530 resultados para fish stock management
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Runs have dwindled in many parts of California and additional protection or management actions are needed to protect the fish from further declines. The following is a report requested by the Fish and Game Commission on the status and current management of spring-run chinook salmon stocks. Fish counts presented in this report were developed by a variety of methods. Some of them are estimates of total run-size or spawning escapement, while others are indices of abundance derived from counts of maturing fish in their holding areas. It is important to note the stock assessment method used. Index area counts will always underestimate the true run size, often by a very large margin.
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The fundamental purpose of fisheries management is to ensure sustainable production over time from fish stocks, preferably through regulatory and enhancement actions that promote economic and social well being of the fishers and industries that depend on the resource. To achieve this purpose, management authorities must design, justify and administer (enforce) a collection of restraints on fishing and fishery-related activities. Productivity and management of the fisheries should be based on the understanding that they are complex and dynamic systems. Physical, chemical and biological components support a community of organisms that is unique to the these systems. All these components are in constant change but mainly dictated by human interference in the water body ecosystem.
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Nile perch (Lates niloticus), tilapia (Oreochromis spp), dagaa (Rastrineobola argentea, silver cyprinid), and haplochromines (Tribe Haplochromini) form the backbone of the commercial fishery on Lake Victoria. These fish stocks account for about 70% of the total catch in the three riparian states Uganda, Kenya, and Tanzania. The lake fisheries have been poorly managed, in part due to inadequate scientific analysis and management advice. The overall objective of this project was to model the stocks of the commercial fisheries of Lake Victoria with the view of determining reference points and current stock status. The Schaefer biomass model was fitted to available data for each stock (starting in the 1960s or later) in the form of landings, catch per unit effort, acoustic survey indices, and trawl survey indices. In most cases, the Schaefer model did not fit all data components very well, but attempts were made to find the best model for each stock. When the model was fitted to the Nile perch data starting from 1996, the estimated current biomass is 654 kt (95% CI 466–763); below the optimum of 692 kt and current harvest rate is 38% (33–73%), close to the optimum of 35%. At best, these can be used as tentative guidelines for the management of these fisheries. The results indicate that there have been strong multispecies interactions in the lake ecosystem. The findings from our study can be used as a baseline reference for future studies using more complex models, which could take these multispecies interactions into account.
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The National Fisheries Resources Research Institute (NaFIRRI), the Directorate of Fisheries Resources (DiFR), the Local Government fisheries staff and those from the Beach Management Units (BMUs) of the riparian districts to Lake Victoria regularly and jointly conduct Frame and Catch Assessment Surveys. The information obtained is used to guide fisheries management and development. We reveal the trends in the commercial fish catch landings and fishing effort on the Uganda side of Lake Victoria, over a 15 year period (2000-2015) and provide the underlying factors to the observed changes. The contribution of the high value large size species (Nile perch and Tilapia) to the commercial catch of Lake Victoria has significantly reduced while that of the low value small size species, Mukene has increased over a ten year (2005-2015)period. The information is intended to update and sensitize the key stakeholders on the status of the Lake Victoria fisheries. In addition, the information provided is expected to guide policy formulation and management planning by the fisheries managers at all levels including the BMUs and Landing Site Management Committees (LSMCs), the Local government fisheries staff and the Directorate of Fisheries Resources. The information is anticipated to create awareness among the lakeside fisher communities to reverse the current trend in fish declines.
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v.1 - Text and Summaries (272 page document)
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Enclosed is a bibliography of 556 published articles, technical reports, theses, dissertations, and books that form the basis for a conceptual model of salt marsh management on Merritt Island, Florida (Section 1). A copy of each item is available on file at the Florida Cooperative Fish and Wildlife Research Unit, Gainesville. Some relevant proprietary items and unpublished drafts have not been included pending permission of the authors. We will continue to add pertinent references to our bibliography and files. Currently, some topics are represented by very few items. As our synthesis develops, we will be able to indicate a subset of papers most pertinent to an understanding of the ecology and management of Merritt Island salt marshes. (98 page document)
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Diking and holding water on salt marshes ("impounding" the marsh) is a management technique used on Merritt Island National Wildlife Refuge (MINWR) and elsewhere in the Southeast to: a) prevent the reproduction of saltmarsh mosquitos, and b) attract wintertering waterfowl and other marsh, shore, and wading birds. Because of concern that diking and holding water may interfere with the production of estuarine fish and shellfish, impoundment managers are being asked to consider altering management protocol to reduce or eliminate any such negative influence. How to change protocol and preserve effective mosquito control and wildlife management is a decision of great complexity because: a) the relationships between estuarine organisms and the fringing salt marshes at the land-water interface are complex, and b) impounded marshes are currently good habitat for a variety of species of fish and wildlife. Most data collection by scientists and managers in the area has not been focused on this particular problem. Furthermore, collection of needed data may not be possible before changes in protocol are demanded. Therefore, the purpose of this document is two-fold: 1) to suggest management alternatives, given existing information, and 2) to help identify research needs that have a high probability of leading to improved simultaneous management of mosquitos, waterfowl, other wildlife, freshwater fish, and estuarine fish and shellfish on the marshland of the Merritt Island National Wildlife Refuge. (92 page document)
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Management options for the Silver Springs free-ranging rhesus macaque population range from removal to active maintenance of the population in situ. Selection of a management option is dependent upon which issues are perceived to be true problems. Management options are presented along with their effectiveness in dealing with issues previously described.(31 page document)
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EXECUTIVE SUMMARY 1. DECADAL-SCALE CLIMATE EVENTS 1.1 Introduction 1.2 Basin-scale Patterns 1.3 Long Time Series in the North Pacific 1.4 Decadal Climate Variability in Ecological Regions of the North Pacific 1.5 Mechanisms 1.6 References 2. COHERENT REGIONAL RESPONSES 2.1 Introduction 2.2 Central North Pacific (CNP) 2.3 California Current System (CCS) 2.4 Gulf of Alaska (GOA) 2.5 Bering Sea and Aleutian Islands 2.6 Western North Pacific (WNP) 2.7 Coherence in Regional Responses to the 1998 Regime Shift 2.8 Climate Indicators for Detecting Regime Shifts 2.9 References 3. IMPLICATIONS FOR THE MANAGEMENT OF MARINE RESOURCES 3.1 Introduction 3.2 Response Time of Biota to Regime Shifts 3.3 Response Time of Management to Regime Shifts 3.4 Provision of Stock Assessment Advice 3.5 Decision Rules 3.6 References 4. SUGGESTED LITERATURE 4.1 Climate Regimes 4.2 Impacts on Lower Trophic Levels 4.3 Impacts on Fish and Higher Trophic Levels 4.4 Impacts on Ecosystems and Possible Mechanisms 4.5 Regimes and Fisheries Management APPENDIX 1: RECENT ECOSYSTEM CHANGES IN THE CENTRAL NORTH PACIFIC A1.1 Introduction A1.2 Physical Oceanography A1.3 Lower Trophic Levels A1.4 Invertebrates A1.5 Fishes A1.6 References APPENDIX 2: RECENT ECOSYSTEM CHANGES IN THE CALIFORNIA CURRENT SYSTEM A2.1 Introduction A2.2 Physical Oceanography A2.3 Lower Trophic Levels A2.4 Invertebrates A2.5 Fishes A2.6 References APPENDIX 3: RECENT ECOSYSTEM CHANGES IN THE GULF OF ALASKA A3.1 Introduction A3.2 Physical Oceanography A3.3 Lower Trophic Levels A3.4 Invertebrates A3.5 Fishes A3.6 Higher Trophic Levels A3.7 Coherence in Gulf of Alaska Fish A3.8 Combined Standardized Indices of Recruitment and Survival Rate A3.9 References APPENDIX 4: RECENT ECOSYSTEM CHANGES IN THE BERING SEA AND ALEUTIAN ISLANDS A4.1 Introduction A4.2 Bering Sea Environmental Variables and Physical Oceanography A4.3 Bering Sea Lower Trophic Levels A4.4 Bering Sea Invertebrates A4.5 Bering Sea Fishes A4.6 Bering Sea Higher Trophic Levels A4.7 Coherence in Bering Sea Fish Responses A4.8 Combined Standardized Indices of Bering Fish Recruitment and Survival Rate A4.9 Aleutian Islands A4.10 References APPENDIX 5: RECENT ECOSYSTEM CHANGES IN THE WESTERN NORTH PACIFIC A5.1 Introduction A5.2 Sea of Okhotsk A5.3 Tsushima Current Region and Kuroshio/Oyashio Current Region A5.4 Bohai Sea, Yellow Sea, and East China Sea A5.5 References (168 page document)
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As a step to address the problems of coastal fisheries in Asia, the WorldFish Center joined forces with fisheries agencies from eight developing Asian countries (Bangladesh, India, Indonesia, Malaysia, The Philippines, Sri Lanka, Thailand and Vietnam) and the Asian Development Bank, to implement a project entitled “Sustainable Management of Coastal Fish Stocks in Asia” (also known as the “TrawlBase” project). The project was implemented between 1998 and 2001. The main achievements of this partnership were: (a) Development of a database called “Fisheries Resource Information System and Tools” (FiRST), which contains trawl research survey data and socioeconomic information for selected fisheries, and facilitates its analysis; (b) Evaluation of the extent of resource decline and over-fishing, both biological and economic, in the region; (c) Identification of the measures needed to manage coastal fisheries in the participating countries, resulting in draft strategies and action plans; and (d) Strengthening of national capacity in coastal fisheries assessment, planning and management.
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I REPORT OF THE PICES WORKSHOP ON THE OKHOTSK SEA AND ADJACENT AREAS (pdf, 0.1 Mb) 1. Outline of the workshop 2. Summary reports from sessions 3. Recommendations of the workshop 4. Acknowledgments II SCIENTIFIC PAPERS SUBMITTED FROM SESSIONS 1. Physical Oceanography Sessions (pdf, 4 Mb) A. Circulation and water mass structure of the Okhotsk Sea and Northwestern Pacific Valentina D. Budaeva & Vyacheslav G. Makarov Seasonal variability of the pycnocline in La Perouse Strait and Aniva Gulf Valentina D. Budaeva & Vyacheslav G. Makarov Modeling of the typical water circulations in the La Perouse Strait and Aniva Gulf region Nina A. Dashko, Sergey M. Varlamov, Young-Ho Han & Young-Seup Kim Anticyclogenesis over the Okhotsk Sea and its influence on weather Boris S. Dyakov, Alexander A. Nikitin & Vadim P. Pavlychev Research of water structure and dynamics in the Okhotsk Sea and adjacent Pacific Howard J. Freeland, Alexander S. Bychkov, C.S. Wong, Frank A. Whitney & Gennady I. Yurasov The Ohkotsk Sea component of Pacific Intermediate Water Emil E. Herbeck, Anatoly I. Alexanin, Igor A. Gontcharenko, Igor I. Gorin, Yury V. Naumkin & Yury G. Proshjants Some experience of the satellite environmental support of marine expeditions at the Far East Seas Alexander A. Karnaukhov The tidal influence on the Sakhalin shelf hydrology Yasuhiro Kawasaki On the formation process of the subsurface mixed water around the Central Kuril Islands Lloyd D. Keigwin Northwest Pacific paleohydrography Talgat R. Kilmatov Physical mechanisms for the North Pacific Intermediate Water formation Vladimir A. Luchin Water masses in the Okhotsk Sea Andrey V. Martynov, Elena N. Golubeva & Victor I. Kuzin Numerical experiments with finite element model of the Okhotsk Sea circulation Nikolay A. Maximenko, Anatoly I. Kharlamov & Raissa I. Gouskina Structure of Intermediate Water layer in the Northwest Pacific Nikolay A. Maximenko & Andrey Yu. Shcherbina Fine-structure of the North Pacific Intermediate Water layer Renat D. Medjitov & Boris I. Reznikov An experimental study of water transport through the Straits of Okhotsk Sea by electromagnetic method Valentina V. Moroz Oceanological zoning of the Kuril Islands area in the spring-summer period Yutaka Nagata Note on the salinity balance in the Okhotsk Sea Alexander D. Nelezin Variability of the Kuroshio Front in 1965-1991 Vladimir I. Ponomarev, Evgeny P. Varlaty & Mikhail Yu. Cheranyev An experimental study of currents in the near-Kuril region of the Pacific Ocean and in the Okhotsk Sea Stephen C. Riser, Gennady I. Yurasov & Mark J. Warner Hydrographic and tracer measurements of the water mass structure and transport in the Okhotsk Sea in early spring Konstantin A. Rogachev & Andrey V. Verkhunov Circulation and water mass structure in the southern Okhotsk Sea, as observed in summer, 1994 Lynne D. Talley North Pacific Intermediate Water formation and the role of the Okhotsk Sea Anatoly S. Vasiliev & Fedor F. Khrapchenkov Seasonal variability of integral water circulation in the Okhotsk Sea B. Sea ice and its relation to circulation and climate V.P. Gavrilo, G.A. Lebedev & A.P. Polyakov Acoustic methods in sea ice dynamics studies Nina M. Pestereva & Larisa A. Starodubtseva The role of the Far-East atmospheric circulation in the formation of the ice cover in the Okhotsk Sea Yoshihiko Sekine Anomalous Oyashio intrusion and its teleconnection with Subarctic North Pacific circulation, sea ice of the Okhotsk Sea and air temperature of the northern Asian continent C. Waves and tides Vladimir A. Luchin Characteristics of the tidal motions in the Kuril Straits George V. Shevtchenko On seasonal variability of tidal constants in the northwestern part of the Okhotsk Sea D. Physical oceanography of the Japan Sea/East Sea Mikhail A. Danchenkov, Kuh Kim, Igor A. Goncharenko & Young-Gyu Kim A “chimney” of cold salt waters near Vladivostok Christopher N.K. Mooers & Hee Sook Kang Preliminary results from a numerical circulation model of the Japan Sea Lev P. Yakunin Influence of ice production on the deep water formation in the Japan Sea 2. Fisheries and Biology Sessions (pdf, 2.8 Mb) A. Communities of the Okhotsk Sea and adjacent waters: composition, structure and dynamics Lubov A. Balkonskaya Exogenous succession of the southwestern Sakhalin algal communities Tatyana A. Belan, Yelena V. Oleynik, Alexander V. Tkalin & Tat’yana S. Lishavskaya Characteristics of pelagic and benthic communities on the North Sakhalin Island shelf Lev N. Bocharov & Vladimir K. Ozyorin Fishery and oceanographic database of Okhotsk Sea Victor V. Lapko Interannual dynamics of the epipelagic ichthyocen structure in the Okhotsk Sea Valentina I. Lapshina Quantitative seasonal and year-to-year changes of phytoplankton in the Okhotsk Sea and off Kuril area of the Pacific Lyudmila N. Luchsheva Biological productivity in anomalous mercury conditions (northern part of Okhotsk Sea) Inna A. Nemirovskaya Origin of hydrocarbons in the ecosystems of coastal region of the Okhotsk Sea Tatyana A. Shatilina Elements of the Pacific South Kuril area ecosystem Vyacheslav P. Shuntov & Yelena P. Dulepova Biota of the Okhotsk Sea: Structure of communities, the interannual dynamics and current status B. Abundance, distribution, dynamics of the common fishes of the Okhotsk Sea Yuri P. Diakov Influence of some abiotic factors on spatial population dynamics of the West Kamchatka flounders (Pleuronectidae) Gordon A. McFarlane, Richard J. Beamish & Larisa M. Zverkova An examination of age estimates of walleye pollock (Theragra chalcogramma) from the Sea of Okhotsk using the burnt otolith method and implications for stock assessment and management Larisa P. Nikolenko Migration of Greenland turbot (Reinhardtius hippoglossoides) in the Okhotsk Sea Galina M. Pushnikova Fisheries impact on the Sakhalin-Hokkaido herring population Vidar G. Wespestad Is pollock overfished? C. Salmon of the Okhotsk Sea: biology, abundance and stock identification Vladimir A. Belyaev, Alexander Yu. Zhigalin Epipelagic Far Eastern sardine of the Okhotsk Sea Yuri E. Bregman, Victor V. Pushnikov, Lyudmila G. Sedova & Vladimir Ph. Ivanov A preliminary report on stock status and productive capacity of horsehair crab Erimacrus isenbeckii (Brandt) in the South Kuril Strait Natalia T. Dolganova Mezoplankton distribution in the West Japan Sea Vladimir V. Efremov, Richard L. Wilmot, Christine M. Kondzela, Natalia V. Varnavskaya, Sharon L. Hawkins & Maria E. Malinina Application of pink and chum salmon genetic baseline to fishery management Vyacheslav N. Ivankov & Valentina V. Andreyeva Strategy for culture, breeding and numerous dynamics of Sakhalin salmon populations Alla M. Kovalevskaya, Natalia I. Savelyeva & Dmitry M. Polyakov Primary production in Sakhalin shelf waters Tatyana N. Krupnova Some reasons for resource reduction of Laminaria japonica (Primorye region) Lyudmila N. Luchsheva & Anatoliy I. Botsul Mercury in bottom sediments of the northeastern Okhotsk Sea Pavel A. Luk’yanov, Natalia I. Belogortseva, Alexander A. Bulgakov, Alexander A. Kurika & Olga D. Novikova Lectins and glycosidases from marine macro and micro-organisms of Japan and Okhotsk Seas Boris A. Malyarchuk, Olga A. Radchenko, Miroslava V. Derenko, Andrey G. Lapinski & Leonid L. Solovenchuk PCR-fingerprinting of mitochondrial genome of chum salmon, Oncorhynchus keta Alexander A. Mikheev Chaos and relaxation in dynamics of the pink salmon (Oncorhynchus gorbuscha) returns for two regions Yuri A. Mitrofanov & Larisa N. Lesnikova Fish-culture of Pacific Salmons increases the number of heredity defects Larisa P. Nikolenko Abundance of young halibut along the West Kamchatka shelf in 1982-1992 Sergey A. Nizyaev Living conditions of golden king crab Lithodes aequispina in the Okhotsk Sea and near the Kuril Islands Ludmila A. Pozdnyakova & Alla V. Silina Settlements of Japanese scallop in Reid Pallada Bay (Sea of Japan) Galina M. Pushnikova Features of the Southwest Okhotsk Sea herring Vladimir I. Radchenko & Igor I. Glebov Present state of the Okhotsk herring stock and fisheries outlook Alla V. Silina & Ida I. Ovsyannikova Distribution of the barnacle Balanus rostratus eurostratus near the coasts of Primorye (Sea of Japan) Galina I. Victorovskaya Dependence of urchin Strongylocentrotus intermedius reproduction on water temperature Anatoly F. Volkov, Alexander Y. Efimkin & Valery I. Chuchukalo Feeding habits of Pacific salmon in the Sea of Okhotsk and in the Pacific waters of Kuril Islands in summer 1993 Larisa M. Zverkova & Georgy A. Oktyabrsky Okhotsk Sea walleye pollock stock status Tatyana N. Zvyagintseva, Elena V. Sundukova, Natalia M. Shevchenko & Ludmila A. Elyakova Water soluble polysaccharides of some Far-Eastern seaweeds 3. Biodiversity Program (pdf, 0.2 Mb) A. Biodiversity of island ecosystems and seasides of the North Pacific Larissa A. Gayko Productivity of Japanese scallop Patinopecten yessoensis (IAY) culture in Posieta Bay (Sea of Japan) III APPENDICES 1. List of acronyms 2. List of participants (Document pdf contains 431 pages)
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Working paper NPALB/87/21 submitted to the 10th North Pacific Albacore Workshop. Paper reports the results of ongoing research on validated age and growth models and the elucidation of stock structure for the North Pacific albacore. (Document pdf contains 22 pages)
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Document contains 4 pages.
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We hypothesize that the richness and diversity of the biota in Lake Moraine (42°50’47”N, 75°31’39”W) in New York have been negatively impacted by 60 years of macrophyte and algae management to control Eurasian watermilfoil ( Myriophyllum spicatum L.) and associated noxious plants. To test this hypothesis we compare water quality characteristics, richness and selected indicators of plant diversity, zooplankton, benthic macroinvertebrates and fish in Lake Moraine with those in nearby Hatch Lake (42°50’06”N, 75°40’67”W). The latter is of similar size and would be expected to have similar biota, but has not been subjected to management. Measurements of temperature, pH, oxygen, conductivity, Secchi transparency, calcium, total phosphorus and nitrites + nitrates are comparable. Taxa richness and the diversity indices applied to the aquatic macrophytes are similar in both lakes. (PDF has 8 pages.)
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Document contains 4 pages.