印度洋黄鳍金枪鱼渔业资源开发策略评价

Exploitation Strategy Evaluation for Yollowfin Tuna in the Indian Ocean

运用单位补充量模型和Schaefer剩余产量模型,对印度洋黄鳍金枪鱼渔业的开发策略进行了评价。单位补充量模型指示的生物学参考点Fmax、F0.1、F20%SPR、F40%SPR分别为0.76、0.44、0.56、0.32,相应的产量控制参考值分别为36.7万t、34.6万t、36.1万t和34.2万t。随着捕捞死亡系数增加,未来10 a的相对渔获量将逐渐增加,但相对剩余亲体量却逐渐下降。捕捞死亡系数控制在0.3以内,未来10 a内相对剩余亲体量下降20%以下的概率将低于10%;捕捞死亡系数在0.6以上时,发生该事件的概率达到90%以上。当总许可捕捞产量分别为30万t、35万t、40万t和45万t时,未来10 a内的黄鳍金枪鱼资源量将分别呈增长、稳定、缓慢下降和快速下降趋势。从模拟的结果来看,应把捕捞死亡系数降低到0.5以下、总产量控制在35万t以内,才能保证渔业产量的长期稳定。图2,表4,参27。

Exploitation strategy of yellowfin tuna in the Indian Ocean was evaluated using per recruit model and Schaefer production model. Fmax、F0.1、F20%SPR、F40%SPR inferred from per recruit model was 0.76,0.44,0.56,0.32 and the corresponding referrence catch was 367, 346,361,342 thousand tons.The relative catch will increase with fishing mortality in the next ten years, but vice versa with relative residual spawner biomass.The probablity of relative residual spawner biomss below 20% will be lower than 10% if the fishing mortality is controled within 0.3, but greater than 90% if the fishing mortality is greater than 0.6.The biomass will show increscent, stable, slowly descendent, and quickly descendent trend in the next ten year when total allowable catch is set at 300,350,400, and 450 thousand tons. It is suggested that the production would be stable if fishing mortality was controlled below 0.5 and total catch was limited within 350 thousand tons.