890 resultados para Salmon fisheries.


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Nearshore 0-group western Baltic cod are frequently caught as bycatch in the commercial pound net fishery. Pound net fishermen from the Danish Isle of Funen and Lolland and the German Isle of Fehmarn have recorded their catches of small cod between September and December 2008. Abundance patterns were analysed, particularly concerning the influence of abiotic factors (hydrography, meteorology) and the differences between sampling sites. Catch per unit effort (CPUE) differed by site and location, whereas CPUE were highest at Lolland. Correlation between catch and wind/currents were generally weak. However, wind directions and current speeds seem to affect the catch rates. Finally an algorithm was developed to calculate a recruitment index for western Baltic cod recruitment success based on previous analyses.

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Fish muscle as food is to be seen as highly perishable. In unfrozen fish, freshness is considered the most important quality attribute. It is well known that there are several biochemical changes that can affect dramatically the texture of fish muscle. Immediately after death the fish texture is soft and elastic. In connection with rigor mortis the fish texture changes markedly. It becomes harder during rigor and after its resolution it becomes softer. This softness increases due to proteolysis during further storage at refrigerated conditions. Texture is a very important indicator for evaluating the quality of fish. Barroso et al. (1997) have recently reviewed mechanical methods in use for texture measurements on fresh fish. Further reviews on texture measurement performed on fish muscle were recently published underlining the importance of texture as quality attribute (Hyldig et al 2001, Coppes et al. 2002). The position along the fish can influence the results and was investigated by several authors (Sigurgis-ladottir et. al. 1999). Different methods have been compared for their ability to differentiate between recently killed salmon and salmon stored on ice for up to 24 days (Veland et al. 1999).

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ENGLISH: Seasonal changes in the climatology, oceanography and fisheries of the Panama Bight are determined mainly by the latitudinal movements of the ITCZ over the region. Evaporation is about 980 mm annually. Rainfall is probably much less than previous estimates because of a discontinuity in the ITCZ. Freshwater runoff from the northern watershed varies from 22 X 109 m3/mo in October-November to 11 X 109 m3/mo in February-March; from the southeastern watershed it varies from 16 X 109 m3/mo in April-June to 9 X 109 m3/mo in October-December. Total annual runoff is about 350 X 109m3. A marked salinity front is found at all seasons off the eastern shore. In the northern part of the Bight temperatures in the upper layers remained fairly constant from May to November; by February the mean temperature had decreased by 4°C and sharp gradients existed in the geographic distributions. Salinities in the upper layers decreased steadily from May to November; by February the mean salinity had increased by 2.5‰. The mean depth of the mixed layer increased from 27 m in May to 40 m in November; by February upwelling decreased it to 18 m. Between November and February upwelling had doubled the amount of P04-P and tripled that of NO3-N in the euphotic zone; surface phytoplankton production and standing crop, and zooplankton concentrations also doubled during this period. Upwelling was about 1.5 m/mo during May-November and about 9.0 m/mo during November-February, the annual total is about 48 m, Mean primary production is about 0.3 gC/m2day during May-December and about 0.6 gC/m2day during January-April; annual production is about 140 gC/m2. A thermal ridge occurred in February running from the northern to the southwestern part of the Bight. Within this ridge was a marked thermal dome coinciding with the center of the cyclonic circulation cell. Upwelling in the dome averaged 16 m/mo in November-February. The fisheries of the Panama Bight annually produce about 30,000 metric tons of food species and about 68,000 m.t. of species used for reduction. Most attempts to further the understanding of tuna ecology were unsuccessful. The apparent abundances of yellowfin and skipjack in the northern part of the Bight appear to be related to the seasonal cycle of upwelling and enrichment, as abundances are greatest in April and May when food appears to be plentiful. The life-cycle of the anchoveta in the Gulf of Panama also appears to be related to upwelling; the species mass varies from about 39,000 m.t. in December to about 169,000 m.t, in April. About 19.1 X 1012 anchoveta eggs are spawned annually. The life-cycles of shrimp in the Panama Bight appear to be related to upwelling as catches are greatest in May-July, about 3-5 months after peak upwelling, and annual catches are inversely correlated with sea level. SPANISH: Los cambios estacionales en la climatología, oceanografía y pesquerías del Panamá Bight están determinados principalmente por el movimiento latitudinal sobre la región de la Zona de Convergencia Intertropical (ZCIT). La evaporación es de unos 980 mm al año. La pluviosidad es probablemente muy inferior a las estimaciones previas a causa de la descontinuidad en la ZCIT. El drenaje de agua dulce, de la vertiente septentrional, varía de 22 x 109m3/mes en octubre-noviembre hasta 11 x 109m3/mes en febreromarzo; el de la vertiente sudeste varía de 16 x 109m3/mes en abril-junio a 9 x 109m3/mes en octubre-diciembre. El drenaje total, anual, es alrededor de 350 x 109m3. En todas las estaciones frente al litoral oriental se encuentra un frente de salinidad marcada. En la parte septentrional del Bight las temperaturas en las capas superiores permanecieron más bien constantes de mayo a noviembre; en febrero la temperatura media había disminuido en unos 4°C y existieron gradientes agudos en las distribuciones geográficas. Las salinidades en las capas superiores disminuyeron constantemente de mayo a noviembre; en febrero la salinidad media había aumentado en 2.5‰. La profundidad media de la capa mixta aumentó de 27 m en mayo a 40 m en noviembre; en febrero el afloramiento disminuyó el espesor de la capa mixta hasta 18 m. Entre noviembre y febrero el afloramiento había duplicado la cantidad de PO4-P y triplicado la de NO3-N en la zona eufótica; la producción superficial de fitoplancton y la biomasa primaria y las concentraciones de zooplancton también se duplicaron durante este período. El afloramiento era cerca de 1.5 mimes durante mayo-noviembre y de unos 9.0 mimes durante noviembre-febrero, el total anual es de unos 48 m. La producción media primaria es aproximadamente de 0.3 gC/m2 al día durante mayo-diciembre y cerca de 0.6 gC/m2 al día durante enero-abril; la producción anual es de unos 140 gC/m2. En febrero apareció una convexidad termal que se extendió de la parte norte a la parte sudoeste del Bight. Dentro de esta convexidad se encontró un domo termal marcado el cual coincidió con el centro de la circulación ciclonal de la célula. El afloramiento en el domo tuvo un promedio de 16 mimes en noviembre-febrero. Las pesquerías del Panamá Bight producen anualmente de cerca 30,000 toneladas métricas de especies alimenticias y unas 68,000 t.m. de especies usadas para la reducción. La mayoría de los esfuerzos realizados con el fin de adquirir más conocimiento sobre la ecología del atún no tuvo éxito. La abundancia aparente del atún aleta amarilla y del barrilete en la parte septentrional del Bight parece estar relacionada con el ciclo estacional del afloramiento y del enriquecimiento, ya que la abundancia mayor en abril y mayo cuando parece que hay abundancia es de alimento. El ciclo de vida de la anchoveta en el Golfo de Panamá parece también que está relacionada al afloramiento. La masa de la especie varía de unas 39,000 t.m. en diciembre a cerca de 169,000 t.m. en abril. Aproximadamente 19.1 x 1012 huevos de anchoveta son desovados anualmente. Los ciclos de vida del camarón en el Panamá Bight parecen estar relacionados con el afloramiento ya que las capturas son superiores en mayo-julio, unos 3-5 meses después del ápice del afloramiento, y las capturas anuales se correlacionan inversamente con el nivel del mar. (PDF contains 340 pages.)

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The UNDP/FAO supported Federal Fisheries Project for the Development of Artisanal and Inshore Fisheries in Nigeria has the specific objective of increasing fish production through an integrated approach aimed at upgrading the rural coastal fishermen and improving their living conditions. The project has an operating life-span of three years and envisages a total outlay of nearly N3 million in terms of personnel and services. This paper attempts to review the activities of the project during the first two years of the operational phase and highlight some of its specific achievements.

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Lake Chad fisheries contributes about 13% of all fish produced by the inland and coastal states of the nation and supports a large population of fishermen and allied workers. The species of freshwater fish produced from the Lake such as Gymnarchus, Clarias and Heterotis are very popular with the fish consumers in Nigeria; hence Lake Chad processed fish is transported long distances to southern Nigerian markets. Lake Chad thus contributes significantly to the provision of fish protein and to the Green Revolution Programme

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The fisheries laws and regulations presently operative in Nigeria are on marine waters. These include: 1) The Sea Fisheries Decree (Act) of 1971; 2) The Sea Licencing Regulations of 1971; 3) The Sea Fisheries (Fishing) Regulations of 1972; and 4) The exclusive Economic Zone Decree of 1978. Attempts have also been made to produce the Inland waters Fisheries Regulation

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Artisanal fishery is the main type of fishing practised occupationally by the fishermen along the upper sectors of the Cross River. No form of mechanised fishing has so far been introduced to the fishermen in these areas. This study has attempted to find out the different gears used, when and where used along the main river channel, its tributaries and flood plains. An effort has also been made to provide some information on the types of fishes caught with the different gears. Recommendation for effective management are also advanced

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Details are given of a programme for fresh fish collection and distribution in Ondo State, Nigeria. Collection centers, organization and managerial structure, collection scheme, trade system, price determination, management and distribution are described

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Problems faced by the fishery sector in Nigeria are examined and the role that agricultural cooperatives play in fishery development considered. The importance of improving the marketing and distribution system through fishermen cooperatives is stressed. It is concluded that for the successful implementation of fishery products, there is need for regular communication, cooperation and collaboration among relative agencies

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This paper reviews available past fisheries statistics data and examines the basis of derivation of the estimates and concludes that much needs to be done to establish reliable fisheries data based on well defined methodology. Subsequently, fish consumption data for the ten-year-period 1971-1979 were related to the yearly population that consumes the fish

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The sprat of the Baltic Sea is not as short-lived as inother Seas probably because fish predator species arerestricted mainly on cod and salmon. Sea bird popula-tions are much smaller and marine mammals are rare inthe Baltic Sea. The sprat stock biomass is fluctuatingstrongly. The fluctuation is mainly influenced by thestock recruitment and is also dependent on the strengthof the cod stock. After a strong decrease during the1980ies sprat catches increased again from 1992 onwardsand reached a peak with over half a million tonnes in 1997. At about the same time the character of the BalticSea sprat fishery changed from catches mainly for hu-man consumption to catches mainly for industrial pur-poses initiated by the fishery of Sweden. The recentrecord high catches of sprat have been possible only dueto the low level of the cod stock of the main Baltic SeaBasins over some years. A sprat fishery on such a highcatch level might cause conflicts with a recovering codstock in future.

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Raw fillets of saithe, red fish and salmon were stored over a period of 2 days at 6 to 9 °C before preparing by frying, deep-frying or cooking in a microwave oven. The raw and prepared fillets were tested for bacterial loads, TVBN (total volatile basic nitrogene) and for the sensorial status. It was shown that saithe and red fish started more rapidly to spoil under these conditions than salmon. The fillets showed growing bacterial populations and produced high amounts of TVBN. Sensory changes, especially in flavour and odour, took place but the scores kept in an acceptable range. The investigations indicated that it is possible to store raw fillets for 1 or even 2 days in refrigerator but due to the loss of quality it is recommended to use only really fresh fillets stored in very clean containers. It was further shown that it is very important to heat fillets sufficiently during cooking or frying in order to destroy all microorganisms and to obtain safe and stable meals.

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An overview is presented on the M74-Syndrome of Baltic salmon which is known since 1974 and which, since 1992, has caused considerable losses of artificially produced yolk-sac larvae in Swedish and Finnish hatcheries responsible for compensatory salmon stocking programmes. The syndrome only affects offspring of wild salmon ascending the rivers for spawning and not offspring derived from salmon broodstocks permanently kept in hatcheries. The syndrome seems to be restricted to the Baltic Sea where it has been recorded in all of the remaining Swedish (except the west coast) and Finnish salmon rivers as well as in populations of Estonian rivers and the Russian River Neva. In Sweden and in Finland, the syndrome has been recorded in recent years in offspring of up to 80 % of female salmon used for spawning and resulted in a larval mortality of up to 90 %. A nutrition-associated thiamine (vitamin B1) deficiency is considered as primary cause. However, other environmental factors seem to be involved in addition. There is concern that the syndrome constitutes a major threat with respect to the survival of the few still naturally reproducing populations of Baltic salmon.

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The industrial fisheries as opposed to artisanal fisheries in Cross River State, Nigeria, is discussed, considering the prospect of industrial fisheries in the State and identifying the major fish and shrimp resources within the coastal waters. Industrial fishing was introduced in 1973 when the state government invited a Japaneese company to carry out a joint exploratory shrimp fishing venture. The contributions made by the Seastate Seafoods Company, the Eyib's Nutritional Food and the Arawak Fishing Companies towards the increase in the number of fishing fleet in the state are noted.

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Fish production from Nigeria comes mainly from 3 sources, namely - artisans engaged in either part-time or full-time fishing, commercial trawlers fishing in inshore and offshore waters, and fish farming in enclosures (ponds, tanks and raceways). An account is given of the current situation in Nigeria, considering over exploitation of fish, the fish's environment, fish utilization, and fish marketing