摘要: |
利用35年的东海区带鱼年渔获量资料与长江径流及东海温、盐断面资料、SST和黑潮流量资料,分析了东海渔获量年际变化与海洋环境的关系。结果表明,东海渔获量与长江径流和黑潮暖流的变化有密切的关系,长江径流量大时,东海渔获量高;反之,则低。1960年以来东海区渔获量的4次长期波动与长江径流的年代际变化基本一致。东海渔获量的丰、欠与黑潮(流量)的强、弱呈反位相变化,秋季的黑潮流量与渔获量的变化关系尤其显著;黑潮强(弱)时,东海渔获量低(高)。受长江径流和黑潮的影响,渔获量与盐度的高相关区夏季位于长江口区,秋季则位于黑潮左侧的盐锋内;东海渔获量高(低)分别-9区域内盐度的低(高)变化相一致。东海区渔获量与不同季节SST变化的高相关区(即渔场区)关系密切,冬季(2月)位于东海北部的大沙渔场,春(5月)、夏季(8月)位于长江口舟山渔场,秋末初冬(12月)位于舟山及陆架暖流区,渔获量丰年与渔场区SST正异常相对应。 |
关键词: 长江径流量,黑潮流量,温度,盐度,带鱼渔获量,东海 |
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基金项目:中国科学院知识创新工程资助项目,KZCX2-207号 |
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RELATIONSHIP BETWEEN HAIRTAIL(TRICHIURUS HAUMELA) CATCHES AND MARINE HYDROLOGIC ENVIRONMENT IN EAST CHINA SEA |
CHEN Yong-Li1, WANG Fan1, BAI Xue-Zhi1, BAI Hong1, JI Feng-Ying2
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1.Institute of Oceanology,Chinese Academy of Sciences;2.National Marine Information and Data Service
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Abstract: |
This paper studied the relationships between temperatrue/salinity variation and fish catches in the East China Sea(ECS). Using annual hairtail catch data(1960-1994)in ECS, combined with volumes of Changjiang River discharge and Kuroshio transportation, sea surface temperature(SST), and temperature/salinity recordings along 3 1。N, the relationships between annual catch of hairtail(Trichiurus haumela) and marine. hydrologic environment in the ECS were analyzed using correlation analysis method.
The demersal fishery resource in the ECS indicated that their high dense areas are mainly distributed in the Changjiang River mouth and Zhoushan area, and Dasha areas as well as the areas where Kuroshio passes. Accounting for 44.04% of total catch, hairtail is a dominant species in the ECS. Annual catch of hairtail shows very obvious interannual trends increasing from the 1960s to the mid-1970s with a peak of 520 thousand tons in 1974 and decreasing from 1975 to the late 1980s with a trough of 290 thousand tons in 1988. With a higher peak in 1994, the catch reaches the maximum of 650 thousand tons. Maximum entropy spectral analysis reveal of that hairtail catch varied in about 7.3a, 9.7a and 22a periods, reflecting obvious interdecadal variation. The catch of hairtail in the Zhoushan fishing ground positively correlates with the Changjiang Rivers summertime runoff; large discharge results in a high catch and vice versa. Four long-term fluctuations since the 1 960s are essentially consistent with decadal variation of Changjiang River discharge.
The catch of hairtail in the ECS is significantly negative correlated with the Kuroshio volume transport in autumn and winter, especially in autumn. Strong transport result in low catch and vice versa. Relationship between catch and salinity were also significant. Hairtail catch related to salinity along 31°N showing a strong negative correlation in the Kuroshio Current area in autumn, and in the Changjiang River mouth and its adjacent area in summer. This indicated that increasing salinity on the west side of the Kuroshio front was unfavorable to the fish group gathering. In summer, the area adjacent to Changjiang River mouth receive large amount of freshwater and nutrients for fish living. Seasonal variation of fishing grounds in the ECS is closely related with SST. There are significant positive correlation between SST and hartail catch in the Changjiang River mouth in spring and summer, on the outer shelf in autumn, and in Dasha area in winter. Indeed, hairtail appears to have a partiality for aggregation in warmer areas consistent with fishing grounds. They winter in Dasha, spawn near the Changjiang River mouth in spring and summer, and migrate on the outer shelf in autumn.
Both the Kuroshio and the Changjiang River runoff are major circulation elements affecting the distributions of temperature and salinity as well as nutrients, hence fishery resources in the ECS, and they have a close relationships on fish catches in the ECS. |
Key words: Changjiang River discharge, Kuroshio volume transport, Temperature, Salinity, Hairtail catch, East China Sea |