Estimation of the total fish biomass in the Baltic Sea during the 20th century
Estimation of the total fish biomass in the Baltic Sea during the 20th century
复制标题
20 世纪波罗的海鱼类总生物量的估算
DOI：
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发表时间：
1997
期刊：
影响因子：
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通讯作者：
F. Thurow
中科院分区：
文献类型：
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作者：
F. Thurow
渔获物组成和产量数据被用来估计鱼类生物量的演变。这些结果与波兰和瑞典渔业的渔获率进行了比较。这两个系列的估计生物量和捕获率都表明，本世纪上半叶的生物量很低。随后，在1970年代增加到800万吨以上。收益率基本上呈现出相同的图景。1970年代末达到了近100万吨的最高渔获量。1900至1945年间，捕鱼死亡率有所上升。此后，由于生物量的增长(1940-1950、1965-1970年)或捕捞eVort的增长(1950-1965、1970-1975)，产量增加。有证据表明，富营养化导致波罗的海鱼类种群生物量增加。
Catch composition and yield data are used to estimate the evolution of fish biomass. These results are compared with the catch rates of Polish and Swedish fisheries. Both series, estimated biomasses and catch rates, suggest that biomass was low during the first half of this century. Subsequently, it increased to over 8 million tonnes in the 1970s. The yield shows essentially the same picture. Peak catches of almost 1 million tonnes were achieved at the end of the 1970s. Fishing mortality increased between 1900 and 1945. After this time, yield increased because of growing biomass (1940‐1950, 1965‐1970) or because of growing fishing eVort (1950‐1965, 1970‐1975). There is evidence to indicate that eutrophication has caused the increase in biomass of Baltic fish stocks.