东海带鱼渔获量对捕捞压力和气候变动的响应

为了解捕捞压力和气候变动对东海带鱼渔业产量的共同影响,对1956-2006年东海带鱼渔获量进行了分析.东海带鱼渔获量时间序列可划分成变化趋势和年间变动.变化趋势主要归因于捕捞努力量的单调增长,Fox模型拟合结果,东海带鱼渔获量与捕捞努力量关系显著(P＜0.01).移除趋势后,其年间变动与陆地降水、季风风速、海表水温和热带气旋影响指数相关(P＜0.05).结果表明,气候变动影响到东海带鱼渔获量年间变动:陆地降雨和径流携带大量营养盐进入沿岸生态系统；而季风则驱动营养盐的扩散和循环,影响着营养盐的利用效率；水温的升高不仅有利于带鱼的性腺发育与成熟,还能增加带鱼的饵料供应；热带气旋所形成的水团流动、风生混合、上升流等能促进营养盐供应并增加水域的生物量.从捕捞努力量和气候变量拟合东海带鱼渔获量的结果来看,与实际渔获量显著相关(P＜0.01),并且能够很好地反映出实际带鱼渔获量的变化趋势和年间变动.这说明渔获量的变化受到捕捞效应和气候变动的双重影响,未来气候变化将有利于东海带鱼渔业产量的增加,且渔获量年间变动幅度将会比以往更大.

Responses of Trichiurus japonicus catches to fishing and climate variability in the East China Sea

To understand the responses of hairtail(Trichiurus japonicus)catches to fishing and climate variability in the East China Sea(ECS),the time series of hairtail catches between 1956 and 2006 in the ECS was analyzed,which could be partitioned into inter-annual variation and internal trend.The internal trend was attributed to the monotonic growth of fishing efforts,the result of which was fitted by the Fox model showed that the relation between hairtail catch and fishing efforts was significant(P<0.01).After detrending the catch,variation in the catch was greatly affected by the climate fluctuation,which mainly included land precipitation,monsoon wind speeds,sea surface temperature and a proposed index of tropical cyclones(P<0.05).Variation of those main climatic factors and fishing efforts were significantly correlated with the annual catch(P<0.01).In conclusion,the land runoff brought nutrients to the coastal water,and the monsoons controlled the distribution and availability of the nutrients.In addition,the increase of water temperature was not only positive for the gonad development and maturity of hairtail,but also helpful to the availability of baits for hairtail.Thirdly,the tropical cyclones mobilized nutrient elements and enhanced biological production in many ways such as water mass moving,wind mixing,and upwelling.The paper concluded that both fishing efforts and climate change had influence on the variation of hairtail catch,and the climate changes in the future could be helpful to the increase of hairtail catch in the ECS,but also may result in a much bigger amplitude of catch variation.