利用栖息地指数模型预测秘鲁外海茎柔鱼热点区

Forecasting hotspots of Dosidicus gigas in the offshore waters of Peru using habitat suitability model

中文关键词: 茎柔鱼  栖息地指数  热点区  秘鲁外海

英文关键词: Dosidicus gigas  Habitat suitability index  Hotspots  Offshore waters of Peru

中文摘要:

      利用栖息地指数模型准确地预测了秘鲁外海茎柔鱼的热点区。根据2008-2010年1-12月期间我国鱿钓渔船在秘鲁外海的生产数据，结合实时的海表温及海表面高度数据，分别建立以作业次数、单位捕捞努力量渔获量为基础的适应性指数。利用算术平均数模型建立基于海表温和海表面高度的栖息地指数模型，并利用2011年生产及环境数据对栖息地指数模型进行验证。结果显示，以作业次数为基础的适应性指数符合正态分布，而以单位捕捞努力量渔获量为基础的适应性指数显著性检验不显著，因此，只建立以作业次数为基础的模型。结果表明，以作业次数为基础的栖息地指数模型都高估了茎柔鱼热点区的范围，但大体范围基本一致，这说明其能较好地预测茎柔鱼的热点区。

英文摘要:

      Dosidicus gigas, jumbo flying squid, is widely distributed in the eastern Pacific Ocean, and has become one of the most important target species for Chinese squid jigging vessels. There is a great potential for exploitation due to the abundance of this species. The precise forecasting of hotspots could provide scientific guidance for squid jigging fleets. Hotspots of D. gigas are closely related to the abundance distribution which is affected by marine environmental factors including sea surface temperature and sea surface height. We established the suitability index of D. gigas based on either catch per unit fishing effort or fishing effort, with two data resources: the fishery data from Chinese squid jigging produced from 2008 to 2010, and the environmental data including real-time sea surface temperature and sea surface height obtained from remote sensing. Then we used the arithmetic average model to establish different habitat suitability index. We also used the established model based on the fishing catch and marine environmental data in 2011 to test the habitat suitability index model. We found that the suitability index based on fishing effort and environmental factors was consistent with the normal distribution (P<005). However, the suitability index based on catch per unit fishing effort and environmental factors was not significant (P>0.05). We hence used the habitat suitability index model based on fishing effort to forecast the hotspots of D. gigas. It was found that in the area where the habitat suitability index was higher than 0.6, the catch accounted for 48% of the total, the fishing effort occupied 46% of the total, and the CPUE ranged from 5.23 to 5.76 t/d. We also found that the forecasted hotspots of D. gigas were basically located in the actual fishing area, which indicated that this model could effectively forecast the hotspots of D. gigas.