WorldWideScience

Sample records for fish stock assessment

  1. Assessment demersal fish stocks Mauritania

    NARCIS (Netherlands)

    Corten, A.A.H.M.; Goudswaard, P.C.; Heessen, H.J.L.

    2006-01-01

    The RIVO project "Assessment of demersal fish stocks in Mauritania" was commissioned by the Ministry of Foreign Affairs of The Netherlands to produce information on the state of the demersal fish stocks (species that live near the bottom) in Mauritania, in particular octopus and shrimps. These stock

  2. Statistical aspects of fish stock assessment

    DEFF Research Database (Denmark)

    Berg, Casper Willestofte

    Fish stock assessments are conducted for two main purposes: 1) To estimate past and present fish abundances and their commercial exploitation rates. 2) To predict the consequences of different management strategies in order to ensure a sustainable fishery in the future. This thesis concerns...... statistical aspects of fish stocks assessment, which includes topics such as time series analysis, generalized additive models (GAMs), and non-linear state-space/mixed models capable of handling missing data and a high number of latent states and parameters. The aim is to improve the existing methods...... for stock assessment by application of state-of-the-art statistical methodology. The main contributions are presented in the form of six research papers. The major part of the thesis deals with age-structured assessment models, which is the most common approach. Conversion from length to age distributions...

  3. Annual trends in catchability and fish stock assessments

    OpenAIRE

    2003-01-01

    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...

  4. Annual trends in catchability and fish stock assessments

    DEFF Research Database (Denmark)

    Marchal, P.; Ulrich, Clara; Korsbrekke, K.;

    2003-01-01

    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...

  5. Catchability: a key parameter for fish stock assessment

    OpenAIRE

    1996-01-01

    Catchability is a concept in fishery biology which reflects the efficiency of a particular fishery. Its quantitative magnitude is expressed by the catchability coefficient, which relates the biomass abundance to the capture or fishing mortality. This paper is a comprehensive review of catchability including the development of our knowledge, interpretation and estimation. Catchability patterns indicate that the catchability coefficient has been used in two main lines: (a) increased efficiency ...

  6. Statistical modelling of fish stocks

    DEFF Research Database (Denmark)

    Kvist, Trine

    1999-01-01

    for modelling the dynamics of a fish population is suggested. A new approach is introduced to analyse the sources of variation in age composition data, which is one of the most important sources of information in the cohort based models for estimation of stock abundancies and mortalities. The approach combines...... and it is argued that an approach utilising stochastic differential equations might be advantagous in fish stoch assessments....

  7. Assessing effects of stocked trout on nongame fish assemblages in southern Appalachian Mountain streams

    Science.gov (United States)

    Weaver, D.; Kwak, Thomas J.

    2013-01-01

    Fisheries managers are faced with the challenge of balancing the management of recreational fisheries with that of conserving native species and preserving ecological integrity. The negative effects that nonnative trout species exert on native trout are well documented and include alteration of competitive interactions, habitat use, and production. However, the effects that nonnative trout may exert on nongame fish assemblages are poorly understood. Our objectives were to quantify the effects of trout stocking on native nongame fish assemblages intensively on one newly stocked river, the North Toe River, North Carolina, and extensively on other southern Appalachian Mountain streams that are annually stocked with trout. In the intensive study, we adopted a before-after, control-impact (BACI) experimental design to detect short-term effects on the nongame fish assemblage and found no significant differences in fish density, species richness, species diversity, or fish microhabitat use associated with trout stocking. We observed differences in fish microhabitat use between years, however, which suggests there is a response to environmental changes, such as the flow regime, which influence available habitat. In the extensive study, we sampled paired stocked and unstocked stream reaches to detect long-term effects from trout stocking; however, we detected no differences in nongame fish density, species richness, species diversity, or population size structure between paired sites. Our results revealed high inherent system variation caused by natural and anthropogenic factors that appear to overwhelm any acute or chronic effect of stocked trout. Furthermore, hatchery-reared trout may be poor competitors in a natural setting and exert a minimal or undetectable impact on native fish assemblages in these streams. These findings provide quantitative results necessary to assist agencies in strategic planning and decision making associated with trout fisheries, stream

  8. Fish stock assessment under data limitations developing a new method based on a size-structured theoretical ecology framework

    DEFF Research Database (Denmark)

    Kokkalis, Alexandros

    -series. The method provides estimates of fishing mortality and the FMSY reference point, it is tested and validated, and is implemented as software package making it easy to use by stakeholders of different levels. The basis of the method is a size-based theoretical ecology framework that describes exploited fish...... for fish stocks that are not assessed. The goal of the thesis is to develop a new data-limited stock assessment method that is: rooted in theoretical ecology, requires only information about the size composition of the catch or surveys (i.e. aging is not required), and does not require time......-likelihood optimisation framework to estimate model parameters. The data-limited method estimates at the same time the fishing mortality rate and the biological reference point FMSY . Minimum data requirements consist of a single size frequency distribution fromthe commercial catch or a scientific survey. If the total...

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

    DEFF Research Database (Denmark)

    Gascuel, Didier; Coll, Marta; Fox, Clive

    2016-01-01

    Stock-based and ecosystem-based indicators are used to provide a new diagnosis of the fishing impact and environmental status of European seas. In the seven European marine ecosystems covering the Baltic and the North-east Atlantic, (i) trends in landings since 1950 were examined; (ii) syntheses ...

  10. SIS - Fish Assessment

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Fish Assessment data set within the Species Information System (SIS) constraints information related to fishery stock assessments, including assessment meta-data...

  11. 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

    NARCIS (Netherlands)

    Dickey-Collas, M.; Pastoors, M.A.; Keeken, van O.A.

    2007-01-01

    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 condi

  12. CURRENT STATE OF FISHERIES AND ASSESSMENT OF FISH STOCKS IN THE WESTERN MIDDLE OF THE CASPIAN SEA. PROSPECTS FOR THE USE OF THE FISH RESOURCES

    Directory of Open Access Journals (Sweden)

    A. S. Abdusamadov

    2016-01-01

    Full Text Available Aim. To aim is to assess stocks and the fisheries of aquatic biological resources in the western part of the middle Caspian Sea and perspectives for the use of their resource potential.Methods. On the basis of the literature sources and our own data on the fish inventory in the western part of the Middle Caspian, we discuss possible reasons for emerging environmental, economic and other problems in the use of biological resources.Results. The main negative factors are the large-scale poaching, resulting in a catastrophic reduction in stocks of sturgeon and other valuable fish species of the Caspian Sea, a natural penetration of alien organisms (Mnemiopsis and overfishing of some species. The potential danger is large-scale development of oil and gas fields in the Caspian Sea, which can lead to even worse situation for the biological resources of the sea.Conclusions. In order to preserve the biological resources of the sea it is necessary to create conditions for steadily developing fishing and fish processing enterprises, thus ensuring the satisfaction of the constant demand for fish products and an increase in the revenue base of the budget and the well-being of the Russian population.

  13. Aquaculture, Capture Fisheries, and Wild Fish Stocks

    OpenAIRE

    Shan Jiang

    2007-01-01

    In a general equilibrium model, this paper examines how the rise of aquaculture and the decline of wild fish stocks are related. Two factors, population growth and technological improvement in aquaculture, have been studied in an aquaculture restricted entry case and an aquaculture free entry case. Both factors raise aquaculture production, while changes in wild fish stocks hinge on entry conditions. In the restricted entry case, population growth reduces wild fish stocks, but technological p...

  14. Comparison of the frequentist properties of Bayes and the maximum likelihood estimators in an age-structured fish stock assessment model

    DEFF Research Database (Denmark)

    Nielsen, Anders; Lewy, Peter

    2002-01-01

    A simulation study was carried out for a separable fish stock assessment model including commercial and survey catch-at-age and effort data. All catches are considered stochastic variables subject to sampling and process variations. The results showed that the Bayes estimator of spawning biomass ...

  15. Stock Assessment Supplementary Information (SASINF)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In the interest of efficiency, clarity and standardization of stock assessment materials, the stock assessment reports for the 2015 Groundfish update have been...

  16. Fish stocking density impacts tank hydrodynamics

    DEFF Research Database (Denmark)

    Rasmussen, Michael R.; Lunger, Angela; Laursen, Jesper;

    2006-01-01

    hydrodynamics was established using in-tank-based Rhodamine WT fluorometry at a flow rate of 0.23 l s-1 (tank exchange rate of 1.9 h-1). With increasing numbers of animals, curvilinear relationships were observed for dispersion coefficients and tank mixing times. Stocking densities of 3, 6, 9 and 12 kg m-3......The effect of stocking density upon the hydrodynamics of a circular tank, configured in a recirculation system, was investigated. Red drums Sciaenops ocellatus of approximately 140 g wet weight, were stocked at five rates varying from 0 to 12 kg m-3. The impact of the presence of fish upon tank...

  17. Stock assessment of fish species Labeo rohita, Tor tor and Labeo calbasu in the rivers of Vindhyan region, India.

    Science.gov (United States)

    Dwivedi, Amitabh Chandra; Nautiyal, Prakash

    2012-03-01

    A study was conducted on the economically important fishes Labeo rohita (Hamilton 1822), Tortor (Hamilton 1822) and Labeo calbasu (Hamilton 1822) stocks from the Ken, the Paisuni and the Tons rivers in the Vindhyan region. Asymptotic length was maximum in L. rohita (946, 833 and 962 mm) as compared with T. tor (822, 787 and 946 mm) and minimum in L. calbasu (567, 612 and 692 mm) in the Ken, the Paisuni and the Tons rivers, respectively. The growth coefficient and total mortality was maximum in T. torcompared to L. rohita and minimum in L. calbasu. Fishing mortality was maximum in T. tor (2.9, 4.57 and 3.44) and minimum in L. calbasu (0.51, 1.21 and 1.18) while natural mortality was maximum in L. rohita (0.74, 0.94 and 1.86) and minimum in L. calbasu (0.47, 0.65 and 0.68). Natural mortality indicated that the habitat was more suitable for L. calbasu. Comparatively, fishing pressure was very high in T. tor than L. rohita and L. calbasu. Exploitation rate was maximum in T. tor (0.71, 0.82 and 0.84) compared to L. rohita (0.77, 0.74 and 0.56) and minimum in L. calbasu (0.52, 0.65 and 0.63) in the Ken, Paisuni and Tons rivers, respectively.

  18. 78 FR 19002 - Marine Mammal Protection Act; Draft Revised Stock Assessment Reports for Two Stocks of West...

    Science.gov (United States)

    2013-03-28

    ...: March 14, 2013. Stephen Guertin, Deputy Director, Fish and Wildlife Service. BILLING CODE 4310-55-P ... Fish and Wildlife Service Marine Mammal Protection Act; Draft Revised Stock Assessment Reports for Two Stocks of West Indian Manatee AGENCY: Fish and Wildlife Service, Interior. ACTION: Notice of...

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

    DEFF Research Database (Denmark)

    Möllmann, Christian; Lindegren, Martin; Blenckner, Thorsten;

    2014-01-01

    Theory behind ecosystem-based management (EBM) and ecosystem-based fisheries management (EBFM) is nowwell developed. However, the implementation of EBFM exemplified by fisheries management in Europe is still largely based on single-species assessments and ignores the wider ecosystem context...... 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 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...

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

    DEFF Research Database (Denmark)

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

    2015-01-01

    The World Conference on Stock Assessment Methods (July 2013) included a workshop on testing assessment methods through simulations. The exercise was made up of two steps applied to datasets from 14 representative fish stocks from around the world. Step 1 involved applying stock assessments to dat...

  1. 77 FR 47043 - Draft 2012 Marine Mammal Stock Assessment Reports

    Science.gov (United States)

    2012-08-07

    ... Jim Carretta, Southwest Fisheries Science Center, 8604 La Jolla Shores Drive, La Jolla, CA 92037-1508....) requires NMFS and the U.S. Fish and Wildlife Service (FWS) to prepare stock assessments for each stock of... included: Hawaiian monk seal, Southern Resident killer whale, Hawaii Insular false killer whale,...

  2. 76 FR 52940 - Draft 2011 Marine Mammal Stock Assessment Reports

    Science.gov (United States)

    2011-08-24

    ... Jim Carretta, Southwest Fisheries Science Center, 8604 La Jolla Shores Drive, La Jolla, CA 92037-1508....) requires NMFS and the U.S. Fish and Wildlife Service (FWS) to prepare stock assessments for each stock of... (Hawaiian monk seal, Southern Resident killer whale, Hawaii Insular false killer whale, and Hawaii...

  3. POTENTIAL PRODUCTION OF DEMERSAL FISH STOCK IN THE MALACCA STRAIT OF INDONESIA

    Directory of Open Access Journals (Sweden)

    Purwanto Purwanto

    2015-06-01

    Full Text Available Malacca Strait is one of the main fishing areas for demersal fishery in Indonesia. To support the management of that fishery, an assessment of the demersal fish stock was conducted. This study estimated that the maximum sustainable yield and the optimal catch per unit effortof demersal fishery in the Malacca Strait were about 106.8 thousand tons/year and 28.5 tons per unit of Danish seine, respectively, resulting from the operation of 3,752 Danish seines. Unfortunately, fishing effort was higher than its optimum level and the fish stock was over-exploited since 2003. To recover the demersal fish stock to its optimum level and to ensure the optimal fish production from demersal fishery in the Malacca Strait, it was necessary to reduce fishing effort at about 67% from its level in 2011.

  4. Fish stock assessment of piraputanga Brycon microlepis in the Cuiabá River basin, Pantanal of Mato Grosso, Brazil

    Directory of Open Access Journals (Sweden)

    L. A. de F. MATEUS

    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.

  5. Dynamics and management of stage-structured fish stocks

    OpenAIRE

    2012-01-01

    With increasing fishing pressures having brought several stocks to the brink of collapse, there is a need for developing efficient harvesting methods that account for factors beyond merely yield or profit. We consider the dynamics and management of a stage-structured fish stock. Our work is based on a consumer-resource model which De Roos et al. (2008) have derived as an approximation of a physiologically-structured counterpart. First, we rigorously prove the existence of steady states in bot...

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

    DEFF Research Database (Denmark)

    Collie, J.S.; Gislason, Henrik

    2001-01-01

    variation. For a prey species like sprat, fishing mortality reference levels should be conditioned on the level of predation 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...

  7. The utilization of patin fish head for instant stock paste

    Science.gov (United States)

    Hartanto, Gabriela Mawi; Rahmawati, Della; Puteri, Maria Gunawan

    2017-01-01

    Patin fish is a developing industries that produce 67% of waste which 33% is the head. High protein content in patin fish head (PFH) open an opportunity to produce something that has higher economic value and can be used as human consumption, which is stock. In this study, PFH hydrolysis with acid, enzyme and heat were observed for their yield of protein, in correlation to taste & national standard for stock. Enzyme hydrolysis is chosen as the selected method with the highest protein and soluble amino acid which is 18.78 ± 7.50 mg BSA equivalent / ml and 0.854 ± 4.35 mg Tyrosine eq / ml. The hydrolysate was made into stock by mixing with other ingredient by the help of Design Expert to create selected formula. The formula composition is fish hydrolysate 27.29%, salt 19.17%, caramel 18.52%, garlic 6%, pepper 3.104%, oil 18.52% and water 7.47%. This formula receive 7.13 value from hedonic scale 1-9, which means the formula like moderately based on overall acceptance. For 4 gram stock, 150 ml of water was chosen as the preferable dilution volume for the stock with ranking test. Total nitrogen of the instant stock paste with selected hydrolysis method and formula fulfill National Standard according to SNI No. 01-4218 with 0.077% nitrogen amount.

  8. Eco-label conveys reliable information on fish stock health to seafood consumers.

    Directory of Open Access Journals (Sweden)

    Nicolás L Gutiérrez

    Full Text Available 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 the performance of MSC-certified fish stocks has yet been conducted. We compared status and abundance trends of 45 certified stocks with those of 179 uncertified stocks, finding that 74% of certified fisheries were above biomass levels that would produce maximum sustainable yield, compared with only 44% of uncertified fisheries. On average, the biomass of certified stocks increased by 46% over the past 10 years, whereas uncertified fisheries increased by just 9%. As part of the MSC process, fisheries initially go through a confidential pre-assessment process. When certified fisheries are compared with those that decline to pursue full certification after pre-assessment, certified stocks had much lower mean exploitation rates (67% of the rate producing maximum sustainable yield vs. 92% for those declining to pursue certification, allowing for more sustainable harvesting and in many cases biomass rebuilding. From a consumer's point of view this means that MSC-certified seafood is 3-5 times less likely to be subject to harmful fishing than uncertified seafood. Thus, MSC-certification accurately identifies healthy fish stocks and conveys reliable information on stock status to seafood consumers.

  9. Intelligent Fish Freshness Assessment

    Directory of Open Access Journals (Sweden)

    Hamid Gholam Hosseini

    2008-01-01

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

  10. Dynamics and management of stage-structured fish stocks.

    Science.gov (United States)

    Meng, Xinzhu; Lundström, Niklas L P; Bodin, Mats; Brännström, Åke

    2013-01-01

    With increasing fishing pressures having brought several stocks to the brink of collapse, there is a need for developing efficient harvesting methods that account for factors beyond merely yield or profit. We consider the dynamics and management of a stage-structured fish stock. Our work is based on a consumer-resource model which De Roos et al. (in Theor. Popul. Biol. 73, 47-62, 2008) have derived as an approximation of a physiologically-structured counterpart. First, we rigorously prove the existence of steady states in both models, that the models share the same steady states, and that there exists at most one positive steady state. Furthermore, we carry out numerical investigations which suggest that a steady state is globally stable if it is locally stable. Second, we consider multiobjective harvesting strategies which account for yield, profit, and the recovery potential of the fish stock. The recovery potential is a measure of how quickly a fish stock can recover from a major disturbance and serves as an indication of the extinction risk associated with a harvesting strategy. Our analysis reveals that a small reduction in yield or profit allows for a disproportional increase in recovery potential. We also show that there exists a harvesting strategy with yield close to the maximum sustainable yield (MSY) and profit close to that associated with the maximum economic yield (MEY). In offering a good compromise between MSY and MEY, we believe that this harvesting strategy is preferable in most instances. Third, we consider the impact of harvesting on population size structure and analytically determine the most and least harmful harvesting strategies. We conclude that the most harmful harvesting strategy consists of harvesting both adults and juveniles, while harvesting only adults is the least harmful strategy. Finally, we find that a high percentage of juvenile biomass indicates elevated extinction risk and might therefore serve as an early-warning signal of

  11. Single and multispecies reference points for Baltic fish stocks

    DEFF Research Database (Denmark)

    Gislason, Henrik

    1999-01-01

    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....... 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...

  12. Impact of fishing and stocking practices on Coregonid diversity

    Science.gov (United States)

    Anneville, Orlane; Lasne, Emilien; Guillard, Jean; Eckmann, Reiner; Stockwell, Jason D.; Gillet, Christian; Yule, Daniel

    2015-01-01

    Fish species diversity can be lost through interacting stressors including habitat loss, stocking and overfishing. Although a multitude of stressors have played a role in the global decline of coregonid (Coregonus spp.) diversity, a number of contemporary studies have identified habitat loss stemming from eutrophication as the primary cause. Unfortunately, reconstructing the role of fishing and stocking practices can be difficult, because these records are incomplete or appear only in hard-to-access historic grey literature. Based on an illustrative set of historic and contemporary studies, we describe how fisheries management practices may have contributed to coregonid diversity loss in European and North American lakes. We provide case studies examining how fishing and stocking may reduce coregonid diversity through demographic decline and introgressive hybridization. In some lakes, fisheries management practices may have led to a loss of coregonid diversity well before issues with habitat degradation manifested. Our review suggests that fish conservation policies could beneficially consider the relative importance of all stressors, including management practices, as potential drivers of diversity loss.

  13. Topmouth gudgeon Pseudorasbora parva: a side effect of fish stocking

    Directory of Open Access Journals (Sweden)

    Michał Nowak

    2009-12-01

    Full Text Available he topmouth gudgeon Pseudorasbora parva is an eastern-Asian cyprinid species, which inrelatively short time has colonised nearly the whole Europe. In some regions it has become a notablereproduction success and significantly disrupted native ecosystems. Such a fast expansion is mostprobably caused by uncontrolled transfers of stocking fish, mainly Asian carps, i.e., Ctenopharyngodonidella, and Hypophthalmichthys spp. The case of P. parva invasion demonstrates the risk oftranslocations of fish, as well as urgent need of more caution and prevention in order to avoid furthersuch unexpected guests.

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

    Energy Technology Data Exchange (ETDEWEB)

    Dodson, Guy; Pero, Vincent

    2002-01-01

    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).

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

    DEFF Research Database (Denmark)

    Vinther, Morten; Eero, Margit

    2013-01-01

    GAM analyses to predict local cod densities and combine this with spatio-temporal data of fishing effort based on VMS (Vessel Monitoring System). To quantify local fishing impact on the stock, retention probability of the gears is taken into account. The results indicate a substantial decline...

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

    DEFF Research Database (Denmark)

    Pécuchet, Lauréne; Nielsen, J. Rasmus; Christensen, Asbjørn

    2015-01-01

    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.......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...

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

    Science.gov (United States)

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

    2015-01-01

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

  18. Eastern Baltic cod in distress: biological changes and challenges for stock assessment

    DEFF Research Database (Denmark)

    Eero, Margit; Hjelm, Joakim; Behrens, Jane;

    2015-01-01

    The eastern Baltic (EB) cod (Gadus morhua) stock was depleted and overexploited for decades until the mid-2000s, when fishing mortality rapidly declined and biomass started to increase, as shown by stock assessments. These positive developments were partly assigned to effective management measure...

  19. An Applied Framework for Incorporating Multiple Sources of Uncertainty in Fisheries Stock Assessments.

    Directory of Open Access Journals (Sweden)

    Finlay Scott

    Full Text Available Estimating fish stock status is very challenging given the many sources and high levels of uncertainty surrounding the biological processes (e.g. natural variability in the demographic rates, model selection (e.g. choosing growth or stock assessment models and parameter estimation. Incorporating multiple sources of uncertainty in a stock assessment allows advice to better account for the risks associated with proposed management options, promoting decisions that are more robust to such uncertainty. However, a typical assessment only reports the model fit and variance of estimated parameters, thereby underreporting the overall uncertainty. Additionally, although multiple candidate models may be considered, only one is selected as the 'best' result, effectively rejecting the plausible assumptions behind the other models. We present an applied framework to integrate multiple sources of uncertainty in the stock assessment process. The first step is the generation and conditioning of a suite of stock assessment models that contain different assumptions about the stock and the fishery. The second step is the estimation of parameters, including fitting of the stock assessment models. The final step integrates across all of the results to reconcile the multi-model outcome. The framework is flexible enough to be tailored to particular stocks and fisheries and can draw on information from multiple sources to implement a broad variety of assumptions, making it applicable to stocks with varying levels of data availability The Iberian hake stock in International Council for the Exploration of the Sea (ICES Divisions VIIIc and IXa is used to demonstrate the framework, starting from length-based stock and indices data. Process and model uncertainty are considered through the growth, natural mortality, fishing mortality, survey catchability and stock-recruitment relationship. Estimation uncertainty is included as part of the fitting process. Simple model

  20. An Applied Framework for Incorporating Multiple Sources of Uncertainty in Fisheries Stock Assessments.

    Science.gov (United States)

    Scott, Finlay; Jardim, Ernesto; Millar, Colin P; Cerviño, Santiago

    2016-01-01

    Estimating fish stock status is very challenging given the many sources and high levels of uncertainty surrounding the biological processes (e.g. natural variability in the demographic rates), model selection (e.g. choosing growth or stock assessment models) and parameter estimation. Incorporating multiple sources of uncertainty in a stock assessment allows advice to better account for the risks associated with proposed management options, promoting decisions that are more robust to such uncertainty. However, a typical assessment only reports the model fit and variance of estimated parameters, thereby underreporting the overall uncertainty. Additionally, although multiple candidate models may be considered, only one is selected as the 'best' result, effectively rejecting the plausible assumptions behind the other models. We present an applied framework to integrate multiple sources of uncertainty in the stock assessment process. The first step is the generation and conditioning of a suite of stock assessment models that contain different assumptions about the stock and the fishery. The second step is the estimation of parameters, including fitting of the stock assessment models. The final step integrates across all of the results to reconcile the multi-model outcome. The framework is flexible enough to be tailored to particular stocks and fisheries and can draw on information from multiple sources to implement a broad variety of assumptions, making it applicable to stocks with varying levels of data availability The Iberian hake stock in International Council for the Exploration of the Sea (ICES) Divisions VIIIc and IXa is used to demonstrate the framework, starting from length-based stock and indices data. Process and model uncertainty are considered through the growth, natural mortality, fishing mortality, survey catchability and stock-recruitment relationship. Estimation uncertainty is included as part of the fitting process. Simple model averaging is used to

  1. AFSC/REFM: Alaska Stock Assessment Results Archive (SARA)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Each year over 50 Alaskan groundfish stock assessments report the condition of Alaskan fisheries resources in the U.S. Exclusive Economic Zone. Stock assessment...

  2. Age-structure-dependent recruitment: a meta-analysis applied to Northeast Atlantic fish stocks

    NARCIS (Netherlands)

    Brunel, T.P.A.

    2010-01-01

    Exploitation alters the age structure of fish stocks. Several stock-specific studies have suggested that changes in the age structure might have consequences for subsequent recruitment, but the evidence is not universal. To investigate how common such effects are among 39 Northeast Atlantic fish sto

  3. Application of a Bayesian method to data-poor stock assessment by using Indian Ocean albacore (Thunnus alalunga) stock assessment as an example

    Institute of Scientific and Technical Information of China (English)

    GUAN Wenjiang; TANG Lin; ZHU Jiangfeng; TIAN Siquan; XU Liuxiong

    2016-01-01

    It is widely recognized that assessments of the status of data-poor fish stocks are challenging and that Bayesian analysis is one of the methods which can be used to improve the reliability of stock assessments in data-poor situations through borrowing strength from prior information deduced from species with good-quality data or other known information. Because there is considerable uncertainty remaining in the stock assessment of albacore tuna (Thunnus alalunga) in the Indian Ocean due to the limited and low-quality data, we investigate the advantages of a Bayesian method in data-poor stock assessment by using Indian Ocean albacore stock assessment as an example. Eight Bayesian biomass dynamics models with different prior assumptions and catch data series were developed to assess the stock. The results show (1) the rationality of choice of catch data series and assumption of parameters could be enhanced by analyzing the posterior distribution of the parameters; (2) the reliability of the stock assessment could be improved by using demographic methods to construct a prior for the intrinsic rate of increase (r). Because we can make use of more information to improve the rationality of parameter estimation and the reliability of the stock assessment compared with traditional statistical methods by incorporating any available knowledge into the informative priors and analyzing the posterior distribution based on Bayesian framework in data-poor situations, we suggest that the Bayesian method should be an alternative method to be applied in data-poor species stock assessment, such as Indian Ocean albacore.

  4. Effects of changes in stock productivity and mixing on sustainable fishing and economic viability

    DEFF Research Database (Denmark)

    Bastardie, Francois; Nielsen, J. Rasmus; Eero, Margit

    2016-01-01

    have induced alternative individual vessel spatial effort allocation and economic performance by affecting fishing costs and by changing the relative stock abundance and size distribution. Stock mixing heavily influences profit and stock abundance for stocks that have experienced increased fishing...... and conditions greatly reduce the overall cod spawning stock biomass, thus changing the landing size composition and associated fishery profits. As a cumulative effect, fishing efforts are redirected towards western areas depending on management (quotas). However, total profits are less affected when traditional...... fishing opportunities and switching possibilities for other species and areas are maintained. Our evaluation indicates that current management mechanisms cannot correct for potential detrimental effects on cod fisheries when effort re-allocation changes landing origins. By investigating different economic...

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

    DEFF Research Database (Denmark)

    Jepsen, Niels; Klenke, Reinhard; Sonnesen, Per Michael;

    2010-01-01

    One of the main obstacles to resolving the conflict between an increasing population of cormorants, Phalacrocorax carbo sinensis, and the fishing industry is the lack of documentation of the effect of the birds’ predation on fish stocks. Tagging and releasing fish with coded wire tags followed...

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

    DEFF Research Database (Denmark)

    MacKenzie, Brian; Myers, R.A.; Bowen, K.G.

    2003-01-01

    Few marine ecologists have addressed important questions about the relative productivity and carrying capacity of different ecosystems required to support fish populations. Whereas many researchers have investigated interannual variability in recruitment within a stock, we asked whether...

  7. Choosing the observational likelihood in state-space stock assessment models

    DEFF Research Database (Denmark)

    Albertsen, Christoffer Moesgaard; Nielsen, Anders; Thygesen, Uffe Høgsbro

    By implementing different observational likelihoods in a state-space age-based stock assessment model, we are able to compare the goodness-of-fit and effects on estimated fishing mortallity for different model choices. Model fit is improved by estimating suitable correlations between agegroups. We...

  8. Accounting for correlated observations in an age-based state-space stock assessment model

    DEFF Research Database (Denmark)

    Berg, Casper Willestofte; Nielsen, Anders

    2016-01-01

    Fish stock assessment models often relyon size- or age-specific observations that are assumed to be statistically independent of each other. In reality, these observations are not raw observations, but rather they are estimates from a catch-standardization model or similar summary statistics based...

  9. Stakeholder participation in the management of North East Atlantic pelagic fish stocks

    DEFF Research Database (Denmark)

    Coers, Aukje; Raakjær, Jesper; Olesen, Christian

    2012-01-01

    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...... 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...

  10. THE EFFECT OF STOCKING FISH PRODUCTION ON THE QUALITY OF WATER DISCHARGED FROM THE HATCHERY

    Directory of Open Access Journals (Sweden)

    Małgorzata Bonisławska

    2016-09-01

    Full Text Available The aim of this study was to assess the effect of a fish hatchery (Stocking-Breeding Centre in Goleniów -OHZ, focused on the production and on-growing of stocking material, on the quality of post-production water. The following parameters were determined: dissolved oxygen, organic matter content, buffering capacity, the concentration of some forms of nitrogen and phosphorus ((N-NH4+, N-NO2–, N-NO3-, total nitrogen, P-PO43-, total phosphorus and the concentration of chloride ions. The study also included the measurements of water temperature, electrolytic conductivity and pH. It was shown that the water supplied to the hatchery had good quality, providing optimum conditions for growth and living of fry and juvenile forms of various fish species (most indices were within the range of the first water quality class. Production activities at the hatchery caused a reduction in the quality of discharged post-production water with respect to indicators such as total suspended solids, organic matter and phosphorus.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-09-01

    In 1980, the United States Congress enacted the Northwest Power Planning and Conservation Act (PL 96-501, 1980), which established the Northwest Power and Conservation Council (NPCC), formerly the Northwest Power Planning Council. The NPCC was directed by Congress to develop a regional Power Plan and also the Columbia River Basin Fish and Wildlife Program (FWP) to restore or replace losses of fish caused by construction and operation of hydroelectric dams in the Columbia River Basin. In developing the FWP, Congress specifically directed NPCC to solicit recommendations for measures to be included in the Program from the region's fish and wildlife agencies and Indian tribes. All measures adopted by the Council were also required to be consistent with the management objectives of the agencies and tribes [Section 4.(h)(6)(A)], the legal rights of Indian tribes in the region [Section 4.(h)(6)(D)] and be based upon and supported by the best available scientific knowledge [Section 4.(h)(6)(B)]. The Resident Fish Stock Status above Chief Joseph and Grand Coulee Dams Project, also known as the Joint Stock Assessment Project (JSAP) specifically addresses NPPC Council measure 10.8B.26 of the 1994 program. The Joint Stock Assessment Project is a management tool using ecosystem principles to manage artificial fish assemblages and native fish in altered environments existing in the Columbia River System above Chief Joseph and Grand Coulee Dams (Blocked Area). A three-phase approach of this project will enhance the fisheries resources of the Blocked Area by identifying data gaps, filling data gaps with research, and implementing management recommendations based on research results. The Blocked Area fisheries information is housed in a central location, allowing managers to view the entire system while making decisions, rather than basing management decisions on isolated portions of the system. The JSAP is designed and guided jointly by fisheries managers in the Blocked Area

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-01-01

    In 1980, the United States Congress enacted the Northwest Power Planning and Conservation Act (PL 96-501, 1980), which established the Northwest Power Planning Council (NPPC). The NPPC was directed by Congress to develop a regional Power Plan and also the Columbia River Basin Fish and Wildlife Program (FWP) to restore or replace losses of fish caused by construction and operation of hydroelectric dams in the Columbia River Basin. In developing the FWP, Congress specifically directed NPPC to solicit recommendations for measures to be included in the Program from the region's fish and wildlife agencies and Indian tribes. All measures adopted by the Council were also required to be consistent with the management objectives of the agencies and tribes [Section 4.(h)(6)(A)], the legal rights of Indian tribes in the region [Section 4.(h)(6)(D)] and be based upon and supported by the best available scientific knowledge [Section 4.(h)(6)(B)]. The Resident Fish Stock Status above Chief Joseph and Grand Coulee Dams Project, also known as the Joint Stock Assessment Project (JSAP) specifically addresses NPPC Council measure 10.8B.26 of the 1994 program. The Joint Stock Assessment Project is a management tool using ecosystem principles to manage artificial fish assemblages and native fish in altered environments existing in the Columbia River System above Chief Joseph and Grand Coulee Dams (Blocked Area). A three-phase approach of this project will enhance the fisheries resources of the Blocked Area by identifying data gaps, filling data gaps with research, and implementing management recommendations based on research results. The Blocked Area fisheries information is housed in a central location, allowing managers to view the entire system while making decisions, rather than basing management decisions on isolated portions of the system. The JSAP is designed and guided jointly by fisheries managers in the Blocked Area and the Columbia Basin Blocked Area Management Plan

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

    DEFF Research Database (Denmark)

    Bartolino, V.; Margonski, P.; Lindegren, Martin;

    2014-01-01

    Climate change and anthropogenic disturbances may affect marine populations and ecosystems through multiple pathways. In this study we present a framework in which we integrate existing models and knowledge on basic regulatory processes to investigate the potential impact of future scenarios of f......-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...... 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...... 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...

  14. Choosing the observational likelihood in state-space stock assessment models

    DEFF Research Database (Denmark)

    Albertsen, Christoffer Moesgaard; Nielsen, Anders; Thygesen, Uffe Høgsbro

    2016-01-01

    Data used in stock assessment models result from combinations of biological, ecological, fishery, and sampling processes. Since different types of errors propagate through these processes it can be difficult to identify a particular family of distributions for modelling errors on observations...... a priori. By implementing several observational likelihoods, modelling both numbers- and proportions-at-age, in an age based state-space stock assessment model, we compare the model fit for each choice of likelihood along with the implications for spawning stock biomass and average fishing mortality. We...... propose using AIC intervals based on fitting the full observational model for comparing different observational likelihoods. Using data from four stocks, we show that the model fit is improved by modelling the correlation of observations within years. However, the best choice of observational likelihood...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-02-01

    In 1980, the United States Congress enacted the Northwest Power Planning and Conservation Act (PL 96-501, 1980), which established the Northwest Power and Conservation Council (NPCC), formerly the Northwest Power Planning Council. The NPCC was directed by Congress to develop a regional Power Plan and also the Columbia River Basin Fish and Wildlife Program (FWP) to restore or replace losses of fish caused by construction and operation of hydroelectric dams in the Columbia River Basin. In developing the FWP, Congress specifically directed NPCC to solicit recommendations for measures to be included in the Program from the region's fish and wildlife agencies and Indian tribes. All measures adopted by the Council were also required to be consistent with the management objectives of the agencies and tribes [Section 4.(h)(6)(A)], the legal rights of Indian tribes in the region [Section 4.(h)(6)(D)] and be based upon and supported by the best available scientific knowledge [Section 4.(h)(6)(B)]. The Resident Fish Stock Status above Chief Joseph and Grand Coulee Dams Project, also known as the Joint Stock Assessment Project (JSAP) specifically addresses NPPC Council measure 10.8B.26 of the 1994 program. The Joint Stock Assessment Project is a management tool using ecosystem principles to manage artificial and native fish assemblages in altered environments existing in the Columbia River System above Chief Joseph and Grand Coulee Dams (Blocked Area). A three-phase approach of this project will enhance the fisheries resources of the Blocked Area by identifying data gaps, filling data gaps with research, and implementing management recommendations based on research results. The Blocked Area fisheries information is housed in a central location, allowing managers to view the entire system while making decisions, rather than basing management decisions on isolated portions of the system. The JSAP is designed and guided jointly by fisheries managers in the Blocked Area. The

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-11-01

    In 1980, the United States Congress enacted the Northwest Power Planning and Conservation Act (PL 96-501, 1980), which established the Northwest Power and Conservation Council (NPCC), formerly the Northwest Power Planning Council. The NPCC was directed by Congress to develop a regional Power Plan and also the Columbia River Basin Fish and Wildlife Program (FWP) to restore or replace losses of fish caused by construction and operation of hydroelectric dams in the Columbia River Basin. In developing the FWP, Congress specifically directed NPCC to solicit recommendations for measures to be included in the Program from the region's fish and wildlife agencies and Indian tribes. All measures adopted by the Council were also required to be consistent with the management objectives of the agencies and tribes [Section 4.(h)(6)(A)], the legal rights of Indian tribes in the region [Section 4.(h)(6)(D)] and be based upon and supported by the best available scientific knowledge [Section 4.(h)(6)(B)]. The Resident Fish Stock Status above Chief Joseph and Grand Coulee Dams Project, also known as the Joint Stock Assessment Project (JSAP) specifically addresses NPPC Council measure 10.8B.26 of the 1994 program. The Joint Stock Assessment Project is a management tool using ecosystem principles to manage artificial and native fish assemblages in altered environments existing in the Columbia River System above Chief Joseph and Grand Coulee Dams (Blocked Area). A three-phase approach of this project will enhance the fisheries resources of the Blocked Area by identifying data gaps, filling data gaps with research, and implementing management recommendations based on research results. The Blocked Area fisheries information is housed in a central location, allowing managers to view the entire system while making decisions, rather than basing management decisions on isolated portions of the system. The JSAP is designed and guided jointly by fisheries managers in the Blocked Area. The

  17. Assessments of the lesser sandeel ( Ammodytes marinus ) in the North Sea based on revised stock divisions

    DEFF Research Database (Denmark)

    Pedersen, S.A.; Lewy, Peter; Wright, P.

    1999-01-01

    for the different aggregations. Based on a geographical division of the North Sea in a number of proposed assessment regions, regional as well as whole North Sea sandeel assessments are presented based on revised data (e.g, catch in numbers at age and effort). The assessments suggest regional differences in fishing...... effort, catch per unit effort, yield, fishing and natural mortality. A better understanding of sandeel growth is important for stock and catch predictions because previous studies indicate that the variability of mean weight-at-age is one of the most important factors influencing the precision...

  18. 75 FR 46912 - Draft 2010 Marine Mammal Stock Assessment Reports

    Science.gov (United States)

    2010-08-04

    ..., Southwest Fisheries Science Center, 8604 La Jolla Shores Drive, La Jolla, CA 92037-1508. Send comments or... Marine Mammal Protection Act (MMPA) (16 U.S.C. 1361 et seq.) requires NMFS and the U.S. Fish and Wildlife... conservation issues (Perrin et al. 2009). The former Hawaii stock of spinner dolphin was renamed as the...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-07-21

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

  20. The advantages of mosquito biocontrol by stocking edible fish in rice paddies.

    Science.gov (United States)

    Wu, N; Liao, G H; Li, D F; Luo, Y L; Zhong, G M

    1991-09-01

    Edible fish stocked in rice fields at a density of 600-800 fry per mu (1 mu = 1/15 hectare) for 150-170 days may act as an effective mosquito biocontrol agent. Common carp (Cyprinus carpio), grass carp Ctenopharyngodon idella) and Tilopia spp. killed late stage larvae and pupae of Anopheles sinensis and Culex tritaeniorrhyncus in laboratory and field trials. Stocking of fish in experimental rice fields decreased larval numbers significantly in comparison with control areas. Expansion of fish stocking in rice fields on a large scale over several years correlated with a marked decrease in malaria transmission. The addition of fish to the rice fields also resulted in increased yields. A ditch-ridge system of field arrangements is described for optimization of fish handling. Preliminary cost-benefit analysis indicates that this approach to mosquito control conveys considerable economic advantage and thus provides incentive to the community to participate in vector control programs. Farmers' experience in Guangxi over a number of years indicates that the use of edible fish for this purpose can be carried on a large, commercially viable scale.

  1. Do lake littoral benthic invertebrates respond differently to eutrophication, hydromorphological alteration, land use and fish stocking?

    Directory of Open Access Journals (Sweden)

    Šiling Rebeka

    2016-01-01

    Full Text Available In order to provide adequate guidelines in freshwater management, managers need reliable bioindicators that can respond differently to varied stressors. Managers also have to consider hierarchical structure of environmental factors. Thus, our research aims to test the independence of taxa responses along environmental gradients and to examine in what order natural and anthropogenic factors constrain the structure of littoral benthic assemblages. The rank of explained variance of littoral benthic assemblage's variable group hierarchy was: land use > landscape characteristics > eutrophication > fish stocking > hydromorphological alteration. We determined nine gradients (two natural and seven stressor gradients, separated into five groups based on statistically significant differences in responsiveness of taxa. Apart from responsiveness to natural factors, littoral benthic invertebrates could be used as bioindicators for stressors reflecting urbanization, eutrophication, hydromorphological alteration and fish stocking. The taxonomical composition of littoral benthic invertebrates, especially when taxa with preference for certain relatively narrow environmental conditions along gradients are present, can be used to identify effects of key stressors. Our findings have profound implications for ecological assessment and management of lakes, as they indicate that benthic invertebrates can be used when the effects of multiple stressors need to be disentangled.

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

    NARCIS (Netherlands)

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

    1999-01-01

    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 towe

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

    NARCIS (Netherlands)

    Wudneh, T.

    1998-01-01

    The biology of the fish stocks of the major species in the Bahir Dar Gulf of Lake Tana, the largest lake in Ethiopia, has been studied based on data collected during August 1990 to September 1993. The distribution, reproduction patterns, growth and mortality dynamics and gillnet selectivity of these

  4. Stock assessment of fishery target species in Lake Koka, Ethiopia.

    Science.gov (United States)

    Tesfaye, Gashaw; Wolff, Matthias

    2015-09-01

    Effective management is essential for small-scale fisheries to continue providing food and livelihoods for households, particularly in developing countries where other options are often limited. Studies on the population dynamics and stock assessment on fishery target species are thus imperative to sustain their fisheries and the benefits for the society. In Lake Koka (Ethiopia), very little is known about the vital population parameters and exploitation status of the fishery target species: tilapia Oreochromis niloticus, common carp Cyprinus carpio and catfish Clarias gariepinus. Our study, therefore, aimed at determining the vital population parameters and assessing the status of these target species in Lake Koka using length frequency data collected quarterly from commercial catches from 2007-2012. A total of 20,097 fish specimens (distributed as 7,933 tilapia, 6,025 catfish and 6,139 common carp) were measured for the analysis. Von Bertalarffy growth parameters and their confidence intervals were determined from modal progression analysis using ELEFAN I and applying the jackknife technique. Mortality parameters were determined from length-converted catch curves and empirical models. The exploitation status of these target species were then assessed by computing exploitation rates (E) from mortality parameters as well as from size indicators i.e., assessing the size distribution of fish catches relative to the size at maturity (Lm), the size that provides maximum cohort biomass (Lopt) and the abundance of mega-spawners. The mean value of growth parameters L∞, K and the growth performance index ø' were 44.5 cm, 0.41/year and 2.90 for O. niloticus, 74.1 cm, 0.28/year and 3.19 for C. carpio and 121.9 cm, 0.16/year and 3.36 for C. gariepinus, respectively. The 95 % confidence intervals of the estimates were also computed. Total mortality (Z) estimates were 1.47, 0.83 and 0.72/year for O. niloticus, C. carpio and C. gariepinus, respectively. Our study suggest that

  5. Spatially-Resolved Influence of Temperature and Salinity on Stock and Recruitment Variability of Commercially Important Fishes in the North Sea.

    Science.gov (United States)

    Akimova, Anna; Núñez-Riboni, Ismael; Kempf, Alexander; Taylor, Marc H

    2016-01-01

    Understanding of the processes affecting recruitment of commercially important fish species is one of the major challenges in fisheries science. Towards this aim, we investigated the relation between North Sea hydrography (temperature and salinity) and fish stock variables (recruitment, spawning stock biomass and pre-recruitment survival index) for 9 commercially important fishes using spatially-resolved cross-correlation analysis. We used high-resolution (0.2° × 0.2°) hydrographic data fields matching the maximal temporal extent of the fish population assessments (1948-2013). Our approach allowed for the identification of regions in the North Sea where environmental variables seem to be more influential on the fish stocks, as well as the regions of a lesser or nil influence. Our results confirmed previously demonstrated negative correlations between temperature and recruitment of cod and plaice and identified regions of the strongest correlations (German Bight for plaice and north-western North Sea for cod). We also revealed a positive correlation between herring spawning stock biomass and temperature in the Orkney-Shetland area, as well as a negative correlation between sole pre-recruitment survival index and temperature in the German Bight. A strong positive correlation between sprat stock variables and salinity in the central North Sea was also found. To our knowledge the results concerning correlations between North Sea hydrography and stocks' dynamics of herring, sole and sprat are novel. The new information about spatial distribution of the correlation provides an additional help to identify mechanisms underlying these correlations. As an illustration of the utility of these results for fishery management, an example is provided that incorporates the identified environmental covariates in stock-recruitment models.

  6. Resilience and Critical Stock Size in a Stochastic Recruitment Model

    NARCIS (Netherlands)

    Grasman, J.; Huiskes, M.J.

    2001-01-01

    A stochastic model for fish recruitment is fitted to data after performing an age-structured stock assessment. The main aim is to investigate the relation between safe levels of spawning stock size and fish stock resilience. Resilience indicators, such as stock recovery time and the frequency that a

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-01-01

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

  8. CORMORANT (Phalacrocorax carbo sinensis AND DAMAGES ON FISH STOCK CAUSED BY CORMORANT HYPER POPULATION

    Directory of Open Access Journals (Sweden)

    Krešimir Pažur

    2002-12-01

    Full Text Available The results of recent foreign and domestic investigations on the damages found on the fish stock of cyprinid ponds and rivers caused by hyper population of cormorants are presented. Cormorant has been for almost 30 years a protected bird species in Europe. As a species which was imported to Europe, they have no any natural enemies in European area to keep bioecological balance, thus their protection resulted in increasing their populations by 25 times from 1970. Therefore, it is questionable how opportune it is to protect the bird imported in Europe from China in the 17th century by the Dutch to catch fish in England and France while the damages it caused on the fish stock of the northern Europe were known already at the beginning of the 19th century, as reported by B r e hm (1892.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-05-11

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

  10. Effects of acid rock drainage on stocked rainbow trout (Oncorhynchus mykiss): an in-situ, caged fish experiment.

    Science.gov (United States)

    Todd, Andrew S; McKnight, Diane M; Jaros, Chris L; Marchitto, Thomas M

    2007-07-01

    In-situ caged rainbow trout (Oncorhynchus mykiss) studies reveal significant fish toxicity and fish stress in a river impacted by headwater acid rock drainage (ARD). Stocked trout survival and aqueous water chemistry were monitored for 10 days at 3 study sites in the Snake River watershed, Colorado, U.S.A. Trout mortality was positively correlated with concentrations of metals calculated to be approaching or exceeding conservative toxicity thresholds (Zn, Mn, Cu, Cd). Significant metal accumulation on the gills of fish stocked at ARD impacted study sites support an association between elevated metals and fish mortality. Observations of feeding behavior and significant differences in fish relative weights between study site and feeding treatment indicate feeding and metals-related fish stress. Together, these results demonstrate the utility of in-situ exposure studies for stream stakeholders in quantifying the relative role of aqueous contaminant exposures in limiting stocked fish survival.

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

    DEFF Research Database (Denmark)

    Kokkalis, Alexandros; Thygesen, Uffe Høgsbro; Nielsen, Anders;

    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......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...

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

    DEFF Research Database (Denmark)

    Kraus, Gerd; Hinrichsen, Hans-Harald; Voss, Rüdiger;

    2012-01-01

    At present, several cod stocks are outside safe biological limits and are managed under recovery plans. For these stocks Total Allowable Catches (TAC's) are generally low and quotas are accompanied by a broad variety of technical measures influencing the fishing patterns. Consequently, the input...... data to stock assessment models relying on catch statistics from the commercial fisheries is potentially biased and the perception of stock status may be incorrect. Egg production methods (EPM) provide a fishery independent alternative. Additionally, they provide better estimates of stock reproductive...... potential (SRP). Eastern Baltic cod (Gad us morhua callarias L) has severely declined throughout the 2nd half of the 1980s and 1st half of the 1990s due to climate-driven adverse hydrographic conditions and high fishing intensity. Since 2007 the stock is managed under a long-term management plan and showed...

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

    Directory of Open Access Journals (Sweden)

    Federico Buti

    2010-08-01

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

  14. 75 FR 6058 - Federal Sport Fish Restoration; California Department of Fish and Game Fish Hatchery and Stocking...

    Science.gov (United States)

    2010-02-05

    ... Fish and Wildlife Service Federal Sport Fish Restoration; California Department of Fish and Game Fish.... Under the Sport Fish Restoration Act (SFRA), FWS proposes to fund actions associated with the operation...: Under the SFRA (Pub. L. 106-408), FWS has authority to grant Federal funds from the Sport...

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

    Science.gov (United States)

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

    2013-07-01

    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.

  16. Oxygen depletion in coastal seas and the effective spawning stock biomass of an exploited fish species.

    Science.gov (United States)

    Hinrichsen, H-H; von Dewitz, B; Dierking, J; Haslob, H; Makarchouk, A; Petereit, C; Voss, R

    2016-01-01

    Environmental conditions may have previously underappreciated effects on the reproductive processes of commercially exploited fish populations, for example eastern Baltic cod, that are living at the physiological limits of their distribution. In the Baltic Sea, salinity affects neutral egg buoyancy, which is positively correlated with egg survival, as only water layers away from the oxygen consumption-dominated sea bottom contain sufficient oxygen. Egg buoyancy is positively correlated to female spawner age/size. From observations in the Baltic Sea, a field-based relationship between egg diameter and buoyancy (floating depth) could be established. Hence, based on the age structure of the spawning stock, we quantify the number of effective spawners, which are able to reproduce under ambient hydrographic conditions. For the time period 1993-2010, our results revealed large variations in the horizontal extent of spawning habitat (1000-20 000 km(2)) and oxygen-dependent egg survival (10-80%). The novel concept of an effective spawning stock biomass takes into account offspring that survive depending on the spawning stock age/size structure, if reproductive success is related to egg buoyancy and the extent of hypoxic areas. Effective spawning stock biomass reflected the role of environmental conditions for Baltic cod recruitment better than the spawning stock biomass alone, highlighting the importance of including environmental information in ecosystem-based management approaches.

  17. Assessments to determine the effect of current and alternate ladder operations on brood stock collection and behavior of hatchery fall Chinook Salmon at Spring Creek National Fish Hatchery during 2003-2005

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Spring Creek National Fish Hatchery traditionally operates an adult ladder, without closure, from the start of the tule fall Chinook salmon run in late August until...

  18. Assessments to determine the effect of current and alternate ladder operations on brood stock collection and behavior of hatchery fall Chinook Salmon at Little White Salmon National Fish Hatchery during 2004-05

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Production of upriver bright fall Chinook salmon at Little White Salmon National Fish Hatchery was introduced as part of the John Day Dam mitigation program in the...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-05-11

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-02-20

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

  1. Portfolio theory as a management tool to guide conservation and restoration of multi-stock fish populations

    Science.gov (United States)

    DuFour, Mark R.; May, Cassandra J.; Roseman, Edward F.; Ludsin, Stuart A.; Vandergoot, Christopher S.; Pritt, Jeremy J.; Fraker, Michael E.; Davis, Jeremiah J.; Tyson, Jeffery T.; Miner, Jeffery G.; Marschall, Elizabeth A.; Mayer, Christine M.

    2015-01-01

    Habitat degradation and harvest have upset the natural buffering mechanism (i.e., portfolio effects) of many large-scale multi-stock fisheries by reducing spawning stock diversity that is vital for generating population stability and resilience. The application of portfolio theory offers a means to guide management activities by quantifying the importance of multi-stock dynamics and suggesting conservation and restoration strategies to improve naturally occurring portfolio effects. Our application of portfolio theory to Lake Erie Sander vitreus (walleye), a large population that is supported by riverine and open-lake reef spawning stocks, has shown that portfolio effects generated by annual inter-stock larval fish production are currently suboptimal when compared to potential buffering capacity. Reduced production from riverine stocks has resulted in a single open-lake reef stock dominating larval production, and in turn, high inter-annual recruitment variability during recent years. Our analyses have shown (1) a weak average correlation between annual river and reef larval production (ρ̄ = 0.24), suggesting that a natural buffering capacity exists in the population, and (2) expanded annual production of larvae (potential recruits) from riverine stocks could stabilize the fishery by dampening inter-annual recruitment variation. Ultimately, our results demonstrate how portfolio theory can be used to quantify the importance of spawning stock diversity and guide management on ecologically relevant scales (i.e., spawning stocks) leading to greater stability and resilience of multi-stock populations and fisheries.

  2. The response of stock prices to dividend news on the Ghana stock market: An empirical assessment

    Directory of Open Access Journals (Sweden)

    Gideon Boako

    2015-04-01

    Full Text Available An important assumption of the signaling hypothesis is that dividend change announcements are positively correlated with share price reactions and future changes in earnings. However, Miller and Modigliani (1961sustains that, dividend policy is irrelevant in arriving at a firm value, if the capital market is perfect. The purpose of this paper is to assess the potency of the dividend irrelevance theory on the Ghana stock market by using the Johansen-Juselius cointegration methodology on daily data of dividends, earnings and stock prices from January 2011 to December 2013. The results establish that equity prices in Ghana are not in sync with dividend announcements. However, the incorporation of earnings in the cointegration model provides varying result. The findings indicate that equity price change movements in Ghana are not responsive to dividend news.

  3. Implications of fisheries during the spawning season for the sustainable management and recovery of depleted fish stocks: a conceptual framework

    NARCIS (Netherlands)

    Rijnsdorp, A.D.

    2009-01-01

    Fishing during the spawning season may negatively affects the reproductive potential and reproductive dynamics of exploited fish stocks due to a variety of mechanisms such as the disturbance of the natural spawning behaviour, effects on the age, size and sex composition of the spawning population an

  4. Sampling for Soil Carbon Stock Assessment in Rocky Agricultural Soils

    Science.gov (United States)

    Beem-Miller, Jeffrey P.; Kong, Angela Y. Y.; Ogle, Stephen; Wolfe, David

    2016-01-01

    Coring methods commonly employed in soil organic C (SOC) stock assessment may not accurately capture soil rock fragment (RF) content or soil bulk density (rho (sub b)) in rocky agricultural soils, potentially biasing SOC stock estimates. Quantitative pits are considered less biased than coring methods but are invasive and often cost-prohibitive. We compared fixed-depth and mass-based estimates of SOC stocks (0.3-meters depth) for hammer, hydraulic push, and rotary coring methods relative to quantitative pits at four agricultural sites ranging in RF content from less than 0.01 to 0.24 cubic meters per cubic meter. Sampling costs were also compared. Coring methods significantly underestimated RF content at all rocky sites, but significant differences (p is less than 0.05) in SOC stocks between pits and corers were only found with the hammer method using the fixed-depth approach at the less than 0.01 cubic meters per cubic meter RF site (pit, 5.80 kilograms C per square meter; hammer, 4.74 kilograms C per square meter) and at the 0.14 cubic meters per cubic meter RF site (pit, 8.81 kilograms C per square meter; hammer, 6.71 kilograms C per square meter). The hammer corer also underestimated rho (sub b) at all sites as did the hydraulic push corer at the 0.21 cubic meters per cubic meter RF site. No significant differences in mass-based SOC stock estimates were observed between pits and corers. Our results indicate that (i) calculating SOC stocks on a mass basis can overcome biases in RF and rho (sub b) estimates introduced by sampling equipment and (ii) a quantitative pit is the optimal sampling method for establishing reference soil masses, followed by rotary and then hydraulic push corers.

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

    Science.gov (United States)

    Hutchings, J A

    2014-12-01

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

  6. Parasites as biological tags of fish stocks: a meta-analysis of their discriminatory power.

    Science.gov (United States)

    Poulin, Robert; Kamiya, Tsukushi

    2015-01-01

    The use of parasites as biological tags to discriminate among marine fish stocks has become a widely accepted method in fisheries management. Here, we first link this approach to its unstated ecological foundation, the decay in the similarity of the species composition of assemblages as a function of increasing distance between them, a phenomenon almost universal in nature. We explain how distance decay of similarity can influence the use of parasites as biological tags. Then, we perform a meta-analysis of 61 uses of parasites as tags of marine fish populations in multivariate discriminant analyses, obtained from 29 articles. Our main finding is that across all studies, the observed overall probability of correct classification of fish based on parasite data was about 71%. This corresponds to a two-fold improvement over the rate of correct classification expected by chance alone, and the average effect size (Zr = 0·463) computed from the original values was also indicative of a medium-to-large effect. However, none of the moderator variables included in the meta-analysis had a significant effect on the proportion of correct classification; these moderators included the total number of fish sampled, the number of parasite species used in the discriminant analysis, the number of localities from which fish were sampled, the minimum and maximum distance between any pair of sampling localities, etc. Therefore, there are no clear-cut situations in which the use of parasites as tags is more useful than others. Finally, we provide recommendations for the future usage of parasites as tags for stock discrimination, to ensure that future applications of the method achieve statistical rigour and a high discriminatory power.

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

    DEFF Research Database (Denmark)

    Kokkalis, Alexandros; Thygesen, Uffe Høgsbro; Nielsen, Anders

    2015-01-01

    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...

  8. AFSC: Various fish maturity studies

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Knowledge of the reproductive biology of fish and crab stocks is critical to stock assessment estimates of the reproductive potential (typically measured as spawning...

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

    Science.gov (United States)

    Duncan, Stephen; Hepburn, Cameron; Papachristodoulou, Antonis

    2011-01-21

    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.

  10. Analyzing fish stocks dynamics using CPUE and PRCF:a new approach for the fishery management

    Institute of Scientific and Technical Information of China (English)

    G Vzquez-Prada

    2014-01-01

    Catch per unit effort has been used in many fisheries researches worldwide like an abundance or density index. Parallel to this issue, partial ratio correlation function is a technique used to identify the density dependent structure underlying ecological time series. Although partial ratio correlation function is widely used in ecological fields, it has not been much used in fisheries and aquatic sciences. In this synthesis, a new combination of statistical techniques is proposed to diagnose the order of the population dynamic of fish stocks, as the first knowledge of the type of factors that may be regulating them, included human predation as an exogenous factor.

  11. Pike ( Esox lucius L.) stocking as a biomanipulation tool .1. Effects on the fish population in Lake Lyng, Denmark

    DEFF Research Database (Denmark)

    Berg, Søren; Jeppesen, E.; Søndergaard, M.

    1997-01-01

    From 1990-1993 juvenile pike (Esox lucius) were stocked each spring in the eutrophic Lake Lyng (9.9 ha, max. depth 7.6 m, mean depth 2.4 m) in densities between 515 and 3616 pike ha(- 1). In 1989-90 the fish population consisted mainly of roach (Rutilus rutilus), rudd (Scardinius erythrophthalmus......), perch (Perca fluviatilis) and ruffe (Gymnocephalus cernuus), and total fish biomass was estimated at 477 kg ha(-1). Prior to stocking pike was not present in the lake. Following the first year of stocking, the density of roach, rudd and ruffe fry expressed as catch per unit effort decreased...... significantly by 64 to 97%. In 1991 ruffe disappeared completely. The pike stocking did not affect the density of perch significantly. The growth of pike was high and also the growth of perch increased significantly from 1990 to 1991 (p

  12. Annual Coded Wire Tag Program; Oregon Stock Assessment, 2001 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, Mark; Mallette, Christine; Murray, William

    2002-03-01

    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 2001 contract period: Objective 1--Over 1 million juvenile salmon were coded-wire by this program (Table 1); Objective 2--ODFW recovered and processed over 40,000 snout collected from coded-wire tagged fish (Table 2); Objective 3--Survival data is summarized below; Objective 4--The last group of VIE tagged coho was released in 2001 and returning coho were samples at Sandy Hatchery. This sampling showed only 1 of 1,160 returning coho VIE marked as juveniles retained the VIE mark as adults.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-03-01

    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.

  14. Stocking of Offsite Waters for Hungry Horse Dam Mitigation; Creston National Fish Hatchery, 2002-2003 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-02-01

    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 141,000 westslope cutthroat eggs (M012 strain) was acquired from the State of Montana Washoe Park State Fish Hatchery in May 2002 for this objective. We also received an additional 22,000 westslope cutthroat eggs, MO12 strain naturalized, from feral fish at Rogers Lake, Flathead County, Montana. The fish were reared using approved fish culture techniques as defined in the U.S. Fish and Wildlife Service, Fish Hatchery Management guidelines. Survival from the swim up fry stage to stocking was 95.6%. We achieved a 0.80 feed conversion this year on a new diet, Skretting ''Nutra Plus''. 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 vary yearly based on results of biological monitoring and adaptive management. 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 54,000 rainbow trout eggs (Arlee strain) was acquired from the Ennis National Fish Hatchery in December 2002 for this objective. The fish were reared using approved fish culture techniques as defined in the U.S. Fish and Wildlife Service, Fish Hatchery Management guidelines. Survival from the swim up fry stage to stocking was 99.9%. We achieved a 0.79 feed conversion this year on a new diet, Skretting ''Nutra Plus''. Arlee rainbow trout are being used for this objective because the stocking locations are terminal basin reservoirs and habitat conditions and returns to the creel are unsuitable for native cutthroat. Post release survival and angler success is monitored annually

  15. Status and trends of the major roundfish, flatfish, and pelagic fish stocks in the North Sea : Thirty-year overview

    DEFF Research Database (Denmark)

    Serchuk, F.M.; Kirkegaard, Eskild; Daan, N.

    1996-01-01

    Changes in the status of the major roundfish, flatfish, and pelagic stocks in the North Sea over the past 30 years are reviewed. Synopses are presented on trends in catches, fishing mortality, spawning-stock biomass, and recruitment for eight stocks (cod, haddock, whiting, saithe, plaice, sole......, herring, and mackerel), together with an evaluation of the current state of these resources and the most resent management advice provided by the ICES Advisory, Committee on Fishery Management. (C) 1996 International Council for the Exploration of the Sea...

  16. Uncertainties in Stock Assessment and the Precautionary Management Suggestions for the Anchovy (Engraulis japonicus) Stock in the Yellow Sea

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

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

  17. Bayesian stock assessment of Pacific herring in Prince William Sound, Alaska

    Science.gov (United States)

    Moffitt, Steven D.; Hulson, Peter-John F.

    2017-01-01

    The Pacific herring (Clupea pallasii) population in Prince William Sound, Alaska crashed in 1993 and has yet to recover, affecting food web dynamics in the Sound and impacting Alaskan communities. To help researchers design and implement the most effective monitoring, management, and recovery programs, a Bayesian assessment of Prince William Sound herring was developed by reformulating the current model used by the Alaska Department of Fish and Game. The Bayesian model estimated pre-fishery spawning biomass of herring age-3 and older in 2013 to be a median of 19,410 mt (95% credibility interval 12,150–31,740 mt), with a 54% probability that biomass in 2013 was below the management limit used to regulate fisheries in Prince William Sound. The main advantages of the Bayesian model are that it can more objectively weight different datasets and provide estimates of uncertainty for model parameters and outputs, unlike the weighted sum-of-squares used in the original model. In addition, the revised model could be used to manage herring stocks with a decision rule that considers both stock status and the uncertainty in stock status. PMID:28222151

  18. Stocking of Offsite Waters for Hungry Horse Dam Mitigation Creston National Fish Hatchery, FY 2006 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Hooley, Sharon

    2009-03-20

    A total of 350,000, M012 strain, westslope cutthroat trout (WCT) eggs were received from Montana Fish Wildlife & Parks (MFWP), Washoe Park State Fish Hatchery in June of 2005 to accomplish this fishery management objective. These eggs were incubated, hatched and reared entirely inside the hatchery nursery building using a protected well water supply. Fish grew according to schedule and survival was excellent. The hatchery achieved a 0.78 feed fed to pounds gained conversion ratio for this group of WCT. Not all of the progenies from this fish lot were used for Hungry Horse Dam Fishery Mitigation Implementation. Some were used for other regional fishery management projects. Westslope cutthroat trout were reared using approved fish culture techniques as recommended in the USFWS Fish Hatchery Management Handbook and also utilizing a regimen adapted for hatchery specific site conditions. The fish health for these WCT was very good. Survival from first feeding fry stage to stocking was 79%. The hatchery had an annual fish health inspection performed by the USFWS Bozeman Fish Health Center in mid March of 2006. This inspection found all fish lots at Creston to be disease free. The Montana State Fish Health Board has placed the hatchery under a limited quarantine since May of 2005 due to an epizootic of Furunculosis. This classification has allowed the Creston NFH to stock disease free fish in locations approved by regional fish managers. The hatchery has been working with the State Fish Pathologist to remove the limited quarantine classification from the facility. Although fish health for all station fish lots remains disease free, MFWP has asserted it will not remove the limited quarantine until the new influent water treatment system, including the ultraviolet disinfection unit, is running full time, year round. The USFWS is working to secure the additional funding necessary to operate the treatment building year round. Distribution of the WCT took place from March

  19. Agonistic behavior among three stocked trout species in a novel reservoir fish community

    Science.gov (United States)

    Budy, Phaedra; Hafen, Konrad

    2015-01-01

    The popularity of reservoirs to support sport fisheries has led to the stocking of species that did not co-evolve, creating novel reservoir fish communities. In Utah, the Bear Lake strain of Bonneville Cutthroat Trout Oncorhynchus clarkii utah and tiger trout (female Brown Trout Salmo trutta × male Brook Trout Salvelinus fontinalis) are being more frequently added to a traditional stocking regimen consisting primarily of Rainbow TroutO. mykiss. Interactions between these three predatory species are not well understood, and studies evaluating community interactions have raised concern for an overall decrease of trout condition. To evaluate the potential for negative interactions among these species, we tested aggression in laboratory aquaria using three-species and pairwise combinations at three densities. Treatments were replicated before and after feeding. During the three-species trials Rainbow Trout initiated 24.8 times more aggressive interactions than Cutthroat Trout and 10.2 times more aggressive interactions than tiger trout, and tiger trout exhibited slightly (1.9 times) more aggressive initiations than Cutthroat Trout. There was no significant difference in behavior before versus after feeding for any species, and no indication of increased aggression at higher densities. Although Rainbow Trout in aquaria may benefit from their bold, aggressive behavior, given observations of decreased relative survival in the field, these benefits may be outweighed in reservoirs, possibly through unnecessary energy expenditure and exposure to predators.

  20. A continuous time delay-difference type model (CTDDM) applied to stock assessment of the southern Atlantic albacore Thunnus alalunga

    Science.gov (United States)

    Liao, Baochao; Liu, Qun; Zhang, Kui; Baset, Abdul; Memon, Aamir Mahmood; Memon, Khadim Hussain; Han, Yanan

    2016-09-01

    A continuous time delay-diff erence model (CTDDM) has been established that considers continuous time delays of biological processes. The southern Atlantic albacore ( Thunnus alalunga) stock is the one of the commercially important tuna population in the marine world. The age structured production model (ASPM) and the surplus production model (SPM) have already been used to assess the albacore stock. However, the ASPM requires detailed biological information and the SPM lacks the biological realism. In this study, we focus on applying a CTDDM to the southern Atlantic albacore ( T. alalunga) species, which provides an alternative method to assess this fishery. It is the first time that CTDDM has been provided for assessing the Atlantic albacore ( T. alalunga) fishery. CTDDM obtained the 80% confidence interval of MSY (maximum sustainable yield) of (21 510 t, 23 118t). The catch in 2011 (24 100 t) is higher than the MSY values and the relative fishing mortality ratio ( F 2011/ F MSY) is higher than 1.0. The results of CTDDM were analyzed to verify the proposed methodology and provide reference information for the sustainable management of the southern Atlantic albacore stock. The CTDDM treats the recruitment, the growth, and the mortality rates as all varying continuously over time and fills gaps between ASPM and SPM in this stock assessment.

  1. Life history inhomogeneity in Baltic Sea whitefish populations revealed by otolith strontium signatures – identification of stocked fish

    Directory of Open Access Journals (Sweden)

    Henry Hägerstrand

    2015-11-01

    The strontium concentrations in the otolith cores of whitefish from River Tornionjoki were higher than that of the four otoliths with low core strontium from fishes caught at sea (Table 1. Supposing that this latter group represent stocked fish raised in freshwater ponds, the vast majority of River Tornionjoki whitefish is naturally reproduced fish. This is plausible because in River Tornionjoki, the major whitefish spawning river in Finland, no larger stocking have been made since 1990s (Jokikokko and Huhmarniemi 2014. In conclusion, the concentration of otolith core strontium differs in whitefish hatched in fresh-water and in whitefish hatched in river water or in brackish Baltic Sea water. This difference can be used to reveal stocked whitefish. Barium concentration may be an even better indicator in this respect than strontium, as previous results indicate (Hägerstrand et al., 2015. Stocked river spawning whitefish appear in large amount at the southern feeding grounds around the Åland Islands, as already indicated by e.g. Leskelä et al. (2009.

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

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, Mark; Mallette, Christine; Murray, William

    2003-03-01

    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.

  3. Poor-data and data-poor species stock assessment using a Bayesian hierarchical approach.

    Science.gov (United States)

    Jiao, Yan; Cortés, Enric; Andrews, Kate; Guo, Feng

    2011-10-01

    Appropriate inference for stocks or species with low-quality data (poor data) or limited data (data poor) is extremely important. Hierarchical Bayesian methods are especially applicable to small-area, small-sample-size estimation problems because they allow poor-data species to borrow strength from species with good-quality data. We used a hammerhead shark complex as an example to investigate the advantages of using hierarchical Bayesian models in assessing the status of poor-data and data-poor exploited species. The hammerhead shark complex (Sphyrna spp.) along the Atlantic and Gulf of Mexico coasts of the United States is composed of three species: the scalloped hammerhead (S. lewini), the great hammerhead (S. mokarran), and the smooth hammerhead (S. zygaena) sharks. The scalloped hammerhead comprises 70-80% of the catch and has catch and relative abundance data of good quality, whereas great and smooth hammerheads have relative abundance indices that are both limited and of low quality presumably because of low stock density and limited sampling. Four hierarchical Bayesian state-space surplus production models were developed to simulate variability in population growth rates, carrying capacity, and catchability of the species. The results from the hierarchical Bayesian models were considerably more robust than those of the nonhierarchical models. The hierarchical Bayesian approach represents an intermediate strategy between traditional models that assume different population parameters for each species and those that assume all species share identical parameters. Use of the hierarchical Bayesian approach is suggested for future hammerhead shark stock assessments and for modeling fish complexes with species-specific data, because the poor-data species can borrow strength from the species with good data, making the estimation more stable and robust.

  4. Microsatellite assessment of walrus (Odobenus rosmarus rosmarus stocks in Canada

    Directory of Open Access Journals (Sweden)

    Aaron BA Shafer

    2014-12-01

    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.

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

    Data.gov (United States)

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

  6. Fish stock surveys from 41 sites on the islands of Oahu and Hawaii from September 11, 1952 to December 28, 2000 (NODC Accession 0002754)

    Data.gov (United States)

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

  7. AFSC/REFM: North Pacific Groundfish Stock Assessment Chapters, 1998-present

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Members of the Alaska Fisheries Science Center's (AFSC) Stock Assessment and Multispecies Assessments Program are responsible for determining the condition of...

  8. Length-based assessment of coral reef fish populations in the main and northwestern Hawaiian islands.

    Science.gov (United States)

    Nadon, Marc O; Ault, Jerald S; Williams, Ivor D; Smith, Steven G; DiNardo, Gerard T

    2015-01-01

    The coral reef fish community of Hawaii is composed of hundreds of species, supports a multimillion dollar fishing and tourism industry, and is of great cultural importance to the local population. However, a major stock assessment of Hawaiian coral reef fish populations has not yet been conducted. Here we used the robust indicator variable "average length in the exploited phase of the population ([Formula: see text])", estimated from size composition data from commercial fisheries trip reports and fishery-independent diver surveys, to evaluate exploitation rates for 19 Hawaiian reef fishes. By and large, the average lengths obtained from diver surveys agreed well with those from commercial data. We used the estimated exploitation rates coupled with life history parameters synthesized from the literature to parameterize a numerical population model and generate stock sustainability metrics such as spawning potential ratios (SPR). We found good agreement between predicted average lengths in an unfished population (from our population model) and those observed from diver surveys in the largely unexploited Northwestern Hawaiian Islands. Of 19 exploited reef fish species assessed in the main Hawaiian Islands, 9 had SPRs close to or below the 30% overfishing threshold. In general, longer-lived species such as surgeonfishes, the redlip parrotfish (Scarus rubroviolaceus), and the gray snapper (Aprion virescens) had the lowest SPRs, while short-lived species such as goatfishes and jacks, as well as two invasive species (Lutjanus kasmira and Cephalopholis argus), had SPRs above the 30% threshold.

  9. Length-based assessment of coral reef fish populations in the main and northwestern Hawaiian islands.

    Directory of Open Access Journals (Sweden)

    Marc O Nadon

    Full Text Available The coral reef fish community of Hawaii is composed of hundreds of species, supports a multimillion dollar fishing and tourism industry, and is of great cultural importance to the local population. However, a major stock assessment of Hawaiian coral reef fish populations has not yet been conducted. Here we used the robust indicator variable "average length in the exploited phase of the population ([Formula: see text]", estimated from size composition data from commercial fisheries trip reports and fishery-independent diver surveys, to evaluate exploitation rates for 19 Hawaiian reef fishes. By and large, the average lengths obtained from diver surveys agreed well with those from commercial data. We used the estimated exploitation rates coupled with life history parameters synthesized from the literature to parameterize a numerical population model and generate stock sustainability metrics such as spawning potential ratios (SPR. We found good agreement between predicted average lengths in an unfished population (from our population model and those observed from diver surveys in the largely unexploited Northwestern Hawaiian Islands. Of 19 exploited reef fish species assessed in the main Hawaiian Islands, 9 had SPRs close to or below the 30% overfishing threshold. In general, longer-lived species such as surgeonfishes, the redlip parrotfish (Scarus rubroviolaceus, and the gray snapper (Aprion virescens had the lowest SPRs, while short-lived species such as goatfishes and jacks, as well as two invasive species (Lutjanus kasmira and Cephalopholis argus, had SPRs above the 30% threshold.

  10. Stock assessment in inland fisheries: a foundation for sustainable use and conservation

    Science.gov (United States)

    Lorenzen, Kai; Cowx, Ian G.; Entsua-Mensah, R. E. M.; Lester, Nigel P.; Koehn, J.D.; Randall, R.G.; So, N.; Bonar, Scott A.; Bunnell, David; Venturelli, Paul A.; Bower, Shannon D.; Cooke, Steven J.

    2016-01-01

    Fisheries stock assessments are essential for science-based fisheries management. Inland fisheries pose challenges, but also provide opportunities for biological assessments that differ from those encountered in large marine fisheries for which many of our assessment methods have been developed. These include the number and diversity of fisheries, high levels of ecological and environmental variation, and relative lack of institutional capacity for assessment. In addition, anthropogenic impacts on habitats, widespread presence of non-native species and the frequent use of enhancement and restoration measures such as stocking affect stock dynamics. This paper outlines various stock assessment and data collection approaches that can be adapted to a wide range of different inland fisheries and management challenges. Although this paper identifies challenges in assessment, it focuses on solutions that are practical, scalable and transferrable. A path forward is suggested in which biological assessment generates some of the critical information needed by fisheries managers to make effective decisions that benefit the resource and stakeholders.

  11. Fish Stock Endogeneity in a Harvest Function: ‘El Niño’ Effects on the Chilean Jack Mackerel Fishery

    Directory of Open Access Journals (Sweden)

    Sebastián Vergara

    2007-03-01

    Full Text Available There are several examples of pelagic fisheries that have experienced fishing collapse when facing downward abundance cycles. Improving understanding about pelagic catch’s stock dependence can help avoid new cases of fishing collapse. This paper analyses the possible endogeneity of the fish stock variable in a pelagic fishery harvest function. The harvest function is estimated using panel data and ‘El Niño’ episodes as instrumental variable for the Chilean jack mackerel biomass. This strategy produces consistent estimates of the fish biomass coefficient. The paper makes two contributions. First, it corrects for endogeneity of the fish stock variable, an issue often underestimated in empirical fishery economics. Secondly, it shows that ‘El Niño’ episodes have negative effects on the Chilean jack mackerel biomass.

  12. The use of Depletion Methods to assess Mediterranean cephalopod stocks under the current EU Data Collection Framework

    Directory of Open Access Journals (Sweden)

    S. KELLER

    2015-11-01

    Full Text Available Fuelled by the raising importance of cephalopod fisheries in Europe, there have been demands from scientists and stakeholders for their assessment and management. However, little has been done to improve the data collection in order to analyse cephalopod populations under the EU Data Collection Framework (DCF. While the DCF allows member states to design flexible national sampling programmes, it establishes the minimum data requirements (MDR each state is obliged to fulfil. In this study, it was investigated whether such MDR currently set by the DCF allow the application of depletion models (DMs to assess European cephalopod stocks. Squid and cuttlefish fisheries from the western Mediterranean were used as a case study. This exercise sheds doubt on the suitability of the MDR to properly assess and manage cephalopod stocks by means of DMs. Owing to the high plasticity of life-history traits in cephalopod populations, biological parameters should be estimated during the actual depletion period of the fished stocks, in contrast with the triennial sampling established by the DCF. In order to accurately track the depletion event, the rapid growth rates of cephalopods implies that their populations should be monitored at shorter time scales (ideally weekly or biweekly instead of quarterly as required by the DCF. These measures would not demand additional resources of the ongoing DCF, but a redistribution of sampling efforts during the depletion period. Such changes in the sampling scheme could be designed and undertaken by the member states or directly integrated as requirements.

  13. Insights into fisheries management practices: using the theory of planned behavior to explain fish stocking among a sample of Swiss anglers.

    Directory of Open Access Journals (Sweden)

    Eike von Lindern

    Full Text Available Using inadequate management tools often threatens the natural environment. This study focuses on the example of Swiss recreational fishermen (hereafter called "anglers" as recreational fisheries management stakeholders. In recreational fisheries, fish stocking conducted by anglers has been identified as one important factor associated with declining fish catches. We therefore aimed to a gain insights into why anglers want to maintain fish stocking and b identify entry points for interventions to promote more pro-ecological management practices. Results (N = 349 showed that the majority of anglers think very uncritically about stocking and that they frequently engage in it. We conclude that outcome expectancies and beliefs about risks, in combination with a lack of stocking success controls are the main reasons that anglers retain stocking measures. We suggest that providing anglers with direct experience and feedback about stocking success is suitable to change their intentions regarding stocking and their actual stocking behavior, and thus, to promote more pro-ecological management methods. From a more general perspective, the results of this study are likely to help improve pro-ecological ecosystem management in other domains where problems similar to those in recreational fisheries management might exist.

  14. Insights into fisheries management practices: using the theory of planned behavior to explain fish stocking among a sample of Swiss anglers.

    Science.gov (United States)

    von Lindern, Eike; Mosler, Hans-Joachim

    2014-01-01

    Using inadequate management tools often threatens the natural environment. This study focuses on the example of Swiss recreational fishermen (hereafter called "anglers") as recreational fisheries management stakeholders. In recreational fisheries, fish stocking conducted by anglers has been identified as one important factor associated with declining fish catches. We therefore aimed to a) gain insights into why anglers want to maintain fish stocking and b) identify entry points for interventions to promote more pro-ecological management practices. Results (N = 349) showed that the majority of anglers think very uncritically about stocking and that they frequently engage in it. We conclude that outcome expectancies and beliefs about risks, in combination with a lack of stocking success controls are the main reasons that anglers retain stocking measures. We suggest that providing anglers with direct experience and feedback about stocking success is suitable to change their intentions regarding stocking and their actual stocking behavior, and thus, to promote more pro-ecological management methods. From a more general perspective, the results of this study are likely to help improve pro-ecological ecosystem management in other domains where problems similar to those in recreational fisheries management might exist.

  15. Annual stock assessment – CWT (USFWS): Annual report 2003

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — 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...

  16. Stock assessment of the red spiny lobster (Panulirus argus caught in the tropical southwestern Atlantic

    Directory of Open Access Journals (Sweden)

    Humber A Andrade

    2015-03-01

    Full Text Available The stocks of the red spiny lobster (Panulirus argus (Latreille, 1804 in the Caribbean and in the Brazilian coast are of considerable economic importance. There are important genetic differences between the Brazilian and Caribbean populations, which support separated stock assessment. The present study provides an assessment of the Brazilian stock of P. argus using a biomass dynamic model based on a Bayesian approach. Assuming that the catch per unit effort is a valid index of relative abundance, the results of the analysis indicate that stocks have been heavily overexploited since the 1980s. The present-day scenario is pessimistic, and there is evidence that the stock may be close to collapse.

  17. Food web and fish stock changes in central Chile: comparing the roles of jumbo squid (Dosidicus gigas) predation, the environment, and fisheries

    Science.gov (United States)

    Neira, Sergio; Arancibia, Hugo

    2013-10-01

    We analyzed recent food web and fish stock changes in the central Chile marine ecosystem, comparing the roles of jumbo squid (Dosidicus gigas) as predator, the environment, and fishing. To accomplish this we used food web modeling and the Ecopath with Ecosim software (EwE). The principal fish stocks have experienced wide decadal fluctuations in the past 30 years, including stock collapses of horse mackerel (Trachurus murphyi) and hake (Merluccius gayi), and there was a large influx of jumbo squid during the mid-2000s. We used two EwE models representing the food web off central Chile to test the hypothesis that predation by jumbo squid has been significant in explaining the dynamics of the main fishing resources and other species in the study area. Results indicate that predation by jumbo squid on fish stocks is lower than that of other predators (e.g. hake) and the fishery. Long-term fluctuations (1978-2004) in the biomass of the main fish stocks (as well as other components of the food web) seem to be related to fishing and to variation in primary production, rather than to predation by jumbo squid alone. Jumbo squid seems to play a role as predator rather than prey in the system, but its impacts are low when compared with the impacts of other predators and fishing. Therefore, we conclude that jumbo squid predation on its prey was not the primary force behind the collapse of important fish stocks off central Chile. Future efforts should be directed to better understanding factors that trigger sudden increases in jumbo squid abundance off central Chile, as well as modeling its trophic impacts.

  18. Environmental Assessment : Marais Des Cygnes NWR fishing plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This Environmental Assessment is for the implemetation of a fishing program on Marais Des Cygnes National Wildlife Refuge. The Findning of No Significant Impact...

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

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This Environmental Assessment considers the biological, environmental, and socioeconomic effects of establishing a sport fishing program at Meredosia National...

  20. Performance of precautionary reference points in providing management advice on North Sea fish stocks

    NARCIS (Netherlands)

    Piet, G.J.; Rice, J.C.

    2004-01-01

    For 17 stocks in the North Sea. the performance and effectiveness of management advice using precautionary reference points was evaluated. Three criteria were used to identify whether a stock was within safe biological limits: SSB F-pa, or SSB F-pa. Four scenario

  1. Zooplankton standing stock assessment and fishery resources in the indian seas

    Digital Repository Service at National Institute of Oceanography (India)

    Goswami, S.C.; Sarupria, J.S.; Bhargava, R.M.S.

    Based on data from 1864 samples collected over a period of 12 years (1976-88), an assessment of zooplankton standing stock (biomass), secondary production and potential fishery resources has been made. The areas studied included Arabian Sea, Bay...

  2. Active Fish Tracking Sonar (AFTS) for Assessing Fish Behavior

    Energy Technology Data Exchange (ETDEWEB)

    Hedgepeth, J (Tenera Environmental, LLC); Johnson, Gary E.(BATTELLE (PACIFIC NW LAB)); Skalski, John R.; Burczynski, J (BioSonics Inc.)

    2002-11-01

    Active fish tracking sonars (AFTS) were used in 2001 to study fish movement in response to intake occlusion plates at The Dalles Dam on the Columbia River. AFTS provides three-dimensional fish tracks by aligning the axis of a split-beam transducer with a fish target. High-speed stepper motors move the transducer so that a tracked target remains on-axis. Occlusion plates with lateral extensions covered the top half of the turbine intakes to produce a fish friendly near-dam environment. Two AFTS were positioned at the center of Main Unit 1, one each for monitoring installed and removed plate conditions. A regression analysis showed that occlusion plates had pronounced effects on fish movement along the dam. The plates appeared to inhibit movement toward the spillway, movement toward the dam (especially in front of the turbine intake), and movement downward toward the turbines. Fish fate (as opposed to movement directions from regression slopes) into particular areas was determined using Markov-chain analysis. The sluiceway (a safer passage route above the turbine intake) zone of influence was larger with the occlusion plates installed, contrary to the regression results. In addition, the probability of passage out the near turbine and bottom sides of the sample volume was about 50% lower with occlusion plates installed.

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

    DEFF Research Database (Denmark)

    Lindegren, Martin; Waldo, Staffan; Nilsson, P. Anders;

    2013-01-01

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

  4. Environmental risk assessment of alkylphenols from offshore produced water on fish reproduction.

    Science.gov (United States)

    Beyer, Jonny; Myhre, Lars Petter; Sundt, Rolf C; Meier, Sonnich; Tollefsen, Knut-Erik; Vabø, Rune; Klungsøyr, Jarle; Sanni, Steinar

    2012-04-01

    Concern has been raised over whether environmental release of alkylphenols (AP) in produced water (PW) discharges from the offshore oil industry could impose a risk to the reproduction of fish stocks in the North Sea. An environmental risk assessment (ERA) was performed to determine if environmental exposure to PW APs in North Sea fish populations is likely to be high enough to give effects on reproduction endpoints. The DREAM (Dose related Risk and Effect Assessment Model) software was used in the study and the inputs to the ERA model included PW discharge data, fate information of PW plumes, fish distribution information, as well as uptake and elimination information of PW APs. Toxicodynamic data from effect studies with Atlantic cod (Gadus morhua) exposed to APs were used to establish a conservative environmental risk threshold value for AP concentration in seawater. By using the DREAM software to 1) identify the areas of highest potential risk and 2) integrate fish movement and uptake/elimination rates of APs for the chosen areas we found that the environmental exposure of fish to APs from PW is most likely too low to affect reproduction in wild populations of fish in the North Sea. The implications related to risk management of offshore PW and uncertainties in the risk assessment performed are discussed.

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

    DEFF Research Database (Denmark)

    Skov, Christian; Perrow, M.R.; Berg, Søren;

    2002-01-01

    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...... 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...

  6. Assessment of Intellectual Capital in Joint-Stock Companies

    Directory of Open Access Journals (Sweden)

    Rima Tamošiūnienė

    2015-12-01

    Full Text Available The evaluation of intellectual capital factors is an essential part for the management of joint-stock companies. Many authors indicate that successful intellectual capital management increases value added in joint-stock companies. Nevertheless, intellectual capital is a complex and challenging concept as there is still no clear guidance, what the intellectual capital features and its structural parts are. Theoretical research revealed that scientists accentuate various intellectual capital parts depending basically on the type of their research, on the level of the research (micro, mezzo, macro, variables they selected to investigate and similar. This research paper gives an insight what drivers can be increasing value added in joint-stock companies.

  7. Environmental life cycle assessments of fish food products with emphasis on the fish catch process

    OpenAIRE

    2012-01-01

    Sustainable development embraces economics, society and nature and is the global context for this PhD-thesis. Modern fishery is dependent on fossil fuels, which use is the antithesis of sustainable fishery. Environmental degradation is closely related to health aspects, which are increasingly important to consumers and other stakeholders. For the fish food product (FFP), the main focus of prior research has been on threatened stock populations. Less attention has been focused on environmental...

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

    Directory of Open Access Journals (Sweden)

    Widien Khoufi

    2012-11-01

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

  9. Is the Stock of VET Skills Adequate? Assessment Methodologies.

    Science.gov (United States)

    Blandy, Richard; Freeland, Brett

    In Australia and elsewhere, four approaches have been used to determine whether stocks of vocational education and training (VET) skills are adequate to meet industry needs. The four methods are as follows: (1) the manpower requirements approach; (2) the international, national, and industry comparisons approach; (3) the labor market analysis…

  10. 78 FR 19446 - Marine Mammal Stock Assessment Reports

    Science.gov (United States)

    2013-04-01

    ... determining if this stock is declining or growing. The population size as of the 2010/2011 census season was... population size since the first census was conducted until present. Comment 34: The southern resident killer... separate management approaches (Baird et al. 2008, Albertson 2011, poster). This should be updated in...

  11. 77 FR 29969 - Marine Mammal Stock Assessment Reports

    Science.gov (United States)

    2012-05-21

    ... cetacean ``strandings'' in the Northern Gulf of Mexico, of which 95% stranded dead. Most of these were... majority of the pilot whales died. Response: Strandings are not part of the status of stocks determination... these two stranding events. In the cases where strandings are caused by human activities, any...

  12. 75 FR 12498 - Marine Mammal Stock Assessment Reports

    Science.gov (United States)

    2010-03-16

    ... from Gordon Waring, Northeast Fisheries Science Center, 166 Water Street, Woods Hole, MA 02543. Copies.... Stocks for which PBR is undetermined should be designated ``strategic'' because the lack of a PBR makes... Comment 11.) Comments on Alaska Regional Reports Comment 7: Loss of sea ice due to global warming is...

  13. 78 FR 66681 - Draft 2013 Marine Mammal Stock Assessment Reports

    Science.gov (United States)

    2013-11-06

    ... workshops, expert opinion, and analysis of historic injury cases to develop new criteria for distinguishing... (Alaska resident; northern resident; Gulf of Alaska, Aleutian Islands, and Bering Sea transient; AT1 transient; west coast transient stocks), harbor porpoise (southeast Alaska, Gulf of Alaska, and Bering...

  14. 78 FR 3399 - Draft 2012 Marine Mammal Stock Assessment Reports

    Science.gov (United States)

    2013-01-16

    ... SARs may be requested from Gordon Waring, Northeast Fisheries Science Center, 166 Water St., Woods Hole... northeast sink gillnet serious injury and mortality estimates for several Atlantic marine mammal stocks... estimated fishery-related mortality attributed to the Northeast sink gillnet fishery during...

  15. An assessment of illegal fishing in Gonarezhou National Park, Zimbabwe

    NARCIS (Netherlands)

    Gandiwa, E.; Zisadza-Gandiwa, P.; Mutandwa, M.; Sandram, S.

    2012-01-01

    Illegal fishing is a worldwide problem. In this study we present the first assessment of illegal fishing in Gonarezhou National Park (GNP), Zimbabwe. Information on illegal fishing was gathered from a total of 39 illegal fishers who were arrested within GNP between February and October 2011. Data wa

  16. Otter ( Lutra lutra ) predation on stocked brown trout ( Salmo trutta ) in two Danish lowland rivers

    DEFF Research Database (Denmark)

    Jacobsen, Lene

    2005-01-01

    This study aimed to evaluate otter predation on stocked trout. Large hatchery-reared trout (16-30 cm) were stocked into two Danish rivers with different fish populations. Otter diet before and after trout stocking was determined by analysing 685 spraints, collected regularly during the 35-day study...... period. Fish composition in the rivers before stocking was assessed by electrofishing. In River Trend, a typical trout river, the proportion of trout in the otter diet increased from 8% before stocking to 33% a few days after stocking. Moreover, trout lengths in the diet changed significantly towards...... the lengths of stocked trout, indicating that newly stocked trout were preferred to wild trout. In River Skals, dominated by cyprinids, there was no change in otter diet after stocking of hatchery trout, i.e., these were ignored by otter. Otter predation should be taken into account together with fish...

  17. Assessment of South Pacific Albacore Stock (Thunnus alalunga ) by Improved Schaefer Model

    Institute of Scientific and Technical Information of China (English)

    Wang Chien-Hsiung; Wang Shyh-Bin

    2006-01-01

    Based on catch and effort data of tuna longline fishery operating in the South Pacific Ocean, the South Pacific albacore stock was assessed by an improved Schaefer model. The results revealed that the intrinsic growth rate was about1.283 74 and carrying capacities vareied in the range from 73 734 to 266 732 metric tons. The growth ability of this species is remarkable. Stock dynamics mainly depends on environmental conditions. The stock is still in good condition. However, the continuous decreasing of biomass in recent years should be noticed.

  18. Principles of fish welfare assessment in farm rearing conditions

    Directory of Open Access Journals (Sweden)

    Relić Renata R.

    2010-01-01

    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.

  19. ASSESSMENT OF STOCK AND SPATIAL DISTRIBUTION OF SOLE (SOLEA SOLEA, L. IN ALBANIAN COAST USING RAPIDO TRAWL

    Directory of Open Access Journals (Sweden)

    Enton Spaho

    2012-06-01

    Full Text Available Common sole (Solea solea Linnaeus, 1758 is still not a specific target of fishery in Albania, but it represents an important target of the mixed-species catches of bottom trawlers and set netters operating in the coastal areas in the upper part of Albanian Adriatic Sea. Sole landings are low, amounting very few tonnes, but the demand will likely increase in the next future, because of the high quality of the fish fillet and the increase of consumers demand for wild sea fish. In order to identify the spawning areas and assess the spatial distribution and biomass of this species a rapido trawl survey was performed in year 2007. The smallest specimens were mostly concentrated in the shallowest stratum and the largest ones between 30 and 100 m depth. Solea Stock Biomass (SSB was 354 t, corresponding to 64% of the overall population recorded at sea at that time. In the context of fisheries, the Albanian fishing fleet involve a number of different fishing gears, while rapido trawl is introduced recently. The special technical and operating characteristics of rapido trawl makes it very effective in sole fishery and less harmful for the sea benthos and the species inhabiting it. This study aimed the estimation of spatial distribution of common sole and its biomass in the Albanian coast using rapido trawl gear.

  20. 77 FR 27246 - Marine Mammal Protection Act; Stock Assessment Report

    Science.gov (United States)

    2012-05-09

    ... Department of Fish and Game Bull. 1:134-135. Cameron, G.A., and K.A. Forney. 2000. Preliminary estimates of... Cruz. Siniff, D.B., and K. Ralls. 1991. Reproduction, survival, and tag loss in California sea...

  1. 1982 Aleutian Islands salmon stock assessment study: Legislative report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes a comprehensive research study of the Aleutian Islands salmon resources in 1982. The study encompassed the area west of Unimak Pass to Attu...

  2. CTD data - Pre-recruit surveys to aid stock assessment

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Annual surveys of juvenile fish and ecosystem status have been conducted since 2011 surveying the entire coast of Oregon and southern Washington. Trawl surveys are...

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

    Directory of Open Access Journals (Sweden)

    Obe Bernardine Wuraola

    2011-09-01

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

  4. Improving capacity of stock assessment for sea turtles: using ocean circulation modeling to inform genetic mixed stock analysis

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Genetic approaches have been useful for assigning stock ID to sea turtles caught as bycatch in fisheries, or determining stock composition at foraging grounds. In...

  5. 76 FR 34054 - Marine Mammal Stock Assessment Reports

    Science.gov (United States)

    2011-06-10

    ... describe the troll and charter boat fisheries and the practice of ``fishing'' dolphins, note the existence... fisheries. Response: Acknowledgement of anecdotal reports of bycatch of spotted dolphins by the Hawaii troll...) by the commercial and recreational troll fishery has also been noted in the SARs for...

  6. Data evaluation of data limited stocks: Dab, flounder, Witch, Lemon Sole, Brill, Turbot and Horse mackerel

    NARCIS (Netherlands)

    Hammen, van der T.; Poos, J.J.

    2012-01-01

    Several commercially important demersal fish stocks for the North Sea fisheries are classified by ICES (International Council for the Exploration of the Sea) as “data limited” stocks, which are stocks for which the data are insufficient to perform a full analytical assessment and forecast (ICES 2012

  7. A model of a fishery with fish stock involving delay equations.

    Science.gov (United States)

    Auger, P; Ducrot, Arnaud

    2009-12-13

    The aim of this paper is to provide a new mathematical model for a fishery by including a stock variable for the resource. This model takes the form of an infinite delay differential equation. It is mathematically studied and a bifurcation analysis of the steady states is fulfilled. Depending on the different parameters of the problem, we show that Hopf bifurcation may occur leading to oscillating behaviours of the system. The mathematical results are finally discussed.

  8. AFSC/REFM: Isolation by distance (IBD) Alaskan fish stock structure modeling (NCEI Accession 0130929)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This model study examines several management strategies for two marine fish species subject to isolation-by-distance (IBD): Pacific cod in the Aleutian Islands (AI)...

  9. Characterization, development and multiplexing of microsatellite markers in three commercially exploited reef fish and their application for stock identification

    Directory of Open Access Journals (Sweden)

    Laura Taillebois

    2016-08-01

    Full Text Available Thirty-four microsatellite loci were isolated from three reef fish species; golden snapper Lutjanus johnii, blackspotted croaker Protonibea diacanthus and grass emperor Lethrinus laticaudis using a next generation sequencing approach. Both IonTorrent single reads and Illumina MiSeq paired-end reads were used, with the latter demonstrating a higher quality of reads than the IonTorrent. From the 1–1.5 million raw reads per species, we successfully obtained 10–13 polymorphic loci for each species, which satisfied stringent design criteria. We developed multiplex panels for the amplification of the golden snapper and the blackspotted croaker loci, as well as post-amplification pooling panels for the grass emperor loci. The microsatellites characterized in this work were tested across three locations of northern Australia. The microsatellites we developed can detect population differentiation across northern Australia and may be used for genetic structure studies and stock identification.

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

    Science.gov (United States)

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

    2008-01-01

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

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

    Science.gov (United States)

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

    2014-12-01

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

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

    Data.gov (United States)

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

  13. Climate change and credibility of fish stock agreements : the case of the north-east arctic cod

    OpenAIRE

    Ekerhovd, Nils-Arne

    2010-01-01

    We simulate how an increase in the productivity of the North-East Arctic cod stock would affect the Russian-Norwegian cooperation on the management of the stock. The productivity increase is linked to environmental conditions in the sea and to climate change through a temperature-dependent stock-recruitment relationship, where the numbers of recruits is positively related to the sea temperature given the spawning stock biomass. Increased recruitment and productivity of the stock improved the...

  14. Sources of errors and uncertainties in the assessment of forest soil carbon stocks at different scales

    DEFF Research Database (Denmark)

    Vanguelova, E. I.; Bonifacio, E.; De Vos, B.;

    2016-01-01

    for assessing SOC stocks with the highest possible accuracy at each scale. This review identifies where potential sources of errors and uncertainties related to forest SOC stock estimation occur at five different scales---sample, profile, plot, landscape/regional and European. Recommendations are also provided...... temporal changes and spatial differences in SOC. This requires sufficiently detailed data to predict SOC stocks at appropriate scales within the required accuracy so that only significant changes are accounted for. When designing sampling campaigns, taking into account factors influencing SOC spatial...... and temporal distribution (such as soil type, topography, climate and vegetation) are needed to optimise sampling depths and numbers of samples, thereby ensuring that samples accurately reflect the distribution of SOC at a site. Furthermore, the appropriate scales related to the research question need...

  15. RMT Assessments of the Market Latent Information Embedded in the Stocks' Raw, Normalized, and Partial Correlations

    Directory of Open Access Journals (Sweden)

    Dror Y. Kenett

    2009-01-01

    Full Text Available We present here assessment of the latent market information embedded in the raw, affinity (normalized, and partial correlations. We compared the Zipf plot, spectrum, and distribution of the eigenvalues for each matrix with the results of the corresponding random matrix. The analysis was performed on stocks belonging to the New York and Tel Aviv Stock Exchange, for the time period of January 2000 to March 2009. Our results show that in comparison to the raw correlations, the affinity matrices highlight the dominant factors of the system, and the partial correlation matrices contain more information. We propose that significant stock market information, which cannot be captured by the raw correlations, is embedded in the affinity and partial correlations. Our results further demonstrate the differences between NY and TA markets.

  16. 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)

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

    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.

  17. A framework for assessing global change risks to forest carbon stocks in the United States.

    Directory of Open Access Journals (Sweden)

    Christopher W Woodall

    Full Text Available 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 context of global change across the US. For the purposes of this analysis, forest C was divided into five pools, two live (aboveground and belowground biomass and three dead (dead wood, soil organic matter, and forest floor with a risk framework parameterized using the US's national greenhouse gas inventory and associated forest inventory data across current and projected future Köppen-Geiger climate zones (A1F1 scenario. Results suggest that an initial forest C risk matrix may be constructed to focus attention on short- and long-term risks to forest C stocks (as opposed to implementation in decision making using inventory-based estimates of total stocks and associated estimates of variability (i.e., coefficient of variation among climate zones. The empirical parameterization of such a risk matrix highlighted numerous knowledge gaps: 1 robust measures of the likelihood of forest C stock change under climate change scenarios, 2 projections of forest C stocks given unforeseen socioeconomic conditions (i.e., land-use change, and 3 appropriate social responses to global change events for which there is no contemporary climate/disturbance analog (e.g., severe droughts in the Lake States. Coupling these current technical/social limits of developing a risk matrix to the biological processes of forest ecosystems (i.e., disturbance events and interaction among diverse forest C pools, potential positive feedbacks, and forest resiliency/recovery suggests an operational

  18. A framework for assessing global change risks to forest carbon stocks in the United States.

    Science.gov (United States)

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

    2013-01-01

    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 context of global change across the US. For the purposes of this analysis, forest C was divided into five pools, two live (aboveground and belowground biomass) and three dead (dead wood, soil organic matter, and forest floor) with a risk framework parameterized using the US's national greenhouse gas inventory and associated forest inventory data across current and projected future Köppen-Geiger climate zones (A1F1 scenario). Results suggest that an initial forest C risk matrix may be constructed to focus attention on short- and long-term risks to forest C stocks (as opposed to implementation in decision making) using inventory-based estimates of total stocks and associated estimates of variability (i.e., coefficient of variation) among climate zones. The empirical parameterization of such a risk matrix highlighted numerous knowledge gaps: 1) robust measures of the likelihood of forest C stock change under climate change scenarios, 2) projections of forest C stocks given unforeseen socioeconomic conditions (i.e., land-use change), and 3) appropriate social responses to global change events for which there is no contemporary climate/disturbance analog (e.g., severe droughts in the Lake States). Coupling these current technical/social limits of developing a risk matrix to the biological processes of forest ecosystems (i.e., disturbance events and interaction among diverse forest C pools, potential positive feedbacks, and forest resiliency/recovery) suggests an operational forest C

  19. Fish stomach contents in benthic macroinvertebrate assemblage assessments

    Directory of Open Access Journals (Sweden)

    TH. Tupinambás

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

  20. Assessment of Carbon Stocks in the Topsoil Using Random Forest and Remote Sensing Images.

    Science.gov (United States)

    Kim, Jongsung; Grunwald, Sabine

    2016-11-01

    Wetland soils are able to exhibit both consumption and production of greenhouse gases, and they play an important role in the regulation of the global carbon (C) cycle. Still, it is challenging to accurately evaluate the actual amount of C stored in wetlands. The incorporation of remote sensing data into digital soil models has great potential to assess C stocks in wetland soils. Our objectives were (i) to develop C stock prediction models utilizing remote sensing images and environmental ancillary data, (ii) to identify the prime environmental predictor variables that explain the spatial distribution of soil C, and (iii) to assess the amount of C stored in the top 20-cm soils of a prominent nutrient-enriched wetland. We collected a total of 108 soil cores at two soil depths (0-10 cm and 10-20 cm) in the Water Conservation Area 2A, FL. We developed random forest models to predict soil C stocks using field observation data, environmental ancillary data, and spectral data derived from remote sensing images, including Satellite Pour l'Observation de la Terre (spatial resolution: 10 m), Landsat Enhanced Thematic Mapper Plus (30 m), and Moderate Resolution Imaging Spectroradiometer (250 m). The random forest models showed high performance to predict C stocks, and variable importance revealed that hydrology was the major environmental factor explaining the spatial distribution of soil C stocks in Water Conservation Area 2A. Our results showed that this area stores about 4.2 Tg (4.2 Mt) of C in the top 20-cm soils.

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

    Energy Technology Data Exchange (ETDEWEB)

    Holderman, Charles

    2009-06-26

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

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

    Science.gov (United States)

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

    2009-04-01

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

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

    Directory of Open Access Journals (Sweden)

    Luis Fernando da Silva Rodrigues-Filho

    2009-01-01

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

  4. Division of Aquatic Resources (DAR), Division of Lands and Natural Resources (DLNR) of the State of Hawaii Fish Stock Surveys from 41 sites on Oahu and Island of Hawaii from 1952-2000 (NODC Accession 0002754)

    Data.gov (United States)

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

  5. Developing Cost-Effective Field Assessments of Carbon Stocks in Human-Modified Tropical Forests.

    Directory of Open Access Journals (Sweden)

    Erika Berenguer

    Full Text Available Across the tropics, there is a growing financial investment in activities that aim to reduce emissions from deforestation and forest degradation, such as REDD+. However, most tropical countries lack on-the-ground capacity to conduct reliable and replicable assessments of forest carbon stocks, undermining their ability to secure long-term carbon finance for forest conservation programs. Clear guidance on how to reduce the monetary and time costs of field assessments of forest carbon can help tropical countries to overcome this capacity gap. Here we provide such guidance for cost-effective one-off field assessments of forest carbon stocks. We sampled a total of eight components from four different carbon pools (i.e. aboveground, dead wood, litter and soil in 224 study plots distributed across two regions of eastern Amazon. For each component we estimated survey costs, contribution to total forest carbon stocks and sensitivity to disturbance. Sampling costs varied thirty-one-fold between the most expensive component, soil, and the least, leaf litter. Large live stems (≥10 cm DBH, which represented only 15% of the overall sampling costs, was by far the most important component to be assessed, as it stores the largest amount of carbon and is highly sensitive to disturbance. If large stems are not taxonomically identified, costs can be reduced by a further 51%, while incurring an error in aboveground carbon estimates of only 5% in primary forests, but 31% in secondary forests. For rapid assessments, necessary to help prioritize locations for carbon- conservation activities, sampling of stems ≥20cm DBH without taxonomic identification can predict with confidence (R2 = 0.85 whether an area is relatively carbon-rich or carbon-poor-an approach that is 74% cheaper than sampling and identifying all the stems ≥10cm DBH. We use these results to evaluate the reliability of forest carbon stock estimates provided by the IPCC and FAO when applied to human

  6. Assessment of soil organic carbon stocks under future climate and land cover changes in Europe.

    Science.gov (United States)

    Yigini, Yusuf; Panagos, Panos

    2016-07-01

    Soil organic carbon plays an important role in the carbon cycling of terrestrial ecosystems, variations in soil organic carbon stocks are very important for the ecosystem. In this study, a geostatistical model was used for predicting current and future soil organic carbon (SOC) stocks in Europe. The first phase of the study predicts current soil organic carbon content by using stepwise multiple linear regression and ordinary kriging and the second phase of the study projects the soil organic carbon to the near future (2050) by using a set of environmental predictors. We demonstrate here an approach to predict present and future soil organic carbon stocks by using climate, land cover, terrain and soil data and their projections. The covariates were selected for their role in the carbon cycle and their availability for the future model. The regression-kriging as a base model is predicting current SOC stocks in Europe by using a set of covariates and dense SOC measurements coming from LUCAS Soil Database. The base model delivers coefficients for each of the covariates to the future model. The overall model produced soil organic carbon maps which reflect the present and the future predictions (2050) based on climate and land cover projections. The data of the present climate conditions (long-term average (1950-2000)) and the future projections for 2050 were obtained from WorldClim data portal. The future climate projections are the recent climate projections mentioned in the Fifth Assessment IPCC report. These projections were extracted from the global climate models (GCMs) for four representative concentration pathways (RCPs). The results suggest an overall increase in SOC stocks by 2050 in Europe (EU26) under all climate and land cover scenarios, but the extent of the increase varies between the climate model and emissions scenarios.

  7. California Fish Passage Assessment Database [ds69

    Data.gov (United States)

    California Department of Resources — The Passage Assessment Database shapefile contains locations of known and potential barriers to salmonid migration in California streams with additional information...

  8. Stable Oxygen and Carbon Isotope Methods in Identification of Fish Stocks%鱼群识别的氧、碳稳定同位素方法

    Institute of Scientific and Technical Information of China (English)

    高永文; 鲁安怀; 王清印; 张慧琴

    2011-01-01

    鱼群识别是渔业科学和管理上的重要课题之一.本文以海鱼和迎游鱼的具体研究为例,扼要地阐明鱼耳石的氧、碳稳定同位素成分研究,特别是δ18O和813C的关联分析,在鱼群识别方面的效果和应用.鱼耳石是一种存在于真骨鱼类内耳中层状的,矿物成分以文石为主的钙碳酸盐岩结构体.与基因分析方法相比,鱼耳石的氧、碳稳定同位素方法具有两个显著的优点,一是耳石的微结构能提供鱼类不同生长阶段的时间序列和细节;二是耳石的形成机制能提供鱼类生活的周围环境和历史信息.因此,鱼耳石中δ18O和δ13C的关联分析在鱼群识别中发挥着独特的作用.%Identification of fish stocks is one of the most important tasks in fisheries science and management. In this paper,we illustrate the effect and application of stable oxygen and carbon isotopic composition of otoliths and the correlation of δ18O versus δ13C in identification of marine and anadromous fish stocks. Otoliths are aragonitic carbonate structures found in the inner ear of teleost fish and display rhythmic growth patterns. Compared with genetic methods in fish stock identification,stable oxygen and carbon isotope analyses have two distinct advantages in determining (1)a time series from the otolith microstructure to separation of the different life stages of marine and anadromous fish; and (2)the oceanographic and environmental conditions to which the fish were exposed. Thus,the isotopic signatures of otoliths and the correlation of δ1SO versus δ13C play a new and important role in identification of fish stocks.

  9. The Fish Bowl: A Strategy for Assessing Independent Reading.

    Science.gov (United States)

    Katz, Claudia Anne; Kuby, Sue Ann

    2001-01-01

    Explains Fish Bowl, an activity for upper elementary and middle school students to share what they read and a method for teachers to assess student understanding of a book. Discusses benefits of reading aloud a summary of the book, reading a passage from the book, asking appropriate questions, and answering questions. (LRW)

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

    Directory of Open Access Journals (Sweden)

    Phutchard Vicharnakorn

    2014-06-01

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

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

    Directory of Open Access Journals (Sweden)

    Goran Vujić

    2010-01-01

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

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

    Directory of Open Access Journals (Sweden)

    M. W. Warren

    2012-06-01

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

  13. Time changes in fishing power in the Danish cod fisheries of the Baltic Sea

    DEFF Research Database (Denmark)

    Marchal, P.; Nielsen, J. Rasmus; Hovgård, Holger;

    2001-01-01

    Using nominal fishing effort to control fishing mortality and using cpue data from commercial fisheries as abundance indices require ability to correct fishing power for temporal development. It is often assumed in ICES stock assessments that fishing power Is constant over time. However, experience...

  14. The Stock Potency of Demersal Fish Resource at The Coastal Zone, East Kutai District in East Kalimantan

    Directory of Open Access Journals (Sweden)

    Juliani Juliani

    2014-04-01

    Full Text Available The objective of this research was to estimate the potency of demersal fish resource spread over three sub-districts i.e. Sangkulirang, Sandaran and Kaliorang in Kutai district, East Kalimantan province. The result showed that the highest total biomass was produced by aquatic zone of Sandaran sub-district with 1,763,713.6 ton/zone and the density stock was 13,566.5 kg/km2. It was followed by Sangkulirang sub-district with 264,653.3 ton/zone and 6,640.4 kg/km2, respectively and then by Kaliorang sub-district with 58.086,5 ton/zone and 2,768.0 kg/km2, respectively. In term of species particularly from crustaseaae family, the most economic aquatic zone was found in Sangkulirang sub-district. The export product species Penaeus sp was obtained from Penaeus monodon, Metapenaeus monoceros, Metapenaeus sp, Parapenaeopsis sculptilis, Penaeus sp, and lobster which was accounted by 3,381.6 tons/zone, 83,199 tons/zone, 14,492.7 tons/zone, 24,691.3 tons/zone, 41,331.1 tons/zone, and 1,073.5 tons/zone, respectively. It was followed by Sandaran sub-district with export product species was Penaeus merguensis 33,495.7 tons/zone and non-export products were Parapenaeopsis sculptilis 63,641.7 tons/zone, Penaeus sp 16,747.8 tons/zone, Metapenaeus sp 1.674,8 tons/zone, Caridina sp 1.562.572,2 tons/zone, and Scylla serrata 3,349.6 tons/zone. Next was Kaliorang sub-district which accounted by Penaeus merguensis 62.2 tons/zone and Metapenaeus monoceros 49.7 tons/zone. In situ measurement on seven physical-chemical quality parameters of water which compared to the standardized of sea water showed that water quality found in coastal zone of Kaliorang, Sangkulirang and Sandaran sub-district, East Kutai province was suitable and feasible for the aquatic and living of marine habitats Normal 0 false false false IN X-NONE X-NONE

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

    Directory of Open Access Journals (Sweden)

    Cesare Zanasi

    2012-01-01

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

  16. Improving the assessment of instream flow needs for fish populations

    Energy Technology Data Exchange (ETDEWEB)

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

    1991-01-01

    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.

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

    Directory of Open Access Journals (Sweden)

    Lebedeva Lyudmyla M.

    2013-03-01

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

  18. Editorial note on reproductive biology of fishes

    OpenAIRE

    A. C. TSIKLIRAS; K. I. STERGIOU; Froese, Rainer

    2013-01-01

    Fish reproductive biology (onset and duration of spawning, sex ratio, maturity stages, length and age at maturity, and fecundity) is important in fisheries research, stock assessment, and management. In this editorial note, we provide some criteria and recommendations on issues of fish reproductive biology, which may be useful in research planning, data analysis and presentation, as well as in manuscript preparation.

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

    Energy Technology Data Exchange (ETDEWEB)

    Christian, Richard

    2004-02-01

    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

  20. Informing species conservation at multiple scales using data collected for marine mammal stock assessments.

    Directory of Open Access Journals (Sweden)

    Alana Grech

    Full Text Available BACKGROUND: Conservation planning and the design of marine protected areas (MPAs requires spatially explicit information on the distribution of ecological features. Most species of marine mammals range over large areas and across multiple planning regions. The spatial distributions of marine mammals are difficult to predict using habitat modelling at ecological scales because of insufficient understanding of their habitat needs, however, relevant information may be available from surveys conducted to inform mandatory stock assessments. METHODOLOGY AND RESULTS: We use a 20-year time series of systematic aerial surveys of dugong (Dugong dugong abundance to create spatially-explicit models of dugong distribution and relative density at the scale of the coastal waters of northeast Australia (∼136,000 km(2. We interpolated the corrected data at the scale of 2 km * 2 km planning units using geostatistics. Planning units were classified as low, medium, high and very high dugong density on the basis of the relative density of dugongs estimated from the models and a frequency analysis. Torres Strait was identified as the most significant dugong habitat in northeast Australia and the most globally significant habitat known for any member of the Order Sirenia. The models are used by local, State and Federal agencies to inform management decisions related to the Indigenous harvest of dugongs, gill-net fisheries and Australia's National Representative System of Marine Protected Areas. CONCLUSION/SIGNIFICANCE: In this paper we demonstrate that spatially-explicit population models add value to data collected for stock assessments, provide a robust alternative to predictive habitat distribution models, and inform species conservation at multiple scales.

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

    Data.gov (United States)

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

  2. Probabilistic ecorisk assessment for fish, mammals, and birds at the Great Dismal Swamp National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The primary objective of this study was to conduct a probabilistic ecological risk assessment for birds and evaluate risk to fish and mammals that may be exposed to...

  3. Big Oaks National Wildlife Refuge : Environmental Action Statement, Environmental Assessment, Interim Hunting and Fishing Plan : 2004

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document contains the Environmental Action Statement, Environmental Assessment, and Interim Hunting and Fishing Plan for Big Oaks National Wildlife Refuge from...

  4. Environmental Assessment Pondicherry Division Silvio O. National Fish and Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — In the September 2, 2003, Environmental Assessment, the U.S. Fish and Wildlife Service (Service) considered the environmental effects of acquiring 4,004 acres (+1-)...

  5. Water Resource Inventory and Assessment (WRIA)- Big Muddy National Fish & Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This Water Resource Inventory and Assessment (WRIA) Summary Report for Big Muddy National Fish & Wildlife Refuge describes current hydrologic information,...

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

    DEFF Research Database (Denmark)

    Jørgensen, Ole A; Treble, M.A.

    2014-01-01

    The paper presents the background and the input parameters from research surveys and the commercial fishery to the assessment of the Greenland halibut stock component in NAFO Subarea 0 + Div. 1A offshore + Div. 1B-1F. During 2006-2009 catches have been around 24,000 tons. Catches increased to 26 ...

  7. 76 FR 61092 - Stock Assessment Reports for Dusky, Sandbar, and Blacknose Sharks in the U.S. Atlantic and Gulf...

    Science.gov (United States)

    2011-10-03

    ..., and Blacknose Sharks in the U.S. Atlantic and Gulf of Mexico AGENCY: National Marine Fisheries Service... blacknose sharks in the Atlantic and Gulf of Mexico. The reports summarize the consensus of an independent... final stock assessment reports for dusky, sandbar, and blacknose sharks should be sent to Peter...

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

    DEFF Research Database (Denmark)

    Laugen, Ane T.; Engelhard, Georg H.; Whitlock, Rebecca

    2014-01-01

    Managing fisheries resources to maintain healthy ecosystems is one of the main goals of the ecosystem approach to fisheries (EAF). While a number of international treaties call for the implementation of EAF, there are still gaps in the underlying methodology. One aspect that has received substant...... 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......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...... 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...

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

    Science.gov (United States)

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

    2008-02-01

    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”, β obeys Γ-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 β model, and empirically examine the agreement between the model and an imaginary portfolio with Dow Jones indices. It turns out that the single β model gives good approximation to portfolios composed of the assets with non-Gaussian and correlated returns.

  10. Challenging the knowledge bio-based fisheries of tropical tuna stocks: assessing genomic population structure in yellowfin (Thunnus albacares

    Directory of Open Access Journals (Sweden)

    Carlo Pecoraro

    2014-06-01

    The YFT genetic population structure will be investigated at global scale (between- and within-ocean, using next-generation sequencing (2b-RAD method for genotyping by sequencing through examination of Single Nucleotide Polymorphisms (SNPs. This approach can represent a major advancement over classical techniques used until now (i.e. based on allozymes, DNA microsatellites and mitochondrial DNA in order to reveal the YFT stock structure between and within each ocean. The novel genomic data that will be generated can potentially reveal YFT population structure at a level not possible through classical latter approaches with significant implication for YFT stock assessment and management. In fact a carelessness of the proper genetic structure might lead to the over-exploitation and depletion of some populations with dramatic consequences for the long-term conservation and sustainable use of YFT stocks.

  11. Application of a Delay-Difference Model for the Stock Assessment of Southern Atlantic Albacore (Thunnus alalunga)

    Institute of Scientific and Technical Information of China (English)

    ZHANG Kui; LIU Qun; KALHORO Muhsan Ali

    2015-01-01

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

  12. Stock assessment of Haliporoides triarthrus (Fam. Solenoceridae) off Mozambique: a preliminary analysis

    OpenAIRE

    Torstensen, E.; Pacule, H.

    1992-01-01

    The pink shrimp, Haliporoides triarthrus, is an important species in the deep-water shrimp fishery in Mozambique. Total catches are in the range of 1,500 to 2,700 tons, with the pink shrimp accounting for 70-90%. Estimates of growth parameters and of natural mortality are used for a preliminary assessment of the fishery, based on length-structured virtual population analysis and yield-per-recruit analyses. With an arbitrarily chosen terminal fishing mortality F, the results indicate a situati...

  13. Genetic stock assessment of spawning arctic cisco (Coregonus autumnalis) populations by flow cytometric determination of DNA content.

    Science.gov (United States)

    Lockwood, S F; Bickham, J W

    1991-01-01

    Intraspecific variation in cellular DNA content was measured in five Coregonus autumnalis spawning populations from the Mackenzie River drainage, Canada, using flow cytometry. The rivers assayed were the Peel, Arctic Red, Mountain, Carcajou, and Liard rivers. DNA content was determined from whole blood preparations of fish from all rivers except the Carcajou, for which kidney tissue was used. DNA content measurements of kidney and blood preparations of the same fish from the Mountain River revealed statistically indistinguishable results. Mosaicism was found in blood preparations from the Peel, Arctic Red, Mountain, and Liard rivers, but was not observed in kidney tissue preparations from the Mountain or Carcajou rivers. The Liard River sample had significantly elevated mean DNA content relative to the other four samples; all other samples were statistically indistinguishable. Significant differences in mean DNA content among spawning stocks of a single species reinforces the need for adequate sample sizes of both individuals and populations when reporting "C" values for a particular species.

  14. Effect of stocking densities on growth, production and survival rate of red tilapia in hapa at fish hatchery Chilya Thatta, Sindh, Pakistan

    Directory of Open Access Journals (Sweden)

    Abdul Malik Daudpota

    2014-12-01

    Full Text Available Effect of stocking density on growth, production and survival of red tilapia (Oreochromis mossambicus × O. niloticus were conducted in hapa for 60 days at Chilya Thatta. Tilapia fry (4.5±0.02 cm, 2.0±0.01 g were stocked into hapa (4.5x2.4x1 m. Three treatments with two replicates were used: T1-200; T2-250 and T3-300 fry/hapa. Fry were fed twice a daily with pelleted feed containing 35% protein, 5% of total biomass. After 60 days, the highest growth were determined in T1 (49.8±0.0 g while in T3 lowest growth (29.09±0.0 g was recorded. Production (9.56, 10.13 and 8.12 kg/m3/60days in T1, T2 and T3 respectively were significantly different (P0.05. Survival was significantly different among treatments (P<0.01. Highest survival (100% was attained in T1 with lower stocking density, followed by T2 (98% and T3 (95%. Water quality parameters recorded throughout the study period were found within the ranges for fish culture such as temperature 27.2 to 28.5 °C, dissolved oxygen 5.8 to 6.4 mg/l, pH 6.9 to 7.6, ammonia from 0.45 to 0.51 mg/l, hardness 106 to 110 ppm and nitrite 0.151 to 0.162 mg/l.

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

    Directory of Open Access Journals (Sweden)

    Calcagnotto Daniela

    2000-01-01

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

  16. AVALIAÇÃO DA AQUISIÇÃO, ESTOCAGEM E VENDA DE PEIXES EM UM ESTABELECIMENTO DE PESCA ESPORTIVA EVALUATION OF ACQUISITION, STOCKING AND SALE OF FISH IN A SPORTIVE FISHING ENTERPRISE

    Directory of Open Access Journals (Sweden)

    Eduardo Gomes Sanches

    2009-07-01

    Full Text Available Analisou-se a dinâmica de movimentação de peixes (aquisição, estocagem e venda em um empreendimento de pesca esportiva do tipo “pesque e solte”. No período compreendido entre outubro de 1999 e dezembro de 2003 foram realizadas visitas mensais a um empreendimento situado na Via Castelo Branco, no Estado de São Paulo, efetuando-se o levantamento dos dados a partir das “comandas de venda” e das notas fiscais de compra de peixes. Obtiveram-se, para cada espécie citada, as quantidades (em quilos adquiridas pelo pesqueiro (entrada de peixes e pelos clientes-pescadores (saída de peixes, cujo número também se registrou. Tais dados permitiram determinar a aquisição média de peixes por pescador por mês, conhecer as épocas de maior frequência de público, as espécies preferidas para aquisição, a biomassa estocada no viveiro etc. O acompanhamento mostrou que a dinâmica de movimentação de peixes praticada leva à imobilização de capital, põe em risco a segurança sanitária do plantel e torna a propriedade uma exportadora de poluição via água de despejo. Os parâmetros para a seleção das espécies, as técnicas de manejo, bem como os estímulos oferecidos à aquisição dos exemplares pescados são insuficientes, conspirando para a perda de rentabilidade do empreendimento. O povoamento com novos exemplares deve obedecer ao ritmo de saída (pesca/venda dos peixes, evitando-se ultrapassar a capacidade de suporte do viveiro. Portanto, não se deve ter na disponibilidade de exemplares por m3 o único fator para aumentar a captura por unidade de esforço de pesca, pois isso pode levar a um aumento descontrolado da população total do viveiro.
     
    PALAVRAS-CHAVES: Aquisição, estocagem, venda, pesca esportiva, pesque-pague. The dynamics of the movement of fish was analyzed (acquisition, stock and sale in a enterprise of sporting fishing or “fee fishing”. In the period understood between October of 1999 and

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

    Directory of Open Access Journals (Sweden)

    Antonio Di Franco

    Full Text Available 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

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

    Science.gov (United States)

    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

    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

  19. Assessing Dispersal Patterns of Fish Propagules from an Effective Mediterranean Marine Protected Area

    Science.gov (United States)

    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

    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

  20. Assessing potential health risks to fish and humans using mercury concentrations in inland fish from across western Canada and the United States

    Science.gov (United States)

    Lepak, Jesse M; Hooten, Mevin B.; Eagles-Smith, Collin A.; Tate, Michael T.; Lutz, Michelle A.; Ackerman, Joshua T.; Willacker, James J.; Jackson, Allyson K.; Evers, David C.; Wiener, James G.; Pritz, Colleen Flanagan; Davis, Jay

    2016-01-01

    Fish represent high quality protein and nutrient sources, but Hg contamination is ubiquitous in aquatic ecosystems and can pose health risks to fish and their consumers. Potential health risks posed to fish and humans by Hg contamination in fish were assessed in western Canada and the United States. A large compilation of inland fish Hg concentrations was evaluated in terms of potential health risk to the fish themselves, health risk to predatory fish that consume Hg contaminated fish, and to humans that consume Hg contaminated fish. The probability that a fish collected from a given location would exceed a Hg concentration benchmark relevant to a health risk was calculated. These exceedance probabilities and their associated uncertainties were characterized for fish of multiple size classes at multiple health-relevant benchmarks. The approach was novel and allowed for the assessment of the potential for deleterious health effects in fish and humans associated with Hg contamination in fish across this broad study area. Exceedance probabilities were relatively common at low Hg concentration benchmarks, particularly for fish in larger size classes. Specifically, median exceedances for the largest size classes of fish evaluated at the lowest Hg concentration benchmarks were 0.73 (potential health risks to fish themselves), 0.90 (potential health risk to predatory fish that consume Hg contaminated fish), and 0.97 (potential for restricted fish consumption by humans), but diminished to essentially zero at the highest benchmarks and smallest fish size classes. Exceedances of benchmarks are likely to have deleterious health effects on fish and limit recommended amounts of fish humans consume in western Canada and the United States. Results presented here are not intended to subvert or replace local fish Hg data or consumption advice, but provide a basis for identifying areas of potential health risk and developing more focused future research and monitoring efforts.

  1. Fish Creek Federally Endangered Freshwater Mussel Impact Assessment

    Data.gov (United States)

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

  2. Microbiological Quality Assessment of Frozen Fish and Fish Processing Materials from Bangladesh

    Science.gov (United States)

    Sanjee, Sohana Al; Karim, Md. Ekramul

    2016-01-01

    The present study aims at the microbiological analysis of export oriented frozen fishes, namely, Jew fish, Tongue Sole fish, Cuttle fish, Ribbon fish, Queen fish, and fish processing water and ice from a view of public health safety and international trade. Microbiological analysis includes the determination of total viable aerobic count by standard plate count method and enumeration of total coliforms and fecal coliforms by most probable number method. The presence of specific fish pathogens such as Salmonella spp. and Vibrio cholerae were also investigated. The TVAC of all the samples was estimated below 5 × 105 cfu/g whereas the total coliforms and fecal coliforms count were found below 100 MPN/g and 10 MPN/g, respectively, which meet the acceptable limit specified by International Commission of Microbiological Specification for Food. The microbiological analysis of water and ice also complies with the specifications having TVAC < 20 cfu/mL, and total coliforms and fecal coliforms count were below the limit detection of the MPN method. Specific fish pathogens such as Salmonella sp. and V. cholerae were found absent in all the samples under the investigation. From this study, it can be concluded that the investigated frozen fishes were eligible for export purpose and also safe for human consumption. PMID:27019847

  3. Microbiological Quality Assessment of Frozen Fish and Fish Processing Materials from Bangladesh

    Directory of Open Access Journals (Sweden)

    Sohana Al Sanjee

    2016-01-01

    Full Text Available The present study aims at the microbiological analysis of export oriented frozen fishes, namely, Jew fish, Tongue Sole fish, Cuttle fish, Ribbon fish, Queen fish, and fish processing water and ice from a view of public health safety and international trade. Microbiological analysis includes the determination of total viable aerobic count by standard plate count method and enumeration of total coliforms and fecal coliforms by most probable number method. The presence of specific fish pathogens such as Salmonella spp. and Vibrio cholerae were also investigated. The TVAC of all the samples was estimated below 5×105 cfu/g whereas the total coliforms and fecal coliforms count were found below 100 MPN/g and 10 MPN/g, respectively, which meet the acceptable limit specified by International Commission of Microbiological Specification for Food. The microbiological analysis of water and ice also complies with the specifications having TVAC<20 cfu/mL, and total coliforms and fecal coliforms count were below the limit detection of the MPN method. Specific fish pathogens such as Salmonella sp. and V. cholerae were found absent in all the samples under the investigation. From this study, it can be concluded that the investigated frozen fishes were eligible for export purpose and also safe for human consumption.

  4. Microbiological Quality Assessment of Frozen Fish and Fish Processing Materials from Bangladesh.

    Science.gov (United States)

    Sanjee, Sohana Al; Karim, Md Ekramul

    2016-01-01

    The present study aims at the microbiological analysis of export oriented frozen fishes, namely, Jew fish, Tongue Sole fish, Cuttle fish, Ribbon fish, Queen fish, and fish processing water and ice from a view of public health safety and international trade. Microbiological analysis includes the determination of total viable aerobic count by standard plate count method and enumeration of total coliforms and fecal coliforms by most probable number method. The presence of specific fish pathogens such as Salmonella spp. and Vibrio cholerae were also investigated. The TVAC of all the samples was estimated below 5 × 10(5) cfu/g whereas the total coliforms and fecal coliforms count were found below 100 MPN/g and 10 MPN/g, respectively, which meet the acceptable limit specified by International Commission of Microbiological Specification for Food. The microbiological analysis of water and ice also complies with the specifications having TVAC coliforms and fecal coliforms count were below the limit detection of the MPN method. Specific fish pathogens such as Salmonella sp. and V. cholerae were found absent in all the samples under the investigation. From this study, it can be concluded that the investigated frozen fishes were eligible for export purpose and also safe for human consumption.

  5. A test for the relative strength of maternal and stock effects in spring Chinook salmon (Oncorhynchus tshawytscha) from two different hatcheries (Study site: Warm Springs Hatchery; Stocks: Warm Springs Hatchery and Carson Hatchery; Year class: 1993): Chapter 10

    Science.gov (United States)

    Wetzel, Lisa A.; Rubin, Stephen P.; Reisenbichler, Reginald R.; Stenberg, Karl D.; Rubin, Stephen P.; Reisenbichler, Reginald R.; Wetzel, Lisa A.; Hayes, Michael C.

    2012-01-01

    An experiment was undertaken to determine the relative strength of maternal and stock effects in Chinook salmon (Oncorhynchus tshawytscha) reared in a common environment, as a companion study to our investigation of hatchery and wild Chinook salmon. Pure-strain and reciprocal crosses were made between two hatchery stocks (Carson and Warm Springs National Fish Hatcheries). The offspring were reared together in one of the hatcheries to the smolt stage, and then were transferred to a seawater rearing facility (USGS-Marrowstone Field Station). Differences in survival, growth and disease prevalence were assessed. Fish with Carson parentage grew to greater size at the hatchery and in seawater than the pure-strain Warm Springs fish, but showed higher mortality at introduction to seawater. The analyses of maternal and stock effects were inconclusive, but the theoretical responses to different combinations of maternal and stock effects may be useful in interpreting stock comparison studies.

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

    Data.gov (United States)

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

  7. Draft Alaska marine mammal stock assessments 1998, sea otters, polar bear and walrus

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The 1994 amendments to the Marine Mammal Protection Ad of 1972 (MMPA) included specific language requiring the U.S. Fish and Wildlife Service (FWS) and the National...

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

    Energy Technology Data Exchange (ETDEWEB)

    Jammazi, Rania, E-mail: jamrania2@yahoo.f [International finance group-Tunisia, Faculty of Management and Economic Sciences of Tunis, Boulevard du 7 novembre, El Manar University, B.P. 248, C.P. 2092, Tunis Cedex (Tunisia); Aloui, Chaker, E-mail: chaker.aloui@fsegt.rnu.t [International finance group-Tunisia, Faculty of Management and Economic Sciences of Tunis, Boulevard du 7 novembre, El Manar University, B.P. 248, C.P. 2092, Tunis Cedex (Tunisia)

    2010-03-15

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Jammazi, Rania; Aloui, Chaker [International finance group-Tunisia, Faculty of Management and Economic Sciences of Tunis, Boulevard du 7 novembre, El Manar University, B.P. 248, C.P. 2092, Tunis Cedex (Tunisia)

    2010-03-15

    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)

  10. Stock market

    OpenAIRE

    Pachlerová, Šárka

    2017-01-01

    This bachelor thesis deals with the stock market in the Czech republic. The first part of this work is focused on the characteristics concepts of the stock market. It is comprised of the definitions of the financial market, stocks, commodities, the stock exchange indexes and others. Introduction to the term Forex and definition of the types of stock exchanges and exchange trades. Introduction to the OTC trading and how the stock exchange work. In the analytical part there is introduction t...

  11. Preliminary assessment of factors influencing riverine fish communities in Massachusetts.

    Science.gov (United States)

    Armstrong, David S.; Richards, Todd A.; Brandt, Sara L.

    2010-01-01

    The U.S. Geological Survey, in cooperation with the Massachusetts Department of Conservation and Recreation (MDCR), Massachusetts Department of Environmental Protection (MDEP), and the Massachusetts Department of Fish and Game (MDFG), conducted a preliminary investigation of fish communities in small- to medium-sized Massachusetts streams. The objective of this investigation was to determine relations between fish-community characteristics and anthropogenic alteration, including flow alteration and impervious cover, relative to the effect of physical basin and land-cover (environmental) characteristics. Fish data were obtained for 756 fish-sampling sites from the Massachusetts Division of Fisheries and Wildlife fish-community database. A review of the literature was used to select a set of fish metrics responsive to flow alteration. Fish metrics tested include two fish-community metrics (fluvial-fish relative abundance and fluvial-fish species richness), and five indicator species metrics (relative abundance of brook trout, blacknose dace, fallfish, white sucker, and redfin pickerel). Streamflows were simulated for each fish-sampling site using the Sustainable Yield Estimator application (SYE). Daily streamflows and the SYE water-use database were used to determine a set of indicators of flow alteration, including percent alteration of August median flow, water-use intensity, and withdrawal and return-flow fraction. The contributing areas to the fish-sampling sites were delineated and used with a Geographic Information System (GIS) to determine a set of environmental characteristics, including elevation, basin slope, percent sand and gravel, percent wetland, and percent open water, and a set of anthropogenic-alteration variables, including impervious cover and dam density. Two analytical techniques, quantile regression and generalized linear modeling, were applied to determine the association between fish-response variables and the selected environmental and

  12. Assessment of mercury intake associated with fish consumption in Serbia

    OpenAIRE

    Janković, Saša; Antonijević, Biljana; Ćurčić, Marijana; Radičević, Tatjana; Stefanović, Srđan; Nikolić, Dragica; Ćupić, Vitomir

    2012-01-01

    Nutritional benefits of fish can be attributed primarily to the content of high-quality proteins, vitamins, elements and omega-3 polyunsaturated fatty acids. On the other hand, fish and fishery products are susceptible to contamination by chemicals that have been recognized as ubiquitous environmental pollutants such as toxic elements and polychlorinated organic compounds. Fish consumption could be therefore considered as one of the major sources of human exposure to all above-mentioned envir...

  13. Careful risk assessment needed to evaluate transgenic fish

    OpenAIRE

    Van Eenennaam, Alison L.; Olin, Paul G.

    2006-01-01

    The reproductive biology of fish makes them particularly amenable to genetic manipulation. A genetically engineered or “transgenic” Atlantic salmon is currently undergoing federal regulatory review, and international research is being conducted on many other species. The innate ability of fish to escape confinement and potentially invade native ecosystems elevates the ecological concerns associated with their genetic modification. Escaped transgenic fish will not invariably result in deleteri...

  14. Contribution of conservation genetics in assessing neotropical freshwater fish biodiversity

    Directory of Open Access Journals (Sweden)

    NM. Piorski

    Full Text Available Human activities have a considerable impact on hydrographic systems and fish fauna. The present review on conservation genetics of neotropical freshwater fish reveals that DNA analyses have been promoting increased knowledge on the genetic structure of fish species and their response to environmental changes. This knowledge is fundamental to the management of wild fish populations and the establishment of Evolutionary Significant Units capable of conserving genetic integrity. While population structuring can occur even in long-distance migratory fish, isolated populations can show reduced genetic variation and be at greater risk of extinction. Phylogeography and phylogeny have been powerful tools in understanding the evolution of fish populations, species and communities in distinct neotropic environments. Captive fish can be used to introduce new individuals and genes into the wild and their benefits and disadvantages can be monitored through genetic analysis. Understanding how fish biodiversity in neotropical freshwaters is generated and maintained is highly important, as these habitats are transformed by human development and fish communities are increasingly exploited as food sources to sustain a growing human population.

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

    Directory of Open Access Journals (Sweden)

    José Antonio Morales Castro

    2014-12-01

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

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

    DEFF Research Database (Denmark)

    Teschner, E.C.; Kraus, G.; Neuenfeldt, Stefan

    2010-01-01

    for organisms living under these conditions. For cod e.g. a direct relationship between oxygen availability and food intake with a decreasing ingestion rate at hypoxia could be revealed. In the present study, the effects of oxygen deficiency on consumption rates were investigated and how these translate...... to stock size estimates in multi-species models. Based on results from laboratory experiments, a model was fitted to evacuation rates at different oxygen levels and integrated into the existing consumption model for Baltic cod. Individual mean oxygen corrected consumption rates were 0.1–10.9% lower than...... the uncorrected ones. At the currently low predator stock size, however, the effect of oxygen-reduced consumption on the total amount of eaten prey biomass and thus predation mortalities was only marginal. But should successful management lead to higher cod stock sizes in the future, then total predation...

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

    Science.gov (United States)

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

    2014-09-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    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

    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.

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

    Science.gov (United States)

    Arreguín-Sánchez, F; Solís-Ramírez, M J; González de la Rosa, M E

    2000-01-01

    The octopus (Octopus maya) is one of the most important fish resources in the Mexican Gulf of Mexico with a mean annual yield of 9000 ton, and a reasonable number of jobs created; O. maya represents 80% of the total octopus catch, followed by Octopus vulgaris. There are two artisanal fleets based on Octopus maya and a middle-size fleet that covers both species. Catch-at-length structured data from the artisanal fleets, for the 1994 season (August 1st to December 15th) were used to analyze the O. maya population dynamics and stock and to estimate the current level of exploitation. Von Bertalanffy growth parameters were: L infinity = 252 mm, mantle length; K = 1.4 year-1; oscillation parameters C = 1.0, WP = 0.6; and tz = 0.842 years. A rough estimate of natural mortality was M = 2.2, total mortality from catch curve Z = 8.77, and exploitation rate F/Z = 0.75. This last value suggests an intensive exploitation, even when yield per recruit analysis indicates both fleets may increase the minimum legal size on about 10% to increase yields. The length-based VPA also shows that the stock is being exploited under its maximum acceptable biological limit. These apparently contradictory results are explained by biological and behavioral characteristics of this species. Because most females die after reproduction, a new gross estimation of natural mortality was computed as M = 3.3. The new estimate of exploitation rate was F/Z = 0.57. This new value coincides with results from the length-VPA and the Thompson and Bell methods, the former suggesting that a reduction of 20% in fishing mortality may provide larger yields. This fishery resource is fully exploited and current management measures must be revised to sustain and probably optimize yields.

  20. Molecular cytogenetics of pituitary adenomas, assessed by FISH technique.

    Science.gov (United States)

    Kontogeorgos, George

    2004-01-01

    Fluorescent in situ hybridization (FISH) represents a moden molecular pathology technique, alternative to conventional cytogenetics (karyotyping). In addition to metaphase spreads, it can be applied directly to interphase nuclei. The latter makes the FISH technique powerful for pathologists for it integrates molecular genetics and classic cytogenetics and brings them together to a single framework for morphologic evaluation. Interphase FISH can be applied to imprints from fresh tissue or to paraffin sections after proteinase K digestion. Centromeric, telomeric and locus DNA-sequence specific probes can be used to identify aneuploidy or gene mutations. Several protocols combine molecular cytogenetics with classic karyotyping. Other sophisticated, FISH-based protocols have been introduced. Among them, comparative genomic hybridization is very important for it can detect non-balanced chromosomal aberrations of uncultured tumor cells and provide overall genomic information in a single experiment. This review presents the principles and applications of FISH technique for the investigation of the cytogenetic background of pituitary adenomas.

  1. Efficiency comparisons of fish sampling gears for a lentic ecosystem health assessments in Korea

    Directory of Open Access Journals (Sweden)

    Jeong-Ho Han

    2016-12-01

    Full Text Available The key objective of this study was to analyze the sampling efficiency of various fish sampling gears for a lentic ecosystem health assessment. A fish survey for the lentic ecosystem health assessment model was sampled twice from 30 reservoirs during 2008–2012. During the study, fishes of 81 species comprising 53,792 individuals were sampled from 30 reservoirs. A comparison of sampling gears showed that casting nets were the best sampling gear with high species richness (69 species, whereas minnow traps were the worst gear with low richness (16 species. Fish sampling efficiency, based on the number of individual catch per unit effort, was best in fyke nets (28,028 individuals and worst in minnow traps (352 individuals. When we compared trammel nets and kick nets versus fyke nets and casting nets, the former were useful in terms of the number of fish individuals but not in terms of the number of fish species.

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

    Science.gov (United States)

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

    2015-08-01

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

  3. Stock Markets

    Institute of Scientific and Technical Information of China (English)

    亚玲

    2005-01-01

    There are stock markets in large cities in many countries. Stock markets in Paris, London, Tokyo, Shanghai and New York are among the largest and most well-known. The stock market, also called stock exchange, is a place where people can buy or sell shares of a factory or company. And each share means certain ownership of a factory or company.

  4. Assessment of Bioaerosol concentrations in a live stocks industrial slaughterhouse in Shiraz

    Directory of Open Access Journals (Sweden)

    A Kasaei nasab

    2013-05-01

    .Conclusion: Bioaerosols concentration in live stocks industrial slaughterhouse is higher than the threshold limit and suggested range. Therefore, it is essential to take measures, such as improving the process and technical-engineering interventions including the use of suitable ventilation systems and also management personal monitoring measures.

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

    Science.gov (United States)

    Menezes, Rui; Oliveira, Álvaro

    2015-04-01

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

  6. Stock market synchronicity: an alternative approach to assessing the information impact of Australian IFRS

    NARCIS (Netherlands)

    S. Bissessur; A. Hodgson

    2012-01-01

    How has the mandatory adoption in 2005 of International Financial Reporting Standards in (IFRS) affected information flow for investors in Australia? This paper investigates impact by examining synchronicity issues. Morck et al. (2000) label the degree to which stock prices depend upon market and in

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

    Directory of Open Access Journals (Sweden)

    Jan A. Venter

    2012-09-01

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

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

    Directory of Open Access Journals (Sweden)

    Rašković Božidar S.

    2011-01-01

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

  9. Assessment of Radiation and Heavy Metals Risk due to the Dietary Intake of Marine Fishes (Rastrelliger kanagurta) from the Straits of Malacca.

    Science.gov (United States)

    Khandaker, M U; Asaduzzaman, Kh; Nawi, S M; Usman, A R; Amin, Y M; Daar, E; Bradley, D A; Ahmed, H; Okhunov, A A

    2015-01-01

    The environment of the Straits of Malacca receives pollution as a result of various industrial and anthropogenic sources, making systematic studies crucial in determining the prevailing water quality. Present study concerns concentrations of natural radionuclides and heavy metals in marine fish (Rastrelliger kanagurta) collected from the Straits of Malacca, since aquatic stock form an important source of the daily diet of the surrounding populace. Assessment was made of the concentrations of key indicator radionuclides (226Ra, 232Th, 40K) and heavy metals (As, Mn, Fe, Cr, Ni, Zn, Cu, Co, Sr, Al, Hg and Pb) together with various radiation indices linked to the consumption of seafish. The annual effective dose for all detected radionuclides for all study locations has been found to be within UNSCEAR acceptable limits as has the associated life-time cancer risk. The overall contamination of the sampled fish from heavy metals was also found to be within limits of tolerance.

  10. Assessment of Radiation and Heavy Metals Risk due to the Dietary Intake of Marine Fishes (Rastrelliger kanagurta from the Straits of Malacca.

    Directory of Open Access Journals (Sweden)

    M U Khandaker

    Full Text Available The environment of the Straits of Malacca receives pollution as a result of various industrial and anthropogenic sources, making systematic studies crucial in determining the prevailing water quality. Present study concerns concentrations of natural radionuclides and heavy metals in marine fish (Rastrelliger kanagurta collected from the Straits of Malacca, since aquatic stock form an important source of the daily diet of the surrounding populace. Assessment was made of the concentrations of key indicator radionuclides (226Ra, 232Th, 40K and heavy metals (As, Mn, Fe, Cr, Ni, Zn, Cu, Co, Sr, Al, Hg and Pb together with various radiation indices linked to the consumption of seafish. The annual effective dose for all detected radionuclides for all study locations has been found to be within UNSCEAR acceptable limits as has the associated life-time cancer risk. The overall contamination of the sampled fish from heavy metals was also found to be within limits of tolerance.

  11. Fishery stock assessment of Kiddi shrimp (Parapenaeopsis stylifera) in the Northern Arabian Sea Coast of Pakistan by using surplus production models

    Science.gov (United States)

    Mohsin, Muhammad; Mu, Yongtong; Memon, Aamir Mahmood; Kalhoro, Muhammad Talib; Shah, Syed Baber Hussain

    2016-09-01

    Pakistani marine waters are under an open access regime. Due to poor management and policy implications, blind fishing is continued which may result in ecological as well as economic losses. Thus, it is of utmost importance to estimate fishery resources before harvesting. In this study, catch and effort data, 1996-2009, of Kiddi shrimp Parapenaeopsis stylifera fishery from Pakistani marine waters was analyzed by using specialized fishery software in order to know fishery stock status of this commercially important shrimp. Maximum, minimum and average capture production of P. stylifera was observed as 15 912 metric tons (mt) (1997), 9 438 mt (2009) and 11 667 mt/a. Two stock assessment tools viz. CEDA (catch and effort data analysis) and ASPIC (a stock production model incorporating covariates) were used to compute MSY (maximum sustainable yield) of this organism. In CEDA, three surplus production models, Fox, Schaefer and Pella-Tomlinson, along with three error assumptions, log, log normal and gamma, were used. For initial proportion (IP) 0.8, the Fox model computed MSY as 6 858 mt (CV=0.204, R 2=0.709) and 7 384 mt (CV=0.149, R 2=0.72) for log and log normal error assumption respectively. Here, gamma error produced minimization failure. Estimated MSY by using Schaefer and Pella-Tomlinson models remained the same for log, log normal and gamma error assumptions i.e. 7 083 mt, 8 209 mt and 7 242 mt correspondingly. The Schafer results showed highest goodness of fit R 2 (0.712) values. ASPIC computed MSY, CV, R 2, F MSY and B MSY parameters for the Fox model as 7 219 mt, 0.142, 0.872, 0.111 and 65 280, while for the Logistic model the computed values remained 7 720 mt, 0.148, 0.868, 0.107 and 72 110 correspondingly. Results obtained have shown that P. stylifera has been overexploited. Immediate steps are needed to conserve this fishery resource for the future and research on other species of commercial importance is urgently needed.

  12. Public awareness of mercury in fish: analysis of public awareness and assessment of fish consumption in vermont.

    Science.gov (United States)

    Damsky, William E; Duncan, Elizabeth; Flanagan, Noreen; Fromhold, Karen; Dung, Hyunh; Meyer, Russell; Sax, Jordan; Delaney, Thomas; Bress, William; Hoffman-Contois, Razelle; Carney, Jan K

    2009-11-16

    Exposure to mercury from environmental sources, such as fish consumption, poses potential health risks to the public. The state of Vermont has developed educational brochures and posters displaying safe fish consumption guidelines in order to educate the public regarding mercury exposure through fish. In this study, a group of medical students from the University of Vermont College of Medicine, in partnership with the Vermont Department of Health, conducted a study in Chittenden County, Vermont in order to assess both fish consumption practices and overall awareness of such safe eating guidelines and mercury advisories. A total of 166 Vermont residents were surveyed during a six week period. The results of this survey suggest that in Chittenden county of Vermont, these educational efforts are markedly successful, with 48% of respondents being specifically aware of the safe eating guidelines. Further, these results suggest that 61% of those respondents that reported low monthly canned tuna consumption had a decreased their consumption in response to the safe eating guidelines. last, a series of specific, yet widely applicable recommendations are presented for future public educational efforts regarding mercury exposure through fish consumption.

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

    Data.gov (United States)

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

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

    Data.gov (United States)

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

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

    Data.gov (United States)

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

  16. Fishing

    Institute of Scientific and Technical Information of China (English)

    姜群山

    2002-01-01

    @@ Last Saturday my cousin (表兄) came to my home. We were very happy to see each other. We decided that the next day we went to fish. We got up very early that day. When we left home,the moon could still be seen in the sky.

  17. SOFish ver. 1.2 - A Decision Support System for Fishery Managers in Managing Complex Fish Stocks

    Science.gov (United States)

    Supriatna, A. K.; Sholahuddin, A.; Ramadhan, A. P.; Husniah, H.

    2016-01-01

    Sustainability is an important issue in a fishery industry. A manager of the fishery industry is responsible in deciding the best harvest that is able to sustain the industry while it should also guarantee the profitability of the industry. The most used concept in determining the best harvest in many fisheries industries is the Maximum Sustainable Yield (MSY). It represents the maximum amount of biomass that can be taken out from the fish population without harming the sustainability of the fishery. In other words, it is used to keep the population size stay over a threshold value of population level whenever harvesting activities is going on until indefinite time. In this paper we discuss a Decision Support System (DSS) for fishery managers in estimating the best harvest in a fishery industry. The best harvest is known as the Maximum Sustainable Yield (MSY) of the fishery. The DSS produces the MSY based on the discretization of some mathematical models of population growth, including the most popular models, such as Verhulst, Gompertz and Richards models. We also adding a biological complexity into the models, i.e. the presence of various degree of intra-specific competition of the population, which enhances the realism of the model and the DSS.

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

    Science.gov (United States)

    Kunsook, Chutapa; Gajaseni, Nantana; Paphavasit, Nittharatana

    2014-08-01

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

  19. Assessing carbon stocks and modelling win-win scenarios of carbon sequestration through land-use changes

    Energy Technology Data Exchange (ETDEWEB)

    Ponce-Hernandez, R.; Koohafkan, P.; Antoine, J. (eds.)

    2004-07-01

    This publication presents a methodology and software tools for assessing carbon stocks and modelling scenarios of carbon sequestration that were developed and tested in pilot field studies in Mexico and Cuba. The models and tools enable the analysis of land use change scenarios in order to identify in a given area (watershed or district) land use alternatives and land management practices that simultaneously maximize food production, maximize soil carbon sequestration, maximize biodiversity conservation and minimize land degradation. The objective is to develop and implement 'win-win' options that satisfy the multiple goals of farmers, land users and other stakeholders in relation to food security, carbon sequestration, biodiversity and land conservation.

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

    Directory of Open Access Journals (Sweden)

    Raziyeh Masalegooha

    2015-05-01

    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.

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

    Science.gov (United States)

    Agusa, Tetsuro; Kunito, Takashi; Sudaryanto, Agus; Monirith, In; Kan-Atireklap, Supawat; Iwata, Hisato; Ismail, Ahmad; Sanguansin, Joompol; Muchtar, Muswerry; Tana, Touch Seang; Tanabe, Shinsuke

    2007-02-01

    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.

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

    Directory of Open Access Journals (Sweden)

    MR. SIMON KAMAU GATEI

    2012-11-01

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

  3. Problems of assessment of efficiency of managing corporate rights in joint stock companies

    Directory of Open Access Journals (Sweden)

    Kurinnyy Oleksandr V.

    2013-03-01

    Full Text Available The goal of the article lies in identification of specific features of formation, implementation and practical use of the balanced scorecard of efficiency of managing corporate rights in domestic joint stock companies. Complexity of formation of the balanced scorecard of efficiency of managing property of shareholders is due to a necessity of ensuring deliberateness of the combination of financial and non-financial indicators for formalisation of managerial goals, establishment of a connection between financial parameters and operation indicators of enterprise activity and also attempt to determine the whole cost of an enterprise, which would be adequate to the market value of its assets. Taking into account the above, the article defines efficiency of managing shares of the joint stock as the degree of correlation between the goal, regulatory set functions, managerial actions and results of execution of managerial duties by managers. Prospect of further studies in this direction is development of methodical basis of formation and functioning of the balanced scorecard of efficiency of the use of shares of corporate rights in a joint stock company.

  4. Fish survey, fishing duration, shellfish resource assessment, and other data from the COMMANDO and other platforms as part of Outer Continental Shelf Environmental Assessment Program (OCSEAP) from 21 May 1976 to 16 September 1976 (NODC Accession 7700432)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish survey, fishing duration, shellfish resource assessment, and other data were collected from the COMMANDO and other platforms from 21 May 1976 to 16 September...

  5. Fish survey - fishing duration, shellfish resource assessment, and other data from the Beaufort Sea as part of Outer Continental Shelf Environmental Assessment Program (OCSEAP) from 22 June 1976 to 21 September 1976 (NODC Accession 7800003)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish survey, fishing duration, shellfish resource assessment, and other data were collected from the Beaufort Sea from 22 June 1976 to 21 September 1976. Data were...

  6. Stock Status

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data inform the public of the most recent stock status for all stocks (FSSI and non-FSSI) in the fishery management unit contained in a fishery managment plan....

  7. 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)

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

    2015-08-01

    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 α-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.

  8. Climate change vulnerability of native and alien freshwater fishes of California: a systematic assessment approach.

    Directory of Open Access Journals (Sweden)

    Peter B Moyle

    Full Text Available Freshwater fishes are highly vulnerable to human-caused climate change. Because quantitative data on status and trends are unavailable for most fish species, a systematic assessment approach that incorporates expert knowledge was developed to determine status and future vulnerability to climate change of freshwater fishes in California, USA. The method uses expert knowledge, supported by literature reviews of status and biology of the fishes, to score ten metrics for both (1 current status of each species (baseline vulnerability to extinction and (2 likely future impacts of climate change (vulnerability to extinction. Baseline and climate change vulnerability scores were derived for 121 native and 43 alien fish species. The two scores were highly correlated and were concordant among different scorers. Native species had both greater baseline and greater climate change vulnerability than did alien species. Fifty percent of California's native fish fauna was assessed as having critical or high baseline vulnerability to extinction whereas all alien species were classified as being less or least vulnerable. For vulnerability to climate change, 82% of native species were classified as highly vulnerable, compared with only 19% for aliens. Predicted climate change effects on freshwater environments will dramatically change the fish fauna of California. Most native fishes will suffer population declines and become more restricted in their distributions; some will likely be driven to extinction. Fishes requiring cold water (<22°C are particularly likely to go extinct. In contrast, most alien fishes will thrive, with some species increasing in abundance and range. However, a few alien species will likewise be negatively affected through loss of aquatic habitats during severe droughts and physiologically stressful conditions present in most waterways during summer. Our method has high utility for predicting vulnerability to climate change of diverse fish

  9. Climate change vulnerability of native and alien freshwater fishes of California: a systematic assessment approach.

    Science.gov (United States)

    Moyle, Peter B; Kiernan, Joseph D; Crain, Patrick K; Quiñones, Rebecca M

    2013-01-01

    Freshwater fishes are highly vulnerable to human-caused climate change. Because quantitative data on status and trends are unavailable for most fish species, a systematic assessment approach that incorporates expert knowledge was developed to determine status and future vulnerability to climate change of freshwater fishes in California, USA. The method uses expert knowledge, supported by literature reviews of status and biology of the fishes, to score ten metrics for both (1) current status of each species (baseline vulnerability to extinction) and (2) likely future impacts of climate change (vulnerability to extinction). Baseline and climate change vulnerability scores were derived for 121 native and 43 alien fish species. The two scores were highly correlated and were concordant among different scorers. Native species had both greater baseline and greater climate change vulnerability than did alien species. Fifty percent of California's native fish fauna was assessed as having critical or high baseline vulnerability to extinction whereas all alien species were classified as being less or least vulnerable. For vulnerability to climate change, 82% of native species were classified as highly vulnerable, compared with only 19% for aliens. Predicted climate change effects on freshwater environments will dramatically change the fish fauna of California. Most native fishes will suffer population declines and become more restricted in their distributions; some will likely be driven to extinction. Fishes requiring cold water (fishes will thrive, with some species increasing in abundance and range. However, a few alien species will likewise be negatively affected through loss of aquatic habitats during severe droughts and physiologically stressful conditions present in most waterways during summer. Our method has high utility for predicting vulnerability to climate change of diverse fish species. It should be useful for setting conservation priorities in many different

  10. [Rapid ecological assessment of tropical fish communities in a gold mine area of Costa Rica].

    Science.gov (United States)

    Espinoza Mendiola, Mario

    2008-12-01

    Gold mining impacts have generated a great concern regarding aquatic systems and habitat fragmentation. Anthropogenic disturbances on the structure and heterogeneity of a system can have an important effect on aquatic community stability. Ecological rapid assessments (1996, 2002, and 2007) were employed to determine the structure, composition and distribution of tropical fish communities in several rivers and smaller creeks from a gold mining area in Cerro Crucitas, Costa Rica. In addition, species composition and relative abundance were related with habitat structure. A total of 35 species were registered, among which sardine Astyanax aeneus (Characidae) and livebearer Alfaro cultratus (Poeciliidae) were the most abundant fish (71%). The highest species richness was observed in Caño Crucitas (s=19) and Minas Creek (s=18). Significant differences in fish communities structure and composition from Infiernillo river and Minas creek were observed (lamda = 0.0, F(132, 66) = 2.24, p fish species and habitat structure was observed. This study reveals a high complexity in tropical fish communities that inhabit a gold mine area. Furthermore, it highlights the importance of habitat heterogeneity in fish community dynamics. The loss and degradation of aquatic systems in Cerro Crucitas can have a strong negative effect on fish community structure and composition of local species. A better understanding of the use of specific habitats that serve as essential fish habitats can improve tropical fish conservation and management strategies, thus increasing local diversity, and thereby, the biological importance of the area.

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

    Data.gov (United States)

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

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

    Directory of Open Access Journals (Sweden)

    M. W. Warren

    2012-11-01

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

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

    DEFF Research Database (Denmark)

    Laursen, Danielle Caroline

    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...... 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...

  14. AFSC/REFM: Groundfish Survey of the Chukchi Sea in 2013 by Shelf Habitat and Ecology of Fish and Zooplankton (SHELFZ)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Alaska Fisheries Science Centers (AFSC) Status of Stocks and Multispecies Assessment (SSMA) Programs Fishery Interaction Team (FIT) conducted an offshore fish...

  15. Aboveground carbon in Quebec forests: stock quantification at the provincial scale and assessment of temperature, precipitation and edaphic properties effects on the potential stand-level stocking.

    Science.gov (United States)

    Duchesne, Louis; Houle, Daniel; Ouimet, Rock; Lambert, Marie-Claude; Logan, Travis

    2016-01-01

    Biological carbon sequestration by forest ecosystems plays an important role in the net balance of greenhouse gases, acting as a carbon sink for anthropogenic CO2 emissions. Nevertheless, relatively little is known about the abiotic environmental factors (including climate) that control carbon storage in temperate and boreal forests and consequently, about their potential response to climate changes. From a set of more than 94,000 forest inventory plots and a large set of spatial data on forest attributes interpreted from aerial photographs, we constructed a fine-resolution map (∼375 m) of the current carbon stock in aboveground live biomass in the 435,000 km(2) of managed forests in Quebec, Canada. Our analysis resulted in an area-weighted average aboveground carbon stock for productive forestland of 37.6 Mg ha(-1), which is lower than commonly reported values for similar environment. Models capable of predicting the influence of mean annual temperature, annual precipitation, and soil physical environment on maximum stand-level aboveground carbon stock (MSAC) were developed. These models were then used to project the future MSAC in response to climate change. Our results indicate that the MSAC was significantly related to both mean annual temperature and precipitation, or to the interaction of these variables, and suggest that Quebec's managed forests MSAC may increase by 20% by 2041-2070 in response to climate change. Along with changes in climate, the natural disturbance regime and forest management practices will nevertheless largely drive future carbon stock at the landscape scale. Overall, our results allow accurate accounting of carbon stock in aboveground live tree biomass of Quebec's forests, and provide a better understanding of possible feedbacks between climate change and carbon storage in temperate and boreal forests.

  16. Aboveground carbon in Quebec forests: stock quantification at the provincial scale and assessment of temperature, precipitation and edaphic properties effects on the potential stand-level stocking

    Directory of Open Access Journals (Sweden)

    Louis Duchesne

    2016-03-01

    Full Text Available Biological carbon sequestration by forest ecosystems plays an important role in the net balance of greenhouse gases, acting as a carbon sink for anthropogenic CO2 emissions. Nevertheless, relatively little is known about the abiotic environmental factors (including climate that control carbon storage in temperate and boreal forests and consequently, about their potential response to climate changes. From a set of more than 94,000 forest inventory plots and a large set of spatial data on forest attributes interpreted from aerial photographs, we constructed a fine-resolution map (∼375 m of the current carbon stock in aboveground live biomass in the 435,000 km2 of managed forests in Quebec, Canada. Our analysis resulted in an area-weighted average aboveground carbon stock for productive forestland of 37.6 Mg ha−1, which is lower than commonly reported values for similar environment. Models capable of predicting the influence of mean annual temperature, annual precipitation, and soil physical environment on maximum stand-level aboveground carbon stock (MSAC were developed. These models were then used to project the future MSAC in response to climate change. Our results indicate that the MSAC was significantly related to both mean annual temperature and precipitation, or to the interaction of these variables, and suggest that Quebec’s managed forests MSAC may increase by 20% by 2041–2070 in response to climate change. Along with changes in climate, the natural disturbance regime and forest management practices will nevertheless largely drive future carbon stock at the landscape scale. Overall, our results allow accurate accounting of carbon stock in aboveground live tree biomass of Quebec’s forests, and provide a better understanding of possible feedbacks between climate change and carbon storage in temperate and boreal forests.

  17. Climate-Smart Livestock Systems: An Assessment of Carbon Stocks and GHG Emissions in Nicaragua

    Science.gov (United States)

    Gaitán, Lucía; Läderach, Peter; Graefe, Sophie; Rao, Idupulapati; van der Hoek, Rein

    2016-01-01

    Livestock systems in the tropics can contribute to mitigate climate change by reducing greenhouse gas (GHG) emissions and increasing carbon accumulation. We quantified C stocks and GHG emissions of 30 dual-purpose cattle farms in Nicaragua using farm inventories and lifecycle analysis. Trees in silvo-pastoral systems were the main C stock above-ground (16–24 Mg ha-1), compared with adjacent secondary forests (43 Mg C ha-1). We estimated that methane from enteric fermentation contributed 1.6 kg CO2-eq., and nitrous oxide from excreta 0.4 kg CO2-eq. per kg of milk produced. Seven farms that we classified as climate-smart agriculture (CSA) out of 16 farms had highest milk yields (6.2 kg cow-1day-1) and lowest emissions (1.7 kg CO2-eq. per kg milk produced). Livestock on these farms had higher-quality diets, especially during the dry season, and manure was managed better. Increasing the numbers of CSA farms and improving CSA technology will require better enabling policy and incentives such as payments for ecosystem services. PMID:28030599

  18. Climate-Smart Livestock Systems: An Assessment of Carbon Stocks and GHG Emissions in Nicaragua.

    Science.gov (United States)

    Gaitán, Lucía; Läderach, Peter; Graefe, Sophie; Rao, Idupulapati; van der Hoek, Rein

    2016-01-01

    Livestock systems in the tropics can contribute to mitigate climate change by reducing greenhouse gas (GHG) emissions and increasing carbon accumulation. We quantified C stocks and GHG emissions of 30 dual-purpose cattle farms in Nicaragua using farm inventories and lifecycle analysis. Trees in silvo-pastoral systems were the main C stock above-ground (16-24 Mg ha-1), compared with adjacent secondary forests (43 Mg C ha-1). We estimated that methane from enteric fermentation contributed 1.6 kg CO2-eq., and nitrous oxide from excreta 0.4 kg CO2-eq. per kg of milk produced. Seven farms that we classified as climate-smart agriculture (CSA) out of 16 farms had highest milk yields (6.2 kg cow-1day-1) and lowest emissions (1.7 kg CO2-eq. per kg milk produced). Livestock on these farms had higher-quality diets, especially during the dry season, and manure was managed better. Increasing the numbers of CSA farms and improving CSA technology will require better enabling policy and incentives such as payments for ecosystem services.

  19. 基于Bayes方法的渤海渔业资源动态评析%A Stock Assessment of Bohai Sea by Bayes-based Pella-Tomlinson Model

    Institute of Scientific and Technical Information of China (English)

    李九奇; 聂小杰; 叶昌臣; 尹增强

    2012-01-01

    研究利用来自于黄渤海渔政局的内部统计资料,采用基于Bayes方法的Pella-Tomlinson模型对渤海渔业资源动态进行了科学评析,评析结果显示:渤海渔业资源的环境容纳量为3.5×106~5.5×106t;渔业资源综合种群的内禀增长率r为0.9~1.6;1979年渔业资源年平均生物量为2 332 523 t,尔后持续上升到1985年的最高值4 251 292 t,1985年以后又持续下降到2002年的最低值2 250 709 t;渤海渔业资源的最大持续产量MSY约为140×104t左右;支持MSY所需的捕捞努力量约为817 771 kW,到1991年捕捞努力量增加到963 564 kW,此时已超过获得MSY时需要的捕捞努力量,即从1991年开始出现捕捞过度。%The fish stock assessment is important groundwork for present-day fish stock management,The report presents a stock assessment of Bohai Sea by Bayes-based Pella-Tomlinson model.All of the data used in this study are from the Bohai-Yellow Sea Fisheries Administration Bureau.The research results show that the carrying capacity K of Bohai Sea is about 3.5×106-5.5×106 t and the Intrinsic growth rate r is about 0.9-1.6;the estimated stock biomass increased from approximately 2332523 t in 1979 to the maximum value 4251292 t in 1985 and then declined to less than 2250709 t in 2002;the estimated MSY is 1400000 t;the estimated effort for achieving MSY is 817771 kW and the effort is 963564 kW in 1991,since then overfishing was started.

  20. Combining telephone surveys and fishing catches self-report: the French sea bass recreational fishery assessment.

    Directory of Open Access Journals (Sweden)

    Delphine Rocklin

    Full Text Available 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 that half of the total catches (mainly small fish were released at sea and that the mean length of a kept sea bass was 46.6 cm. We highlighted different patterns of fishing methods and type of gear used. Catches from boats were greater than from the shore, both in abundance and biomass, considering mean values per fishing trip as well as CPUE. Spearfishers caught the highest biomass of sea bass per fishing trip, but the fishing rod with lure was the most effective type of gear in terms of CPUE. Longlines had the highest CPUE value in abundance but not in biomass: they caught numerous but small sea bass. Handlines were less effective, catching few sea bass in both abundance and biomass. We estimated that the annual total recreational sea bass catches was 3,173 tonnes of which 2,345 tonnes were kept. Since the annual commercial catches landings were evaluated at 5,160 tonnes, recreational landings represent 30% of the total fishing catches on the Atlantic coasts of France. Using fishers' self-reports was a valuable way to obtain new information on data-poor fisheries. Our results underline the importance of evaluating recreational fishing as a part of the total amount of fisheries catches. More studies are critically needed to assess overall fish resources caught in order to develop effective fishery management tools.

  1. Summary of management techniques, catches and escapement for the Kuskokwim area coho salmon stocks

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — We have three primary stocks of coho salmon in the Kuskokwim Area commercial fishery. The Kuskokwim, Kanektok and Goodnews Rivers' stocks. The Kuskokwim River stock...

  2. Clinical methods for the assessment of the effects of environmental stress on fish health

    Science.gov (United States)

    Wedemeyer, Gary A.; Yasutake, William T.

    1977-01-01

    Clinical methods are presented for biological monitoring of hatchery and native fish populations to assess the effects of environmental stress on fish health. The choice of methods is based on the experience of the authors and the judgment of colleagues at fishery laboratories of the U.S. Fish and Wildlife Service. Detailed analysis methods, together with guidelines for sample collection and for the interpretation of results, are given for tests on blood (cell counts, chloride, cholesterol, clotting time, cortisol, glucose, hematocrit, hemoglobin, lactic acid, methemoglobin, osmolality, and total protein); water (ammonia and nitrite content); and liver and muscle (glycogen content).

  3. Stream fishes and desirable fish stocks

    DEFF Research Database (Denmark)

    Dieperink, C.; Sand-Jensen, K.

    2006-01-01

    , 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.......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...

  4. Stream fishes and desirable fish stocks

    DEFF Research Database (Denmark)

    Dieperink, C.; Sand-Jensen, K.

    2006-01-01

    Freshwater fi sh communities have always been valuable resources for society, particularly the species that migrate between freshwater and the sea. Historically, eel, salmon and trout were so abundant that good fi shing luck could turn a capable fi sherman into a wealthy person. Unfortunately, mi...

  5. Fish species, Fish biomass, Fishery survey, invertebrate species, and other variables collected from midwater net tows, and bottom trawl observations using net, trawl, and other instruments from the Arctic Ocean, and Beaufort Sea from August 6, 2008 to August 21, 2008 (NODC Accession 0112823)

    Data.gov (United States)

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

  6. Global assessment of soil organic carbon stocks and spatial distribution of histosols: the Machine Learning approach

    Science.gov (United States)

    Hengl, Tomislav

    2016-04-01

    Preliminary results of predicting distribution of soil organic soils (Histosols) and soil organic carbon stock (in tonnes per ha) using global compilations of soil profiles (about 150,000 points) and covariates at 250 m spatial resolution (about 150 covariates; mainly MODIS seasonal land products, SRTM DEM derivatives, climatic images, lithological and land cover and landform maps) are presented. We focus on using a data-driven approach i.e. Machine Learning techniques that often require no knowledge about the distribution of the target variable or knowledge about the possible relationships. Other advantages of using machine learning are (DOI: 10.1371/journal.pone.0125814): All rules required to produce outputs are formalized. The whole procedure is documented (the statistical model and associated computer script), enabling reproducible research. Predicted surfaces can make use of various information sources and can be optimized relative to all available quantitative point and covariate data. There is more flexibility in terms of the spatial extent, resolution and support of requested maps. Automated mapping is also more cost-effective: once the system is operational, maintenance and production of updates are an order of magnitude faster and cheaper. Consequently, prediction maps can be updated and improved at shorter and shorter time intervals. Some disadvantages of automated soil mapping based on Machine Learning are: Models are data-driven and any serious blunders or artifacts in the input data can propagate to order-of-magnitude larger errors than in the case of expert-based systems. Fitting machine learning models is at the order of magnitude computationally more demanding. Computing effort can be even tens of thousands higher than if e.g. linear geostatistics is used. Many machine learning models are fairly complex often abstract and any interpretation of such models is not trivial and require special multidimensional / multivariable plotting and data mining

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

    Directory of Open Access Journals (Sweden)

    Paolo Guidetti

    Full Text Available 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.

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

    Science.gov (United States)

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

    2006-09-01

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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

    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.

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

    Science.gov (United States)

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

    2013-04-01

    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

  11. It is the economy, stupid! Projecting the fate of fish populations using ecological-economic modeling.

    Science.gov (United States)

    Quaas, Martin F; Reusch, Thorsten B H; Schmidt, Jörn O; Tahvonen, Olli; Voss, Rudi

    2016-01-01

    Four marine fish species are among the most important on the world market: cod, salmon, tuna, and sea bass. While the supply of North American and European markets for two of these species - Atlantic salmon and European sea bass - mainly comes from fish farming, Atlantic cod and tunas are mainly caught from wild stocks. We address the question what will be the status of these wild stocks in the midterm future, in the year 2048, to be specific. Whereas the effects of climate change and ecological driving forces on fish stocks have already gained much attention, our prime interest is in studying the effects of changing economic drivers, as well as the impact of variable management effectiveness. Using a process-based ecological-economic multispecies optimization model, we assess the future stock status under different scenarios of change. We simulate (i) technological progress in fishing, (ii) increasing demand for fish, and (iii) increasing supply of farmed fish, as well as the interplay of these driving forces under different scenarios of (limited) fishery management effectiveness. We find that economic change has a substantial effect on fish populations. Increasing aquaculture production can dampen the fishing pressure on wild stocks, but this effect is likely to be overwhelmed by increasing demand and technological progress, both increasing fishing pressure. The only solution to avoid collapse of the majority of stocks is institutional change to improve management effectiveness significantly above the current state. We conclude that full recognition of economic drivers of change will be needed to successfully develop an integrated ecosystem management and to sustain the wild fish stocks until 2048 and beyond.

  12. Assessment of micronuclei induction in peripheral erythrocytes of fish exposed to xenobiotics under controlled conditions

    Energy Technology Data Exchange (ETDEWEB)

    Bolognesi, Claudia [Environmental Carcinogenesis Unit, National Institute for Research on Cancer, L.go Rosanna Benzi, 10, 16132 Genoa (Italy)]. E-mail: claudia.bolognesi@istge.it; Perrone, Emanuela [Environmental Carcinogenesis Unit, National Institute for Research on Cancer, L.go Rosanna Benzi, 10, 16132 Genoa (Italy); Roggieri, Paola [Environmental Carcinogenesis Unit, National Institute for Research on Cancer, L.go Rosanna Benzi, 10, 16132 Genoa (Italy); Pampanin, Daniela M. [IRIS - International Research Institute of Stavanger AS, Mekjarvik 12, N-4070 Randaberg (Norway); Sciutto, Andrea [Environmental Carcinogenesis Unit, National Institute for Research on Cancer, L.go Rosanna Benzi, 10, 16132 Genoa (Italy)

    2006-06-01

    The aim of the present study was to standardize and to assess the predictive value of the cytogenetic analysis by MN test in fish erythrocytes as a biomarker for marine environmental contamination. MN frequency baseline in erythrocytes was evaluated in a number of fish species from a reference area (S. Teresa, La Spezia Gulf) and genotoxic potential of a number of common chemical contaminants and mixtures was determined in fish experimentally exposed in aquarium under controlled conditions. Fish (Scophthalmus maximus) were exposed for 3 weeks to 50 ppb of single chemicals (dialkyl phthalate, bisphenol A, tetrabromodiphenyl ether), 30 ppb nonylphenol and mixtures (North Sea oil and North Sea oil with alkylated phenols). Chromosomal damage was determined as micronuclei (MN) frequency in fish erythrocytes. Nuclear anomalies such as blebbed, notched and lobed nuclei were also recorded. Significant increase in MN frequency was observed in erythrocytes of fish exposed to bisphenol A and tetrabromodiphenylether. Chemical mixture North Sea oil + alkylated phenols induced the highest MN frequency (2.95 micronucleated cells/1000 cells compared to 1 MNcell/1000 cells in control animals). The study results revealed that micronucleus test, as an index of cumulative exposure, appears to be a sensitive model to evaluate genotoxic compounds in fish under controlled conditions.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1982-04-01

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

  14. Assessment of the Impact of Extension Services on Fish Farming in Ekiti State, Nigeria

    Directory of Open Access Journals (Sweden)

    Agbebi, F. O.

    2012-03-01

    Full Text Available The study was carried out to assess the impact of access to extension services on fish farming in Ekiti State, Nigeria. Specifically, the study investigated the socio – economic characteristics of fish farmers, information disseminated to fish farmers, attributes of extension agents, and farmers’ access to extension services and farmers profitability. A well-structured questionnaire was used to collect information from the farmers and a sample size of 90 fish farmers was selected from the six local government selected. Analysis of data was carried out using frequency and percentage tables and Gross Margin analysis was used to determine the profitability of the farmers. There was relationship between farmers’ access to extension services and their profitability. It was recommended that extension agents should intensify their efforts in reaching farmers and passing useful information to them in order to increase farmers’ profitability.

  15. Development and assessment of a physics-based simulation model to investigate residential PM2.5 infiltration across the US housing stock

    Science.gov (United States)

    The Lawrence Berkeley National Laboratory Population Impact Assessment Modeling Framework (PIAMF) was expanded to enable determination of indoor PM2.5 concentrations and exposures in a set of 50,000 homes representing the US housing stock. A mass-balance model is used to calculat...

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

    Directory of Open Access Journals (Sweden)

    Mildred M. Labata

    2012-06-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-07-01

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

  18. A moving target--incorporating knowledge of the spatial ecology of fish into the assessment and management of freshwater fish populations.

    Science.gov (United States)

    Cooke, Steven J; Martins, Eduardo G; Struthers, Daniel P; Gutowsky, Lee F G; Power, Michael; Doka, Susan E; Dettmers, John M; Crook, David A; Lucas, Martyn C; Holbrook, Christopher M; Krueger, Charles C

    2016-04-01

    Freshwater fish move vertically and horizontally through the aquatic landscape for a variety of reasons, such as to find and exploit patchy resources or to locate essential habitats (e.g., for spawning). Inherent challenges exist with the assessment of fish populations because they are moving targets. We submit that quantifying and describing the spatial ecology of fish and their habitat is an important component of freshwater fishery assessment and management. With a growing number of tools available for studying the spatial ecology of fishes (e.g., telemetry, population genetics, hydroacoustics, otolith microchemistry, stable isotope analysis), new knowledge can now be generated and incorporated into biological assessment and fishery management. For example, knowing when, where, and how to deploy assessment gears is essential to inform, refine, or calibrate assessment protocols. Such information is also useful for quantifying or avoiding bycatch of imperiled species. Knowledge of habitat connectivity and usage can identify critically important migration corridors and habitats and can be used to improve our understanding of variables that influence spatial structuring of fish populations. Similarly, demographic processes are partly driven by the behavior of fish and mediated by environmental drivers. Information on these processes is critical to the development and application of realistic population dynamics models. Collectively, biological assessment, when informed by knowledge of spatial ecology, can provide managers with the ability to understand how and when fish and their habitats may be exposed to different threats. Naturally, this knowledge helps to better evaluate or develop strategies to protect the long-term viability of fishery production. Failure to understand the spatial ecology of fishes and to incorporate spatiotemporal data can bias population assessments and forecasts and potentially lead to ineffective or counterproductive management actions.

  19. A moving target—incorporating knowledge of the spatial ecology of fish into the assessment and management of freshwater fish populations

    Science.gov (United States)

    Cooke, Steven J.; Martins, Eduardo G; Struthers, Daniel P; Gutowsky, Lee F G; Powers, Michael H.; Doka, Susan E; Dettmers, John M.; Crook, David A; Lucas, Martyn C.; Holbrook, Christopher; Krueger, Charles C.

    2016-01-01

    Freshwater fish move vertically and horizontally through the aquatic landscape for a variety of reasons, such as to find and exploit patchy resources or to locate essential habitats (e.g., for spawning). Inherent challenges exist with the assessment of fish populations because they are moving targets. We submit that quantifying and describing the spatial ecology of fish and their habitat is an important component of freshwater fishery assessment and management. With a growing number of tools available for studying the spatial ecology of fishes (e.g., telemetry, population genetics, hydroacoustics, otolith microchemistry, stable isotope analysis), new knowledge can now be generated and incorporated into biological assessment and fishery management. For example, knowing when, where, and how to deploy assessment gears is essential to inform, refine, or calibrate assessment protocols. Such information is also useful for quantifying or avoiding bycatch of imperiled species. Knowledge of habitat connectivity and usage can identify critically important migration corridors and habitats and can be used to improve our understanding of variables that influence spatial structuring of fish populations. Similarly, demographic processes are partly driven by the behavior of fish and mediated by environmental drivers. Information on these processes is critical to the development and application of realistic population dynamics models. Collectively, biological assessment, when informed by knowledge of spatial ecology, can provide managers with the ability to understand how and when fish and their habitats may be exposed to different threats. Naturally, this knowledge helps to better evaluate or develop strategies to protect the long-term viability of fishery production. Failure to understand the spatial ecology of fishes and to incorporate spatiotemporal data can bias population assessments and forecasts and potentially lead to ineffective or counterproductive management actions.

  20. 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

    Energy Technology Data Exchange (ETDEWEB)

    Christensen, S. W.; Goodyear, C. P.; Kirk, B. L.

    1982-03-01

    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.

  1. Olfactory toxicity in fishes.

    Science.gov (United States)

    Tierney, Keith B; Baldwin, David H; Hara, Toshiaki J; Ross, Peter S; Scholz, Nathaniel L; Kennedy, Christopher J

    2010-01-21

    Olfaction conveys critical environmental information to fishes, enabling activities such as mating, locating food, discriminating kin, avoiding predators and homing. All of these behaviors can be impaired or lost as a result of exposure to toxic contaminants in surface waters. Historically, teleost olfaction studies have focused on behavioral responses to anthropogenic contaminants (e.g., avoidance). More recently, there has been a shift towards understanding the underlying mechanisms and functional significance of contaminant-mediated changes in fish olfaction. This includes a consideration of how contaminants affect the olfactory nervous system and, by extension, the downstream physiological and behavioral processes that together comprise a normal response to naturally occurring stimuli (e.g., reproductive priming or releasing pheromones). Numerous studies spanning several species have shown that ecologically relevant exposures to common pollutants such as metals and pesticides can interfere with fish olfaction and disrupt life history processes that determine individual survival and reproductive success. This represents one of the pathways by which toxic chemicals in aquatic habitats may increasingly contribute to the decline and at-risk status of many commercially and ecologically important fish stocks. Despite our emerging understanding of the threats that pollution poses for chemical communication in aquatic communities, many research challenges remain. These include: (1) the determination of specific mechanisms of toxicity in the fish olfactory sensory epithelium; (2) an understanding of the impacts of complex chemical mixtures; (3) the capacity to assess olfactory toxicity in fish in situ; (4) the impacts of toxins on olfactory-mediated behaviors that are still poorly understood for many fish species; and (5) the connections between sublethal effects on individual fish and the long-term viability of wild populations. This review summarizes and integrates

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

    Science.gov (United States)

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

    2004-01-01

    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.

  3. Assessing Potential Conservation and Restoration Areas of Freshwater Fish Fauna in the Indian River Basins

    Science.gov (United States)

    Bhatt, Jay P.; Manish, Kumar; Mehta, Rajender; Pandit, Maharaj K.

    2016-05-01

    Conservation efforts globally are skewed toward terrestrial ecosystems. To date, conservation of aquatic ecosystems, in particular fish fauna, is largely neglected. We provide a country-wide assessment of Indian river ecosystems in order to identify and prioritize areas for protection and restoration of freshwater fish fauna. Using various biodiversity and anthropogenic attributes, coupled with tools of ecological modeling, we delineated areas for fish fauna conservation and restoration in the 20 major river basins of India. To do this, we used prioritization analyses and reserve selection algorithms to derive conservation value index (CVI) and vulnerability index (VI) of the river basins. CVI was estimated using endemicity, rarity, conservation value, and taxonomic singularity, while VI was estimated using a disturbance index derived from percent geographic area of the basin under human settlements, human population density, predominant land use, and total number of exotic fish species in each basin. The two indices, CVI and VI, were converted into geo-referenced maps, and each map was super-imposed onto species richness and forest cover maps, respectively. After superimposition, areas with high CVI and low VI shade intensities were delineated for conservation, while areas with high CVI and high VI shade intensities were demarcated for restoration. In view of the importance of freshwater fish for human livelihoods and consumption, and ecosystems of India's rivers, we call for urgent attention to the conservation of their fish fauna along with restoration of their degraded habitats.

  4. Do North Sea cod (Gadus morhua) fisheries maintain high catch rates at low stock size?

    DEFF Research Database (Denmark)

    Rindorf, Anna; Andersen, Bo Sølgaard

    2008-01-01

    This study presents all investigation of the relationship between stock size of North Sea cod (Gadus morhua) and catch rates in seven commercial fishing fleets. The shape of the relationship was estimated using a model allowing both density-dependent changes in catchability and bias in the assess......This study presents all investigation of the relationship between stock size of North Sea cod (Gadus morhua) and catch rates in seven commercial fishing fleets. The shape of the relationship was estimated using a model allowing both density-dependent changes in catchability and bias...... in the assessment biomass estimates. Catchability in fisheries targeting a mixed species composition either remained constant or decreased with decreasing stock size, whereas catchability in targeted cod fisheries increased with decreasing stock size. However, even ill the cases where catchability increased......, the change was insufficient to compensate for the decrease in stock size, and catch rates of all fleets decreased. Two factors that could lead to nonconstant catchability were investigated: (i) the presence of decoupling between stock size and density ill high-density areas and (ii) the presence...

  5. Assessment of mercury in edible fish fillets at Seney National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report is a follow-up to work conducted by the East Lansing Field Office (ELFO) at Seney National Wildlife Refuge (NWR) in 1987-88 to assess the presence and...

  6. Risk assessment of N-nitrosodimethylamine formed endogenously after fish-with-vegetable meals

    NARCIS (Netherlands)

    Zeilmaker, M.J.; Bakker, M.I.; Schothorst, R.; Slob, W.

    2010-01-01

    The consumption of fish and nitrate-rich vegetables may lead to the formation of the genotoxic carcinogen N-nitrosodimethylamine (NDMA) in the stomach. To assess human cancer risk associated with this formation, a dynamic in vitro gastrointestinal model was used to simulate NDMA formation in the sto

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

    Energy Technology Data Exchange (ETDEWEB)

    Howell, Philip J.

    1986-07-01

    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.

  8. The Assessing of Financial Performance of Accepted Banks in Stock Exchange Market by means of ELETERE Technique

    Directory of Open Access Journals (Sweden)

    Ali Sorayaei

    2014-07-01

    Full Text Available Bank managers are stakeholders of the data analysis for financial performance that these data are important for them. In this regard, they consider valuable financial information and evaluate the bank's situation and will decide according it. This paper presents a method for systematic assessing banks' financial performance. The analysis is based on a set of criteria related to the financial performance of banks. The purpose of this research, ranking the bank listed in Tehran Stock Exchange, according to financial criteria. After a comprehensive review of the research literature and the idea of financial experts have been identified criteria to assess the financial performance of banks (liquidity factors, factors, profitability, and capital adequacy and risk asset structure factors. To increase the accuracy of the study, the weight of financial factors calculates with AHP-FUZZY method. Finally, the final weights obtained, the ELECTRE algorithm has been implemented to rank the banks. The results show that the KAR AFARIN bank is on top and ANSAR Bank, PASARGAD and the EGHTESAD NOVIN were ranked second, third and fourth and the MELAT bank, SADERAT and TEJARAT got the ratings from the eighth to the tenth.

  9. 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)

    A. M. Snow

    2008-01-01

    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

  10. Protocol for assessing brain function in fish and the effectiveness of methods used to stun and kill them

    NARCIS (Netherlands)

    Kestin, S.C.; Vis, van de J.W.; Robb, D.H.F.

    2002-01-01

    A method for the evaluation of brain function in fish has been developed which is based on assessments of self-initiated behaviours, responses to stimulation, and reflexes. These assessments were validated in several freshwater and marine species and applied to evaluate the brain function of fish wh

  11. The 2014 FDA assessment of commercial fish: practical considerations for improved dietary guidance

    OpenAIRE

    McGuire, Jennifer; Kaplan, Jason; Lapolla, John; Kleiner, Rima

    2016-01-01

    The U.S. Food and Drug Administration (FDA) recently released its report: A Quantitative Assessment of the Net Effects on Fetal Neurodevelopment from Eating Commercial Fish (As Measured by IQ and also by Early Age Verbal Development in Children). By evaluating the benefits and potential concerns of eating fish during pregnancy and breastfeeding, the analysis suggests that pregnant women consuming two seafood meals (8–12 oz) per week could provide their child with an additional 3.3 IQ points b...

  12. The larvae of decapods and fishes of Amba estuary, Maharashtra

    Digital Repository Service at National Institute of Oceanography (India)

    Paulinose, V.T.; Devi, C.B.L.; Govindan, K.; Gajbhiye, S.N.; Nair, V.R.

    larvae to the total zooplankton population were 3.63 and 0.03 respectively. In the assessment of larval stocks environmental parameters and the presence of adult fish caught in the area were considered. The estuarine area supported fairly high fishery...

  13. Assessing the added value of the recent declaration on unregulated fishing for sustainable governance of the central Arctic Ocean

    DEFF Research Database (Denmark)

    Shephard, Grace Elizabeth; Dalen, Kari; Peldszus, Regina

    2016-01-01

    The ‘Declaration concerning the prevention of unregulated high seas fishing in the central Arctic Ocean’ signed by the Arctic 5 nations, limits unregulated high seas fishing in the central part of the Arctic Ocean, and holds potential social, economic and political impacts for numerous stakeholders....... In this paper, the four Interim Measures in the Declaration are discussed and what value these measures bring beyond the existing international agreements is explored. It is found that even though the Declaration fills a gap in the management of potential fish stocks in the central Arctic Ocean, adopts...... understanding of the fisheries as well as the broader Arctic environment. Furthermore, the research generated by this measure will provide an important decision base for both regulation and management of human activity in the Arctic....

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

    Data.gov (United States)

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

  15. Integrated ecosystem assessment of Vieques, Puerto Rico Fish Assessment and Monitoring Data (NODC Accession 0125235)

    Data.gov (United States)

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

  16. The 2014 FDA assessment of commercial fish: practical considerations for improved dietary guidance.

    Science.gov (United States)

    McGuire, Jennifer; Kaplan, Jason; Lapolla, John; Kleiner, Rima

    2016-07-13

    The U.S. Food and Drug Administration (FDA) recently released its report: A Quantitative Assessment of the Net Effects on Fetal Neurodevelopment from Eating Commercial Fish (As Measured by IQ and also by Early Age Verbal Development in Children). By evaluating the benefits and potential concerns of eating fish during pregnancy and breastfeeding, the analysis suggests that pregnant women consuming two seafood meals (8-12 oz) per week could provide their child with an additional 3.3 IQ points by age 9. Recent insights from behavioral economics research indicate that other factors, such as concerns about price and methylmercury (MeHg) exposure, appear to reduce fish consumption in many individuals.To assess the net effects of eating commercial fish during pregnancy, we compared the consumption of select fish species necessary to achieve IQ benefits with the amount necessary to have adverse developmental effects due to MeHg exposure. For the species or market types evaluated, the number of servings necessary to reach MeHg exposure to observe an adverse effect was at least twice that the amount estimated to achieve peak developmental benefit. We then reported average costs of fresh and canned or pouched fish, and calculated the cost per week for pregnant women to achieve maximum IQ benefits for their gestating child. Canned light tuna was the least expensive option at $1.83 per week to achieve maximum IQ benefit.Due to their relatively low cost, canned and pouched fish products eaten with enough regularity are likely to provide peak cognitive benefits. Because of its popularity, canned and pouched tuna could provide some of the largest cognitive benefits from fish consumption in the U.S. Future FDA consumer advice and related educational initiatives could benefit from a broader perspective that highlights the importance of affordable and accessible fish choices. These observations underscore the importance of clear public health messaging that address both health

  17. Biodiversity assessment of the fishes of Saba Bank atoll, Netherlands Antilles.

    Directory of Open Access Journals (Sweden)

    Jeffrey T Williams

    Full Text Available Biodiversity surveys were conducted on Saba Bank, Netherlands Antilles, to assess ichthyofaunal richness and to compare with published surveys of other Caribbean localities. The primary objective was to estimate the total species richness of the Saba Bank ichthyofauna. A variety of sampling techniques was utilized to survey the fish species of both the visually accessible megafauna and the camouflaged and small-sized species comprising the cryptic ichthyofauna.Based on results presented herein, the number of species known on Saba Bank is increased from 42 previously known species to 270 species. Expected species-accumulation curves demonstrate that the current estimate of species richness of fishes for Saba Bank under represents the actual richness, and our knowledge of the ichthyofauna has not plateaued. The total expected fish-species richness may be somewhere between 320 and 411 species.The Saba Bank ichthyofaunal assemblage is compared to fish assemblages found elsewhere in the Caribbean. Despite the absence of shallow or emergent shore habitats like mangroves, Saba Bank ranks as having the eighth highest ichthyofaunal richness of surveyed localities in the Greater Caribbean. Some degree of habitat heterogeneity was evident. Fore-reef, patch-reef, and lagoonal habitats were sampled. Fish assemblages were significantly different between habitats. Species richness was highest on the fore reef, but 11 species were found only at lagoonal sites.A comprehensive, annotated list of the fishes currently known to occur on Saba Bank, Netherland Antilles, is provided and color photographs of freshly collected specimens are presented for 165 of the listed species of Saba Bank fishes to facilitate identification and taxonomic comparison with similar taxa at other localities. Coloration of some species is shown for the first time. Preliminary analysis indicates that at least six undescribed new species were collected during the survey and these are

  18. Research Fishing

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Accurate and precise stock assessments are predicated on accurate and precise estimates of life history parameters, abundance, and catch across the range of the...

  19. Threshold-dependent sample sizes for selenium assessment with stream fish tissue

    Science.gov (United States)

    Hitt, Nathaniel P.; Smith, David R.

    2015-01-01

    Natural resource managers are developing assessments of selenium (Se) contamination in freshwater ecosystems based on fish tissue concentrations. We evaluated the effects of sample size (i.e., number of fish per site) on the probability of correctly detecting mean whole-body Se values above a range of potential management thresholds. We modeled Se concentrations as gamma distributions with shape and scale parameters fitting an empirical mean-to-variance relationship in data from southwestern West Virginia, USA (63 collections, 382 individuals). We used parametric bootstrapping techniques to calculate statistical power as the probability of detecting true mean concentrations up to 3 mg Se/kg above management thresholds ranging from 4 to 8 mg Se/kg. Sample sizes required to achieve 80% power varied as a function of management thresholds and Type I error tolerance (α). Higher thresholds required more samples than lower thresholds because populations were more heterogeneous at higher mean Se levels. For instance, to assess a management threshold of 4 mg Se/kg, a sample of eight fish could detect an increase of approximately 1 mg Se/kg with 80% power (given α = 0.05), but this sample size would be unable to detect such an increase from a management threshold of 8 mg Se/kg with more than a coin-flip probability. Increasing α decreased sample size requirements to detect above-threshold mean Se concentrations with 80% power. For instance, at an α-level of 0.05, an 8-fish sample could detect an increase of approximately 2 units above a threshold of 8 mg Se/kg with 80% power, but when α was relaxed to 0.2, this sample size was more sensitive to increasing mean Se concentrations, allowing detection of an increase of approximately 1.2 units with equivalent power. Combining individuals into 2- and 4-fish composite samples for laboratory analysis did not decrease power because the reduced number of laboratory samples was compensated for by increased

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

    Directory of Open Access Journals (Sweden)

    Morteza Asadi

    2013-04-01

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

  1. Effects of fishing technique on assessing species composition in aquatic systems in semi-arid Brazil

    Directory of Open Access Journals (Sweden)

    ESF Medeiros

    Full Text Available In most ecological field research, appropriate sampling is critical for the understanding of processes underlying fish populations and communities, and is even more important in heterogeneous environments such as the aquatic systems of the semi-arid region of Brazil. This study intends to make a contribution to the development of sampling programs and gear selection in aquatic systems of semi-arid Brazil by evaluating the effects of different fishing techniques on the assessment of richness and composition of the fish fauna in selected aquatic environments. Six sites were selected to represent typical artificial (reservoirs and natural (intermittent streams environments and four different types of sampling gear were applied to each site during four occasions. The present study shows that when selecting sampling techniques to be used in aquatic systems in semi-arid Brazil, one must consider the objectives of the study, e.g. ecological or taxonomic, in order to decide on inclusion of rare species in the sampling population. Also, the effect of the sampling gear on natural abundances of fish must be considered given that some sampling techniques are highly detrimental to fish population numbers.

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

    Directory of Open Access Journals (Sweden)

    Matono P.

    2012-06-01

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

  3. Population trends, bend use relative to available habitat and within-river-bend habitat use of eight indicator species of Missouri and Lower Kansas River benthic fishes: 15 years after baseline assessment

    Science.gov (United States)

    Wildhaber, Mark L.; Yang, Wen-Hsi; Arab, Ali

    2016-01-01

    A baseline assessment of the Missouri River fish community and species-specific habitat use patterns conducted from 1996 to 1998 provided the first comprehensive analysis of Missouri River benthic fish population trends and habitat use in the Missouri and Lower Yellowstone rivers, exclusive of reservoirs, and provided the foundation for the present Pallid Sturgeon Population Assessment Program (PSPAP). Data used in such studies are frequently zero inflated. To address this issue, the zero-inflated Poisson (ZIP) model was applied. This follow-up study is based on PSPAP data collected up to 15 years later along with new understanding of how habitat characteristics among and within bends affect habitat use of fish species targeted by PSPAP, including pallid sturgeon. This work demonstrated that a large-scale, large-river, PSPAP-type monitoring program can be an effective tool for assessing population trends and habitat usage of large-river fish species. Using multiple gears, PSPAP was effective in monitoring shovelnose and pallid sturgeons, sicklefin, shoal and sturgeon chubs, sand shiner, blue sucker and sauger. For all species, the relationship between environmental variables and relative abundance differed, somewhat, among river segments suggesting the importance of the overall conditions of Upper and Middle Missouri River and Lower Missouri and Kansas rivers on the habitat usage patterns exhibited. Shoal and sicklefin chubs exhibited many similar habitat usage patterns; blue sucker and shovelnose sturgeon also shared similar responses. For pallid sturgeon, the primary focus of PSPAP, relative abundance tended to increase in Upper and Middle Missouri River paralleling stocking efforts, whereas no evidence of an increasing relative abundance was found in the Lower Missouri River despite stocking.

  4. TESTING THE WEAK-FORM EFFICIENCY OF THE ROMANIAN CAPITAL MARKET BY ASSESSING THE RANDOM WALK-LIKE BEHAVIOUR OF STOCK PRICES

    Directory of Open Access Journals (Sweden)

    PAŞCA LUCIAN

    2015-04-01

    Full Text Available This paper attempts to test the efficiency of the Romanian Capital Market by assessing some basic statistical properties of prices for the ten most liquid stocks listed on the Bucharest Stock Exchange. More specifically, by testing if stock price series exhibit a random walk-like behaviour. For robustness of the results, two unit root tests—the Augmented Dickey-Fuller and the Kwiatkowski-Phillips-Schmidt-Shin—are used to measure stationarity for both prices and returns, and determine if price dynamics is determined by an order one integrated process (a proxy for the random walk. Further Lo and MacKinley‘s Variance Ratio Test is applied to study if the variance of returns is a linear time-dependent function (a well-known property of a random variable. The analysis is done for a period between 15 October 1997, or the listing date on the stock exchange, respectively, and 10 April 2013, for both daily and weekly observations. Furthermore, to take into account the distortive effects of the financial turmoil from 2007-2009 on market efficiency, a separate analysis has been conducted for two sub-periods, pre- and post-recession, respectively.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-09-15

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

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

    Directory of Open Access Journals (Sweden)

    TEIXEIRA A.

    2006-04-01

    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.

  7. Geospatial assessment of long-term changes in carbon stocks and fluxes in forests of India (1930-2013)

    Science.gov (United States)

    Reddy, C. Sudhakar; Rakesh, F.; Jha, C. S.; Athira, K.; Singh, Sonali; Alekhya, V. V. L. Padma; Rajashekar, G.; Diwakar, P. G.; Dadhwal, V. K.

    2016-08-01

    The present study has estimated spatial distribution of biomass carbon density from satellite remote sensing data, historical archives and collateral data from 1930 to 2013. The spatial forest canopy density datasets for 1930, 1975, 1985, 1995, 2005 and 2013 were analysed to obtain biomass carbon pools at 5 km grid level. The overall loss of forest cover was 28% from 1930 to 2013. Analysis of change in the forest canopy density indicates that the dense forest cover reduced from 419,175 km2 in 1975 to 390,966 km2 in 2013. The total above ground biomass carbon stock of Indian forest was calculated as 3070.27 Tg C in 2013. Standing biomass carbon stocks varied significantly during different steps of time periods. There are a total 67,184 grid cells with loss of carbon stocks during 1930-1975 followed by 55,742 cells during 1975-1985. The annual carbon loss in the above ground biomass showed the highest decrease during the period of 1930 to 1975 and estimated as 2168.50 Tg C while the net annual loss of carbon is 48.19 Tg C. The maximum observed net annual loss of carbon stocks was 53.97 Tg C during 2005 to 2013. Carbon content for various states shows that maximum carbon stocks were stored in the forests of Arunachal Pradesh (11.27%) in 2013. State-wise change analysis indicates the highest loss of carbon stocks in Tripura (80.99%) from 1930 to 2013. Overall reduction in carbon stock in Indian forests has been estimated as 3079.98 Tg C (50.08%) from 1930 to 2013. The spatial characterization of distribution and changes in carbon stocks can provide useful information for planning and strategic management of resources and fulfilling global initiatives to conserve forest biodiversity.

  8. Public Awareness of Mercury in Fish: Analysis of Public Awareness and Assessment of Fish Consumption in Vermont

    OpenAIRE

    Damsky, William E.; Duncan, Elizabeth; Flanagan, Noreen; Fromhold, Karen; Dung, Hyunh; Meyer, Russell; Sax, Jordan; Delaney, Thomas; Bress, William; Hoffman-Contois, Razelle; Carney, Jan K.

    2009-01-01

    Exposure to mercury from environmental sources, such as fish consumption, poses potential health risks to the public. The state of Vermont has developed educational brochures and posters displaying safe fish consumption guidelines in order to educate the public regarding mercury exposure through fish. In this study, a group of medical students from the University of Vermont College of Medicine, in partnership with the Vermont Department of Health, conducted a study in Chittenden County, Vermo...

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

    Energy Technology Data Exchange (ETDEWEB)

    N/A

    1998-08-01

    This environmental assessment (EA) has been prepared to assess potential environmental impacts associated with the U.S. Department of Energy's proposed action: the transfer of the 1100 Area, southern rail connection and rolling stock to a non-federal entity. Impact information contained herein will be used by the U.S. Department of Energy, Richland Operations Office Manager, to determine if the proposed action is a major federal action significantly affecting the quality of the human environment. If the proposed action is determined to be major and significant, an environmental impact statement will be prepared. If the proposed action is determined not to be major and significant, a Finding of No Significant Impact (FONSI) will be issued and the action can proceed. Criteria used to evaluate significance can be found in Title 40, Code of Federal Regulations (CFR) 1508.27. This EA was prepared in compliance with the ''National Environmental Policy Act'' (NEPA) of 1969, as amended, the Council on Environmental Quality (CEQ) Regulations for Implementing the Procedural Provisions of NEPA (40 CFR 1500-1508), and the U.S. Department of Energy Implementing Procedures for NEPA (10 CFR 1021). The following is a description of each section of the EA. (1) Purpose and Need for Action. This provides a brief statement concerning the problem or opportunity the U.S. Department of Energy is addressing with the proposed action. As necessary, background information is provided. (2) Description of the Proposed Action. A description with sufficient detail to identify potential environmental impacts is provided. (3) Alternatives to the Proposed Action. Reasonable alternative actions, which would address the Purpose and Need, are described. A no action alternative, as required by 10 CFR 1021, also is described. (4) Affected Environment. This provides a brief description of the locale in which the proposed action takes place, and which may be environmentally

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

    Science.gov (United States)

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

    2003-01-01

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

  11. Assessing the sensitivity of habitats to fishing: from seabed maps to sensitivity maps.

    Science.gov (United States)

    Eno, N C; Frid, C L J; Hall, K; Ramsay, K; Sharp, R A M; Brazier, D P; Hearn, S; Dernie, K M; Robinson, K A; Paramor, O A L; Robinson, L A

    2013-10-01

    In the Welsh part of the Irish Sea, a method was developed for assessing the sensitivity of different seabed habitats to existing fishing activities, across a range of potential fishing intensities. The resistance of 31 habitats and their associated biological assemblage to damage by 14 categories of fishing activity were assessed along with the rate at which each habitat would recover following impact (resilience). Sensitivity was scored based on a combination of the resistance of a habitat to damage and its subsequent rate of recovery. The assessments were based, wherever possible, on scientific literature, with expert judgement used to extrapolate results to habitat and gear combinations not directly examined in the published literature. The resulting sensitivity matrices were then subject to further peer review at a series of workshops. Following consensus on the habitat sensitivity, these data were combined with the most resolved sea-floor habitat maps. These habitat sensitivity maps can help inform the development of site-specific management plans, as well as having a place in spatial planning and aiding managers in developing dialogue with other stakeholders. A case study of their application is provided.

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

    Directory of Open Access Journals (Sweden)

    Erika da Silva Maciel

    2014-06-01

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

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

    Science.gov (United States)

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

    2013-12-01

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

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

    Science.gov (United States)

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

    2001-07-01

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

  15. Extraction of fish body oil fromSardinella longiceps by employing direct steaming method and its quantitative and qualitative assessment

    Institute of Scientific and Technical Information of China (English)

    Moorthy Pravinkumar; Lawrence Xavier Eugien; Chinnathambi Viswanathan; Sirajudeen Mohammad Raffi

    2015-01-01

    Objective:To analyze the quantitative and qualitative properties of the extracted fish oil from Sardinella longiceps(S. longiceps). Methods: Four size groups ofS. longiceps were examined for the extraction of fish oil based on length. The size groups included Group I (size range of 7.1–10.0 cm), Group II (size range of 10.1–13.0 cm), GroupIII (size range of 13.1–16.0 cm) and Group IV (size range of 16.1–19.0 cm). Fish oil was extracted from the tissues ofS. longiceps by direct steaming method. The oil was then subjected to the determination of specific gravity, refractive index, moisture content, free fatty acids, iodine value, peroxide value, saponification value and observation of colour. Results: The four groups showed different yield of fish oil that Group IV recorded the highest values of (165.00 ± 1.00) mL/kg followed by GroupIII [(145.66 ± 1.15) mL/kg] and Group II [(129.33 ± 0.58) mL/kg], whereas Group I recorded the lowest values of (78.33 ± 0.58) mL/kg in monsoon season, and the average yield was (180.0 ± 4.9) mL/kg fish tissues. These analytical values of the crude oil were well within the acceptable standard values for both fresh and stocked samples. Conclusions:The information generated in the present study pertaining to the quantitative and qualitative analysis of fish oil will serve as a reference baseline for entrepreneurs and industrialists in future for the successful commercial production of fish oil by employing oil sardines.

  16. Extraction of fish body oil from Sardinella longiceps by employing direct steaming method and its quantitative and qualitative assessment

    Directory of Open Access Journals (Sweden)

    Moorthy Pravinkumar

    2015-12-01

    Full Text Available Objective: To analyze the quantitative and qualitative properties of the extracted fish oil from Sardinella longiceps (S. longiceps. Methods: Four size groups of S. longiceps were examined for the extraction of fish oil based on length. The size groups included Group I (size range of 7.1–10.0 cm, Group II (size range of 10.1–13.0 cm, Group III (size range of 13.1–16.0 cm and Group IV (size range of 16.1– 19.0 cm. Fish oil was extracted from the tissues of S. longiceps by direct steaming method. The oil was then subjected to the determination of specific gravity, refractive index, moisture content, free fatty acids, iodine value, peroxide value, saponification value and observation of colour. Results: The four groups showed different yield of fish oil that Group IV recorded the highest values of (165.00 ± 1.00 mL/kg followed by Group III [(145.66 ± 1.15 mL/kg] and Group II [(129.33 ± 0.58 mL/kg], whereas Group I recorded the lowest values of (78.33 ± 0.58 mL/ kg in monsoon season, and the average yield was (180.0 ± 4.9 mL/kg fish tissues. These analytical values of the crude oil were well within the acceptable standard values for both fresh and stocked samples. Conclusions: The information generated in the present study pertaining to the quantitative and qualitative analysis of fish oil will serve as a reference baseline for entrepreneurs and industrialists in future for the successful commercial production of fish oil by employing oil sardines.

  17. Growth and contribution of stocked channel catfish, Ictalurus punctatus (Rafinesque, 1818): the importance of measuring post-stocking performance

    Science.gov (United States)

    Stewart, David R.; Long, James M.

    2015-01-01

    In this study it was sought to quantify post-stocking growth, survival, and contribution of advanced size (178 mm total length [TL]) channel catfish Ictalurus punctatus fingerlings, something rarely done. Channel catfish populations were evaluated before (May 2010) and after (May to August 2011 and 2012) stocking. Relative abundance, stocking contribution, and growth were different (P < 0.05) in the two study impoundments (lakes Lone Chimney and Greenleaf, Oklahoma). For fish stocked in Lake Lone Chimney, stocking contribution was lower (3–35%), and average length and weight of stocked fish by age-2 reached 230 mm TL and 85 g, whereas the stocking contribution (84–98%) and growth in length (340 mm TL) and weight (280 g) were higher by age-2 in Lake Greenleaf. Given these unambiguous differences of post-stocking performance, benchmark metrics that represent population-level information such as relative abundance and average length and weight of the sample masked these significant differences, highlighting the importance of marking hatchery-fish and then following them through time to determine the effectiveness of stocking. These results suggest that stock enhancement programmes would benefit from studies that quantify post-stocking performance of hatchery fish.

  18. COMPARATIVE ASSESSMENT OF THE CLONE OF STOCK М9ЕМLA AVERAGEGROWING APPLE-TREE

    Directory of Open Access Journals (Sweden)

    Alferov V. A.

    2016-09-01

    Full Text Available In FSBRI «North-Caucasus zonal scientific-research institute of horticulture and viticulture» (Krasnodar there was carried out the comparative economicbiological study of the average-height apple-tree stock М9ЕМLA in comparison with initial weakgrowing stock М9 in manifold, nursery and garden. Manifold bushes of the clone M9ЕMLA is quite worse in force than the stock М9 and were less branchy. Output of standard per hectare of manifold at the clone M9ЕMLA was on 35,5 thousand units more, and а standard condition of cuttings - on 13,2 % higher, than at the stock М9. Cuttings of the clone were less spiked and better rooted. In the first field of nursery, the plants of the clone had a vertical growth of the central conductor, slightly weaved and were more suitable to inoculation. The output of standard plants, in the variant with the use of clone M9ЕMLA by the variety Champion, in average for 2006-2010 was on 3112 units/hа, and on the variety Prikubanskoye – correspondently on 2470 units/hа higher than grafted on the stock М9. The cost price of 1000 seedlings on the clone M9ЕMLA was on 1962 rubles less than on the stock М9, and the standard of profitability of seedling growing, on the contrary was on 14-19 % higher. In the garden the trees on the clone M9ЕMLA were worse in growth of trees grafted on М9: on volume of the crone on 0,4-0,6 m3 , in diameter of the stem on 9-12 mm, in dependence on the variety, independently on the fact that some trees on clone were more weaker than grafted on the stock М9, their productivity for 2011-2015 was higher as from one tree as from the unit of area. The intensity of fruiting expressed in yield in kilos from a tree on the unit of volume of the top of a tree on the clone M9ЕMLA was on 33-39% higher than at the trees on the stock М9

  19. Arsenic speciation in fish products and seafood as a prerequisite for proper risk assessment

    Directory of Open Access Journals (Sweden)

    Pierluigi Piras

    2015-02-01

    Full Text Available The Boi Cerbus lagoon, facing a mining and industrial site in Sardinia (Italy, is an important fishing area for the local population. Previous studies showed high concentrations of total arsenic (Astot in fish, molluscs and crustaceans sampled in the lagoon, and a possible exceeding of the provisional tolerable weekly intake set by the Joint FAO/WHO Expert Committee on Food Additives by some local consumer groups. However, the percentage of inorganic As (Asinorg should be known for a correct assessment of potential risk, as its toxicity is much higher than that of the organic forms. Eighty samples of 14 different species of fish, molluscs and crustaceans, sampled in the Boi Cerbus lagoon in 3 different seasons (winter, spring and summer, were analysed for Astot by inductively coupled plasma mass spectrometry (ICP-MS and Asinorg by high performance liquid chromatography-ICP-MS. All the data obtained from the analysis were statistically processed to evaluate significant differences based on season, taxon and habitat, in preparation for a subsequent risk assessment.

  20. Assessing Fish and Motile Fauna around Offshore Windfarms Using Stereo Baited Video.

    Directory of Open Access Journals (Sweden)

    Ross A Griffin

    Full Text Available There remains limited knowledge of how offshore windfarm developments influence fish assemblages, particularly at a local scale around the turbine structures. Considering the existing levels of anthropogenic pressures on coastal fish populations it is becoming increasingly important for developers and environmental regulators to gain a more comprehensive understanding of the factors influencing fish assemblages. Improving our ability to assess such fish populations in close proximity to structures will assist in increasing this knowledge. In the present study we provide the first trial use of Baited Remote Underwater Stereo-Video systems (stereo BRUVs for the quantification of motile fauna in close proximity to offshore wind turbines. The study was conducted in the Irish Sea and finds the technique to be a viable means of assessing the motile fauna of such environments. The present study found a mixture of species including bottom dwellers, motile crustaceans and large predatory fish. The majority of taxa observed were found to be immature individuals with few adult individuals recorded. The most abundant species were the angular crab (Goneplax rhomboides and the small-spotted catshark (Scyliorhinus canicula. Of note in this study was the generally low abundance and diversity of taxa recorded across all samples, we hypothesise that this reflects the generally poor state of the local fauna of the Irish Sea. The faunal assemblages sampled in close proximity to turbines were observed to alter with increasing distance from the structure, species more characteristic of hard bottom environments were in abundance at the turbines (e.g. Homarus gammarus, Cancer pagarus, Scyliorhinus spp. and those further away more characteristic of soft bottoms (e.g. Norwegian Lobster. This study highlights the need for the environmental impacts of offshore renewables on motile fauna to be assessed using targeted and appropriate tools. Stereo BRUVs provide one of those

  1. A multi-scale GIS and hydrodynamic modelling approach to fish passage assessment: Clarence and Shoalhaven Rivers, NSW Australia

    Science.gov (United States)

    Bonetti, Rita M.; Reinfelds, Ivars V.; Butler, Gavin L.; Walsh, Chris T.; Broderick, Tony J.; Chisholm, Laurie A.

    2016-05-01

    Natural barriers such as waterfalls, cascades, rapids and riffles limit the dispersal and in-stream range of migratory fish, yet little is known of the interplay between these gradient dependent landforms, their hydraulic characteristics and flow rates that facilitate fish passage. The resurgence of dam construction in numerous river basins world-wide provides impetus to the development of robust techniques for assessment of the effects of downstream flow regime changes on natural fish passage barriers and associated consequences as to the length of rivers available to migratory species. This paper outlines a multi-scale technique for quantifying the relative magnitude of natural fish passage barriers in river systems and flow rates that facilitate passage by fish. First, a GIS-based approach is used to quantify channel gradients for the length of river or reach under investigation from a high resolution DEM, setting the magnitude of identified passage barriers in a longer context (tens to hundreds of km). Second, LiDAR, topographic and bathymetric survey-based hydrodynamic modelling is used to assess flow rates that can be regarded as facilitating passage across specific barriers identified by the river to reach scale gradient analysis. Examples of multi-scale approaches to fish passage assessment for flood-flow and low-flow passage issues are provided from the Clarence and Shoalhaven Rivers, NSW, Australia. In these river systems, passive acoustic telemetry data on actual movements and migrations by Australian bass (Macquaria novemaculeata) provide a means of validating modelled assessments of flow rates associated with successful fish passage across natural barriers. Analysis of actual fish movements across passage barriers in these river systems indicates that two dimensional hydraulic modelling can usefully quantify flow rates associated with the facilitation of fish passage across natural barriers by a majority of individual fishes for use in management

  2. Toxicological assessment of fish (Clarias gariepinus) from bitumen-polluted River Oluwa, Nigeria.

    Science.gov (United States)

    Ayandiran, T A; Dahunsi, S O

    2016-02-01

    Toxicological evaluation of Clarias gariepinus from bitumen-polluted River Oluwa, Nigeria, was carried out in furtherance of studies on the environmental impacts of the bitumen exploration in Ondo State, Nigeria. Samples were taken from three different (two polluted and one as control) sites. The effect of changes in monthly seasonal flow rate was assessed for the sites of study. Blood plasma clinical-chemical parameters (BCCPs) and histological changes/lesions in various organs were evaluated as markers of pollution in the fish blood using standard methods. The result of the physicochemical properties of water from the sampling points revealed some of the values conforming to approved standards while others showed deviation. Significant differences were found in the blood and histological endpoints between the control and the polluted sites as well as between the two seasons evaluated across the sites. The public health implications of consuming this fish are fully discussed.

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

    Directory of Open Access Journals (Sweden)

    Mohanad El-Harbawi

    2013-01-01

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

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

    Science.gov (United States)

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

    2015-01-01

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

  5. The Development of Stock Markets: In Search of a Theory

    OpenAIRE

    KAMAL A. EL-WASSAL

    2013-01-01

    This paper aims to provide a framework for the main determinants of stock market development. Assessing stock market development requires not only an understanding of its main determinants but also a clear definition of what “stock market development” means and how progress towards it can be measured. This paper reconsiders the concept of stock market development and suggests five dimensions for assessing it. In addition, it proposes four sets of factors that shape or determine stock market d...

  6. Assessment of Present Anadromous Fish Production Facilities in the Columbia River Basin, US Fish and Wildlife Hatcheries, Final Report.

    Energy Technology Data Exchange (ETDEWEB)

    Delarm, Michael R.; Smith, Robert Z.

    1990-07-01

    The goal of this report is to document current production practices for hatcheries which rear anadromous fish in the Columbia River Basin and to identify those facilities where production can be increased. A total of 85 hatchery and satellite facilities operated by the Idaho Department of Fish and Game, Oregon Department of Fish and Game, US Fish and Wildlife Service, Washington Department of Wildlife, and Washington Department of Fisheries were evaluated. The years 1985 to 1987 were used in this evaluation. During those years, releases averaged 143,306,596 smolts weighing 7,693,589 pounds. A total of 48 hatchery or satellite facilities were identified as having expansion capability. They were estimated to have the potential for increasing production by an 84,448,000 smolts weighing 4,853,306 pounds. 2 refs., 25 tabs.

  7. Ontogenetic shifts in fishes between vegetated and unvegetated tidepools: assessing the effect of physical structure on fish habitat selection.

    Science.gov (United States)

    Oliveira, R R de S; Macieira, R M; Giarrizzo, T

    2016-07-01

    The aim of this study of tidepool fishes was analyse variation in their use of intertidal habitats (rocky shore, mangrove and salt marsh). Specimens were collected during wet and dry periods from 18 tidepools in the three habitats. A total of 7690 specimens, belonging to 19 families and 30 species, was captured. The fish assemblage in rocky shore pools was clearly distinct from that of vegetated habitats (mangrove and salt marshes). The rocky shore fauna was dominated by permanent resident species, whereas pools in mangrove and salt marsh habitats were inhabited primarily by opportunistic and transient species. Habitat segregation by ontogenetic stage (e.g. smaller individuals in mangroves, intermediate size classes in salt marsh and sub-adults/adults on rocky shores) indicates age-related migration in response to the physical structure of these habitats and to the natural history of each fish species. These findings are important for the development of effective conservation and management plans for intertidal fishes.

  8. The application of image cytometry to viability assessment in dual fluorescence-stained fish spermatozoa.

    Science.gov (United States)

    Flajshans, Martin; Cosson, Jacky; Rodina, Marek; Linhart, Otomar

    2004-01-01

    The viability of spermatozoa has been assessed using SYBR 14 staining for DNA of living cells and propidium iodide staining for DNA of degenerate cells. This dual staining was performed on four fish species (Siberian sturgeon, Acipenser baerii; common carp, Cyprinus carpio; tench, Tinca tinca and wels, Silurus glanis) and the proportions of live and dead spermatozoa were assessed by epifluorescence microscopy and image cytometry. Ten phase contrast and epifluorescent images were recorded per sample, corresponding images were overlaid, and the blended images were evaluated for live and dead spermatozoa, represented by green and red fluorescence signals. Live/dead proportions were assessed, after dual thresholding, by imaging software that counted absolute numbers of objects and computed their frequencies. All sperm heads were found to be labelled, emitting either green or red light. Mean numbers of spermatozoa per image were in the ranges 32-113, 61-105, 48-104 and 29-91 for Siberian sturgeon, common carp, tench and wels, respectively. The corresponding proportions of live spermatozoa were in the ranges 83.56-94.59%, 93.92-97.02%, 76.14-97.76% and 79.45-83.76%. Standard deviations did not exceed 5% of the means. The image cytometric system using dual staining with SYBR 14 and propidium iodide was clearly suitable for assessing the viability of freshwater fish spermatozoa.

  9. Sources of errors and uncertainties in the assessment of forest soil carbon stocks at different scales—review and recommendations

    NARCIS (Netherlands)

    Vanguelova, E.I.; Bonifacio, E.; Vos, De B.; Hoosbeek, M.R.; Berger, T.W.; Vesterdal, L.; Armolaitis, K.; Celi, L.; Dinca, L.; Kjønaas, O.J.; Pavlenda, P.; Pumpanen, J.; Püttsepp,; Reidy, B.; Simončič, P.; Tobin, B.; Zhiyanski, M.

    2016-01-01

    Spatially explicit knowledge of recent and past soil organic carbon (SOC) stocks in forests will improve our understanding of the effect of human- and non-human-induced changes on forest C fluxes. For SOC accounting, a minimum detectable difference must be defined in order to adequately determine te

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-09-01

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

  11. Stock assessment of small yellow croaker in the East China Sea based on multi-source data%基于多源数据的东海小黄鱼资源评估与管理

    Institute of Scientific and Technical Information of China (English)

    刘尊雷; 严利平; 袁兴伟; 杨林林; 刘勇; 黎雨轩; 李圣法; 程家骅; 吴颖

    2013-01-01

    overfished stocks. The proposed control rule consists of relative biomass and relative fishing mortality rate in a deterministic environment and conservative harvest in a fluctuating environment. The results of the Fox model explained 68%of the variance observed for the stock abundance, while the logistic model explained 57%. The parameter estimates were different and the Fox model predicted a much larger decrease in population abundance at the MSY, intrinsic growth rates(r), and initial exploited levels. We compared the fishing mortality/current stock biomass from 1998 to 2006 with the fishing- and stock-related reference points, respec-tively. The results in a determined environment revealed that small yellow croaker stock in the East China Sea was overfished in most years, while the population was not always overfished during the entire period, although its biomass has been decreasing since 1999. However, both the Fox and logistic surplus production models indicate that the small yellow croaker fishery has been consistently over harvested in the fluctuating environment. Har-vesting at a conservative level with either the Fox or logistic model could increase small yellow croaker abun-dance substantially with little decrease in harvest. At a conservative harvest level, there is a 24.7% increase in biomass with a 6.1% decrease in yield with the logistic model and a 44.5% increase in biomass with a 9.4% de-crease in yield with the Fox model. The MSY assessment results from the Fox surplus production model was more conservative than that of logistic model, which is concordant with precautionary fisheries management strategies.

  12. Culture dependent bacteria in commercial fishes: Qualitative assessment and molecular identification using 16S rRNA gene sequencing

    KAUST Repository

    Alikunhi, Nabeel M.

    2016-05-27

    Fish contaminations have been extensively investigated in Saudi coasts, but studies pertaining to bacterial pathogens are meager. We conducted qualitative assessment and molecular identification of culture dependent bacteria in 13 fish species collected from three fishing sites and a local fish market in Jeddah, Saudi Arabia. The bacterial counts of gills, skin, gut and muscle were examined on agar plates of Macconkey’s (Mac), Eosin methylene blue (EMB) and Thiosulfate Citrate Bile Salts (TCBS) culture media. Bacterial counts exhibited interspecific, locational and behavioral differences. Mugil cephalus exhibited higher counts on TCBS (all body-parts), Mac (gills, muscle and gut) and EMB (gills and muscle). Samples of Area I were with higher counts, concurrent to seawater and sediment samples, revealing the influence of residing environment on fish contamination. Among feeding habits, detritivorous fish harbored higher bacterial counts, while carnivorous group accounted for lesser counts. Counts were higher in skin of fish obtained from market compared to field samples, revealing market as a major source of contamination. Bacterial counts of skin were positively correlated with other body-parts indicating influence of surface bacterial biota in overall quality of fish. Hence, hygienic practices and proper storage facilities in the Jeddah fish market is recommended to prevent adverse effect of food-borne illness in consumers. Rahnella aquatilis (Enterobacteriaceae) and Photobacterium damselae (Vibrionaceae) were among the dominant species identified from fish muscle samples using Sanger sequencing of 16S rRNA. This bacterial species are established human pathogens capable of causing foodborne illness with severe antibiotic resistance. Opportunistic pathogens such as Hafnia sp. (Enterobacteriaceae) and Pseudomonas stutzeri (Pseudomonadaceae) were also identified from fish muscle. These findings indicate bacterial contamination risk in commonly consumed fish of

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

    Data.gov (United States)

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

  14. Environmental Assessment of the Proposed Opening of Mathews Brake National Wildlife Refuge to Fishing

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This proposal calls for the opening of Mathews Brake NWR to sport fishing. General regulations pertaining to licenses, creel limits, and methods of taking fish will...

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

    Energy Technology Data Exchange (ETDEWEB)

    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

    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

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

    Science.gov (United States)

    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

    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

  17. 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...

  18. Designing long-term fish community assessments in connecting channels: Lessons from the Saint Marys River

    Science.gov (United States)

    Schaeffer, Jeff; Rogers, Mark W.; Fielder, David G.; Godby, Neal; Bowen, Anjanette K.; O'Connor, Lisa; Parrish, Josh; Greenwood, Susan; Chong, Stephen; Wright, Greg

    2014-01-01

    Long-term surveys are useful in understanding trends in connecting channel fish communities; a gill net assessment in the Saint Marys River performed periodically since 1975 is the most comprehensive connecting channels sampling program within the Laurentian Great Lakes. We assessed efficiency of that survey, with intent to inform development of assessments at other connecting channels. We evaluated trends in community composition, effort versus estimates of species richness, ability to detect abundance changes for four species, and effects of subsampling yellow perch catches on size and age-structure metrics. Efficiency analysis revealed low power to detect changes in species abundance, whereas reduced effort could be considered to index species richness. Subsampling simulations indicated that subsampling would have allowed reliable estimates of yellow perch (Perca flavescens) population structure, while greatly reducing the number of fish that were assigned ages. Analyses of statistical power and efficiency of current sampling protocols are useful for managers collecting and using these types of data as well as for the development of new monitoring programs. Our approach provides insight into whether survey goals and objectives were being attained and can help evaluate ability of surveys to answer novel questions that arise as management strategies are refined.

  19. Proposed best modeling practices for assessing the effects of ecosystem restoration on fish

    Science.gov (United States)

    Rose, Kenneth A; Sable, Shaye; DeAngelis, Donald L.; Yurek, Simeon; Trexler, Joel C.; Graf, William L.; Reed, Denise J.

    2015-01-01

    Large-scale aquatic ecosystem restoration is increasing and is often controversial because of the economic costs involved, with the focus of the controversies gravitating to the modeling of fish responses. We present a scheme for best practices in selecting, implementing, interpreting, and reporting of fish modeling designed to assess the effects of restoration actions on fish populations and aquatic food webs. Previous best practice schemes that tended to be more general are summarized, and they form the foundation for our scheme that is specifically tailored for fish and restoration. We then present a 31-step scheme, with supporting text and narrative for each step, which goes from understanding how the results will be used through post-auditing to ensure the approach is used effectively in subsequent applications. We also describe 13 concepts that need to be considered in parallel to these best practice steps. Examples of these concepts include: life cycles and strategies; variability and uncertainty; nonequilibrium theory; biological, temporal, and spatial scaling; explicit versus implicit representation of processes; and model validation. These concepts are often not considered or not explicitly stated and casual treatment of them leads to mis-communication and mis-understandings, which in turn, often underlie the resulting controversies. We illustrate a subset of these steps, and their associated concepts, using the three case studies of Glen Canyon Dam on the Colorado River, the wetlands of coastal Louisiana, and the Everglades. Use of our proposed scheme will require investment of additional time and effort (and dollars) to be done effectively. We argue that such an investment is well worth it and will more than pay back in the long run in effective and efficient restoration actions and likely avoided controversies and legal proceedings.

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

    Science.gov (United States)

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

    2011-01-01

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

  1. 太湖鱼类放流增殖的有效数量和合理结构%Fish stocking quantities and structures of the fishery resources enhancement in Lake Taihu

    Institute of Scientific and Technical Information of China (English)

    何俊; 谷孝鸿; 王小林; 吴林坤; 陈非洲; 曹萍; 刘家驹; 张宪中

    2012-01-01

    根据2006-2007年太湖生物资源调查,估算出太湖浮游植物、浮游动物、底栖动物和水生植物总渔产潜力约为78494 t.太湖实施以渔改水的生物调控措施,应加大鲢、鳙放流数量和放流规格,在提高鱼产量的同时对抑制太湖蓝藻水华能起到积极作用;推算每年放流鳙约1000×104尾,鲢约300×104尾,规格为20尾/kg为宜.草鱼、团头鲂、青鱼、鲤等要在保护太湖水草和底栖动物资源和生物多样性前提下适当放流,每年宜放流草鱼150×104尾,团头鲂165×104尾,青鱼8×104 ~ 10×104尾,鲤夏花2500×104尾.而对调控鱼类结构小型化、单一化具有重要作用的肉食性鱼类翘嘴铂建议加大放流量,年放流量可扩大至500×104尾左右,在调控的同时提高湖泊渔业附加值.%According to the investigations of biological resources in Lake Taihu during 2006 -2007, we calculated that total fishery yield potential of phytoplankton, zooplankton, zoobenthos and aquatic macrophytes in Lake Taihu was about 78494 t. In order to increase fish yields and inhibit cyanobacteria bloom in Lake Taihu, stocking number of silver carp (Hypohthalmichlhys molitrix Richardson) and bighead carpi Aristichthys nobilis Cuvier) should be increased to 10 million and 3 million tails, respectively, and the specification should be 20 tails per kilogram. To protect resources of aquatic macrophytes and zoobenthos, the reasonable stocking number of grass carp (Ctenopharyngodon idellus Cuvier), blunt snout bream ( Megalobrama amblycephala Yih) , black carp (Mylopharyngodan piceus Richardson) and common carp( Cyprinidae carpio Linnaeus) should be 1. 5 million, 1.65 million, 80 -100 thousand and 25 million tails,respectively. As topmouth cutler such as cutler albumus could play important roles in controlling miniaturization and singleness of fishery structure and increase added-value of fishery economy, its stocking quantity should be increased to S million tails.

  2. Risk and toxicity assessments of heavy metals in sediments and fishes from the Yangtze River and Taihu Lake, China.

    Science.gov (United States)

    Fu, Jie; Hu, Xin; Tao, Xiancong; Yu, Hongxia; Zhang, Xiaowei

    2013-11-01

    Heavy metal pollution is one of the most serous environmental issues globally. To evaluate the metal pollution in Jiangsu Province of China, the total concentrations of heavy metals in sediments and fishes from the Yangtze River and Taihu Lake were analyzed. Ecological risk of sediments and human health risk of fish consumption were assessed respectively. Furthermore, toxicity of samples on expression of the stress responsive genes was evaluated using microbial live cell-array method. The results showed that the heavy metals concentrations in sediments from the Yangtze River were much higher than those in sediments from the Taihu Lake. However, the fishes from the Taihu Lake had higher concentrations of heavy metals than fishes from the Yangtze River. Ecological risk evaluation showed that the heavy metal contaminants in sediments from the Yangtze River posed higher risk of adverse ecological effects, while sediments from the study areas of Taihu Lake were relatively safe. Health risk assessment suggested that the heavy metals in fishes of both Yangtze River and Taihu Lake might have risk of adverse health effects to human. The toxicity assessment indicated that the heavy metals in these sediments and fishes showed transcriptional effects on the selected 21 stress responsive genes, which were involved in the pathways of DNA damage response, chemical stress, and perturbations of electron transport. Together, this field investigation combined with chemical analysis, risk assessment and toxicity bioassay would provide useful information on the heavy metal pollution in Jiangsu Province.

  3. A framework for assessing the feasibility of native fish conservation translocations: Applications to threatened bull trout

    Science.gov (United States)

    Galloway, Benjamin T.; Muhlfeld, Clint C.; Guy, Christopher S.; Downs, Christopher C.; Fredenberg, Wade A.

    2016-01-01

    There is an urgent need to consider more aggressive and direct interventions for the conservation of freshwater fishes that are threatened by invasive species, habitat loss, and climate change. Conservation introduction (moving a species outside its indigenous range to other areas where conditions are predicted to be more suitable) is one type of translocation strategy that fisheries managers can use to establish new conservation populations in areas of refugia. To date, however, there are few examples of successful conservation-based introductions. Many attempts fail to establish new populations—in part because environmental factors that might influence success are inadequately evaluated before the translocation is implemented. We developed a framework to assess the feasibility of rescuing threatened fish populations through translocation into historically unoccupied stream and lake habitats. The suitability of potential introduction sites was evaluated based on four major components: the recipient habitat, recipient community, donor population, and future threats. Specific questions were then developed to evaluate each major component. The final assessment was based on a scoring system that addressed each question by using criteria developed from characteristics representative of highly suitable habitats and populations. This framework was used to evaluate the proposed within-drainage translocation of three Bull Trout Salvelinus confluentus populations in Glacier National Park, Montana. Our results indicated that within-drainage translocation is a feasible strategy for conserving locally adapted populations of Bull Trout through the creation of new areas of refugia in Glacier National Park. The framework provides a flexible platform that can help managers make informed decisions for moving threatened fishes into new areas of refugia for conservation and recovery programs.

  4. Carbon stock assessment for a forest-to-coffee conversion landscape in Sumber-Jaya (Lampung, Indonesia): from allometric equations to land use change analysis

    Institute of Scientific and Technical Information of China (English)

    Meine; van; Noordwijk; Subekti; Rahayu; Kurniatun; Hairiah; Y.; C.; Wulan; A.; Farida; Bruno; Verbist

    2002-01-01

    The change in stored carbon (C) stocks was assessed for a 700 km2 areawhere 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 providea 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. The shoot:root ratio (biomass) of coffee shifted with age, from the 4:1 value often assumed for tropical trees to 2:1. Annual aboveground C stock accumulation rates during the establishment stage after slash-and- burn land clearing were 1, closeto 2 or 3.5 Mg C ha-1a-1 for sun coffee, shade coffee and fallow regrowth, respectively. Forest remnants, shade coffee and sun coffee had soil C stocks in the upper 30 cm of the soil that were 79%, 60% or 45%, respectively, of the values expected for primary forest in Sumatra. Total C stock (time averaged, above - 0.3m in the soil) for forest, shade and sun coffee was 262, 82 and 52 Mg C ha-1, respectively. 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-1 a-1. In the 1984-2000 period forest cover was further reduced to 12.6%, but the landscape lost only 0.39Mg C ha-1 a-1, as forest loss was partially compensated by an increase in shadecoffee 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-1 over a time frame of say 20 years, or 0.5 Mg C ha-1 a-1.

  5. Methylmercury Concentration in Fish and Risk-Benefit Assessment of Fish Intake among Pregnant versus Infertile Women in Taiwan.

    Directory of Open Access Journals (Sweden)

    Hsing-Cheng Hsi

    Full Text Available This study examined methylmercury (MeHg concentrations in fish, the daily MeHg exposure dose, and the risk-benefit of MeHg, ω-3 polyunsaturated fatty acid (ω-3 PUFA, docosahexaenoic acid (DHA, and eicosapentaenoic acid (EPA related to fish intake among pregnant and infertile women in Taiwan. The measured MeHg concentrations in fish did not exceed the Codex guideline level of 1 mg/kg. Swordfish (0.28 ± 0.23 mg/kg and tuna (0.14 ± 0.13 mg/kg had the highest MeHg concentrations. The MeHg concentration in the hair of infertile women (1.82 ± 0.14 mg/kg was significantly greater than that of pregnant women (1.24 ± 0.18 mg/kg. In addition, 80% of infertile women and 68% of pregnant women had MeHg concentrations in hair that exceeded the USEPA reference dose (1 mg/kg. The MeHg concentrations in hair were significantly and positively correlated with the estimated daily MeHg exposure dose. Based on the risk-benefit evaluation results, this paper recommends consumption of fish species with a low MeHg concentration and high concentrations of DHA + EPA and ω-3 PUFA (e.g., salmon, mackerel, and greater amberjack.

  6. Fish products available in Polish market--assessment of the nutritive value and human exposure to dioxins and other contaminants.

    Science.gov (United States)

    Usydus, Zygmunt; Szlinder-Richert, Joanna; Polak-Juszczak, Lucyna; Komar, Katarzyna; Adamczyk, Maria; Malesa-Ciecwierz, Małgorzata; Ruczynska, Wiesława

    2009-03-01

    Chemical analyses were performed on one hundred and twenty of the most popular varieties of fish products (smoked fish, salted fish, and marinated fish) of the fish market in Poland. The contents of the nutritive substances of fish products (protein, micro- and macronutrients, vitamins A(1), D(3), E, and fatty acids) and the chosen contaminant (toxic metals--mercury, cadmium, lead, arsenic; dioxin/furans--PCDDFs; dioxin-like PCB--dl-PCBs; seven congeners of polybrominated diphenyl ethers--PBDEs; organochlorine pesticides--SigmaDDT, HCB, SigmaHCH and marker polychlorinated biphenyls--PCB(7)) levels were determined. It was confirmed that fish products are a good source of digestible proteins, iodine, selenium, and vitamin D(3). The fundamental nutritive benefit of processed fish lies in its highly beneficial fatty acid composition, which is what imparts them healthy nutritive qualities. The high content of long-chain polyunsaturated fatty acids (LC-PUFAs), which is not noted in other food products, is particularly important. The majority of contaminants studied were present in low levels. The possible threats, particularly in the case of pregnant/nursing women and young children, can pose the levels of dioxin/furans (PCDD/Fs) and dioxin-like (dl-PCBs) in smoked Baltic salmon and smoked sprat, elevated in a relation to particular requirements concerning the content of sum of PCDD/Fs and dl-PCBs in fish (8pg WHO-TEQg(-1)). The health benefits and risks stemming from consumption of fish products were determined according to the Provisional Tolerable Weekly Intake (PTWI) for chosen contaminants (Cd, Hg, As, PCDD/Fs+dl-PCB) and the quantity of ingredients that render a fish diet healthy based on data from the EFSA Journal [EFSA (European Food Safety Authority), 2005. Opinion of the scientific panel on contaminants in the food chain on a request from the European Parliament related to the safety assessment of wild and farmed fish. EFSA J. 236, 1-118]. In regard of high

  7. Applications of DNA barcoding to fish landings: authentication and diversity assessment.

    Science.gov (United States)

    Ardura, Alba; Planes, Serge; Garcia-Vazquez, Eva

    2013-12-30

    DNA barcoding methodologies are being increasingly applied not only for scientific purposes but also for diverse real-life uses. Fisheries assessment is a potential niche for DNA barcoding, which serves for species authentication and may also be used for estimating within-population genetic diversity of exploited fish. Analysis of single-sequence barcodes has been proposed as a shortcut for measuring diversity in addition to the original purpose of species identification. Here we explore the relative utility of different mitochondrial sequences (12S rDNA, COI, cyt b, and D-Loop) for application as barcodes in fisheries sciences, using as case studies two marine and two freshwater catches of contrasting diversity levels. Ambiguous catch identification from COI and cyt b was observed. In some cases this could be attributed to duplicated names in databases, but in others it could be due to mitochondrial introgression between closely related species that may obscure species assignation from mtDNA. This last problem could be solved using a combination of mitochondrial and nuclear genes. We suggest to simultaneously analyze one conserved and one more polymorphic gene to identify species and assess diversity in fish catches.

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

    Science.gov (United States)

    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

    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 μg 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.

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

    Science.gov (United States)

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

    2015-05-15

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

  10. Pharmaceutical Metabolism in Fish: Using a 3-D Hepatic In Vitro Model to Assess Clearance

    Science.gov (United States)

    Baron, Matthew G.; Mintram, Kate S.; Owen, Stewart F.; Hetheridge, Malcolm J.; Moody, A. John; Purcell, Wendy M.; Jackson, Simon K.; Jha, Awadhesh N.

    2017-01-01

    At high internal doses, pharmaceuticals have the potential for inducing biological/pharmacological effects in fish. One particular concern for the environment is their potential to bioaccumulate and reach pharmacological levels; the study of these implications for environmental risk assessment has therefore gained increasing attention. To avoid unnecessary testing on animals, in vitro methods for assessment of xenobiotic metabolism could aid in the ecotoxicological evaluation. Here we report the use of a 3-D in vitro liver organoid culture system (spheroids) derived from rainbow trout to measure the metabolism of seven pharmaceuticals using a substrate depletion assay. Of the pharmaceuticals tested, propranolol, diclofenac and phenylbutazone were metabolised by trout liver spheroids; atenolol, metoprolol, diazepam and carbamazepine were not. Substrate depletion kinetics data was used to estimate intrinsic hepatic clearance by this spheroid model, which was similar for diclofenac and approximately 5 fold higher for propranolol when compared to trout liver microsomal fraction (S9) data. These results suggest that liver spheroids could be used as a relevant and metabolically competent in vitro model with which to measure the biotransformation of pharmaceuticals in fish; and propranolol acts as a reproducible positive control. PMID:28045944

  11. Assessment of heavy metals and estimation of human health risk in Tilapia fish from Naik lake of Nagpur, India

    Digital Repository Service at National Institute of Oceanography (India)

    Giripunje, M.D.; Fulke, A.B.; Meshram, P.U.

    trace elements in fish and other seafood from the French market. Food Chem. 127:934-942. ICMR (Indian Council of Medical Research) (2009). Nutrient requirements and recommended dietary allowances for Indians, A Report of the Expert Group... of the Indian Council of Medical Giripunje et al. 29 Research. Final draft. National Institute of Nutrition P 3. Ikem A, Egiebor NO (2005). Assessment of trace elements in canned fishes (mackerel, tuna, salmon, sardines and herrings) marketed...

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

    Data.gov (United States)

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

  13. 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)

    Bennett, B. A.

    1989-03-01

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Marmorek, David

    2004-03-01

    Habitat protection and restoration is a cornerstone of current strategies to restore ecosystems, recover endangered fish species, and rebuild fish stocks within the Columbia River Basin. Strategies featuring habitat restoration include the 2000 Biological Opinion on operation of the Federal Columbia River Power System (FCRPS BiOp) developed by the National Marine Fisheries Service (NMFS), the 2000 Biological Opinion on Bull Trout developed by the US Fish and Wildlife Service (USFWS), and Sub-Basin Plans developed under the Fish and Wildlife Program of the Northwest Power and Conservation Council (NWPCC). There is however little quantitative information about the effectiveness of different habitat restoration techniques. Such information is crucial for helping scientists and program managers allocate limited funds towards the greatest benefits for fish populations. Therefore, it is critical to systematically test the hypotheses underlying habitat restoration actions for both anadromous and resident fish populations. This pilot project was developed through a proposal to the Innovative Projects fund of the NWPCC (ESSA 2002). It was funded by the Bonneville Power Administration (BPA) following reviews by the Independent Scientific Review Panel (ISRP 2002), the Columbia Basin Fish and Wildlife Authority (CBFWA 2002), the NWPCC and BPA. The study was designed to respond directly to the above described needs for information on the effectiveness of habitat restoration actions, including legal measures specified in the 2000 FCRPS BiOp (RPA 183, pg. 9-133, NMFS 2000). Due to the urgency of addressing these measures, the timeline of the project was accelerated from a duration of 18 months to 14 months. The purpose of this pilot project was to explore methods for evaluating past habitat restoration actions and their effects on fish populations. By doing so, the project will provide a foundation of retrospective analyses, on which to build prospective, multi-watershed designs

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

    Energy Technology Data Exchange (ETDEWEB)

    Marmorek, David

    2004-03-01

    Habitat protection and restoration is a cornerstone of current strategies to restore ecosystems, recover endangered fish species, and rebuild fish stocks within the Columbia River Basin. Strategies featuring habitat restoration include the 2000 Biological Opinion on operation of the Federal Columbia River Power System (FCRPS BiOp) developed by the National Marine Fisheries Service (NMFS), the 2000 Biological Opinion on Bull Trout developed by the US Fish and Wildlife Service (USFWS), and Sub-Basin Plans developed under the Fish and Wildlife Program of the Northwest Power and Conservation Council (NWPCC). There is however little quantitative information about the effectiveness of different habitat restoration techniques. Such information is crucial for helping scientists and program managers allocate limited funds towards the greatest benefits for fish populations. Therefore, it is critical to systematically test the hypotheses underlying habitat restoration actions for both anadromous and resident fish populations. This pilot project was developed through a proposal to the Innovative Projects fund of the NWPCC (ESSA 2002). It was funded by the Bonneville Power Administration (BPA) following reviews by the Independent Scientific Review Panel (ISRP 2002), the Columbia Basin Fish and Wildlife Authority (CBFWA 2002), the NWPCC and BPA. The study was designed to respond directly to the above described needs for information on the effectiveness of habitat restoration actions, including legal measures specified in the 2000 FCRPS BiOp (RPA 183, pg. 9-133, NMFS 2000). Due to the urgency of addressing these measures, the timeline of the project was accelerated from a duration of 18 months to 14 months. The purpose of this pilot project was to explore methods for evaluating past habitat restoration actions and their effects on fish populations. By doing so, the project will provide a foundation of retrospective analyses, on which to build prospective, multi-watershed designs

  16. Assessment and assortment: how fishes use local and global cues to choose which school to go to.

    Science.gov (United States)

    Ward, Ashley J W; Hart, Paul J B; Krause, Jens

    2004-08-01

    Animals that live in groups are known preferentially to associate with phenotypically similar individuals. Despite this, groups of mixed phenotypic composition are the norm rather than the exception in several systems in the wild and this, combined with the large sizes of some animal groups, makes accurate global assessment by a choosing individual more difficult. In this study, we investigated the role of local and global information in mediating shoal-choice decisions in three-spined sticklebacks (Gasterosteus aculeatus) by manipulating the positions and phenotypes of stimulus fish in relation to a focal fish. Focal fish were able to assess globally mixed shoals composed of individuals of different body-length classes, preferring to associate with shoals where the majority phenotype matched their own. When local cues were manipulated this preference disappeared, although overall shoal composition remaining constant. Finally, if both stimulus shoals had the same overall composition but differed in their local cues, then the focus fish chose according to which local fish was of matching body length. These findings indicate that both local and global information play an important role in mediating assessment and shoal choice in fishes.

  17. Growth and smolting in lower-mode Atlantic Salmon stocked into the Penobscot River, Maine

    Science.gov (United States)

    Zydlewski, Joseph; O'Malley, Andrew; Cox, Oliver; Ruksznis, Peter; Trial, Joan G.

    2014-01-01

    Restoration of Atlantic Salmon Salmo salar in Maine has relied on hatchery-produced fry and smolts for critical stocking strategies. Stocking fry minimizes domestication selection, but these fish have poor survival. Conversely, stocked smolts have little freshwater experience but provide higher adult returns. Lower-mode (LM) fish, those not growing fast enough to ensure smolting by the time of stocking, are a by-product of the smolt program and are an intermediate hatchery product. From 2002 to 2009, between 70,000 and 170,000 marked LM Atlantic Salmon were stocked into the Pleasant River (a tributary in the Penobscot River drainage, Maine) in late September to early October. These fish were recaptured as actively migrating smolts (screw trapping), as nonmigrants (electrofishing), and as returning adults to the Penobscot River (Veazie Dam trap). Fork length (FL) was measured and a scale sample was taken to retrospectively estimate FL at winter annulus one (FW1) using the intercept-corrected direct proportion model. The LM fish were observed to migrate as age-1, age-2, and infrequently as age-3 smolts. Those migrating as age-1 smolts had a distinctly larger estimated FL at FW1 (>112 mm) than those that remained in the river for at least one additional year. At the time of migration, age-2 and age-3 smolts were substantially larger than age-1 smolts. Returning adult Atlantic Salmon of LM origin had estimated FLs at FW1 that corresponded to smolt age (greater FL for age 1 than age 2). The LM product produces both age-1 and age-2 smolts that have greater freshwater experience than hatchery smolts and may have growth and fitness advantages. The data from this study will allow managers to better assess the probability of smolting age and manipulate hatchery growth rates to produce a targeted-size LM product.

  18. Fishing amplifies forage fish population collapses.

    Science.gov (United States)

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

    2015-05-26

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

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

    Science.gov (United States)

    Saleh, Yousef S; Marie, Mohamed-Assem S

    2015-04-01

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

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

    Directory of Open Access Journals (Sweden)

    A. M. Snow

    2008-01-01

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

  1. Assessment of two nonnative poeciliid fishes for monitoring selenium exposure in the endangered desert pupfish

    Science.gov (United States)

    Saiki, Michael K.; Martin, Barbara A.; May, Thomas W.; Brumbaugh, William G.

    2012-01-01

    We assessed the suitability of two nonnative poeciliid fishes—western mosquitofish (Gambusia affinis) and sailfin mollies (Poecilia latipinna)—for monitoring selenium exposure in desert pupfish (Cyprinodon macularius). Our investigation was prompted by a need to avoid lethal take of an endangered species (pupfish) when sampling fish for chemical analysis. Total selenium (SeTot) concentrations in both poeciliids were highly correlated with SeTot concentrations in pupfish. However, mean SeTot concentrations varied among fish species, with higher concentrations measured in mosquitofish than in mollies and pupfish from one of three sampled agricultural drains. Moreover, regression equations describing the relationship of selenomethionine to SeTot differed between mosquitofish and pupfish, but not between mollies and pupfish. Because selenium accumulates in animals primarily through dietary exposure, we examined fish trophic relationships by measuring stable isotopes (δ13C and δ15N) and gut contents. According to δ13C measurements, the trophic pathway leading to mosquitofish was more carbon-depleted than trophic pathways leading to mollies and pupfish, suggesting that energy flow to mosquitofish originated from allochthonous sources (terrestrial vegetation, emergent macrophytes, or both), whereas energy flow to mollies and pupfish originated from autochthonous sources (filamentous algae, submerged macrophytes, or both). The δ15N measurements indicated that mosquitofish and mollies occupied similar trophic levels, whereas pupfish occupied a slightly higher trophic level. Analysis of gut contents showed that mosquitofish consumed mostly winged insects (an indication of terrestrial taxa), whereas mollies and pupfish consumed mostly organic detritus. Judging from our results, only mollies (not mosquitofish) are suitable for monitoring selenium exposure in pupfish.

  2. L-band synthetic aperture radar (SAR) response to the tropical forest stands for carbon stock assessment

    Science.gov (United States)

    Omar, Hamdan; Che Mat, Nur Laila; Hamzah, Khali Aziz; Ismail, Mohd Hasmadi

    2013-05-01

    Several attempts have been made to obtain forest stand parameters such as stand volume, stand density, basal area, biomass, and carbon stock from synthetic aperture radar (SAR) data. However the relationship between these parameters and radar backscatter has been a challenging issue since the last few years. In this study, L-band ALOS PALSAR satellite image with a spatial resolution of 12.5 m was utilized to identify the most ideal relationship between radar backscatter and aboveground carbon stock (ACS) atdifferent strata of tropical forest stands. The Forest Research Institute Malaysia (FRIM) campus which has about 420 ha of forest area was selected as the study area. Field survey was conducted in which ten (10) test plots (50 × 50 m, 0.25 ha) were established and all trees with the diameter at breast height (dbh) of 5 cm and above were inventoried. The calculated plot-based ACS was divided into six diameter classes - which is defined as strata - ofthe trees within the plot, which are i) 5 cm and above, ii) 10 cm and above, iii) 15 cm and above, iv) 20 cm and above, v) 25 cm and above, and vi) 30 cm and above. The total ACS of each class was correlated to the pixels of SAR backscatter corresponding to the plot location on the ground. Results showed that the forest was sensitive to the backscatter on horizontal-vertical polarized (HV) image as compared with horizontal-horizontal polarized (HH) image and a combination of both HH and HV polarizations. However, only ACS that was calculated based on diameter class of 15 cm and above gave the strongest correlation to the SAR signal. The signals also tend to saturate when carbon stock starts to increase from 180 t ha-1 at around -8 dB. The experiment from the study suggested that only mature trees (i.e. of diameter more than 15 cm) with sufficient canopy height can be included in inventory to obtain accurate carbon stock estimation when using satellite based L-band SAR data.

  3. Protecting the larger fish: an ecological, economical and evolutionary analysis using a demographic model

    DEFF Research Database (Denmark)

    Verdiell, Nuria Calduch

    Many marine fish stocks are reported as overfished on a global scale. This overfishing not only removes fish biomass, but also causes dramatic changes in the age and size structure of fish stocks. In particular, targeting of the larger individuals truncates the age and size structure of stocks...

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

    Science.gov (United States)

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

    2013-09-01

    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).

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-01-01

    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.

  6. Assessing the applicability of FISH-based prematurely condensed dicentric chromosome assay in triage biodosimetry.

    Science.gov (United States)

    Suto, Yumiko; Gotoh, Takaya; Noda, Takashi; Akiyama, Miho; Owaki, Makiko; Darroudi, Firouz; Hirai, Momoki

    2015-03-01

    The dicentric chromosome assay (DCA) has been regarded as the gold standard of radiation biodosimetry. The assay, however, requires a 2-d peripheral blood lymphocyte culture before starting metaphase chromosome analyses to estimate biological doses. Other biological assays also have drawbacks with respect to the time needed to obtain dose estimates for rapid decision on the correct line of medical treatment. Therefore, alternative technologies that suit requirements for triage biodosimetry are needed. Radiation-induced DNA double strand breaks in G0 lymphocytes can be detected as interphase chromosome aberrations by the cell fusion-mediated premature chromosome condensation (PCC) method. The method, in combination with fluorescence in situ hybridization (FISH) techniques, has been proposed in early studies as a powerful tool for obtaining biological dose estimates without 2-d lymphocyte culture procedures. The present work assesses the applicability of FISH-based PCC techniques using pan-centromeric and telomeric peptide nucleic acid (PNA) probes in triage mode biodosimetry and demonstrates that an improved rapid procedure of the prematurely condensed dicentric chromosome (PCDC) assay has the potential for evaluating exposed radiation doses in as short as 6 h after the collection of peripheral blood specimens.

  7. Assessment of water pollution and suitability to fish life in six Italian rivers.

    Science.gov (United States)

    Barghigiani, C; Ristori, T; Scerbo, R; Cini, C; Nottoli, R; Moschini, L; Giaconi, V

    2001-01-01

    This paper reports the results of a monitoring programme of six rivers (Serchio, Cecina, Cascina, ERa, Elsa and Pavone) that drain north-west Tuscany (Italy). In this area, agricultural, industrial and urbanization pressures affect water quality, also in terms of suitability for the survival of aquatic organisms. The river waters were monitored for several physico-chemical parameters (temperature, dissolved oxygen, suspended solids, total ammonia, nitrites, Cu, Cd, Cr, Ni and Pb) in order to assess the anthropogenic impact on the environmental conditions of these watercourses and their suitability for fish life. Statistical data handling was performed for each river and the percentage of physico-chemical parameters that, according to the E.C. law, were over the limits that must not be exceeded to protect fish life, was calculated and a classification was made of the six rivers in this sense. Concerning the metals, inter-element relationships (between chromium and nichel, lead and copper, nichel and lead and copper, copper and lead) were found which allow some remarks on the origins of the anthropogenic impacts, and comparisons were made with two metal-polluted watercourses in northern Italy, the Po and Lambro rivers. From the comparison, the Tuscan rivers showed generally lower metal contamination, especially with respect to the Lambro.

  8. An assessment of high carbon stock and high conservation value approaches to sustainable oil palm cultivation in Gabon

    Science.gov (United States)

    Austin, Kemen G.; Lee, Michelle E.; Clark, Connie; Forester, Brenna R.; Urban, Dean L.; White, Lee; Kasibhatla, Prasad S.; Poulsen, John R.

    2017-01-01

    Industrial-scale oil palm cultivation is rapidly expanding in Gabon, where it has the potential to drive economic growth, but also threatens forest, biodiversity and carbon resources. The Gabonese government is promoting an ambitious agricultural expansion strategy, while simultaneously committing to minimize negative environmental impacts of oil palm agriculture. This study estimates the extent and location of suitable land for oil palm cultivation in Gabon, based on an analysis of recent trends in plantation permitting. We use the resulting suitability map to evaluate two proposed approaches to minimizing negative environmental impacts: a High Carbon Stock (HCS) approach, which emphasizes forest protection and climate change mitigation, and a High Conservation Value (HCV) approach, which focuses on safeguarding biodiversity and ecosystems. We quantify the forest area, carbon stock, and biodiversity resources protected under each approach, using newly developed maps of priority species distributions and forest biomass for Gabon. We find 2.7–3.9 Mha of suitable or moderately suitable land that avoid HCS areas, 4.4 million hectares (Mha) that avoid HCV areas, and 1.2–1.7 Mha that avoid both. This suggests that Gabon’s oil palm production target could likely be met without compromising important ecosystem services, if appropriate safeguards are put in place. Our analysis improves understanding of suitability for oil palm in Gabon, determines how conservation strategies align with national targets for oil palm production, and informs national land use planning.

  9. Hypotheses of spatial stock structure in orange roughy Hoplostethus atlanticus inferred from diet, feeding, condition, and reproductive activity.

    Directory of Open Access Journals (Sweden)

    Matthew R Dunn

    Full Text Available We evaluate hypotheses for meso-scale spatial structure in an orange roughy (Hoplostethus atlanticus stock using samples collected during research trawl surveys off the east coast of New Zealand. Distance-based linear models and generalised additive models were used to identify the most significant biological, environmental, and temporal predictors of variability in diet, proportion of stomachs containing prey, standardised weight of prey, fish somatic weight, fish total weight, and reproductive activity. The diet was similar to that observed elsewhere, and varied with ontogeny, depth, and surface water temperature. Smaller sized and female orange roughy in warmer bottom water were most likely to contain food. Fish condition and reproductive activity were highest at distances more than 20 km from the summit of the hills. Trawl survey catches indicated greater orange roughy densities in hill strata, suggesting hill habitat was favoured. However, analyses of feeding, condition, and reproductive activity indicated hill fish were not superior, despite fish densities on hills being reduced by fishing which, in principle, should have reduced intra-specific competition for food and other resources. Hypotheses for this result include: (1 fish in relatively poor condition visit hills to feed and regain condition and then leave, or (2 commercial fishing has disturbed feeding aggregations and/or caused habitat damage, making fished hills less productive. Mature orange roughy were observed on both flat and hill habitat during periods outside of spawning, and if this spatial structure was persistent then a proportion of the total spawning stock biomass would remain unavailable to fisheries targeting hills. Orange roughy stock assessments informed only by data from hills may well be misleading.

  10. Assessment of the impact of water power developments on fish habitat using a 2-dimensional hydrodynamic model

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, R.D.; King, L.; Donnelly, C.R. [Hatch Acres, Niagara Falls, ON (Canada)

    2005-07-01

    Any work in river and lake systems must satisfy the Ontario Lakes and Rivers Act requirements for protecting fisheries habitat and related resources. Impacts must be assessed and mitigation measures identified to remediate the potential adverse impacts to fish passage or habitat. One popular methodology for evaluating and predicting the potential impacts that a water power facility may have on fish habitat is a procedure called Instream Flow Incremental Methodology (IFIM). IFIM is based on the understanding that fish have specific habitat preferences that vary for different species of fish and their different life stages. In order to investigate changes in physical fish habitat, a Physical Habitat Simulation Model (PHABSIM) was developed within the framework of IFIM. The model produces weighted usable area as a habitat measure. The fish habitat component of River-2D applies the same principles used by the PHABSIM model. An application of the River-2D model is described to allow for a transparent and scientifically defensible simulation of the changes that might occur to fish habitat following the construction of a new facility. Model results were then used to assess the need for and the design of mitigation measures for a proposed development in Ontario. The two-dimensional model was used to identify resting habitat areas within the affected river reach and predict the expected changes to fish habitat under operating conditions. It was concluded that a two-dimensional model has specific advantages over one-dimensional models, because of the ability to solve problems related to flow velocity and depth in specific areas that are not resolvable by one-dimensional models. 8 refs., 7 figs.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-05-01

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

  12. A Change in the Use of Regulatory Criteria for Assessing Potential Impacts of Sound on Fishes.

    Science.gov (United States)

    Jacobs, Fred; Krebs, Justin; Popper, Arthur N

    2016-01-01

    The National Marine Fisheries Service (NMFS) currently uses interim criteria developed on the US West Coast to assess the potential onset of peak and cumulative effects of noise on fishes. Analyses performed for this project provided adequate support for the NMFS to use the peak criterion (i.e., area ensonified by 206 dB re 1 μPa peak sound pressure level [SPL(peak)]) for estimating the incidental take of Hudson River sturgeon. Application of the peak criterion (rather than the cumulative criterion) could have implications for future construction projects because estimates of take using SPL(peak) will generally be considerably lower than estimates of take based on the cumulative sound exposure level.

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

    Directory of Open Access Journals (Sweden)

    Giannetto D.

    2012-01-01

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

  14. Fish Springs National Wildlife Refuge: Draft Comprehensive Conservation Plan and Environmental Assessment

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This draft Comprehensive Conservation Plan (CCP) was written to guide management on Fish Springs NWR for the next 15 years. This plan outlines the Refuge vision and...

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

    Data.gov (United States)

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

  16. Water Resource Inventory and Assessment – Ouray National Wildlife Refuge and Ouray National Fish Hatchery.

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — EXECUTIVE SUMMARY-Ouray National Wildlife Refuge (ONWR) and Ouray National Fish Hatchery (ONFH) share many attributes. Hatchery facilities are within the boundaries...

  17. Illinois River National Wildlife and Fish Refuges Complex: Comprehensive Conservation Plan and Environmental Assessment

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This Comprehensive Conservation Plan (CCP) was written to guide management on Illinois River National Wildlife and Fish Refuges for the next 15 years. This plan...

  18. Pacific Reef Assessment and Monitoring Program Fish Monitoring Brief: Pacific Remote Island Areas 2014

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Two-page summary outlines reef fish and benthic habitat survey efforts conducted by the NOAA Coral Reef Ecosystem Division (CRED) at Wake Atoll NWR in 2014

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

    Data.gov (United States)

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

  20. Carbon Stock Assessment of Dai Homegarden in Xishuangbanna,Yunnan,China%云南西双版纳傣族庭院C储量的研究

    Institute of Scientific and Technical Information of China (English)

    李江; Roberto G.Visco

    2003-01-01

    综合运用样方收获、生物量回归方程及标准木的方法进行样地调查,对西双版纳傣族庭院C储量进行了测定.结果表明傣族庭院的平均C密度为99.85 tons*hm-2.证明传统傣族庭院作为一种生产和生态系统,具有良好的吸收CO2温室气体的能力.%Carbon stock of traditionally managed Dai home gardens in Xishuangbanna, Yunnan was assessed using a method that combined small plot measurements, the use of allometric equations for trees with large dbh and the mean tree technique for bamboo and banana.Results showed the mean carbon stock of Dai home gardens in Xishuangbanna was 99.85 tons*hm-2, suggesting its high potential to curb the rate of CO2 increase in the atmosphere.

  1. ARTIFICIAL FISH PROPAGATION IN KANEV RESERVOIR

    Directory of Open Access Journals (Sweden)

    O. B. Gurbik

    2014-11-01

    Full Text Available Based on the analysis of the dynamics of structural parameters of fish fauna of the Kanev reservoir, we determined the major measures for artificial fish propagation (stocking, which would allow increasing their commercial stocks and maintain biological diversity. It was found that main biological factors, which defined the conditions of existence of fish at different stages of their life cycle in the Kanev reservoir was as a whole favorable for providing sufficient efficiency of measures for stocking it with juveniles of commercially and environmentally valuable fishes. With current state of fish fauna and possibilities of fish hatcheries, the priority in the part of artificial maintenance of fish populations should be given to pike-perch, wels, and tench. An increase of amounts of commercial catches should be based first of all on full-scale stocking with silver and bighead carps, the created stock of which will be available for effective exploitation at a regime, which is protective for native fish fauna. The current bioproductive potential allows increasing the indices of the stock of commercially valuable species up to 120 kg/ha that is twice more than the actual indices for 2012-2013. Key words: fish fauna, artificial propagation, commercial stock, Kanev reservoir.

  2. Factors in exposure assessment: Ethnic and socio-economic differences in fishing and consumption of fish caught along the Savannah River

    Energy Technology Data Exchange (ETDEWEB)

    Burger, J. [Rutgers-the State Univ., Piscataway, NJ (United States). Nelson Biological Lab.]|[Environmental and Occupational health Sciences Inst., Piscataway, NJ (United States); Stephens, W.L.; Boring, C.S. [Environmental and Occupational health Sciences Inst., Piscataway, NJ (United States)]|[Savannah River Ecology Lab., Aiken, SC (United States); Kuklinski, M. [Environmental and Occupational health Sciences Inst., Piscataway, NJ (United States); Gibbons, J.W. [Savannah River Ecology Lab., Aiken, SC (United States); Gochfeld, M. [Environmental and Occupational Health Sciences Inst., Piscataway, NJ (United States)]|[Univ. of Medicine and Dentistry of New Jersey, Newark, NJ (United States). Robert Wood Johnson Medical School

    1999-06-01

    South Carolina has issued fish consumption advisories for the Savannah River based on mercury and radionuclide levels. The authors examine differences in fishing rates and fish consumption of 258 people interviewed while fishing along the Savannah River, as a function of age, education, ethnicity, employment history, and income, and test the assumption that the average consumption of fish is less than the recreational value of 19 kg/year assumed by risk assessors. Ethnicity and education contributed significantly to explaining variations in number of fish meals per month, serving size, and total quantity of fish consumed per year. Blacks fished more often, ate more fish meals of slightly larger serving sizes, and consumed more fish per year than did Whites. Although education and income were correlated, education contributed most significantly to behavior; people who did not graduate from high school ate fish more often, ate more fish per year, and ate more whole fish than people who graduated from high school. Computing consumption of fish for each person individually indicates that (1) people who eat fish more often also eat larger portions, (2) a substantial number of people consume more than the amount of fish used to compute risk to recreational fishermen, (3) some people consume more than the subsistence level default assumption (50 kg/year) and (4) Blacks consume more fish per year than Whites, putting them at greater risk from contaminants in fish. Overall, ethnicity, age, and education contributed to variations in fishing behavior and consumption.

  3. 鄱阳湖翘嘴鳜(Siniperca chuatsi)的生物学参数及资源量的估算%The Assessment of Biological Parameters and Stock Biomass of Siniperca chuatsi in the Poyang Lake

    Institute of Scientific and Technical Information of China (English)

    吴斌; 王庆萍; 方春林; 张燕萍; 傅培峰; 陈文静; 熊小英; 周辉明; 贺刚; 王生

    2015-01-01

    研究基于鄱阳湖渔业资源调查数据,运用软件 FiSAT II 对翘嘴鳜的生物学参数及其资源量进行了初步估算。结果显示,鄱阳湖翘嘴鳜体长范围为77-526 mm;体长和体重的关系式为 W =1.888´10-5L3.042(R2=0.951, n=577),von Bertalanffy 生长方程的各参数为:渐进体长 L∞=551.25 mm,生长系数 K =0.210,理论生长起点年龄 t0=-0.601。总死亡系数 Z=1.06/a,自然死亡系数 M=0.44/a,捕捞死亡系数 F=0.62/a,最适开捕体长为150 mm。鄱阳湖翘嘴鳜开发率 E =0.58,处于资源过度利用状态。鄱阳湖翘嘴鳜的初始资源量估算高达1.92´104 t,最大可持续产量 MSY 为4384.93 t。鄱阳湖翘嘴鳜群体中补充群体和低龄剩余群体的比例明显增加,低龄化和小型化趋势凸显,资源衰退问题突出,但生长潜力依然存在。应采取降低对鄱阳湖翘嘴鳜繁殖群体的捕捞强度、保护产卵场等积极措施来保护这一珍贵的渔业资源。%Mandarin fish (Siniperca chuatsi) is a rare and precious economic species of freshwater fish with a long standing reputation because of its fast growth, meat delicate, delicious and nutrient rich. The mature artificial propagation technology has created good conditions for Siniperca chuatsi large- scale cultivation since 1980 s. However, the wild Siniperca chuatsi population is declining due to over exploitation and environmental pollution in their habitat, which may cause the decline of genetic diversity. Mandarin fish is one of abundant species in Poyang Lake and plays an important role in the lake ecosystem. Based on Poyang Lake fishery resources investigation data, we assessed biological parameters and stock biomass of Siniperca chuatsi using FiSAT II software. The results indicated that the length of Siniperca chuatsi population ranged from 77 to 526 mm, and that the relationship between body length (mm) and body weight (g) can be expressed as W = 1.888´10-5L3.042(R2

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

    Data.gov (United States)

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

  5. Assessing Potential Conservation and Restoration Areas of Freshwater Fish Fauna in the Indian River Basins.

    Science.gov (United States)

    Bhatt, Jay P; Manish, Kumar; Mehta, Rajender; Pandit, Maharaj K

    2016-05-01

    Conservation efforts globally are skewed toward terrestrial ecosystems. To date, conservation of aquatic ecosystems, in particular fish fauna, is largely neglected. We provide a country-wide assessment of Indian river ecosystems in order to identify and prioritize areas for protection and restoration of freshwater fish fauna. Using various biodiversity and anthropogenic attributes, coupled with tools of ecological modeling, we delineated areas for fish fauna conservation and restoration in the 20 major river basins of India. To do this, we used prioritization analyses and reserve selection algorithms to derive conservation value index (CVI) and vulnerability index (VI) of the river basins. CVI was estimated using endemicity, rarity, conservation value, and taxonomic singularity, while VI was estimated using a disturbance index derived from percent geographic area of the basin under human settlements, human population density, predominant land use, and total number of exotic fish species in each basin. The two indices, CVI and VI, were converted into geo-referenced maps, and each map was super-imposed onto species richness and forest cover maps, respectively. After superimposition, areas with high CVI and low VI shade intensities were delineated for conservation, while areas with high CVI and high VI shade intensities were demarcated for restoration. In view of the importance of freshwater fish for human livelihoods and consumption, and ecosystems of India's rivers, we call for urgent attention to the conservation of their fish fauna along with restoration of their degraded habitats.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-07-01

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

  7. Qualitative assessment of the impacts of proposed system operating strategies to resident fish within selected Columbia River Reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Shreffler, D.K.; Geist, D.R.; Mavros, W.V.

    1994-01-01

    The Bonneville Power Administration (BPA), Bureau of Reclamation (BOR), and US Army Corps of Engineers (COE) are presently conducting the System Operation Review (SOR) for the Columbia River basin. The SOR began in 1990 and is expected to provide an operating strategy that will take into consideration multiple uses of the Columbia River system including navigation, flood control, irrigation, power generation, fish migration, fish and wildlife habitat, recreation, water supply, and water quality. This report provides descriptions of each of the non-modeled reservoirs and other specified river reaches. The descriptions focus on the distinct management goals for resident fish: biodiversity, species-specific concerns, and sport fisheries. In addition, this report provides a qualitative assessment of impacts to the resident fish within these reservoirs and river reaches from the 7 alternative system operating strategies. In addition to this introduction, the report contains four more sections. Section 2.0 provides the methods that were used. Reservoir descriptions appear in Section 3.0, which is a synthesis of our literature review and interviews with resident fish experts. Section 4.0 contains a discussion of potential impacts to fish within each of these reservoirs and river reaches from the 7 proposed system operating strategies. The references cited are listed in Section 5.0.

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

    Directory of Open Access Journals (Sweden)

    Ghazala Jabeen*, Muhammad Javed and Hamda Azmat

    2012-01-01

    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.

  9. Illegal fishing of inland water bodies of Nigeria: Kainji experience

    OpenAIRE

    RAJI, A.; Okaeme, A.N.; Omorinkoba, W.; Bwala, R.L.

    2012-01-01

    It is a common knowledge that illegal fishing which includes use of wrong gears, explosives, excessive exploitation of choice stocks, enhancement and stocking of water body and pollution has devastating effects on the critical biomass of fish biodiversity and livelihood activities associated with fishing. Efforts worldwide to arrest these menace are significant because it has been found that illegal fishing has made fishing non sustainable, resulted in poor fishermen catches, and exacerbated...

  10. Integrating the fish embryo toxicity test as triad element for sediment toxicity assessment based on the water framework directive approach

    Energy Technology Data Exchange (ETDEWEB)

    Bartzke, Mariana [Dept. Aquatic Ecotoxicology, Goethe Univ. Frankfurt am Main (Germany); Gobio GmbH, Aarbergen/Kettenbach (Germany); Dept. Bioanalytical Ecotoxicology, Helmholtz Centre for Environmental Research, UFZ, Leipzig (Germany); Delov, Vera [Dept. Aquatic Ecotoxicology, Goethe Univ. Frankfurt am Main (Germany); Gobio GmbH, Aarbergen/Kettenbach (Germany); Ecotoxicology, Fraunhofer Inst. for Molecular Biology and Applied Ecology IME, Aachen (Germany); Stahlschmidt-Allner, Petra; Allner, Bernhard [Gobio GmbH, Aarbergen/Kettenbach (Germany); Oehlmann, Joerg [Dept. Aquatic Ecotoxicology, Goethe Univ. Frankfurt am Main (Germany)

    2010-04-15

    Purpose: The objective of this study was to complement analyses according to the European Union Water Framework Directive (WFD) with a sediment toxicity analysis as part of an integrated river assessment. To this end, Hessian water courses were analyzed using the sediment quality triad concept according to Chapman with chemical analyses, in situ effect evaluations, and ecotoxicological assessments. For the ecotoxicological assessment (fish embryo toxicity test with Danio rerio), a new evaluation scheme was developed, the fish teratogenicity index (FTI), that allows for a classification of sediments into ecological quality classes compliant to the WFD. Materials and methods sediment and macrozoobenthos samples were taken from tributaries of the rivers Fulda and Lahn. Sediments were characterized regarding particle size, carbon, heavy metals, and polyaromatic hydrocarbon content. Macroinvertebrate samples were taken via multi-habitat sampling. The fish embryo toxicity test with D. rerio was conducted as a contact assay on the basis of DIN 38415-6. Results and discussion The integrated assessment indicated a significant influence of heavy metals and carbon content on macroinvertebrate communities. The bioaccessibility of sediment pollutants were clearly demonstrated by the FTI, which showed a wide range of adverse effects. A significant linear relationship between metals and the FTI was detected. However, there was no statistically significant evidence that macroinvertebrate communities were affected by the hydromorphological quality clements at the sampling sites. Conclusions The new scheme for the assessment of fish embryo toxicity test was successfully applied. The results suggest that sediment compounds impact macroinvertebrate communities and early development of fish. It demonstrates that the quality of sediments should be evaluated on a routine basis as part of an integrated river assessment. (orig.)

  11. Assessment of a commercial kit collection for diagnosis of the fish viruses: IHNV, IPNV, SVCV and VHSV

    DEFF Research Database (Denmark)

    Ariel, Ellen; Olesen, Niels Jørgen

    2001-01-01

    A commercial kit collection for the detection of the fish pathogenic viruses, VHSV, IHNV, IPNV, and SVCV, was assessed for its ability to detect isolates in selected panels of the respective viruses. The kit collection, which was based on fluorescence staining of infected cell cultures in tissue...

  12. Stock assessment and management of Dosidicus gigas in the Southeast Pacific Ocean with Schaefer model%基于 Schaefer 模型的东南太平洋茎柔鱼资源评估和管理

    Institute of Scientific and Technical Information of China (English)

    许骆良; 陈新军; 汪金涛; 官文江

    2015-01-01

    Dosidicus gigas is one of the important economic cephalopod in the world.It is widely distributed in the east of Pacific Ocean.Nowadays the yield of Dosidicus gigas occupies more than 50% of the total yield of squid in China mainland.In 2012 ,the yearly catch in China mainland reached 221.1 thousand tons,the number of fishing vessels are more than 250.It is necessary to assess the stock for making the fishery sustainable.Unfortunately lit-tle work is done in this field.The stock assessment and risk analysis of alternative management strategies for Dosi-dicus gigas in the Southeast Pacific Ocean were carried out by using a Bayesian Schaefer model,in which two sce-narios,standard scenario and sensitivity analysis scenario,are considered.The Schaefer model was chosen because of the lack of age-data of Dosidicus gigas and also because the migration mechanism and stock structure of the squid was very complex which was not completely understood by us.In many cases,Schaefer model performed better than many other more complex models such as age-data based models or metapopulation model.For parameters K and q in standard scenario,the posterior distribution are approximately normal distributed.It is totally different with the prior distribution which is set to be uniform distribution.Compared with the two scenarios,the results of posterior distribution of the three parameters are similar .The study indicated that the data of yearly yield and CPUE provided sufficient information for the valuation of model parameters.Under standard scenario,the MSY (maximum sustainable yield)is 1.429 million tons.To maintain MSY,the biomass and fishing mortality should be 2.147 million tons and 0.682,respectively.Under sensitivity analysis scenario,the MSY is 1.525 million tons.To maintain MSY,the biomass and fishing mortality should be 2.296 million tons and 0.691,respectively.Under both scenarios,the fishing mortalities and yearly catches from 2003 to 2012 were lower than reference points F0

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

    Science.gov (United States)

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

    2010-07-01

    Persistent organic pollutants (POPs) encompass an array of anthropogenic organic and elemental substances and their degradation and metabolic byproducts that have been found in the tissues of exposed animals, especially POPs categorized as organohalogen contaminants (OHCs). OHCs have been of concern in the circumpolar arctic for decades. For example, as a consequence of bioaccumulation and in some cases biomagnification of legacy (e.g., chlorinated PCBs, DDTs and CHLs) and emerging (e.g., brominated flame retardants (BFRs) and in particular polybrominated diphenyl ethers (PBDEs) and perfluorinated compounds (PFCs) including perfluorooctane sulfonate (PFOS) and perfluorooctanic acid (PFOA) found in Arctic biota and humans. Of high concern are the potential biological effects of these contaminants in exposed Arctic wildlife and fish. As concluded in the last review in 2004 for the Arctic Monitoring and Assessment Program (AMAP) on the effects of POPs in Arctic wildlife, prior to 1997, biological effects data were minimal and insufficient at any level of biological organization. The present review summarizes recent studies on biological effects in relation to OHC exposure, and attempts to assess known tissue/body compartment concentration data in the context of possible threshold levels of effects to evaluate the risks. This review concentrates mainly on post-2002, new OHC effects data in Arctic wildlife and fish, and is largely based on recently available effects data for populations of several top trophic level species, including seabirds (e.g., glaucous gull (Larus hyperboreus)), polar bears (Ursus maritimus), polar (Arctic) fox (Vulpes lagopus), and Arctic charr (Salvelinus alpinus), as well as semi-captive studies on sled dogs (Canis familiaris). Regardless, there remains a dearth of data on true contaminant exposure, cause-effect relationships with respect to these contaminant exposures in Arctic wildlife and fish. Indications of exposure effects are largely

  14. ASSESSMENT OF THE DEVELOPMЕNT OF POND FORAGE BASE WHEN REARING CARP (CYPRINUS CARPIO CARPIO FISH SEEDS AT FISH FARM «MERKURIY»

    Directory of Open Access Journals (Sweden)

    B. Grishin

    2015-09-01

    Full Text Available Purpose. To assess the development of main components of natural forage base in nursery ponds during the period of rearing the carp fish seeds in monoculture. Methodology. Hydrobiological (bacterioplankton, phytoplankton, zooplankton, zoobenthos and hydrochemical samples have been collected and processes according to generally accepted methods. Findings. Qualitative and quantitative parameters of the development of bacterio-, phyto-, zooplankton and zoobenthos in nursery ponds have been studied when rearing young-of-the-year Lubin few scale carp, Antoninsko-Zozulenets carp and their reciprocal crosses in monoculture (50 thousand fish/ha. General water mineralization in ponds was 292.7–315.7 mg/dm3 and according to O.A. Alekin’s classification, pond water belonged to hydrocarbonate class of calcium group. Water pH was 7.4–7.5. Permanganate values were 12.5–14.9 mgO/dm3. On average, average ammonium nitrogen content, nitrite nitrogen and nitrate nitrogen, mineral phosphorus, total iron did not exceed normative values. Qualitative and quantitative parameters of phyto-, bacterio-, zooplankton of nursery ponds have been studied. The seasonal development of phytoplankton was within 15.96–20.88 mg/dm3 with the predominance of Chlorococcales in the floristic spectrum. The development of bacterioplankton was within 5.08–5.81 mg/dm3. Zooplankton was dominated by cladoceran-copepod complex with average seasonal values of 5.27–17.20 g/m3. Zoobenthos was formed of Diptera larvae (Chironomidae and Chaoboridae with average seasonal biomasses of 0.51–1.8 g/m2. According to saprobic parameters, pond water belonged to β-mesosabrobic zone and corresponded to the water quality class II (“clean enough” category. Fish productivity of nursery ponds was within 617.2–815.2 kg/ha; output of carp young-of-the-year was within 39.82–43.56%, mean weight of young-of-the-year was 31.0–39.3 g. Originality. For the first time we carried out a

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1991-04-01

    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.

  16. Public Review Draft: A Method for Assessing Carbon Stocks, Carbon Sequestration, and Greenhouse-Gas Fluxes in Ecosystems of the United States Under Present Conditions and Future Scenarios

    Science.gov (United States)

    Bergamaschi, Brian A.; Bernknopf, Richard; Clow, David; Dye, Dennis; Faulkner, Stephen; Forney, William; Gleason, Robert; Hawbaker, Todd; Liu, Jinxun; Liu, Shu-Guang; Prisley, Stephen; Reed, Bradley; Reeves, Matthew; Rollins, Matthew; Sleeter, Benjamin; Sohl, Terry; Stackpoole, Sarah; Stehman, Stephen; Striegl, Robert G.; Wein, Anne; Zhu, Zhi-Liang; Zhu, Zhi-Liang

    2010-01-01

    The Energy Independence and Security Act of 2007 (EISA), Section 712, authorizes the U.S. Department of the Interior to develop a methodology and conduct an assessment of the Nation's ecosystems focusing on carbon stocks, carbon sequestration, and emissions of three greenhouse gases (GHGs): carbon dioxide, methane, and nitrous oxide. The major requirements include (1) an assessment of all ecosystems (terrestrial systems, such as forests, croplands, wetlands, shrub and grasslands; and aquatic ecosystems, such as rivers, lakes, and estuaries), (2) an estimation of annual potential capacities of ecosystems to increase carbon sequestration and reduce net GHG emissions in the context of mitigation strategies (including management and restoration activities), and (3) an evaluation of the effects of controlling processes, such as climate change, land use and land cover, and wildlfires. The purpose of this draft methodology for public review is to propose a technical plan to conduct the assessment. Within the methodology, the concepts of ecosystems, carbon pools, and GHG fluxes used for the assessment follow conventional definitions in use by major national and international assessment or inventory efforts. In order to estimate current ecosystem carbon stocks and GHG fluxes and to understand the potential capacity and effects of mitigation strategies, the method will use two time periods for the assessment: 2001 through 2010, which establishes a current ecosystem GHG baseline and will be used to validate the models; and 2011 through 2050, which will be used to assess future potential conditions based on a set of projected scenarios. The scenario framework is constructed using storylines of the Intergovernmental Panel on Climate Change (IPCC) Special Report Emission Scenarios (SRES), along with initial reference land-use and land-cover (LULC) and land-management scenarios. An additional three LULC and land-management mitigation scenarios will be constructed for each

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

    Science.gov (United States)

    Wang, Yang; Wang, Yingbin; Zheng, Ji

    2015-02-01

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

  18. Stock and recruitment in North Sea herring (Clupea harengus); compensation and depensation in the population dynamics

    NARCIS (Netherlands)

    Nash, R.D.M.; Dickey-Collas, M.; Kell, L.T.

    2009-01-01

    The recovery of a stock after severe exploitation is of major interest to fish ecologists and managers alike. Understanding the dynamics of recruitment at low stock sizes is crucial to the simulation of stocks as they recover. Compensation in recruitment has occurred in North Sea herring, and it was

  19. Identifying blue whiting (Micromesistius poutassou) stock structure in the Northeast Atlantic by otolith shape analysis

    DEFF Research Database (Denmark)

    Mahe, Kélig; Oudard, Clémence; Mille, Tiphaine;

    2016-01-01

    Information on stock identification and spatial stock structure provide a basis for understanding fish population dynamics and improving fisheries management. In this study, otolith shape analysis was used to study the stock structure of blue whiting (Micromesistius poutassou) in the northeast At...

  20. Spatial structuring within a reservoir fish population: implications for management

    Science.gov (United States)

    Stewart, David R.; Long, James M.; Shoup, Daniel E.

    2014-01-01

    Spatial structuring in reservoir fish populations can exist because of environmental gradients, species-specific behaviour, or even localised fishing effort. The present study investigated whether white crappie exhibited evidence of improved population structure where the northern more productive half of a lake is closed to fishing to provide waterfowl hunting opportunities. Population response to angling was modelled for each substock of white crappie (north (protected) and south (unprotected) areas), the entire lake (single-stock model) and by combining simulations of the two independent substock models (additive model). White crappie in the protected area were more abundant, consisting of larger, older individuals, and exhibited a lower total annual mortality rate than in the unprotected area. Population modelling found that fishing mortality rates between 0.1 and 0.3 resulted in sustainable populations (spawning potential ratios (SPR) >0.30). The population in the unprotected area appeared to be more resilient (SPR > 0.30) at the higher fishing intensities (0.35–0.55). Considered additively, the whole-lake fishery appeared more resilient than when modelled as a single-panmictic stock. These results provided evidence of spatial structuring in reservoir fish populations, and we recommend model assessments used to guide management decisions should consider those spatial differences in other populations where they exist.

  1. A Preliminary Assessment of Barotrauma Injuries and Acclimation Studies for Three Fish Species

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Richard S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Walker, Ricardo W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Stephenson, John R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-12-15

    Fish that pass hydro structures either through turbine passage, deep spill, or other deep pathways can experience rapid decreases in pressure that can result in barotrauma. In addition to morphology and physiology of the fish’s swim bladder, the severity of barotrauma is directly related to the volume of undissolved gas in fish prior to rapid decompression and the lowest pressure the fish experience as they pass hydro structures (termed the “nadir”). The volume of undissolved gas in fish is influenced by the depth of acclimation (the pressure at which the fish is neutrally buoyant); therefore, determining the depth where fish are neutrally buoyant is a critical precursor to determining the relationship between pressure changes and injury or mortality.

  2. Spatially intensive sampling by electrofishing for assessing longitudinal discontinuities in fish distribution in a headwater stream

    Science.gov (United States)

    Le Pichon, Céline; Tales, Évelyne; Belliard, Jérôme; Torgersen, Christian E.

    2017-01-01

    Spatially intensive sampling by electrofishing is proposed as a method for quantifying spatial variation in fish assemblages at multiple scales along extensive stream sections in headwater catchments. We used this method to sample fish species at 10-m2 points spaced every 20 m throughout 5 km of a headwater stream in France. The spatially intensive sampling design provided information at a spatial resolution and extent that enabled exploration of spatial heterogeneity in fish assemblage structure and aquatic habitat at multiple scales with empirical variograms and wavelet analysis. These analyses were effective for detecting scales of periodicity, trends, and discontinuities in the distribution of species in relation to tributary junctions and obstacles to fish movement. This approach to sampling riverine fishes may be useful in fisheries research and management for evaluating stream fish responses to natural and altered habitats and for identifying sites for potential restoration.

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

    Science.gov (United States)

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

    2011-01-01

    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.

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

    Institute of Scientific and Technical Information of China (English)

    Pierre J Obeid; Bilal E1-Khoury; Joanne Burger; Samer Aouad; Mira Younis; Amal Aoun; John Hanna El-Nakat

    2011-01-01

    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 μg/g in fresh samples,0.0059 to 0.0665 μg/g in frozen samples,and 0.0305 to 0.1190 μg/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.

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

    Science.gov (United States)

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

    2013-07-01

    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 < 0.05) to total organic carbon (TOC) contents in sediments. Biota sediment accumulation factor (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 δ (15)N. The slope of the regression (-0.066 and -0.078) of the log transformed As concentrations and δ (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.

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

    Science.gov (United States)

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

    2013-11-01

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

  7. By-catch impacts in fisheries: utilizing the IUCN red list categories for enhanced product level assessment in seafood LCAs.

    Science.gov (United States)

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

    2013-11-01

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

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

    Science.gov (United States)

    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

    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 μg/kg) for methylmercury. Therefore, fish-eating populations should reduce the quantity of dried shark to efficiently diminish the exposure to mercury.

  9. Distance from a fishing community explains fish abundance in a no-take zone with weak compliance.

    Directory of Open Access Journals (Sweden)

    Sahir Advani

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

  10. Stock Price Expectations and Stock Trading

    OpenAIRE

    Michael D. Hurd; Susann Rohwedder

    2012-01-01

    Background: The fact that many individuals inexplicably fail to buy stocks, despite the historical evidence for a good return on investment has been referred to as the stock market puzzle. However, measurements of the subjective probability of a gain show that people are more pessimistic than historical outcomes would suggest. Further, expectations of future stock price increases apparently depend on old information, which would seem to be at odds with rational expectations in the context of ...

  11. 应用贝叶斯状态空间建模对东海带鱼的资源评估%Using Bayesian state-space modelling to assess Trichiurus japonicus stock in the East China Sea

    Institute of Scientific and Technical Information of China (English)

    张魁; 陈作志

    2015-01-01

    Hairtail (Trichiurus japonicus) is one of the most economically important fish species in the East China Sea and supports one of the most valuable fisheries in China. From 1990 to 2012, the total catch for this fishery ranged from 0.39 to 0.91 million tons. However, most studies on this fishery concentrated on feeding habit, varia-tions of catches, trophic composition, and the stock-recruitment relationship. For management, yield per recruit and surplus production models were applied to analyze the data of this fishery and provide a rough MSY estimate of approximately 7.5×105 tons. Until now, reports on the use of stock assessment models for this fishery are lim-ited, and no uncertainty assessment has been undertaken. Therefore, Bayesian state-space modelling was applied to the catch and catch per unit effort(CPUE) data for this fishery. A state-space model describes the dynamics of two related processes: the observation process, which is a function of the unobserved state process, and the state process, which describes the unobserved population dynamics in terms of biomass or abundance. In the present study, the Pella–Tomlinson surplus production model was used for the state process. We used Bayesian inference because it can take into account more uncertainties that are linked to parameters. In this study, four models were constructed based on Markov Chain Monte Carlo simulation with a mix of information and non-information priors. Marginal posterior distributions of model parameters, biological reference points (BRPs), and unobserved vari-ables were based on 250000 iterations after discarding the first 50000 burn-in iterations to ensure no persistent initial pathologic behavior. Results showed that the best-fit of the four models was model 1, with lognormal priors for the intrinsic rate of increase r and carrying capacity K based on deviance information criterion. Gelman &Rubin’s method was applied for convergence diagnostics, and WINBUGS software computed

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

    Science.gov (United States)

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

    2012-02-01

    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.

  13. Oil risk in oil stocks

    NARCIS (Netherlands)

    Scholtens, Bert; Wang, L

    2008-01-01

    We assess the oil price sensitivities and oil risk premiums of NYSE listed oil & gas firms' returns by using a two-step regression analysis under two different arbitrage pricing models. Thus, we apply the Fama and French (1992) factor returns in a study of oil stocks. In all, we find that the return

  14. Assessing the roles of environmental factors in coastal fish production in the northern Baltic Sea: a Bayesian network application.

    Science.gov (United States)

    Uusitalo, Laura; Kuikka, Sakari; Kauppila, Pirkko; Söderkultalahti, Pirkko; Bäck, Saara

    2012-07-01

    Environmental conditions play a crucial role in the distribution and abundance of fish species in any area. Much research has been attributed to the requirements and tolerance limits of commercially exploited fish species. It is rare, however, that studies have been able to address the relative importance of potentially restrictive environmental factors; extensive enough to allow for estimation of the effect of several environmental factors through the fishes' life span. The coastline of Finland in the northern Baltic Sea offers a unique natural experimental setting that can be used to assess the relative importance of various environmental factors for the species occupying it. The area includes major variations in several crucial environmental factors: salinity, temperature regime, represented by winter ice duration, coastline characteristics, and eutrophic status. Furthermore, Finland has collected extensive and spatially representative data of water quality and environmental factors, as well as a long and extraordinarily spatially detailed data set of commercial catches of several fish species. In this article, we make an attempt to correlate the environmental data to the commercial catches of fish species, assuming that the commercial catches reflect, to some reasonable degree, the productivity of that species in that area (compared to other areas and combinations of environmental factors, not to other species). We use a Bayesian network approach to examine the sensitivity of the species to the environmental factors.

  15. Assessment of Heavy Metals in Water, Sediment, and Fishes of a Large Tropical Hydroelectric Dam in Sarawak, Malaysia

    Directory of Open Access Journals (Sweden)

    Siong Fong Sim

    2016-01-01

    Full Text Available Bakun Hydroelectric Dam in Sarawak is one of the world highest concrete rock filled dams. This paper reports the heavy metals concentrations in water, sediment, and fishes of Bakun Dam. Water and sediment samples were collected from 11 stations and 6 fish species were caught. The samples were digested with open acid digestion and the metals contents were analysed using an atomic absorption spectrophotometer and mercury analyser. The method was validated based on certified reference materials. A higher concentration of Fe and Mn was detected in downstream water with significant longitudinal variation. Cu, Zn, and Hg were present in trace amount. All elements analysed were consistently found in sediment with no risk of contamination. For fish, Hemibagrus planiceps was characterised by higher affinity for Hg accumulation. The concentrations detected in all fish species were within the permissible guideline of 0.5 mg/kg. The health risk assessment suggested that Barbonymus schwanenfeldii, Puntioplites waandersii, Cyclocheilichthys apogon, and Hemibagrus planiceps were characterised by hazard index > 1 implying possible adverse effects. The amount of fish recommended for adults and children was in the range of 500–775 g/week and 33–135 g/week, respectively.

  16. 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)

    Lestelle, Lawrence C.; Gilbertson, Larry G.

    1993-06-01

    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.

  17. Toward an integrated monitoring framework to assess the effects of tropical forest degradation and recovery on carbon stocks and biodiversity.

    Science.gov (United States)

    Bustamante, Mercedes M C; Roitman, Iris; Aide, T Mitchell; Alencar, Ane; Anderson, Liana O; Aragão, Luiz; Asner, Gregory P; Barlow, Jos; Berenguer, Erika; Chambers, Jeffrey; Costa, Marcos H; Fanin, Thierry; Ferreira, Laerte G; Ferreira, Joice; Keller, Michael; Magnusson, William E; Morales-Barquero, Lucia; Morton, Douglas; Ometto, Jean P H B; Palace, Michael; Peres, Carlos A; Silvério, Divino; Trumbore, Susan; Vieira, Ima C G

    2016-01-01

    Tropical forests harbor a significant portion of global biodiversity and are a critical component of the climate system. Reducing deforestation and forest degradation contributes to global climate-change mitigation efforts, yet emissions and removals from forest dynamics are still poorly quantified. We reviewed the main challenges to estimate changes in carbon stocks and biodiversity due to degradation and recovery of tropical forests, focusing on three main areas: (1) the combination of field surveys and remote sensing; (2) evaluation of biodiversity and carbon values under a unified strategy; and (3) research efforts needed to understand and quantify forest degradation and recovery. The improvement of models and estimates of changes of forest carbon can foster process-oriented monitoring of forest dynamics, including different variables and using spatially explicit algorithms that account for regional and local differences, such as variation in climate, soil, nutrient content, topography, biodiversity, disturbance history, recovery pathways, and socioeconomic factors. Generating the data for these models requires affordable large-scale remote-sensing tools associated with a robust network of field plots that can generate spatially explicit information on a range of variables through time. By combining ecosystem models, multiscale remote sensing, and networks of field plots, we will be able to evaluate forest degradation and recovery and their interactions with biodiversity and carbon cycling. Improving monitoring strategies will allow a better understanding of the role of forest dynamics in climate-change mitigation, adaptation, and carbon cycle feedbacks, thereby reducing uncertainties in models of the key processes in the carbon cycle, including their impacts on biodiversity, which are fundamental to support forest governance policies, such as Reducing Emissions from Deforestation and Forest Degradation.

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

    Science.gov (United States)

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

    2015-05-15

    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.

  19. Predictive models in hazard assessment of Great Lakes contaminants for fish

    Science.gov (United States)

    Passino, Dora R. May

    1986-01-01

    A hazard assessment scheme was developed and applied to predict potential harm to aquatic biota of nearly 500 organic compounds detected by gas chromatography/mass spectrometry (GC/MS) in Great Lakes fish. The frequency of occurrence and estimated concentrations of compounds found in lake trout (Salvelinus namaycush) and walleyes (Stizostedion vitreum vitreum) were compared with available manufacturing and discharge information. Bioconcentration potential of the compounds was estimated from available data or from calculations of quantitative structure-activity relationships (QSAR). Investigators at the National Fisheries Research Center-Great Lakes also measured the acute toxicity (48-h EC50's) of 35 representative compounds to Daphnia pulex and compared the results with acute toxicity values generated by QSAR. The QSAR-derived toxicities for several chemicals underestimated the actual acute toxicity by one or more orders of magnitude. A multiple regression of log EC50 on log water solubility and molecular volume proved to be a useful predictive model. Additional models providing insight into toxicity incorporate solvatochromic parameters that measure dipolarity/polarizability, hydrogen bond acceptor basicity, and hydrogen bond donor acidity of the solute (toxicant).

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

    Science.gov (United States)

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

    2016-01-01

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

  1. Fish liver and gill cells as cytogenotoxic indicators in assessment of water quality.

    Science.gov (United States)

    Kaur, Rajbir; Dua, Anish

    2016-09-01

    The present study was aimed to evaluate the effect of municipal wastewater of Tung Dhab drain to freshwater fish Labeo rohita through genotoxicity assays. The idea is to explore and standardize procedures for assessment of toxic impact of pollutant at the cellular level in aquatic species. Hence, chronic, non-renewal toxicity tests were performed with sublethal concentrations (17.7, 26.6 and 35.4 %) of wastewater for exposure durations of 15, 30 and 60 days. Recovery experiments were also performed for duration of 60 days. Higher micronuclei (MN) and binuclei (BN) frequencies were recorded in fluorescently stained liver cells as compared to frequencies obtained for gill cells and erythrocytes. The induced frequencies of MN, BN and nuclear abnormalities (NA) were found in the following order: MN (liver cells) > BN (liver cells) > BN (gill cells) > MN (gill cells) > NA (erythrocytes) > MN (erythrocytes). The results pointed towards the mutagenic nature of water quality of Tung Dhab drain and recommend the incorporation of the liver and gill cells as biomarkers of cytotoxicity over erythrocytes in chronic experiments during water monitoring programs.

  2. Assessing reproductive status in elasmobranch fishes using steroid hormones extracted from skeletal muscle tissue.

    Science.gov (United States)

    Prohaska, Bianca K; Tsang, Paul C W; Driggers, William B; Hoffmayer, Eric R; Wheeler, Carolyn R; Brown, A Christine; Sulikowski, James A

    2013-01-01

    Elasmobranch fishes (sharks, skates, and rays) are particularly susceptible to anthropogenic threats, making a thorough understanding of their life history characteristics essential for proper management. Historically, elasmobranch reproductive data have been collected by lethal sampling, an approach that is problematic for threatened and endangered species. However, recent studies have demonstrated that non-lethal approaches can be as effective as lethal ones for assessment of the reproductive status of an animal. For example, plasma has been used to examine concentrations of steroid hormones. Additionally, skeletal muscle tissue, which can be obtained non-lethally and with minimal stress, can also be used to quantify concentrations of steroid hormones. Skeletal muscle progesterone, testosterone, and estradiol concentrations were determined to be statistically significant indicators of reproductive status in the oviparous Leucoraja erinacea, the yolk-dependent viviparous Squalus acanthias, and the yolk-sac placental viviparous Rhizoprionodon terraenovae. The results of the present study demonstrate that steroid hormones present in non-lethally harvested skeletal muscle tissue can be used as reliable indicators of reproductive status in elasmobranchs.

  3. A hierarchical spatial framework and database for the national river fish habitat condition assessment

    Science.gov (United States)

    Wang, L.; Infante, D.; Esselman, P.; Cooper, A.; Wu, D.; Taylor, W.; Beard, D.; Whelan, G.; Ostroff, A.

    2011-01-01

    Fisheries management programs, such as the National Fish Habitat Action Plan (NFHAP), urgently need a nationwide spatial framework and database for health assessment and policy development to protect and improve riverine systems. To meet this need, we developed a spatial framework and database using National Hydrography Dataset Plus (I-.100,000-scale); http://www.horizon-systems.com/nhdplus). This framework uses interconfluence river reaches and their local and network catchments as fundamental spatial river units and a series of ecological and political spatial descriptors as hierarchy structures to allow users to extract or analyze information at spatial scales that they define. This database consists of variables describing channel characteristics, network position/connectivity, climate, elevation, gradient, and size. It contains a series of catchment-natural and human-induced factors that are known to influence river characteristics. Our framework and database assembles all river reaches and their descriptors in one place for the first time for the conterminous United States. This framework and database provides users with the capability of adding data, conducting analyses, developing management scenarios and regulation, and tracking management progresses at a variety of spatial scales. This database provides the essential data needs for achieving the objectives of NFHAP and other management programs. The downloadable beta version database is available at http://ec2-184-73-40-15.compute-1.amazonaws.com/nfhap/main/.

  4. Solow Residuals Without Capital Stocks

    DEFF Research Database (Denmark)

    Burda, Michael C.; Severgnini, Battista

    2014-01-01

    investment expenditures: one eliminates the capital stock by direct substitution, while the other employs generalized differences of detrended data and the Malmquist index. In short samples, these measures can exhibit consistently lower root mean squared errors than the Solow–Törnqvist counterpart. Capital......We use synthetic data generated by a prototypical stochastic growth model to assess the accuracy of the Solow residual (Solow, 1957) as a measure of total factor productivity (TFP) growth when the capital stock in use is measured with error. We propose two alternative measurements based on current...

  5. Novel Acoustic Techniques for Assessing Fish Schooling in the Context of an Operational Ocean Observatory

    Science.gov (United States)

    2008-09-30

    and onshore waters. A unique acoustic scattering source was identified during the experiment as dense, monotypic aggregations of a pelagic gastropod ...can often reveal hidden coherent structure. IMPACT/ APPLICATIONS The distribution of fish and the variability in their distribution has...direct and waveguide scattering for application to fish. REFERENCES Pitcher, T. J., and J. K. Parrish. 1993. Function of shoaling behavior in teleosts

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-04-01

    ) 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-12-15

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

  8. Assessing the functional diversity of herbivorous reef fishes using a compound-specific stable isotope approach

    KAUST Repository

    Tietbohl, Matthew

    2016-12-01

    Herbivorous coral reef fishes play an important role in helping to structure their environment directly by consuming algae and indirectly by promoting coral health and growth. These fishes are generally separated into three broad groups: browsers, grazers, and excavators/scrapers, with these groupings often thought to have a fixed general function and all fishes within a group thought to have similar ecological roles. This categorization assumes a high level of functional redundancy within herbivorous fishes. However, recent evidence questions the use of this broad classification scheme, and posits that there may actually be more resource partitioning within these functional groupings. Here, I use a compound-specific stable isotope approach (CSIA) to show there appears to be a greater diversity of functional roles than previously assumed within braod functional groups. The δ13C signatures from essential amino acids of reef end-members (coral, macroalgae, detritus, and phytoplankton) and fish muscle were analyzed to investigate differences in resource use between fishes. Most end-members displayed clear isotopic differences, and most fishes within functional groups were dissimilar in their isotopic signature, implying differences in the resources they target. No grazers closely resembled each other isotopically, implying a much lower level of functional redundancy within this group; scraping parrotfish were also distinct from excavating parrotfish and to a lesser degree distinct between scrapers. This study highlights the potential of CSIA to help distinguish fine-scale ecological differences within other groups of reef organisms as well. These results question the utility of lumping nominally herbivorous fishes into broad groups with assumed similar roles. Given the apparent functional differences between nominally herbivorous reef fishes, it is important for managers to incorporate the diversity of functional roles these fish play.

  9. Estuarine fish health assessment: Evidence of wastewater impacts based on nitrogen isotopes and histopathology

    Energy Technology Data Exchange (ETDEWEB)

    Schlacher, Thomas A. [Faculty of Science, Health and Education, University of the Sunshine Coast, Maroochydore DC, QLD 4558 (Australia)], E-mail: tschlach@usc.edu.au; Mondon, Julie A. [School of Life and Environmental Sciences, Deakin University, Warrnambool (Australia)], E-mail: julie.mondon@deakin.edu.au; Connolly, Rod M. [Australian Rivers Institute - Coast and Estuaries and Griffith School of Environment, Griffith University (Australia)], E-mail: r.connolly@griffith.edu.au

    2007-11-15

    Sewage effluent is a powerful agent of ecological change in estuaries. While the effects of sewage pollution on water quality are usually well documented, biological responses of exposed organisms are not. We quantified health impacts in the form of pathological tissue changes across multiple organs in estuarine fish exposed to elevated levels of treated wastewater. Structural pathologies were compared in wild populations of four fish species from two subtropical estuaries on the east coast of Australia that differ substantially in the amount of direct wastewater loadings. Uptake of sewage-derived nitrogen by fish was traced with stable nitrogen isotopes. Pathologies were common in the liver, spleen, gill, kidney and muscle tissues, and included granulomas, melanomacrophage aggregates, and multiple deformities of the gill epithelia. Tissue deformities were more frequent in fish exposed directly to wastewater discharges. Mullet (Valamugil georgii) were most affected, with only a single specimen free of pathologies in the sewage-impacted estuary. Similarly, in those fish that had structural abnormalities, more deformities were generally found in individuals from sites receiving sewage. These spatial contrasts in impaired fish health correspond to significantly enriched {delta}{sup 15}N values in fish muscle as a consequence of fish assimilating sewage-N. Overall, the pattern of lower health and enriched {delta}{sup 15}N values in fish from sewage-impacted areas suggests that organism health is lowered by sewage inputs to estuaries. Measurements of organism health are required to understand the effects of sewage on estuarine ecosystems, and histopathology of fishes is a powerful tool to achieve this.

  10. A Mixed-Method Approach for Quantifying Illegal Fishing and Its Impact on an Endangered Fish Species.

    Science.gov (United States)

    Free, Christopher M; Jensen, Olaf P; Mendsaikhan, Bud

    2015-01-01

    Illegal harvest is recognized as a widespread problem in natural resource management. The use of multiple methods for quantifying illegal harvest has been widely recommended yet infrequently applied. We used a mixed-method approach to evaluate the extent, character, and motivations of illegal gillnet fishing in Lake Hovsgol National Park, Mongolia and its impact on the lake's fish populations, especially that of the endangered endemic Hovsgol grayling (Thymallus nigrescens). Surveys for derelict fishing gear indicate that gillnet fishing is widespread and increasing and that fishers generally use 3-4 cm mesh gillnet. Interviews with resident herders and park rangers suggest that many residents fish for subsistence during the spring grayling spawning migration and that some residents fish commercially year-round. Interviewed herders and rangers generally agree that fish population sizes are decreasing but are divided on the causes and solutions. Biological monitoring indicates that the gillnet mesh sizes used by fishers efficiently target Hovsgol grayling. Of the five species sampled in the monitoring program, only burbot (Lota lota) showed a significant decrease in population abundance from 2009-2013. However, grayling, burbot, and roach (Rutilus rutilus) all showed significant declines in average body size, suggesting a negative fishing impact. Data-poor stock assessment methods suggest that the fishing effort equivalent to each resident family fishing 50-m of gillnet 11-15 nights per year would be sufficient to overexploit the grayling population. Results from the derelict fishing gear survey and interviews suggest that this level of effort is not implausible. Overall, we demonstrate the ability for a mixed-method approach to effectively describe an illegal fishery and suggest that these methods be used to assess illegal fishing and its impacts in other protected areas.

  11. A Mixed-Method Approach for Quantifying Illegal Fishing and Its Impact on an Endangered Fish Species.

    Directory of Open Access Journals (Sweden)

    Christopher M Free

    Full Text Available Illegal harvest is recognized as a widespread problem in natural resource management. The use of multiple methods for quantifying illegal harvest has been widely recommended yet infrequently applied. We used a mixed-method approach to evaluate the extent, character, and motivations of illegal gillnet fishing in Lake Hovsgol National Park, Mongolia and its impact on the lake's fish populations, especially that of the endangered endemic Hovsgol grayling (Thymallus nigrescens. Surveys for derelict fishing gear indicate that gillnet fishing is widespread and increasing and that fishers generally use 3-4 cm mesh gillnet. Interviews with resident herders and park rangers suggest that many residents fish for subsistence during the spring grayling spawning migration and that some residents fish commercially year-round. Interviewed herders and rangers generally agree that fish population sizes are decreasing but are divided on the causes and solutions. Biological monitoring indicates that the gillnet mesh sizes used by fishers efficiently target Hovsgol grayling. Of the five species sampled in the monitoring program, only burbot (Lota lota showed a significant decrease in population abundance from 2009-2013. However, grayling, burbot, and roach (Rutilus rutilus all showed significant declines in average body size, suggesting a negative fishing impact. Data-poor stock assessment methods suggest that the fishing effort equivalent to each resident family fishing 50-m of gillnet 11-15 nights per year would be sufficient to overexploit the grayling population. Results from the derelict fishing gear survey and interviews suggest that this level of effort is not implausible. Overall, we demonstrate the ability for a mixed-method approach to effectively describe an illegal fishery and suggest that these methods be used to assess illegal fishing and its impacts in other protected areas.

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

    NARCIS (Netherlands)

    Batjes, N.H.

    2011-01-01

    The Carbon Benefits Project (CBP) is developing a standardized system for sustainable land management projects to measure, model and report changes in carbon stocks and greenhouse gas (GHG) emissions for use at varying scales. A global framework of soil organic carbon (SOC) stocks under native veget

  13. Movement and mortality of stocked brown trout in a stream

    DEFF Research Database (Denmark)

    Aarestrup, Kim; Jepsen, Niels; Koed, Anders;

    2005-01-01

    The movement and mortality of stocked brown trout Salmo trutta were investigated using radio telemetry. Four brown trout left the study area whereas the remaining fish were stationary. After 5 weeks, 13 out of 50 tagged brown trout were still alive in the stream. Surviving fish had a significantly...

  14. Fish passage assessment of an advanced hydropower turbine and conventional turbine using blade-strike modeling

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Z.; Carlson, T. J.; Dauble, D. D.; Ploskey, G. R. [Pacific Northwest National Laboratory, Richland, WA 99352 (United States)

    2011-07-01

    Hydropower is the largest renewable energy source in the world. However, in the Columbia and Snake River basins, several species of Pacific salmon and steelhead have been listed for protection under the Endangered Species Act due to significant declines of fish population. Dam operators and design engineers are thus faced with the task of making hydroelectric facilities more fish friendly through changes in hydro-turbine design and operation. Public Utility District No. 2 of Grant County, Washington, applied for relicensing from the U.S. Federal Energy Regulatory Commission to replace the 10 turbines at Wanapum Dam with advanced hydropower turbines that were designed to increase power generation and improve fish passage conditions. We applied both deterministic and stochastic blade-strike models to compare fish passage performance of the newly installed advanced turbine to an existing turbine. Modeled probabilities were compared to the results of a large-scale live-fish survival study and a Sensor Fish study under the same operational parameters. Overall, injury rates predicted by the deterministic model were higher than experimental rates of injury, while those predicted by the stochastic model were in close agreement with experimental results. Fish orientation at the time of entry into the plane of the leading edges of the turbine runner blades was an important factor contributing to uncertainty in modeled results. The advanced design turbine had slightly higher modeled injury rates than the existing turbine design; however, no statistical evidence suggested significant differences in blade-strike injuries between the two turbines, thus the hypothesis that direct fish survival rate through the advanced hydropower turbine is equal to or higher than that for fish passing through the conventional turbine could not be rejected. (authors)

  15. Fish Passage Assessment of an Advanced Hydropower Turbine and Conventional Turbine Using Blade-Strike Modeling

    Directory of Open Access Journals (Sweden)

    Zhiqun Deng

    2011-01-01

    Full Text Available Hydropower is the largest renewable energy source in the world. However, in the Columbia and Snake River basins, several species of Pacific salmon and steelhead have been listed for protection under the Endangered Species Act due to significant declines of fish population. Dam operators and design engineers are thus faced with the task of making hydroelectric facilities more fish friendly through changes in hydro-turbine design and operation. Public Utility District No. 2 of Grant County, Washington, applied for relicensing from the U.S. Federal Energy Regulatory Commission to replace the 10 turbines at Wanapum Dam with advanced hydropower turbines that were designed to increase power generation and improve fish passage conditions. We applied both deterministic and stochastic blade-strike models to compare fish passage performance of the newly installed advanced turbine to an existing turbine. Modeled probabilities were compared to the results of a large-scale live-fish survival study and a Sensor Fish study under the same operational parameters. Overall, injury rates predicted by the deterministic model were higher than experimental rates of injury, while those predicted by the stochastic model were in close agreement with experimental results. Fish orientation at the time of entry into the plane of the leading edges of the turbine runner blades was an important factor contributing to uncertainty in modeled results. The advanced design turbine had slightly higher modeled injury rates than the existing turbine design; however, no statistical evidence suggested significant differences in blade-strike injuries between the two turbines, thus the hypothesis that direct fish survival rate through the advanced hydropower turbine is equal to or higher than that for fish passing through the conventional turbine could not be rejected.

  16. Evaluation of offshore stocking of Lake Trout in Lake Ontario

    Science.gov (United States)

    Lantry, B.F.; O'Gorman, R.; Strang, T.G.; Lantry, J.R.; Connerton, M.J.; Schanger, T.

    2011-01-01

    Restoration stocking of hatchery-reared lake trout Salvelinus namaycush has occurred in Lake Ontario since 1973. In U.S. waters, fish stocked through 1990 survived well and built a large adult population. Survival of yearlings stocked from shore declined during 1990–1995, and adult numbers fell during 1998–2005. Offshore stocking of lake trout was initiated in the late 1990s in response to its successful mitigation of predation losses to double-crested cormorants Phalacrocorax auritus and the results of earlier studies that suggested it would enhance survival in some cases. The current study was designed to test the relative effectiveness of three stocking methods at a time when poststocking survival for lake trout was quite low and losses due to fish predators was a suspected factor. The stocking methods tested during 2000–2002 included May offshore, May onshore, and June onshore. Visual observations during nearshore stockings and hydroacoustic observations of offshore stockings indicated that release methods were not a direct cause of fish mortality. Experimental stockings were replicated for 3 years at one site in the southwest and for 2 years at one site in the southeast. Offshore releases used a landing craft to transport hatchery trucks from 3 to 6 km offshore out to 55–60-m-deep water. For the southwest site, offshore stocking significantly enhanced poststocking survival. Among the three methods, survival ratios were 1.74 : 1.00 : 1.02 (May offshore : May onshore : June onshore). Although not statistically significant owing to the small samples, the trends were similar for the southeast site, with survival ratios of 1.67 : 1.00 : 0.72. Consistent trends across years and sites indicated that offshore stocking of yearling lake trout during 2000–2002 provided nearly a twofold enhancement in survival; however, this increase does not appear to be great enough to achieve the 12-fold enhancement necessary to return population abundance to restoration

  17. Differences in survival and growth in hatchery and stream environments, and in maturation of residuls in a stream, between progeny of hatchery and wild steelhead (Study sites: Brushy Fork Creek and Dworshak Hatchery; Stocks:Dworshak hatchery and Fish Creek wild; Year classes: 1992 and 1993): Chapter 1

    Science.gov (United States)

    Rubin, Stephen P.; Reisenbichler, Reginald R.; Wetzel, Lisa A.; Hensleigh, Jay E.; Leonetti,; Rubin, Stephen P.; Reisenbichler, Reginald R.; Wetzel, Lisa A.; Hayes, Michael C.

    2012-01-01

    ). Differences between progeny groups were also found for growth (H>W) and condition (H>W) in the hatchery and downstream migration success of hatchery-reared fish after release (H>W), and for growth (HW for the other), condition (H>W), downstream dispersal (H>W for one year-class; H=W for the other), and maturation of residuals (ovaries weight was greater for H than for W females at ages 4 and 5; testes weight was less for H than for W age-3 males of one year-class) in Brushy Fork. A thunderstorm-induced power outage interrupted flow to the incubation trays at the hatchery and compromised a major tenet of the common garden design for the second year-class, possibly contributing to the inconsistency in relative survivals in Brushy Fork between year-classes. The storm caused the incubation environment to differ between the stocks as a result of reduced oxygen levels and substantially higher densities for H alevins. This difference was illustrated by a 55% loss for H fish during the event, about twice that for W fish.

  18. Environmental Assessment for opening portions of Patoka River National Wildlife Refuge and Management Area for hunting and fishing as proposed in the 1996 Hunting and Fishing Plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The U.S. Fish and Wildlife Service proposes to open portions of the Patoka River National Wildlife Refuge and Management Area (Refuge) for hunting (migratory birds,...

  19. Probabilistic assessment of risks of diethylhexyl phthalate (DEHP) in surface waters of China on reproduction of fish.

    Science.gov (United States)

    Liu, Na; Wang, Yeyao; Yang, Qi; Lv, Yibing; Jin, Xiaowei; Giesy, John P; Johnson, Andrew C

    2016-06-01

    Diethylhexyl phthalate (DEHP) is considered to be an endocrine disruptor, which unlike other chemicals that have either non-specific (e.g., narcotics) or more generalized reactive modes of action, affect the Hypothalamic-pituitary-gonadal (HPG) axis and tend to have specific interactions with particular molecular targets within biochemical pathways. Responding to this challenge, a novel method for deriving predicted no-effect concentration (PNEC) and probabilistic ecological risk assessment (PERAs) for DEHP based on long-term exposure to potentially sensitive species with appropriate apical endpoints was development for protection of Chinese surface waters. PNECs based on potencies to cause lesions in reproductive tissues of fishes, which ranged from 0.04 to 0.20 μg DEHP L(-1), were significantly less than those derived based on other endpoints or other taxa, such as invertebrates. An assessment of risks posed by DEHP to aquatic organisms in surface waters of China showed that 88.17% and 78.85% of surface waters in China were predicted to pose risks to reproductive fitness of fishes with thresholds of protection for aquatic organisms based on 5% (HC5) and 10% (HC10), respectively. Assessment of risks of effects based on effects mediated by the HPG-axis should consider effects on chronic, non-lethal endpoints for specific taxa, especially for reproductive fitness of fishes.

  20. Baseline assessment of fish and benthic communities of the Flower Garden Banks (NODC Accession 0118358)

    Data.gov (United States)

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

  1. Health assessment and mercury analyses of fishes of the Atchafalaya National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Mercury and poor water quality in the Atchafalaya River Basin have been documented by the Louisiana Department of Environmental Quality’s Mercury Monitoring Program....

  2. St. John, USVI fish assessment and monitoring data (2001 - Present): 2011

    Data.gov (United States)

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

  3. La Parguera, Puerto Rico Fish Assessment and Monitoring Data (2002 - Present)

    Data.gov (United States)

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

  4. NCCOS Fish Assessment and Monitoring Photographs, La Parguera, Puerto Rico, (2001 - Present)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The fish photo database provides anecdotal and permanent visual descriptions of benthic organisms, benthic habitat composition, substrate complexity, and other...

  5. St. Croix, USVI Fish Assessment and Monitoring Data (2001 - 2010) (NODC Accession 0125270 and 0125236)

    Data.gov (United States)

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

  6. St. John, USVI fish assessment and monitoring data (2001 - 2011) (NODC Accession 0125236)

    Data.gov (United States)

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

  7. Linking ecoregions, watersheds, and stream habitats with fish: A broad assessment of ecological patterns and integrity

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — It is important for scientists in, and managers of, natural resources to have an ecosystem classification that allows meaningful study and management of large...

  8. NCCOS USVI Fish Assessment and Monitoring Photographs, St. Croix, (2001 - Present)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The fish photo database provides anecdotal and permanent visual descriptions of benthic organisms, benthic habitat composition, substrate complexity, and other...

  9. NCCOS Fish Assessment and Monitoring Photographs, St. John, USVI, (2001 - Present)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The fish photo database provides anecdotal and permanent visual descriptions of benthic organisms, benthic habitat composition, substrate complexity, and other...

  10. Muskrat population estimates for Fish Springs NWR, Utah : An assessment of techniques

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Completion report for a study of muskrat population dynamics and vegetation utilization, being led by Utah State University for a doctorate dissertation. The study...

  11. Baseline assessment of fish and benthic communities of the Flower Garden Banks

    Data.gov (United States)

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

  12. Baseline assessment of fish communities of the Flower Garden Banks (2010 - present): 2011

    Data.gov (United States)

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

  13. Hawaii Coral Reef Assessment and Monitoring Program (CRAMP): Fish Data from 2000 (NODC Accession 0000757)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset consists of CRAMP surveys taken in 2000 and includes quantitative estimates of fish species richness, abundance, and biomass. There are 32 survey sites,...

  14. Baseline assessment of the fish and benthic communities of the Flower Garden Banks (NODC Accession 0118358)

    Data.gov (United States)

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

  15. Contaminant assessment of fish, rangia clams, and sediments in the Lower Pamlico River, North Carolina

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Samples of sediment, rangia clams (Rangia cuneata), gizzard shad (Dorosoma cepedianum), and longnose gar (Lepisosteus osseus) were collected from five sites in the...

  16. Hawaii Coral Reef Assessment and Monitoring Program (CRAMP): Fish Data from 2000 (NODC Accession 0000758)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset consists of CRAMP surveys taken in 2000 and includes quantitative estimates of fish species richness, abundance, and biomass. There are 32 survey sites,...

  17. Baseline assessment of fish communities of the Flower Garden Banks (2010 - present): 2011

    Data.gov (United States)

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

  18. Baseline assessment of fish and benthic communities of the Flower Garden Banks (NODC Accession 0118358)

    Data.gov (United States)

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

  19. Assessment and validation of the CAESAR predictive model for bioconcentration factor (BCF in fish

    Directory of Open Access Journals (Sweden)

    Milan Chiara

    2010-07-01

    Full Text Available Abstract Background Bioconcentration factor (BCF describes the behaviour of a chemical in terms of its likelihood of concentrating in organisms in the environment. It is a fundamental property in recent regulations, such as the European Community Regulation on chemicals and their safe use or the Globally Harmonized System for classification, labelling and packaging. These new regulations consider the possibility of reducing or waiving animal tests using alternative methods, such as in silico methods. This study assessed and validated the CAESAR predictive model for BCF in fish. Results To validate the model, new experimental data were collected and used to create an external set, as a second validation set (a first validation exercise had been done just after model development. The performance of the model was compared with BCFBAF v3.00. For continuous values and for classification purposes the CAESAR BCF model gave better results than BCFBAF v3.00 for the chemicals in the applicability domain of the model. R2 and Q2 were good and accuracy in classification higher than 90%. Applying an offset of 0.5 to the compounds predicted with BCF close to the thresholds, the number of false negatives (the most dangerous errors dropped considerably (less than 0.6% of chemicals. Conclusions The CAESAR model for BCF is useful for regulatory purposes because it is robust, reliable and predictive. It is also fully transparent and documented and has a well-defined applicability domain, as required by REACH. The model is freely available on the CAESAR web site and easy to use. The reliability of the model reporting the six most similar compounds found in the CAESAR dataset, and their experimental and predicted values, can be evaluated.

  20. Environmental Assessment: Lake Yankton Fish Population Renovation Project Yankton County, South Dakota and Cedar County, Nebraska

    Science.gov (United States)

    2014-08-01

    negative impacts from non-native species such as common carp. Long-term benefits to native vegetation at Lake due to the reduction of carp and...Samples for chlorophyll a exceeded the criteria for eastern impounded waters in 80% of the samples collected. Lake Yankton Fish Population Renovation...amphibians, fish, and other wildlife. A potential added benefit to rotenone treatments is the impacts to and elimination of bullfrog tadpoles, reducing

  1. HEALTH CONCERNS ON FISHERY PRODUCTS: ANTIBIOTIC RESISTANCE AND PARASITE RISK ASSESSMENT IN FISH PRODUCTION VALUE CHAINS

    OpenAIRE

    Smaldone, Giorgio

    2014-01-01

    Capture fisheries and aquaculture supplied the world with about 148 million tonnes of fish in 2010, of which about 128 million tonnes were utilized as food for people. The fishery market is becoming much more complex and stratified, with greater diversification among species and product forms and for this reason food safety remains a major concern facing the seafood industry. Along fish value chain there are a lot of concern regarding public health and for this reason the aim of this work was...

  2. Toxicological assessment of spinosad: Implications for integrated control of Aedes aegypti using larvicides and larvivorous fish.

    Science.gov (United States)

    Pereira, Boscolli Barbosa; Caixeta, Evelyn Siqueira; Freitas, Priscila Costa; Santos, Vanessa Santana Vieira; Limongi, Jean Ezequiel; de Campos Júnior, Edimar Olegário; Campos, Carlos Fernando; Souto, Henrique Nazareth; Rodrigues, Tamiris Sabrina; Morelli, Sandra

    2016-01-01

    Integration of larvivorous fish and biolarvicides at low concentrations to control of mosquito larvae in field situations may result in a safer and more effective tool. However, the usefulness of integrated approach depends upon survival and ecological fitness of fish employed. Thus, the aim of this study was to examine the genotoxic effects of combining different sublethal concentrations of spinosad, a naturally occurring neurotoxic insecticide, with male adult poecilid larvivorous guppy (Poecilia reticulata) and platy (Xiphophorus maculatus) fish on Aedes larvae mosquitos. Both fish species have been used for biological control of Aedes larvae in Brazil. Sublethal spinosad exposures were predetermined based on CL50-96hr. Nuclear abnormalities (NA) and micronucleus (MN) frequency in gill cells were measured after 14 d of exposure. Behavioral changes were monitored over 96 h. Although genotoxic effects were not markedly different from control, behavioral changes evaluated based upon the no-observable-effect concentration (NOEC) and lowest-observable-effect concentration (LOEC). Adverse effects were noted at concentrations of 12.6 mg/L (NOEC) and 25.3 mg/L (LOEC) spinosad. Therefore, these insecticide concentrations may be considered as being safe to these fish species and have important implications for integrated approach to control Aedes larvae using natural larvicides and larvivorous fish.

  3. Estimation of the regional stock of residential buildings as a basis for a comparative risk assessment in Germany

    Directory of Open Access Journals (Sweden)

    L. Kleist

    2006-01-01

    Full Text Available One important prerequisite for a comparable quantitative risk assessment for different types of hazards (e.g., earthquakes, windstorms and floods is the use of a common database about and financial appraisal of the assets at risk. For damage assessments it is necessary to represent the values at risk on a regional disaggregated scale and to intersect them with hazard scenarios. This paper presents a methodology and results of a financial appraisal of residential buildings for all communities in Germany. The calculated values are defined as replacement values for the reference year 2000. The resulting average replacement costs for residential buildings per inhabitant amount to EUR 46 600, with considerable differences between communities. The inventory can be used for the calculations of direct losses from various natural disasters within the project 'Risk Map Germany''.

  4. A histology-based fish health assessment of the tigerfish, Hydrocynus vittatus from a DDT-affected area

    Science.gov (United States)

    McHugh, K. J.; Smit, N. J.; Van Vuren, J. H. J.; Van Dyk, J. C.; Bervoets, L.; Covaci, A.; Wepener, V.

    The Pongolapoort Dam (PPD) in the Phongola River, Kwa-Zulu Natal, South Africa and the surrounding area are classified as intermediate to low risk malaria areas and are continually being treated with DDT for malaria vector control. DDT is known as an endocrine disrupting chemical posing estrogenic and anti-androgenic properties and therefore might impact on the health of the 18 freshwater fish species found within this system. Of these species the tigerfish, Hydrocynus vittatus, is targeted by both recreational and local subsistence fishermen and was recently included in the South African threatened or protected species list. Their protected status and importance as a food source therefore emphasises the need for their health status elucidation. Previous research on H. vittatus in the Phongola floodplain highlighted DDT biomagnification in this species. Recent data show that the sum of the DDT levels in February 2009 (5403.9 ng/g lipid) and July 2009 (5537.4 ng/g lipid) is still comparable to the high levels found 30 years earlier. The aim of the current study was thus to determine the health status of H. vittatus in relation to DDT exposure by means of a histology-based fish health assessment protocol. Tigerfish were collected in February 2009 ( n = 30) and July 2009 ( n = 15) and gill, kidney and liver tissue were subjected to histological analyses. Mean Index values showed that the Kidney Index ( IK), Gill Index ( IG) and Fish Index ( IFISH) were higher in fish from the February survey while the Liver Index was higher in those collected during July. Liver alterations identified included intercellular oedema, granular degeneration, vacuolation, nuclear pleomorphism and lymphocyte infiltration. Kidney alterations included dilation of the glomerulus capillaries, vacuolation and hyaline droplet degeneration. Gill alterations identified included telangiectasia and hyperplasia of the secondary lamella, congestion, and rupture of pillar cells. Although histological

  5. Stocking impact and temporal stability of genetic composition in a brackish northern pike population ( Esox lucius L.), assessed using microsatellite DNA analysis of historical and contemporary samples

    DEFF Research Database (Denmark)

    Larsen, Peter Foged; Hansen, Michael Møller; Eg Nielsen, Einar;

    2005-01-01

    During the last decade, brackish northern pike populations in Denmark have been subject to stocking programmes, using nonindigenous pike from freshwater lakes, in order to compensate for drastic population declines. The present study was designed to investigate the genetic impact of stocking...... freshwater pike into a brackish pike population in Stege Nor, Denmark. We analysed polymorphism at eight microsatellite loci in samples representing the indigenous Stege Nor population prior to stocking (ie from 1956 to 1957), along with a sample of the contemporary Stege Nor population and samples from...

  6. Self-assessment of hearing status and risk of noise-induced hearing loss in workers in a rolling stock plant.

    Science.gov (United States)

    Pawlaczyk-Łuszczyńska, Małgorzata; Dudarewicz, Adam; Zamojska, Małgorzata; Sliwinska-Kowalska, Mariola

    2012-01-01

    Noise measurements and questionnaire inquiries were carried out for 124 workers of a rolling stock plant to develop a hearing conservation program. On the basis of that data, the risk of noise-induced hearing loss (NIHL) was evaluated. Additionally, the workers' hearing ability was assessed with the (modified) Amsterdam inventory for auditory disability and handicap, (m)AIADH. The workers had been exposed to noise at A-weighted daily noise exposure levels of 74-110 dB for 1-40 years. Almost one third of the workers complained of hearing impairment and the (m)AIADH results showed some hearing difficulties in over half of them. The estimated risk of hearing loss over 25 dB in the frequency range of 3-6 kHz was 41-50% when the standard method of predicting NIHL specified in Standard No. ISO 1999:1990 was used. This risk increased to 50-67% when noise impulsiveness, coexposure to organic solvents, elevated blood pressure and smoking were included in calculations.

  7. Final Environmental Assessment Proposed Opening of Bogue Chitto National Wildlife Refuge to Upland Game Hunting, Migratory Waterfowl Hunting, Big Game Hunting and Sport and Commercial Fishing

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — 1985 Final Environmental Assessment Proposed Opening of Bogue Chitto National Wildlife Refuge to Upland Game Hunting, Migratory Waterfoul Hunting, Big Game Hunting...

  8. A Vulnerability Assessment of Fish and Invertebrates to Climate Change on the Northeast U.S. Continental Shelf.

    Directory of Open Access Journals (Sweden)

    Jonathan A Hare

    Full Text Available Climate change and decadal variability are impacting marine fish and invertebrate species worldwide and these impacts will continue for the foreseeable future. Quantitative approaches have been developed to examine climate impacts on productivity, abundance, and distribution of various marine fish and invertebrate species. However, it is difficult to apply these approaches to large numbers of species owing to the lack of mechanistic understanding sufficient for quantitative analyses, as well as the lack of scientific infrastructure to support these more detailed studies. Vulnerability assessments provide a framework for evaluating climate impacts over a broad range of species with existing information. These methods combine the exposure of a species to a stressor (climate change and decadal variability and the sensitivity of species to the stressor. These two components are then combined to estimate an overall vulnerability. Quantitative data are used when available, but qualitative information and expert opinion are used when quantitative data is lacking. Here we conduct a climate vulnerability assessment on 82 fish and invertebrate species in the Northeast U.S. Shelf including exploited, forage, and protected species. We define climate vulnerability as the extent to which abundance or productivity of a species in the region could be impacted by climate change and decadal variability. We find that the overall climate vulnerability is high to very high for approximately half the species assessed; diadromous and benthic invertebrate species exhibit the greatest vulnerability. In addition, the majority of species included in the assessment have a high potential for a change in distribution in response to projected changes in climate. Negative effects of climate change are expected for approximately half of the species assessed, but some species are expected to be positively affected (e.g., increase in productivity or move into the region. These

  9. IMPACT OF FISHING AND HABITAT DEGRADATION ON THE DENSITY OF BANGGAI CARDINAL FISH (Pterapogon kauderni, Koumans 1933 IN BANGGAI ARCHIPELAGO, INDONESIA

    Directory of Open Access Journals (Sweden)

    Kamaluddin Kasim

    2014-06-01

    Full Text Available Banggai cardinal fish (Pterapogonkauderni, Koumans 1933 is uncommon example of a marine fish with distributed in small range area while being in highly exploited. This fish is in high demand as an ornamental fish. However, the information on the number of density is limited. An underwater visual fish census survey was conducted in June to July 2010 at 18 fishing sites around Banggai archipelago to estimate the density of the stock and assess the impact of fishing and habitat on density. The areas are divided into three main islands, namely Banggai Island, Peleng Island, Toropot-Tumbak-Labobo Island. The lowest density index of the P. kauderni recorded at Kindandal village on Peleng Island, 0.014 fish/m2while the highest abundance index of 3.0 fish/m2 found at Toropot village at Toropot Island. In three survey sites (Bonebaru and Toropot villages where the fishing activities are still ongoing, the density has declined compared to the survey conducted in 2004. Majority of the villages in Peleng Island have lower density compared with the other islands probably due to the degradation of microhabitat of P. kauderni. In many cases, microhabitat degradation might be as a result of collection of sea urchins and sea anemone for consumption by local community.

  10. Risk Assessment of Heavy Metals in Imported Frozen Fish Scomber scombrus Species Sold in Nigeria: A Case Study in Zaria Metropolis

    Directory of Open Access Journals (Sweden)

    Abdullahi Abubakar

    2015-01-01

    Full Text Available This study assesses the likely health risks to human contamination of heavy metals from fish consumption. The analysis of the idea of fish destination and status (fishing area for heavy metals was determined by the assessment of its risk limits (daily intake of metal and health risk index. Variations in the accumulation of heavy metals concentrations were between various tissues/organs (skin, muscle, gills, liver, intestine, kidneys, brain, and bones across the batches of two fishing origins. Post hoc (Duncan multicomparison shows that there are significant differences (PHg>Pb>Cd>Ni and were above the recommended safety limits outlined by FAO/WHO. However, the consumer’s health risk with the consumption of fish muscles tissues shows that there are greater tendencies for cadmium, lead, and mercury exposure. Also consumption of Scomber scombrus species above the recommended daily intake (stated in this study might lead to ingestion of heavy metals at unacceptable concentrations.

  11. Integrated biomarker response index using a Neotropical fish to assess the water quality in agricultural areas

    Directory of Open Access Journals (Sweden)

    Carlos Eduardo Delfino Vieira

    Full Text Available Aquatic ecosystems in areas with intense agricultural activity are subject to pesticide contamination, which may compromise the health of the fish. In order to verify the quality of the water and the possible effects of pesticides on fish, a method that combines different biomarker responses into an index named "integrated biomarker response" (IBR was applied using the biological alterations in the Neotropical fish Astyanax altiparanae. Fish were maintained in situ at five sites along a stream that runs in an agricultural area and in a stream within a forest fragment, considered a reference site. After seven days of exposure the following alterations were observed in fish confined at experimental sites: increased activity of glutathione-S-transferase (GST and catalase (CAT and increase in the content of reduced glutathione (GSH in liver and gills, reduction of acetylcholinesterase (AChE activity in the brain and muscle, increase in the occurrence of DNA strand breaks and in the frequency of micronuclei (MN and nuclear abnormalities (ENA in erythrocytes. The IBR highlighted three sites as the most affected, as the animals confined at these sites showed greater variations in biological responses. The biomarkers most important for the IBR results were GST, AChE, DNA breaks and ENA.

  12. Assessment of hydraulic fish habitat condition using integrated toolkit: a case study of the Geum river basin, Republic of Korea.

    Science.gov (United States)

    Park, Sangyoung; Kim, Jeongkon; Ko, Ick Hwan; Arthington, Angela; Jones, Gary; Yum, Kyung Taek

    2010-01-01

    Artificial changes of rivers, including construction and operation of dams, inevitably lead to physical and ecological changes throughout waterways and their floodplains. In this study, a conceptual model coupled with integrated numerical modeling is presented for hydraulic fish habitat assessment of the Geum River basin, Republic of Korea. Based on the major events which might have affected the ecological system, a conceptual model was formulated to guide desktop and field studies, modeling and scenario evaluations. The result of hydraulic fish habitat assessment indicated that the construction of the Daecheong Multipurpose Dam (DMD) in the Geum River basin has altered flow magnitudes and reduced the river's flow variability. Changes are evident in the magnitude of medium and small flows and the river experiences increased low flows during the dry season. Black shiner, an endangered fish species in Korea, was selected and analyzed to explore relationships between flow regime change by dams and changes to its preferred habitats. As a result, fewer sensitive riffle-benthic species were observed in the reaches downstream of DMD due to the reduction of suitable habitat conditions such as riffle-pool sequences. The proposed conceptual model and integrated toolkit would allow river managers to isolate the physical and biological effects associated with dam operation and could be useful for developing river management strategies.

  13. Assessing distribution of migratory fishes and connectivity following complete and partial dam removals in a North Carolina River

    Science.gov (United States)

    Raabe, Joshua K.; Hightower, Joseph E.

    2014-01-01

    Fish, especially migratory species, are assumed to benefit from dam removals that restore connectivity and access to upstream habitat, but few studies have evaluated this assumption. Therefore, we assessed the movement of migratory fishes in the springs of 2008 through 2010 and surveyed available habitat in the Little River, North Carolina, a tributary to the Neuse River, after three complete dam removals and one partial (notched) dam removal. We tagged migratory fishes with PIT tags at a resistance-board weir located at a dam removal site (river kilometer [rkm] 3.7) and followed their movements with an array of PIT antennas. The river-wide distribution of fish following removals varied by species. For example, 24–31% of anadromous American Shad Alosa sapidissima, 45–49% of resident Gizzard Shad Dorosoma cepedianum, and 4–11% of nonnative Flathead CatfishPylodictis olivaris passed the dam removal site at rkm 56 in 2009 and 2010. No preremoval data were available for comparison, but reach connectivity appeared to increase as tagged individuals passed former dam sites and certain individuals moved extensively both upstream and downstream. However, 17–28% did not pass the partially removed dam at rkm 7.9, while 20–39% of those that passed remained downstream for more than a day before migrating upstream. Gizzard Shad required the deepest water to pass this notched structure, followed by American Shad then Flathead Catfish. Fish that passed the notched dam accessed more complex habitat (e.g., available substrate size-classes) in the middle and upper reaches. The results provide strong support for efforts to restore currently inaccessible habitat through complete removal of derelict dams.

  14. Refugia of marine fish in the Northeast Atlantic during the Last Glacial Maximum: concordant assessment from archaeozoology and palaeotemperature reconstructions

    Directory of Open Access Journals (Sweden)

    A. J. Kettle

    2010-07-01

    Full Text Available Archaeozoological finds of the remains of marine and amphihaline fish from the Last Glacial Maximum (LGM ca. 21 ka ago show evidence of very different species ranges compared to the present. We show how an ecological niche model (ENM based on palaeoclimatic reconstructions of sea surface temperature and bathymetry can be used to effectively predict the spatial range of marine fish during the LGM. The results indicate that the ranges of marine fish species that are now in Northwestern Europe were almost completely displaced southward from the modern distribution. Significantly, there is strong evidence that there was an invasion of fish of current economic importance into the Western Mediterranean through the Straits of Gibraltar, where they were exploited by Palaeolithic human populations. There has been much recent interest in the marine glacial refugia to understand how the ranges of the economically important fish species will be displaced with the future climate warming. Recent ENM studies have suggested that species ranges may not have been displaced far southward during the coldest conditions of the LGM. However, archaeozoological evidence and LGM ocean temperature reconstructions indicate that there were large range changes, and certain marine species were able invade the Western Mediterranean. These findings are important for ongoing studies of molecular ecology that aim to assess marine glacial refugia from the genetic structure of living populations, and they pose questions about the genetic identity of vanished marine populations during the LGM. The research presents a challenge for future archaeozoological work to verify palaeoclimatic reconstructions and delimit the glacial refugia.

  15. 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.

    Science.gov (United States)

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

    2005-03-01

    Recent substantial declines in northeastern Atlantic cod stocks necessitate improved biological knowledge and the development of techniques to complement standard stock assessment methods (which largely depend on accurate commercial catch data). In 2003, an ichthyoplankton survey was undertaken in the Irish Sea and subsamples of 'cod-like' eggs were analysed using a TaqMan multiplex, PCR (polymerase chain reaction) assay (with specific probes for cod, haddock and whiting). The TaqMan method was readily applied to the large number of samples (n = 2770) generated during the survey and when combined with a manual DNA extraction protocol had a low failure rate of 6%. Of the early stage 'cod-like' eggs (1.2-1.75 mm diameter) positively identified: 34% were cod, 8% haddock and 58% whiting. As previous stock estimates based on egg surveys for Irish Sea cod assumed that the majority of 'cod-like' eggs were from cod, the TaqMan results confirm that there was probably substantial contamination by eggs of whiting and haddock that would have inflated estimates of the stock biomass.

  16. Mercury assessment and evaluation of its impact on fish in the Cecina river basin (Tuscany, Italy)

    Energy Technology Data Exchange (ETDEWEB)

    Scerbo, R. [CNR Istituto di Biofisica, Area della Ricerca Pisa-S. Cataldo, Via G. Moruzzi 1, 56124 Pisa (Italy); Ristori, T. [CNR Istituto di Biofisica, Area della Ricerca Pisa-S. Cataldo, Via G. Moruzzi 1, 56124 Pisa (Italy); Stefanini, B. [CNR Istituto di Biofisica, Area della Ricerca Pisa-S. Cataldo, Via G. Moruzzi 1, 56124 Pisa (Italy); De Ranieri, S. [Dipartimento Scienze Uomo e Ambiente, Universita di Pisa, Via Volta 6, 56100 Pisa (Italy); Barghigiani, C. [CNR Istituto di Biofisica, Area della Ricerca Pisa-S. Cataldo, Via G. Moruzzi 1, 56124 Pisa (Italy)]. E-mail: barghigiani@cibm.it

    2005-05-01

    This paper reports the results of mercury contamination monitoring in the Cecina river basin (Tuscany, Italy). Mercury was measured in the waters, sediments and fish species of the river and its most important tributaries. In fish specimens the organic form was also determined. The results showed high mercury levels in most of the samples analysed. Particularly high concentrations were found in the sediments of the S. Marta canal flowing into the Cecina, where a chlor-alkali plant discharges its wastes, and high levels were still detectable 31 km downstream from the confluence. Near the S. Marta confluence many fish specimens were very contaminated and a study on Leuciscus cephalus cabeda growth suggested that at this site mercury accumulation occurs in these organisms since they are very young. - Mercury entering water from a chlor-alkali plant near Tuscany has led to contamination of river food webs.

  17. Mercury assessment and evaluation of its impact on fish in the Cecina river basin (Tuscany, Italy).

    Science.gov (United States)

    Scerbo, R; Ristori, T; Stefanini, B; De Ranieri, S; Barghigiani, C

    2005-05-01

    This paper reports the results of mercury contamination monitoring in the Cecina river basin (Tuscany, Italy). Mercury was measured in the waters, sediments and fish species of the river and its most important tributaries. In fish specimens the organic form was also determined. The results showed high mercury levels in most of the samples analysed. Particularly high concentrations were found in the sediments of the S. Marta canal flowing into the Cecina, where a chlor-alkali plant discharges its wastes, and high levels were still detectable 31 km downstream from the confluence. Near the S. Marta confluence many fish specimens were very contaminated and a study on Leuciscus cephalus cabeda growth suggested that at this site mercury accumulation occurs in these organisms since they are very young.

  18. Methodological Aspects of Analyzing and Assessing the Per Capita Consumption of Fish and Seafood in the Russian Federation

    Directory of Open Access Journals (Sweden)

    Vladimir Mikhailovich Selin

    2015-12-01

    Full Text Available Globalization of the economy and increased competition leads to the need to strengthen the functions of the Russian government to ensure food security of the country and, accordingly, the consolidation of mechanisms of state regulation of agricultural economy and food markets. The importance of solving the problems of information security, a high degree of reliability of the information provided by the Government of the relevant statistical authorities is growing. The relevance of obtaining high-quality statistical information for the adoption of timely and informed decisions by the government on the management of the national economy has increased significantly during the period of political and economic confrontation between Russia and the West in terms of sanctions and counter-sanctions. Taking fishing industry and its product – the water biological resources – as an example, the author of the present study carried out a structural analysis of the methodology for composing the balance of fish and fish products to determine the per capita level of consumption, described the different approaches to assessing the level of consumption of water biological resources, structured export indicators of water biological resources gathered from various official sources, on the basis of which the author revealed significant differences in the assessment of the situation. The subject of statistics as the problem was raised at the Presidium of the State Council from October 19, 2015 devoted to the development of the fishing industry of the Russian Federation and was reflected as a separate item in the Order of the President following the results of the State Council. Established by the Order of the Federal State Statistics Service dated October 21, 2013 No. 419, the new method of determining the level of per capita consumption of fish and fish products, based on the compilation of the balance of water biological resources, and composed after the

  19. LIFE Segura-Riverlink as a green infrastructure approach to recover the longitudinal connectivity: preliminary data of the fish-based assessment.

    Directory of Open Access Journals (Sweden)

    Ana Sánchez-Pérez

    2015-11-01

    The initial fish-based assessment was completed with significant baseline data showing exotic invasive fishes as dominant and Luciobarbus sclateri as the target species to assess changes at population levels. The project’s outcomes will protect local aquatic and riverine habitats, allow fish reproductive movements along an important fluvial sector, improve ecosystem services, and build a framework of scientific and social knowledge to improve river management quality and to help the implementation and enforcement of EU policy and legislation on biodiversity conservation.

  20. Fish Passage Assessment of an Advanced Hydropower Turbine and Conventional Turbine Using Blade-strike Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Zhiqun; Carlson, Thomas J.; Dauble, Dennis D.; Ploskey, Gene R.

    2011-01-04

    In the Columbia and Snake River basins, several species of Pacific salmon were listed under the Endangered Species Act of 1973 due to significant declines of fish population. Dam operators and design engineers are thus faced with the task of making those hydroelectric facilities more ecologically friendly through changes in hydro-turbine design and operation. Public Utility District No. 2 of Grant County, Washington, applied for re-licensing from the U.S. Federal Energy Regulatory Commission to replace the 10 turbines at Wanapum Dam with advanced hydropower turbines that were designed to increase power generation and improve fish passage conditions. We applied both deterministic and stochastic blade-strike models to the newly installed turbine and an existing turbine. Modeled probabilities were compared to the results of a large-scale live fish survival study and a sensor fish study under the same operational parameters. Overall, injury rates predicted by the deterministic model were higher than experimental rates of injury while those predicted by the stochastic model were in close agreement with experiment results. Fish orientation at the time of entry into the plane of the leading edges of the turbine runner blades was an important factor contributing to uncertainty in modeled results. The advanced design turbine had slightly higher modeled injury rates than the existing turbine design; however, there was no statistical evidence that suggested significant differences in blade-strike injuries between the two turbines and the hypothesis that direct fish survival rate through the advanced hydropower turbine is equal or better than that through the conventional turbine could not be rejected.

  1. Assessing RET/PTC in thyroid nodule fine-needle aspirates: the FISH point of view.

    Science.gov (United States)

    Caria, Paola; Dettori, Tinuccia; Frau, Daniela V; Borghero, Angela; Cappai, Antonello; Riola, Alessia; Lai, Maria L; Boi, Francesco; Calò, Piergiorgio; Nicolosi, Angelo; Mariotti, Stefano; Vanni, Roberta

    2013-08-01

    RET/PTC rearrangement and BRAF(V600E) mutation are the two prevalent molecular alterations associated with papillary thyroid carcinoma (PTC), and their identification is increasingly being used as an adjunct to cytology in diagnosing PTC. However, there are caveats associated with the use of the molecular approach in fine-needle aspiration (FNA), particularly for RET/PTC, that should be taken into consideration. It has been claimed that a clonal or sporadic presence of this abnormality in follicular cells can distinguish between malignant and benign nodules. Nevertheless, the most commonly used PCR-based techniques lack the capacity to quantify the number of abnormal cells. Because fluorescence in situ hybridization (FISH) is the most sensitive method for detecting gene rearrangement in a single cell, we compared results from FISH and conventional RT-PCR obtained in FNA of a large cohort of consecutive patients with suspicious nodules and investigated the feasibility of setting a FISH-FNA threshold capable of distinguishing non-clonal from clonal molecular events. For this purpose, a home brew break-apart probe, able to recognize the physical breakage of RET, was designed. While a ≥3% FISH signal for broken RET was sufficient to distinguish nodules with abnormal follicular cells, only samples with a ≥6.8% break-apart FISH signal also exhibited positive RT-PCR results. On histological analysis, all nodules meeting the ≥6.8% threshold proved to be malignant. These data corroborate the power of FISH when compared with RT-PCR in quantifying the presence of RET/PTC in FNA and validate the RT-PCR efficiency in detecting clonal RET/PTC alterations.

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

    Science.gov (United States)

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

    2006-08-01

    As top predators of pelagic food webs, large fish naturally bioaccumulate mercury (Hg). Determining Hg burdens in commercialized fish is essential considering the concern about effects of contaminants on human health and the legal thresholds that are therefore set for local consumption and/or exportation. Total Hg levels were measured in the muscular tissue of 183 fish of five commercially important species from the tropical zone of the Western Indian Ocean. All individuals were measured and sexed in order to study the impregnation of Hg with size and sex within each species. Values of Hg found in this part of the Indian Ocean were comparable to Hg in muscular tissue of the same species studied in other areas. The highest Hg levels were noted in Swordfish (Xiphias gladius) caught in waters surrounding Reunion Island (3.97+/-2.67 microg g(-1) dry weight). Following the Swordfish, in decreasing order of Hg content, were the Yellowfin Tuna (Thunnus albacares) and the Skipjack (Katsuwonus pelamis), then the Common Dolphinfish (Coryphaena hippurus) and the Wahoo (Acanthocybium solandri). In the North of the Mozambique Channel, Swordfish had higher Hg levels than Yellowfin Tunas, and Dolphinfish exhibited intermediate Hg levels. The size of a fish was a determining factor of its Hg burden, as was the species. Differences in size-normalized Hg levels were observed between the two study zones for Swordfish and Common Dolphinfish. Sex, in contrast, did not influence Hg levels suggesting that females and males have similar feeding habits. The muscular Hg levels presented here suggest that consumers of fish originating from the Western Indian Ocean should limit themselves to one Swordfish based meal per week, or one fish meal a day if they choose to eat tuna or Common Dolphinfish.

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

    Directory of Open Access Journals (Sweden)

    Pourashouri, P.

    2013-03-01

    Full Text Available The present research addresses the quality loss in two different ready-to-eat (RTE seafoods. With this aim, chemical and microbiological parameters were measured in tuna lasagne (TL and hake roe foods which were refrigerated (4°C 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.

    Se estudió la pérdida de calidad de dos productos marinos elaborados (lasaña de atún, TL; huevas de merluza conservados en refrigeración (4 °C durante 35 y 71 días, respectivamente. Ambos alimentos mostraron un desarrollo importante de la oxidación lipídica (formación de peróxidos y compuestos de interacción durante el periodo de conservación, siendo mayor en el caso de TL; asimismo, el producto TL experimentó un importante desarrollo de hidrólisis lipídica. Sin embargo, ambos alimentos experimentaron un desarrollo bajo en microorganismos mesófilos y aminas volátiles; por otra parte, no maniferstaron presencia de microorganismos patógenos a lo largo del periodo de conservación, a pesar de sobrepasar el tiempo de caducidad. De acuerdo con la creciente demanda de nuevas preparaciones de alimentos refrigerados de calidad alta, se recomienda el estudio de las alteraciones lipídicas en elaboraciones basadas en alimentos de origen marino

  4. Natural Propagation and Habitat Improvement, Washington, Volume IIA, Tumwater Falls and Dryden Dam Fish Passage, 1983 Final Report.

    Energy Technology Data Exchange (ETDEWEB)

    Unknown Author

    1984-05-01

    This engineering feasibility and predesign report on the Tumwater Falls and Dryden Dam Fish Passage Project provides BPA with information for planning purposes and will serve as a discussion document for interested agencies. Tumwater Falls and Dryden Dams, both on the Wenatchee River, were built in the early 1900's as diversions for hydropower, and irrigation and hydropower, respectively. The present fishway facilities at both sites are inadequate to properly pass the anadromous fish runs in the Wenatchee River. These runs include spring and summer chinook salmon, sockeye salmon, coho salmon and steelhead trout. Predesign level drawings are provided in this report that represent fishway schemes capable of adequately passing present and projected fish runs. The effects of present passage facilities on anadromous fish stocks is addressed both quantitatively and qualitatively. The quantitative treatment assesses losses of adult migrants due to the structures and places an estimated value on those fish. The dollar figure is estimated to be between $391,000 and $701,000 per year for both structures. The qualitative approach to benefits deals with the concept of stock vigor, the need for passage improvements to help ensure the health of the anadromous fish stock. 29 references, 27 figures, 5 tables.

  5. Using DNA barcoding to assess Caribbean reef fish biodiversity: expanding taxonomic and geographic coverage.

    Directory of Open Access Journals (Sweden)

    Lee A Weigt

    Full Text Available This paper represents a DNA barcode data release for 3,400 specimens representing 521 species of fishes from 6 areas across the Caribbean and western central Atlantic regions (FAO Region 31. Merged with our prior published data, the combined efforts result in 3,964 specimens representing 572 species of marine fishes and constitute one of the most comprehensive DNA barcoding "coverages" for a region reported to date. The barcode data are providing new insights into Caribbean shorefish diversity, allowing for more and more accurate DNA-based identifications of larvae, juveniles, and unknown specimens. Examples are given correcting previous work that was erroneous due to database incompleteness.

  6. Using DNA barcoding to assess Caribbean reef fish biodiversity: expanding taxonomic and geographic coverage.

    Science.gov (United States)

    Weigt, Lee A; Baldwin, Carole C; Driskell, Amy; Smith, David G; Ormos, Andrea; Reyier, Eric A

    2012-01-01

    This paper represents a DNA barcode data release for 3,400 specimens representing 521 species of fishes from 6 areas across the Caribbean and western central Atlantic regions (FAO Region 31). Merged with our prior published data, the combined efforts result in 3,964 specimens representing 572 species of marine fishes and constitute one of the most comprehensive DNA barcoding "coverages" for a region reported to date. The barcode data are providing new insights into Caribbean shorefish diversity, allowing for more and more accurate DNA-based identifications of larvae, juveniles, and unknown specimens. Examples are given correcting previous work that was erroneous due to database incompleteness.

  7. Stocking densities of juvenile Brycon orthotaenia: production parameters and economic benefits in net cages

    Directory of Open Access Journals (Sweden)

    Aline de Assis Lago

    2014-07-01

    Full Text Available Developing a rearing technology requires the determination of the optimum stocking density. This study aimed to determine the best stocking density for Brycon orthotaenia juveniles grown in net cages, during the rearing phase. The research was conducted at the Experimental Farm of EPAMIG, in Felixlândia, Minas Gerais State, in the Três Marias Reservoir. 9,000 fingerlings were distributed into 12 net cages, 2 m3each, according to a completely randomized design with three replications and four different stocking densities (150, 300, 450, 600 fish m-3. Random samples were taken from each net cage, at the onset of the experiment and at 60 rearing days, to assess production parameters, specific growth rate and uniformity. We verified a positive linear relationship (p 0.05 for growth parameters, uniformity and final weight. It can be concluded that the density of 300 fish m-3 is the most suitable, because it provides higher net revenue, survival, and a good feed conversion.

  8. Assessment of Dissolved Oxygen Mitigation at Hydropower Dams Using an Integrated Hydrodynamic/Water Quality/Fish Growth Model

    Energy Technology Data Exchange (ETDEWEB)

    Bevelhimer, Mark S [ORNL; Coutant, Charles C [ORNL

    2006-07-01

    Dissolved oxygen (DO) in rivers is a common environmental problem associated with hydropower projects. Approximately 40% of all FERC-licensed projects have requirements to monitor and/or mitigate downstream DO conditions. Most forms of mitigation for increasing DO in dam tailwaters are fairly expensive. One area of research of the Department of Energy's Hydropower Program is the development of advanced turbines that improve downstream water quality and have other environmental benefits. There is great interest in being able to predict the benefits of these modifications prior to committing to the cost of new equipment. In the case of turbine replacement or modification, there is a need for methods that allow us to accurately extrapolate the benefits derived from one or two turbines with better design to the replacement or modification of all turbines at a site. The main objective of our study was to demonstrate a modeling approach that integrates the effects of flow and water quality dynamics with fish bioenergetics to predict DO mitigation effectiveness over long river segments downstream of hydropower dams. We were particularly interested in demonstrating the incremental value of including a fish growth model as a measure of biological response. The models applied are a suite of tools (RMS4 modeling system) originally developed by the Tennessee Valley Authority for simulating hydrodynamics (ADYN model), water quality (RQUAL model), and fish growth (FISH model) as influenced by DO, temperature, and available food base. We parameterized a model for a 26-mile reach of the Caney Fork River (Tennessee) below Center Hill Dam to assess how improvements in DO at the dam discharge would affect water quality and fish growth throughout the river. We simulated different types of mitigation (i.e., at the turbine and in the reservoir forebay) and different levels of improvement. The model application successfully demonstrates how a modeling approach like this one can be

  9. A Nutritional-Toxicological Assessment of Antarctic Krill Oil versus Fish Oil Dietary Supplements

    Directory of Open Access Journals (Sweden)

    Susan M. Bengtson Nash

    2014-08-01

    Full Text Available Fish oil dietary supplements and complementary medicines are pitched to play a role of increasing strategic importance in meeting daily requirements of essential nutrients, such as long-chain (≥C20, LC omega-3 polyunsaturated fatty acids and vitamin D. Recently a new product category, derived from Antarctic krill, has been launched on the omega-3 nutriceutical market. Antarctic krill oil is marketed as demonstrating a greater ease of absorption due to higher phospholipid content, as being sourced through sustainable fisheries and being free of toxins and pollutants; however, limited data is available on the latter component. Persistent Organic Pollutants (POP encompass a range of toxic, man-made contaminants that accumulate preferentially in marine ecosystems and in the lipid reserves of organisms. Extraction and concentration of fish oils therefore represents an inherent nutritional-toxicological conflict. This study aimed to provide the first quantitative comparison of the nutritional (EPA and DHA versus the toxicological profiles of Antarctic krill oil products, relative to various fish oil categories available on the Australian market. Krill oil products were found to adhere closely to EPA and DHA manufacturer specifications and overall were ranked as containing intermediate levels of POP contaminants when compared to the other products analysed. Monitoring of the pollutant content of fish and krill oil products will become increasingly important with expanding regulatory specifications for chemical thresholds.

  10. Assessing Potential Vulnerability and Response of Fish to Simulated Avian Predation after Exposure to Psychotropic Pharmaceuticals

    Directory of Open Access Journals (Sweden)

    Melanie L. Hedgespeth

    2016-04-01

    Full Text Available Psychotropic pharmaceuticals present in the environment may impact organisms both directly and via interaction strengths with other organisms, including predators; therefore, this study examined the potential effects of pharmaceuticals on behavioral responses of fish to avian predators. Wild-caught juvenile perch (Perca fluviatilis were assayed using a striking bird model after a seven-day exposure to psychotropic pharmaceuticals (the antidepressants fluoxetine or sertraline, or the β-blocker propranolol under the hypotheses that exposure would increase vulnerability to avian predation via increasing the probability of predator encounter as well as degrading evasive behaviors upon encounter. None of the substances significantly affected swimming activity of the fish, nor did they increase vulnerability by affecting encounter probability or evasive endpoints compared to control treatments. Counter to our expectations, fish exposed to 100 μg/L fluoxetine (but no other concentrations or pharmaceuticals were less likely to enter the open area of the arena, i.e., less likely to engage in risky behavior that could lead to predator encounters. Additionally, all fish exposed to environmentally relevant, low concentrations of sertraline (0.12 μg/L and propranolol (0.1 μg/L sought refuge after the simulated attack. Our unexpected results warrant further research as they have interesting implications on how these psychotropic pharmaceuticals may affect predator-prey interactions spanning the terrestrial-aquatic interface.

  11. Assessment of trace metals in fish species of urban rivers in Bangladesh and health implications.

    Science.gov (United States)

    Islam, Md Saiful; Ahmed, Md Kawser; Habibullah-Al-Mamun, Md; Masunaga, Shigeki

    2015-01-01

    Levels of six metals i.e. chromium (Cr), nickel (Ni), copper (Cu), arsenic (As), cadmium (Cd) and lead (Pb) in three fish species (Channa punctatus, Heteropneustes fossilis and Trichogaster fasciata) from three urban rivers in Bangladesh were measured. Concentrations of Cr, Ni, Cu, As, Cd and Pb in fish species were 0.75-4.8, 0.14-3.1, 1.1-7.2, 0.091-0.53, 0.007-0.13, and 0.052-2.7mg/kg ww, respectively. The analyzed metals were significantly different between species and seasons (p<0.05). The target hazard quotients (THQs) and carcinogenic risk (CR) for individual metal showed that As and Pb in muscle was particularly hazardous and potential risk for the low, medium and high fish consumer in Bangladesh. Some of the trace metals' concentrations are higher than the recommended value, which suggest that the water and fish of these rivers are not completely safe for human health.

  12. Assessment of perfluorooctane sulfonate and perfluorooctanoic acid exposure through fish consumption in Italy

    Directory of Open Access Journals (Sweden)

    Andrea Barbarossa

    2016-11-01

    Full Text Available Perfluoroalkyl and polyfluoroalkyl substances (PFASs are pollutants of anthropic origin with possible side effects on human health. Diet, and in particular fish and seafood, is considered the major intake pathway for humans. The present study investigated the levels of perfluorooctane sulfonate (PFOS and perfluorooctanoic acid (PFOA contamination in twenty-five samples of fresh fillet of five widely consumed fish species purchased from large retailers in Italy, to be used for an estimation of the Italian population exposure to these contaminants. PFOS and PFOA were found in all samples, at concentrations up to 1896 (mean=627 ng/kg and 487 ng/kg (mean=75 ng/kg, respectively, confirming the role of fish as high contributor to human exposure. However, a remarkable inter-species variability was observed, and multiple factors were suggested as potentially responsible for such differences, suggesting that the preferential consumption of certain species could likely increase the intake, and thus the exposure. The exposure estimates for both average and high fish consumers resulted far below the tolerable daily intakes for PFOS and PFOA in all age groups, confirming the outcomes of EFSA’s scientific report. In particular, the calculated total dietary exposure for the 95th percentile consumers belonging to the toddler age class, the most exposed group, resulted equal to 9.72 ng/kg body weight (BW/day for PFOS and 8.39 ng/kg BW/day for PFOA.

  13. Distribution of fish species for the generic Appropriate Assessment for the construction of offshore wind farms.

    NARCIS (Netherlands)

    Hofstede, ter R.; Winter, H.V.; Os, O.G.

    2008-01-01

    The Dutch government aims at the production of 450 MW of electricity by offshore wind farms by 2010 and 6000 MW by 2020. Possibly the construction, exploitation and dismantlement of the wind farms will influence fish in the North Sea, which are protected under the European Habitat Directive or are c

  14. Assessing the effect of marine reserves on household food security in Kenyan coral reef fishing communities.

    Science.gov (United States)

    Darling, Emily S

    2014-01-01

    Measuring the success or failure of natural resource management is a key challenge to evaluate the impact of conservation for ecological, economic and social outcomes. Marine reserves are a popular tool for managing coastal ecosystems and resources yet surprisingly few studies have quantified the social-economic impacts of marine reserves on food security despite the critical importance of this outcome for fisheries management in developing countries. Here, I conducted semi-structured household surveys with 113 women heads-of-households to investigate the influence of two old, well-enforced, no-take marine reserves on food security in four coastal fishing communities in Kenya, East Africa. Multi-model information-theoretic inference and matching methods found that marine reserves did not influence household food security, as measured by protein consumption, diet diversity and food coping strategies. Instead, food security was strongly influenced by fishing livelihoods and household wealth: fishing families and wealthier households were more food secure than non-fishing and poorer households. These findings highlight the importance of complex social and economic landscapes of livelihoods, urbanization, power and gender dynamics that can drive the outcomes of marine conservation and management.

  15. Assessing the effect of marine reserves on household food security in Kenyan coral reef fishing communities.

    Directory of Open Access Journals (Sweden)

    Emily S Darling

    Full Text Available Measuring the success or failure of natural resource management is a key challenge to evaluate the impact of conservation for ecological, economic and social outcomes. Marine reserves are a popular tool for managing coastal ecosystems and resources yet surprisingly few studies have quantified the social-economic impacts of marine reserves on food security despite the critical importance of this outcome for fisheries management in developing countries. Here, I conducted semi-structured household surveys with 113 women heads-of-households to investigate the influence of two old, well-enforced, no-take marine reserves on food security in four coastal fishing communities in Kenya, East Africa. Multi-model information-theoretic inference and matching methods found that marine reserves did not influence household food security, as measured by protein consumption, diet diversity and food coping strategies. Instead, food security was strongly influenced by fishing livelihoods and household wealth: fishing families and wealthier households were more food secure than non-fishing and poorer households. These findings highlight the importance of complex social and economic landscapes of livelihoods, urbanization, power and gender dynamics that can drive the outcomes of marine conservation and management.

  16. A Nutritional-Toxicological Assessment of Antarctic Krill Oil versus Fish Oil Dietary Supplements

    Science.gov (United States)

    Bengtson Nash, Susan M.; Schlabach, Martin; Nichols, Peter D.

    2014-01-01

    Fish oil dietary supplements and complementary medicines are pitched to play a role of increasing strategic importance in meeting daily requirements of essential nutrients, such as long-chain (≥C20, LC) omega-3 polyunsaturated fatty acids and vitamin D. Recently a new product category, derived from Antarctic krill, has been launched on the omega-3 nutriceutical market. Antarctic krill oil is marketed as demonstrating a greater ease of absorption due to higher phospholipid content, as being sourced through sustainable fisheries and being free of toxins and pollutants; however, limited data is available on the latter component. Persistent Organic Pollutants (POP) encompass a range of toxic, man-made contaminants that accumulate preferentially in marine ecosystems and in the lipid reserves of organisms. Extraction and concentration of fish oils therefore represents an inherent nutritional-toxicological conflict. This study aimed to provide the first quantitative comparison of the nutritional (EPA and DHA) versus the toxicological profiles of Antarctic krill oil products, relative to various fish oil categories available on the Australian market. Krill oil products were found to adhere closely to EPA and DHA manufacturer specifications and overall were ranked as containing intermediate levels of POP contaminants when compared to the other products analysed. Monitoring of the pollutant content of fish and krill oil products will become increasingly important with expanding regulatory specifications for chemical thresholds. PMID:25170991

  17. Diagnostic model for assessing traceability system performance in fish processing plants

    NARCIS (Netherlands)

    Mgonja, J.T.; Luning, P.A.; Vorst, van der J.G.A.J.

    2013-01-01

    This paper introduces a diagnostic tool that can be used by fish processing companies to evaluate their own traceability systems in a systematic manner. The paper begins with discussions on the rationale of traceability systems in food manufacturing companies, followed by a detailed analysis of the

  18. What is "fallback"?: metrics needed to assess telemetry tag effects on anadromous fish behavior

    Science.gov (United States)

    Frank, Holly J.; Mather, Martha E.; Smith, Joseph M.; Muth, Robert M.; Finn, John T.; McCormick, Stephen D.

    2009-01-01

    Telemetry has allowed researchers to document the upstream migrations of anadromous fish in freshwater. In many anadromous alosine telemetry studies, researchers use downstream movements (“fallback”) as a behavioral field bioassay for adverse tag effects. However, these downstream movements have not been uniformly reported or interpreted. We quantified movement trajectories of radio-tagged anadromous alewives (Alosa pseudoharengus) in the Ipswich River, Massachusetts (USA) and tested blood chemistry of tagged and untagged fish held 24 h. A diverse repertoire of movements was observed, which could be quantified using (a) direction of initial movements, (b) timing, and (c) characteristics of bouts of coupled upstream and downstream movements (e.g., direction, distance, duration, and speed). Because downstream movements of individual fish were almost always made in combination with upstream movements, these should be examined together. Several of the movement patterns described here could fall under the traditional definition of “fallback” but were not necessarily aberrant. Because superficially similar movements could have quite different interpretations, post-tagging trajectories need more precise definitions. The set of metrics we propose here will help quantify tag effects in the field, and provide the basis for a conceptual framework that helps define the complicated behaviors seen in telemetry studies on alewives and other fish in the field.

  19. Rapid Fishery Assessment by Market Survey (RFAMS)--an improved rapid-assessment approach to characterising fish landings in developing countries.

    Science.gov (United States)

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

    2014-01-01

    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 collection across a wide range of fisheries types and geographic areas is required, regardless of the size of the site and scale of the landings. This methodology, which was demonstrated at seven fish landing sites/fish markets in southern Indonesia between July 2008 and January 2011, provides a rapid assessment of the abundance and diversity in the wild catch over a wide variety of taxonomic groups. The approach has wider application for species-rich fisheries in developing countries where there is an urgent need for better data collection protocols, monitoring future changes in market demographics, and evaluating health of fisheries.

  20. Growth, dispersal, mortality, and contribution of largemouth bass stocked into Chickamauga Lake, Tennessee

    Science.gov (United States)

    Hoffman, K.J.; Bettoli, P.W.

    2005-01-01

    Marked fingerling largemouth bass Micropterus salmoides (both northern M. s. salmoides and Florida subspecies M. s. floridanus and their hybrid) were stocked into Chickamauga Lake, Tennessee, to enhance angling and introgress the Florida subspecies into the local gene pool. We evaluated mass marking and stocking success by sampling the stocked fish for 1 year poststocking. More than 128,000 fingerlings (35-64 mm total length) were immersed in a solution of 500 mg/L oxytetracycline (OTC) for 6 h and stocked into four embayments in the lake in spring 2002; two additional embayments served as controls and were not stocked (these embayments contained only wild, indigenous fish). In a blind test, 97% of sagittal otoliths were correctly scored as marked or unmarked. In a subsequent test, the OTC marks were clearly visible on every otolith removed from 240 OTC-treated bass held for 30 d. Age-0 largemouth bass were sampled with DC electrofishing gear at 7-19, 44-61, and 119-139 d after stocking, and sampling was conducted along 100-m transects within 1 km of the stocking sites in each embayment. Of all recaptures in the first sample, 31% occurred more than 600 m from the nearest stocking site, indicating rapid dispersal by some fish. Survival of stocked and wild age-0 largemouth bass was similar and low (4.5-6.9%) in two embayments; in the other two embayments, stocked fish survived at lower rates (0-4.3%) than wild fish (33.7-49.9%). Mean catches of all age-0 largemouth bass in the first sample were positively related to the number of fish stocked. By October 2002, the mean catch of all age-0 largemouth bass was similar among embayments. Contribution of stocked fish declined to approximately 2% (2 of 91 fish) the following spring. Cost per fingerling increased from US$0.35 at stocking to $12.00 at 140 d poststocking. Increasing the abundance of largemouth bass was not the primary objective of this stocking effort, but stocked fish will have to survive much better if