基于多船队作业的东、黄海鲐鱼生物经济模型及管理策略

A Multi-Fleet and Bio-economic Simulation Model and Its Application to Chub Mackerel in the East China Sea and the Yellow Sea

鲐鱼是我国近海大型围网和群众围网船队主要捕捞种类。如何兼顾两种渔业的利益,并从生物、经济和社会效益来科学制定渔业管理目标,是确保该资源可持续利用的重要研究内容之一。本文根据渔获统计等数据,在理论上模拟了50年内(1948年-2048年)大型围网和群众围网捕捞船队的动态变化,探讨5种方案下各渔业捕捞努力量、鲐鱼资源量、产量及利润,以及与其对应的总利润及总产量的动态变化情况。模拟结果表明:所有方案下,资源量在前10年(1998年-2008年)中都出现较大幅度的减少,随后趋于稳定并维持在较低的水平上。在基准方案下,群众围网船队在捕捞努力量、产量及利润方面占优。其余方案中,大型围网船队最终在捕捞努力量和产量占优,但其利润接近于0。结合累计产量和利润,方案c(降低大型围网成本)由于兼顾了大型围网的经济效益及群众围网的社会效益,可认为是目前适合东黄海鲐鱼长期的管理方式。

Chub mackerel （Scomber japonicus） is an important commercial fish which has been caught by both the large scale light purse seining fisheries and the small scale traditional light seining fisheries in China＇s coastal areas in recently years. It is also an important component of marine ecosystems in the East China Sea and the Yellow Sea. In recent years, the fishery has been shown to be fluctuated in population and annual catch, suggesting that the chub mackerel stock might be overfished. To that end, determination of the goals of fishery management by accounting for both the large scale light purse seining fishery and the small scale traditional light seining fishery together with biological, economic and social aims is one of the critical tasks in sustainable utilization of fishery. On the basis of the catch and other types of data, changes in both fisheries were simulated preliminarily with the framework of a multi-fleet and bio-economic simulation model proposed by Seijo in 1994, and dynamic fishing effort, stock, yield, profits, and corresponding total yield and profits under different scenarios during the period 1998 to 2048 were also discussed. The simulations indicated that the stock of chub mackerel has been steady in a low level after decreasing significantly over 10 years from 1998 to 2008. For the baseline simulation, the small scale traditional light seining fishery will be dominant in the fishing effort, yield and profit, whereas the profit of both fisheries is close to zero after 50 years. For the simulation of fishery management measure B, i.e., increasing the catchability coefficient of the large light purse seining fishery, fishery management measure C, i.e., reducing the fishing cost of the large light purse seining fishery, fishery management measure D, i.e., increasing the fishing cost of the small scale traditional light seining fishery, and fishery management measure E, reducing the catchability coefficient of the small scale traditional light seining fishery, the large scale light purse seining fishery will be dominant in the fishing effort, yield and profit while the profit of both fisheries is also close to zero after 50 years. Results also showed that under the baseline scenario, the interest of the large scale light purse seining fishery is decreasing although the total accumulative yield in the 50 years is the highest. Concerning the simulation of measure E, the total accumulative profit in the 50 years is the highest but its corresponding total accumulative profit shows a decreasing trend. Compared with the other measures, the measure C was shown to be best for the long-term management goal of chub mackerel because of its consideration of both fisheries.