?gnvaldur

2005-01-01

343

Harvest Management and Recovery of Snake River Salmon Stocks : Recovery Issues for Threatened and Endangered Snake River Salmon : Technical Report 7 of 11.  

Energy Technology Data Exchange (ETDEWEB)

Management measures to regulate salmon fishing harvest have grown increasingly complex over the past decade in response to the needs for improved protection for some salmon runs and to alter harvest sharing between fisheries. The development of management plans that adequately address both needs is an immensely complicated task, one that involves a multitude of stocks, each with its own migration patterns and capacity to sustain exploitation. The fishing industry that relies on these fish populations is also highly diverse. The management task is made especially difficult because the stocks are often intermingled on the fishing grounds, creating highly mixed aggregates of stocks and species on which the fisheries operate. This situation is the one confronting harvest managers attempting to protect Snake River salmon. This report provides an overview of some of the factors that will need to be addressed in assessing the potential for using harvest management measures in the recovery of Snake River salmon stocks. The major sections of the report include the following: perspectives on harvest impacts; ocean distribution and in-river adult migration timing; description of management processes and associated fisheries of interest; and altemative harvest strategies.

Lestelle, Lawrence C.; Gilbertson, Larry G.

1993-06-01

344

Hexavalent chromium in fish from the Sepetiba Bay in Rio de Janeiro, Brazil: a risk assessment to human health  

Directory of Open Access Journals (Sweden)

Full Text Available Introduction: Certain metals, among them hexavalent chromium influence the stability of ecosystems and cause adverse effects on human health. Thus, this study aimed to estimate a risk model of human health associated with fish consumption from the Sepetiba Bay. Methodology: This risk assessment methodology was developed by the United States Environmental Protection Agency (USEPA. The models were implemented using the USEPA toxicological databases and samples from the Sepetiba Bay, Rio de Janeiro. Results: The intoxication and carcinogenic risk estimated for fish consumption of M. furnieri and C. acoupa species were considered small. Conclusion: Based on the analysis, we conclude that the toxicological risk or carcinogenic injury to health due to fish consumption with high levels of cromo6+ coming from Sepetiba Bay is low. Still, it emphasizes the validity of utilizing monitoring methods in coastal environments, for health and environmental control.

Carla da Costa Cruz

2011-12-01

345

Analysis of fish DNA biomarkers as a molecular-level approach for ecological health assessments in an urban stream.  

Science.gov (United States)

This study was performed to determine the ecosystem health of an urban stream using DNA damage biomarkers of sentinel fish species along with chemical analyses of water and sediments in the impacted and reference zones. The results based on single-cell gel electrophoresis showed that the extent of DNA damage was significantly elevated in the polluted zone. The severity of DNA damage in the impacted zone was largely attributed to high levels of heavy metals, such as As, Zn, Pb, and Ni. The DNA damage biomarker in benthic fish was sensitive to habitat change, which suggested that this fish species and biomarker are excellent tools for risk assessment. The acute toxicity tests demonstrated that SCGE was sufficient to reflect the different genotypes and pollution statuses and to propose the possibility of zebrafish erythrocytes as competitive materials. PMID:25260997

Kang, Nami; Kang, Han-Il; An, Kwang-Guk

2014-11-01

346

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

347

Stock-based vs. fleet-based evaluation of the multi-annual management plan for the cod stocks in the Baltic Sea  

DEFF Research Database (Denmark)

This study evaluated the EU 2008 multi-annual plan for Baltic cod stock recovery. The plan combines harvest control rules that set TACs with reductions in direct effort (E) and fishing mortality (F). Performance and robustness of the plan are tested with a management strategy evaluation model (MSE). Stochastic simulations are carried out under different scenarios of recruitment and sources of uncertainties. Under the different magnitudes of errors investigated, the plan in its current design is likely to reach precautionary targets for the Eastern and the Western Baltic cod stocks by 2015. It is, however, more sensitive to implementation errors (e.g. catch misreporting) than to observation errors (e.g. data collection) when the (i) current settings of the ICES single-stock assessment model are maintained. (ii) intended fishing effort reduction is fully complied with, and (iii) biological parameters are assumed constant. For the Eastern Baltic stock, additional sources of uncertainties from fishery adaptation to the plan are tested using a fleet-based and spatially explicit version of the model which leads to higher reductions in F and no significant change in management robustness. The relative difference between both approaches is mainly due to differences in exploitation patterns in catching the same amount of fish. The effort control is demonstrated to be more efficient when supplemented with a TAC and avoids un-intended effects from fishery responses, e.g. spatial effort reallocation. Medium term economic evaluation of fishery performance shows an initial reduction in profit with effort and TAC reductions, but profit is always positive. (C) 2009 Elsevier B.V. All rights reserved.

Bastardie, Francois; Vinther, Morten

2010-01-01

348

Energy and economic assessment of a solar absorption refrigeration plant in a fish processing factory. A case study in Sicily  

Energy Technology Data Exchange (ETDEWEB)

The aim of the study is the energy and economic assessment of an application of solar cooling for industrial refrigeration in a fish processing factory located in Sicily. The base case is an existing plant with ammonia vapour compression machine. The use of an absorption refrigeration plant powered by parabolic solar collectors is considered as an alternative solution. The energy assessment of the considered system is carried out through detailed simulations for different collector surface and heat storage volume. In order to assess the best configuration of the solar refrigeration system in term of energy and economic performances, a sensitivity analysis is performed. (orig.)

Beccali, M.; Di Pietra, B.; Finocchiaro, P.; Messineo, A.; Panno, D. [Univ. degli Studi di Palermo (Italy). Dipt. di Ricerche Energetiche ed Ambientali

2007-07-01

349

Soil organic carbon stocks assessment in Mediterranean natural areas: A comparison of entire soil profiles and soil control sections.  

Science.gov (United States)

Soil organic carbon (SOC) is an important part of the global carbon (C) cycle. In addition, SOC is a soil property subject to changes and highly variable in space and time. Over time, some researches have analyzed entire soil profile (ESP) by pedogenetic horizons and other researches have analyzed soil control sections (SCS) to different thickness. However, very few studies compare both methods (ESP versus SCS). This research sought to analyze the SOC stock (SOCS) variability using both methods (ESP and SCS) in The Despeñaperros Natural Park, a nature reserve that consists of a 76.8 km(2) forested area in southern Spain. Thirty-four sampling points were selected in the study zone. Each sampling point was analyzed in two different ways, as ESP (by horizons) and as SCS with different depth increments (0-25, 25-50, 50-75 and 75-100 cm). The major goal of this research was to study the SOCS variability at regional scale. The soils investigated in this study included Phaeozems, Cambisols, Regosols and Leptosols. Total SOCS in the Despeñaperros Natural Park was over 28.2% greater when SCS were used compared to ESP, ranging from 0.8144 Tg C (10,604.2 Mg km(-2)) to 0.6353 Tg C (8272.1 Mg km(-2)) respectively (1 Tg = 10(12) g). However, when the topsoil (surface horizon and superficial section control) was analyzed, this difference increased to 59.8% in SCS compared to ESP. The comparison between ESP and SCS showed the effect of mixing pedogenetic horizons when depth increments were analyzed. This indicates an overestimate of T-SOCS when sampling by SCS. PMID:25837298

Parras-Alcántara, L; Lozano-García, B; Brevik, E C; Cerdá, A

2015-05-15

350

Estimating the long-term effects of stocking domesticated trout into wild brown trout ( Salmo trutta ) populations : an approach using microsatellite DNA analysis of historical and contemporary samples  

DEFF Research Database (Denmark)

Indigenous salmonid fish gene pools are affected by domesticated conspecifics, derived from aquaculture escapes and deliberate releases. Variability was examined at nine microsatellite loci in order to assess the long-term impact of stocking domesticated trout in two brown trout populations. The study was based on analysis of two historical samples (194556), represented by old scale collections, and seven contemporary samples (1986-2000). In one population historical and contemporary samples were remarkably genetically similar despite more than a decade of intense stocking. Estimation of admixture proportions showed a small genetic contribution from domesticated trout (approximately 6%), and individual admixture analysis demonstrated a majority of nonadmixed individuals. The expected genetic contribution by domesticated trout was 64%, assessed from the number of stocked trout and assuming equal survival and reproductive performance of wild and domesticated trout. This demonstrates poor performance and low fitness of domesticated trout in the wild. In another population there was a strong genetic contribution from domesticated trout (between 57% and 88% in different samples), both in samples from a broodstock thought to represent the indigenous population and in a sample of wild spawners. Survival of domesticated trout and admixture with indigenous fish in the broodstock and subsequent stocking into the river, combined with a low population size of native trout relative to the number of stocked trout, could explain the observed introgression. Few nonadmixed individuals remained in the introgressed population, and I discuss how individual admixture analysis can be used to identify and conserve nonintrogressed remains of the population.

Hansen, Michael MØller

2002-01-01

351

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

352

Assessment of Heavy Metals in the Fish Collected from the River Ravi, Pakistan  

OpenAIRE

The toxicity of heavy metals viz. aluminium (Al), arsenic (As), barium (Ba), chromium (Cr), nickel (Ni) and zinc (Zn) in fish at three main public fishing sites of the river Ravi viz. Shahdara bridge, Baloki headworks and Sidhnai barrage has been studied from June, 2009 to May, 2010. The concentrations of heavy metals in the body organs (gills, liver, kidney, intestine, reproductive organs, skin, muscle, fins, scales, bones, fats) of three fish species viz. Catla catla, Labeo rohita and Cirrh...

Ghazala Jabeen, Muhammad Javed And Hamda Azmat

2012-01-01

353

Determination and assessment of total mercury levels in local, frozen and canned fish in Lebanon.  

Science.gov (United States)

Fish is an important constituent of the Lebanese diet. However, very little attention in our area is given to bring awareness regarding the effect of the toxicity of mercury (Hg) mainly through fish consumption. This study aimed to report analytical data on total mercury levels in several fish species for the first time in thirty years and to also made individuals aware of the presence and danger from exposure to mercury through fish consumption. Fish samples were selected from local Lebanese markets and fisheries and included 94 samples of which were fresh, frozen, processed, and canned fish. All values were reported as microgram of mercury per gram of fish based on wet weight. The level of mercury ranged from 0.0190 to 0.5700 microg/g in fresh samples, 0.0059 to 0.0665 microg/g in frozen samples, and 0.0305 to 0.1190 microg/g in canned samples. The data clearly showed that higher levels of mercury were detected in local fresh fish as opposed to other types thus placing consumers at higher risk from mercury exposure. Moreover, the data revealed that Mallifa (yellowstripe barracuda/Sphyraena chrysotaenia), Sargous (white seabream/Diplodus sargus), Ghobbos (bogue/Boops boops), and shrimp (Penaeus sp.) were among the types containing the highest amounts of mercury. On the other hand, processed fish such as fish fillet, fish burger, small shrimp and crab are found to contain lower levels of mercury and are associated with lower exposure risks to mercury. Lebanese population should therefore, be aware to consume limited amounts of fresh local fish to minimize exposure to mercury. PMID:22432295

Obeid, Pierre J; El-Khoury, Bilal; Burger, Joanne; Aouad, Samer; Younis, Mira; Aoun, Amal; El-Nakat, John Hanna

2011-01-01

354

Arsenic contamination in the freshwater fish ponds of Pearl River Delta: bioaccumulation and health risk assessment.  

Science.gov (United States)

This study investigated the extent of arsenic (As) contamination in five common species of freshwater fish (northern snakehead [Channa argus], mandrarin fish [Siniperca chuatsi], largemouth bass [Lepomis macrochirous], bighead carp [Aristichthys nobilis] and grass carp [Ctenopharyngodon idellus]) and their associated fish pond sediments collected from 18 freshwater fish ponds around the Pearl River Delta (PRD). The total As concentrations detected in fish muscle and sediment in freshwater ponds around the PRD were 0.05-3.01 mg kg(-1) wet weight (w. wt) and 8.41-22.76 mg kg(-1) dry weight (d. wt), respectively. In addition, the As content was positively correlated (p BSAF) showed that omnivorous fish and zooplankton accumulated higher concentrations of heavy metals from the sediment than carnivorous fish. In addition, feeding habits of fish also influence As accumulation in different fish species. In this study, two typical food chains of the aquaculture ponds were selected for investigation: (1) omnivorous food chain (zooplankton, grass carp and bighead carp) and (2) predatory food chain (zooplankton, mud carp and mandarin fish). Significant linear relationships were obtained between log As and ? (15)N. The slope of the regression (-0.066 and -0.078) of the log transformed As concentrations and ? (15)N values, as biomagnifications power, indicated there was no magnification or diminution of As from lower trophic levels (zooplankton) to fish in the aquaculture ponds. Consumption of largemouth bass, northern snakehead and bighead carp might impose health risks of Hong Kong residents consuming these fish to the local population, due to the fact that its cancer risk (CR) value exceeded the upper limit of the acceptable risk levels (10(-4)) stipulated by the USEPA. PMID:23247527

Cheng, Zhang; Chen, Kun-Ci; Li, Kai-Bin; Nie, Xiang-Ping; Wu, Sheng Chun; Wong, Chris Kong-Chu; Wong, Ming-Hung

2013-07-01

355

Screening level dose rate assessment of fishes exposed to artificial radionuclides of the Beloyarskoe storage pond  

International Nuclear Information System (INIS)

Aquatic biota in the Beloyarskoe storage pond of the nuclear power station are exposed to radioactivity released from the fast-breeder reactor. A simple conservative screening level model was used to estimate absorbed (whole body) dose rates for aquatic organisms. Four species of fishes were studied, (non-bottom-feeding fish, and bottom-feeding fish). The analysis was based on radionuclide concentrations reported in papers published by Russian Academy of Sciences. (authors)

356

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

357

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

358

Concentration and exposure assessment of mercury in commercial fish and other seafood marketed in Oman.  

Science.gov (United States)

The results of this study present analytical data of the mercury levels in several fish and shellfish species to create awareness among individuals of the risks associated with consuming fish contaminated with mercury. Mercury concentrations varied from a mean of 0.02 mg/kg in Indian mackerel to 0.19 mg/kg in shark in both fresh and frozen fish, from 0.02 mg/kg in sardines to 0.18 mg/kg in skipjack tuna in canned fish, and from 0.02 mg/kg in Indian mackerel to 0.79 mg/kg in shark in dried fish. Shellfish contained a slightly higher amount of mercury than fresh or frozen fish with a mean of 0.09 mg/kg. Trophic position, followed by habitat, was the most important factors for variability in mercury concentrations in fish and shellfish. The maximum safe weekly intake (MSWI) values of mercury were significantly higher for herbivores than for carnivores. The MSWI value for total mercury in the case of consuming most (72%) fish species was more than 5 kg; however, the MSWI value was never more than 5 kg in most (66%) shellfish species. Risks were identified upon consumption of 120 g of dried shark when exceeding the provisional tolerable weekly intake threshold (1.6 ?g/kg) for methylmercury. Therefore, fish-eating populations should reduce the quantity of dried shark to efficiently diminish the exposure to mercury. PMID:23701530

Al-Mughairi, Sabra; Yesudhason, Poulose; Al-Busaidi, Moza; Al-Waili, Aaliah; Al-Rahbi, Waleed A K; Al-Mazrooei, Nashwa; Al-Habsi, Saoud H

2013-07-01

359

Augmented Fish Health Monitoring for Washington Department of Wildlife, 1988 Annual Report.  

Energy Technology Data Exchange (ETDEWEB)

The augmented fish health monitoring project is funded by the Bonneville Power Administration with the mandate to collect fish health data on anadromous fish stocks of the Columbia River Basin in a standardized manner. The project began in 1986 and the data reported here was collected in the third year. This segment of the project was carried out by the Washington Department of Wildlife and summarizes fish health findings at anadromous game hatcheries in Washington State operated by the BPA. Information gathered to date has provided impetus to alter facility design and management practices for improved fish health through prevention. Treatment efficacy can be better assessed due to the monthly monitoring of fish stocks and insight is being gained into disease prevention and control. The ultimate goal, of course, is to improve fish health for better survival in the wild. Tagged returns at index hatcheries within this project area will indicate the impact of improving fish health on providing greater adult returns as well as an improved product for the fishery. 2 refs., 3 figs., 15 tabs.

Gearheard, Jim

1988-10-01

360

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

2012-04-01

361

Essays on performance-vested stock options and corporate governance  

OpenAIRE

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...

Bo Qin,

2010-01-01

362

Molecular diversity of Germany's freshwater fishes and lampreys assessed by DNA barcoding.  

Science.gov (United States)

This study represents the first comprehensive molecular assessment of freshwater fishes and lampreys from Germany. We analysed COI sequences for almost 80% of the species mentioned in the current German Red List. In total, 1056 DNA barcodes belonging to 92 species from all major drainages were used to (i) build a reliable DNA barcode reference library, (ii) test for phylogeographic patterns, (iii) check for the presence of barcode gaps between species and (iv) evaluate the performance of the barcode index number (BIN) system, available on the Barcode of Life Data Systems. For over 78% of all analysed species, DNA barcodes are a reliable means for identification, indicated by the presence of barcode gaps. An overlap between intra- and interspecific genetic distances was present in 19 species, six of which belong to the genus Coregonus. The Neighbour-Joining phenogram showed 60 nonoverlapping species clusters and three singleton species, which were related to 63 separate BIN numbers. Furthermore, Barbatula barbatula, Leucaspius delineatus, Phoxinus phoxinus and Squalius cephalus exhibited remarkable levels of cryptic diversity. In contrast, 11 clusters showed haplotype sharing, or low levels of divergence between species, hindering reliable identification. The analysis of our barcode library together with public data resulted in 89 BINs, of which 56% showed taxonomic conflicts. Most of these conflicts were caused by the use of synonymies, inadequate taxonomy or misidentifications. Moreover, our study increased the number of potential alien species in Germany from 14 to 21 and is therefore a valuable groundwork for further faunistic investigations. PMID:25186809

Knebelsberger, Thomas; Dunz, Andreas R; Neumann, Dirk; Geiger, Matthias F

2014-09-01

363

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

Science.gov (United States)

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.

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

364

A feasibility assessment of automated FISH image and signal analysis to assist cervical cancer detection  

Science.gov (United States)

Fluorescence in situ hybridization (FISH) technology provides a promising molecular imaging tool to detect cervical cancer. Since manual FISH analysis is difficult, time-consuming, and inconsistent, the automated FISH image scanning systems have been developed. Due to limited focal depth of scanned microscopic image, a FISH-probed specimen needs to be scanned in multiple layers that generate huge image data. To improve diagnostic efficiency of using automated FISH image analysis, we developed a computer-aided detection (CAD) scheme. In this experiment, four pap-smear specimen slides were scanned by a dual-detector fluorescence image scanning system that acquired two spectrum images simultaneously, which represent images of interphase cells and FISH-probed chromosome X. During image scanning, once detecting a cell signal, system captured nine image slides by automatically adjusting optical focus. Based on the sharpness index and maximum intensity measurement, cells and FISH signals distributed in 3-D space were projected into a 2-D con-focal image. CAD scheme was applied to each con-focal image to detect analyzable interphase cells using an adaptive multiple-threshold algorithm and detect FISH-probed signals using a top-hat transform. The ratio of abnormal cells was calculated to detect positive cases. In four scanned specimen slides, CAD generated 1676 con-focal images that depicted analyzable cells. FISH-probed signals were independently detected by our CAD algorithm and an observer. The Kappa coefficients for agreement between CAD and observer ranged from 0.69 to 1.0 in detecting/counting FISH signal spots. The study demonstrated the feasibility of applying automated FISH image and signal analysis to assist cyto-geneticists in detecting cervical cancers.

Wang, Xingwei; Li, Yuhua; Liu, Hong; Li, Shibo; Zhang, Roy R.; Zheng, Bin

2012-02-01

365

Contents and risk assessment of heavy metals in marine invertebrates from Korean coastal fish markets.  

Science.gov (United States)

The concentrations of the heavy metals cadmium (Cd), mercury (Hg), lead (Pb), chromium, silver, nickel, copper, and zinc in the edible portions of 105 marine invertebrates representing 16 mollusk and crustacean species were accurately determined to evaluate their hazard for human consumption. The samples were collected in 2011 from major fish markets on the coast of Korea and analyzed for Hg using a direct Hg analyzer and for other metals using inductively coupled plasma mass spectrometry. Estimated dietary exposure (EDE) was determined, and a risk assessment was made of the heavy metals to provide information concerning consumer safety. The Cd concentrations, which were the highest for the three hazardous metals (Cd, Hg, and Pb), were significantly higher (P metals in all samples were within the regulatory limits set by Korea and other countries. The EDE was compared with the provisional tolerable daily intake (PTDI) adopted by the Joint FAO/WHO Expert Committee on Food Additives or the U.S. Environmental Protection Agency. The EDE of Cd, Hg, and Pb for each class of marine invertebrate were 0.07 to 2.64, 0.01 to 0.43, and 0.001 to 0.16% of the PTDI, respectively. The total EDE of Cd, Hg, and Pb for marine invertebrates accounted for 4.03, 0.96, and 0.21%, respectively, of the PTDI. The EDE of other metals in each class of marine invertebrate was less than 2% of the PTDI. The hazard index is a reasonable parameter for assessing the risk of heavy metal consumption associated with contaminated food. In the present study, the hazard index for all of the species was less than 1.0, which indicates that the intake of heavy metals from consumption of these marine invertebrates does not represent an appreciable hazard to humans. PMID:24853529

Mok, Jong Soo; Kwon, Ji Young; Son, Kwang Tae; Choi, Woo Seok; Kang, Sung Rim; Ha, Na Young; Jo, Mi Ra; Kim, Ji Hoe

2014-06-01

366

Influences of large- and regional-scale climate on fish recruitment in the Skagerrak-Kattegat over the last century  

Science.gov (United States)

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.

Linderholm, Hans W.; Cardinale, Massimiliano; Bartolino, Valerio; Chen, Deliang; Ou, Tinghai; Svedäng, Henrik

2014-06-01

367

"We Like to Listen to Stories about Fish": Integrating Indigenous Ecological and Scientific Knowledge to Inform Environmental Flow Assessments  

OpenAIRE

Studies that apply indigenous ecological knowledge to contemporary resource management problems are increasing globally; however, few of these studies have contributed to environmental water management. We interviewed three indigenous landowning groups in a tropical Australian catchment subject to increasing water resource development pressure and trialed tools to integrate indigenous and scientific knowledge of the biology and ecology of freshwater fish to assess their water requirements. Th...

Jackson, Sue E.; Douglas, Michael M.; Kennard, Mark J.; Pusey, Brad J.; Jabal Huddleston; Bill Harney; Lenny Liddy; Mona Liddy; Robert Liddy; Lizzy Sullivan; Brenda Huddleston; Melissa Banderson; Andrew McMah; Quentin Allsop

2014-01-01

368

Hexavalent chromium in fish from the Sepetiba Bay in Rio de Janeiro, Brazil: a risk assessment to human health  

OpenAIRE

Introduction: Certain metals, among them hexavalent chromium influence the stability of ecosystems and cause adverse effects on human health. Thus, this study aimed to estimate a risk model of human health associated with fish consumption from the Sepetiba Bay. Methodology: This risk assessment methodology was developed by the United States Environmental Protection Agency (USEPA). The models were implemented using the USEPA toxicological databases and samples from the Sepetiba Bay, Rio de Jan...

Carla da Costa Cruz; Carlos Alexandre Rey Matias; Anne Karin Madureira da Mota; Aldo Pacheco Ferreira; Adalberto Luiz Miranda Filho

2011-01-01

369

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.

370

Rapid assessment of visual impairment (RAVI in marine fishing communities in South India - study protocol and main findings  

Directory of Open Access Journals (Sweden)

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.

Madala Sreenivas R

2011-09-01

371

Quantitative assessment of accumulation of radionuclides in fish organism in dependence on water temperature  

International Nuclear Information System (INIS)

Eperimentally studied are the changes of levels of several indices of radionuclide metabolism in fishes in dependence on water temperature at its absorption directly from water and at introduction into the digestive tract. Presented are the coefficients of radionuclide storage by the fish tissues in the dependence on temperature (scales and fins, gills, head, intestines, skin, muscles, axial skeleton) and the coefficients of radionuclide retention in the whole fish. It is shown that the connection between the coefficient of radionuclide storage in the fish organism and water temperature is described by the logarithmic dependence. At the systematic entering of radionuclides into the digestive tract the retention coefficient of them in the organism expressed in the form of the ratio of residual quantity in the fish to the quantity in day dose is constant

372

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

373

Biomarkers in an invasive fish species, Oreochromis niloticus, to assess the effects of pollution in a highly degraded Brazilian River.  

Science.gov (United States)

Paraiba do Sul watershed is one of the most important Brazilian water bodies (5.5 million people depend on the river). It is in a critical environmental situation, polluted by industrial discharges, non-treated urban wastes, and pesticides, which have had cumulatively negative effects. This study analyzes the effects of pollution, with a biomarker approach, by using the invasive fish species, Oreochromis niloticus, as a sentinel species. The approach comprehends a general biomarker of the health of individual fish, the condition factor, a biomarker of genotoxicity, the micronuclei test; and specific biomarkers of contaminant exposure such as metallothionein (MT) and acetylcholinesterase (AChE) activity. The results revealed different effects in fish from diverse locations with varying degrees of pollution. Low AChE activities were found in fish from the region with strong agriculture activity, showing the effects of pesticides. Fish from an industrialized and heavily environmenta