30 resultados para Afro-Asian Relations

em Aquatic Commons


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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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The amphipod Gammarus lacustris, a regular representative of lacustrine communities, often plays a significant role in the transformation of matter and energy. The object of the present work was to clarify the quantitative side of the feeding of the amphipod under different conditions of habitation. Experimental works on determination of the rate of consumption of food and its dependence on body-weight were carried out in the summer periods 1975-1978 on three water-bodies of the Krasnoyarsk region, of different conditions of habitation for the amphipods.

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Since 1974 we have been collecting statistics on the main fishing gears in the ivorian lagoons. In order to get good estimation of the catches, it is often more convenient to measure the fishes and to convert this data into weights through a length-weight relationship. In this work we computed this relation for 43 species found in the Aby and Ebrié lagoons.

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Hydroclimatic conditions in the Gulf of Guinea between Senegal and Nigeria are briefly described emphasizing the seasonal variations of transparency. Analysis of the Abidjan based shrimp fleet allowed to the description of the seasonal variations of activity rhythms for Côte d'Ivoire, Ghana, and Nigeria. These rhythms are different between seasons, between fishing grounds, and sometimes even between depths on a given ground. These variations follow the turbidity ones. Diurnal activity is observed in very turbid waters, nocturnal and transition activity in clearer ones. The authors assume that the basic behaviour is a nocturnal one, but that the shrimp-trawlers catches reflect some apparently different ones resulting from diel variations in the stock availability. To explain the apparently diurnal behaviour observed most of the year over the whole Gulf of Guinea it is suggested that these generally benthic shrimps become nectonic at night when turbidity is very high. The results obtained in Ivory Coast, Ghana and Nigeria are compared to those from Senegal where hydroclimatic conditions are different. The similarities are emphasized. The differences in observed behaviour are supposedly caused by the cold season water temps which are sufficiently low to disturb the nor mal activity rhythm.

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This study summarizes previously published and updated empirical relations for the estimation of production/biomass ratios in benthic invertebrates; of natural mortality in benthic invertebrates and finfish; and of respiration from production and vice versa in animal populations. AMS-EXCEL spreadsheet containing these equations is available from the author via Email. They are also included in the Ecopath with Ecosim software.

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Recent research demonstrated significantly lower growth and survival of Bristol Bay sockeye salmon (Oncorhynchus nerka) during odd-numbered years of their second or third years at sea (1975, 1977, etc.), a trend that was opposite that of Asian pink salmon (O. gorbuscha) abundance. Here we evaluated seasonal growth trends of Kvichak and Egegik river sockeye salmon (Bristol Bay stocks) during even- and odd-numbered years at sea by measuring scale circuli increments within each g rowth zone of each major salmon age group between 1955 and 2000. First year scale growth was not significantly different between odd- and even-numbered years, but peak growth of age-2 smolts was significantly higher than age-1. smolts. Total second and third year scale growth of salmon was significantly lower during odd- than during even-numbered years. However, reduced scale growth in odd-numbered years began after peak growth in spring and continued through summer and fall even though most pink salmon had left the high seas by late July (10−18% growth reduction in odd vs. even years). The alternating odd and even year growth pattern was consistent before and after the 1977 ocean reg ime shift. During 1977−2000, when salmon abundance was relatively great, sockeye salmon growth was high during specific seasons compared with that during 1955−1976, that is to say, immediately after entry to Bristol Bay, after peak growth in the first year, during the middle of the second growing season, and during spring of the third season. Growth after the spring peak in the third year at sea was relatively low during 1977−2000. We hypothesize that high consumption rates of prey by pink salmon during spring through mid-July of odd-numbered years, coupled with declining zooplankton biomass during summer and potentially cyclic abundances of squid and other prey, contributed to reduced prey availability and therefore reduced growth of Bristol Bay sockeye salmon during late spring through fall of odd-numbered years.

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We analyzed published and archived records for the past 250 years to assess changes in distribution and abundance of Steller sea lions, Eumetopias jubatus, along the Asian coast from the Bering Strait to the Korean Peninsula. We found that the northern extent of Steller sea lion distribution has not changed but that the southern limit has moved north by some 500–900 km (~300–500 n.mi.) over the past 50 years. Additionally, the number of animals and their distribution has changed on the Commander Islands, Kuril Islands, and Kamchatka Peninsula. We found no changes in the number of rookeries in the northern Sea of Okhotsk, but a new rookery was established at Tuleny Island on the eastern coast of Sakhalin Island. We estimate that the total abundance of Steller sea lions along the Asian coast in the late 19th century was about 115,000 animals; during the 1960’s, the total estimate was about 27,000 (including pups), most of which were in the Kuril Islands. The fewest number of Steller sea lions occurred in the northwestern Pacific in the late 1980’s–early 1990’s when only about 13,000 individuals (including pups) were estimated in the entire region. During the 1990’s, and especially in early 2000, an increasing trend in abundance occurred in most areas. Present estimated abundance of Steller sea lions in Asia is about 16,000 individuals (including about 5,000 pups), about half of which occur in the Kuril Islands. Changes in abundance occurred during all time periods but varied by site and period. Specifically, over the past 150 years Steller sea lion abundance at most sites has changed. There were no rookeries on the Commander Islands between 1850 and 1960 and abundance was low, but by 1977, abundance increased to 4,800 individuals and a rookery was established in the mid 1980’s; abundance there has declined since the early 1980’s and in 2004 only 895 individuals (including 221 pups) were counted during the breeding season. Between 1940 and 2004, abundance along the eastern coast of Kamchatka declined from ~7,000 to ~600 individuals, an overall reduction of 90%. Steller sea lion abundance on the Kuril Islands declined by >90% from the 1800’s to 2005; the most severe decline there occurred during 1969–1981. Steller sea lion numbers in the northern part of the Sea of Okhotsk declined during 1930–2002 from 7,200 to 3,100 individuals. Numbers at Tuleny Island have increased since establishment of a rookery there during 1983–2005 and by immigration from other sites.

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The widespread implementation of Extended Fisheries Jurisdiction (EFJ) has confronted coastal states with several resource management problems. One of these consists of the economic relations, if any, that the coastal state should establish with distant-water fishing nations (DWFN's) seeking access to the coastal state's 200-mile zone. Several of the other papers presented here deal with specific aspects of the issue. This paper, on the other hand, will concern itself with the question of the analytical framework to be used by economists in studying this issue. It will offer some suggestions with respect to possible components of the framework. In doing so, the paper will restrict itself to the coastal state's perspective of EFJ and the management issues arising therefrom. It goes without saying, of course, that an enlightened coastal state will attempt to acquaint itself with the DWFN view of the world.

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EXTRACT (SEE PDF FOR FULL ABSTRACT): Whole-core magnetic susceptibility can sometimes be used as a rapid and sensitive indicator of variations in the concentration of terrigenous material. We apply this approach to study the evolution of Plio-Pleistocene climatic cycles of terrigenous sedimentation at Ocean Drilling Program Site 721, on the Owen Ridge in the Arabian Sea.

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The stable isotopic composition of buried soil carbonate and organic matter from northern Pakistan and Nepal can be used to reconstruct aspects of the paleoecology of riverine floodplain ecosystems over the past 17 Myr. Probable dry woodland dominated the floodplain biomass of large rivers ancestral to the modern Indus and Ganges up to 7.3 Myr. Between 7.3 and about 6 Myr, tropical grasses gradually displaced woodland and have dominated floodplain biomasses to the present. The paleovegetational transition beginning about 7.3 Myr likely signals the onset of the strongly seasonal precipitation pattern that typifies the monsoonal climate of the region today. One possible analog to the dry woodland soils of the Miocene are found under the Sal woodlands of the northern Indian subcontinent, while undisturbed modern analogs to the Plio-Pleistocene floodplain grasslands can still be found in the Chitwan area of southern Nepal.

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EXTRACT (SEE PDF FOR FULL ABSTRACT): Recent analyses of terrestrial (pollen) and marine microfossils (foraminifera and radiolaria) in cores V28-204 and RC14-99 from the northwest Pacific Ocean extend the continuous, chronostratigraphically-controlled records of the regional vegetation of the Pacific coast of Japan and offshore marine environments through three full glacial cycles. The high-resolution pollen time series show systematic relationships between fluctuations in Japanese vegetation and global ice volume over the last 350 kyr. ... Comparison with solar insolation at 30°N and with an index of orbital parameters suggests that variation in northeast Asian summer monsoon intensity is related to orbital forcing.