环境因子对3种不同作业类型鲣CPUE的影响研究

Influence of environmental factors on CPUE of three different fishing methods in skipjack tuna fisheries

鲣(Katsuwonus pelamis)广泛分布于各大洋热带和亚热带海域,在世界金枪鱼渔业中占有重要地位,其资源丰度受多种海洋环境因子的影响。为探明降水对不同鲣群体资源分布及变动的影响机制,利用2017—2019年毛里塔尼亚海域双拖渔业数据、2018—2020年中西太平洋围网渔业数据和2010—2020年美洲热带金枪鱼委员会网站记录的延绳钓渔业数据,结合降水、海表面盐度(Sea surface salinity,SSS)和海表面温度(Sea surface temperature,SST)等环境数据,通过广义加性模型(Generalized additive model,GAM)分析鲣的3种不同作业方式的单位捕捞努力量渔获量(Catch per unit effort,CPUE)时空分布及其与降水等环境因子之间的关系。结果表明:月份对双拖和延绳钓作业方式鲣CPUE的影响显著(P<0.05);纬度对3种鲣作业方式的CPUE均存在显著性影响(P<0.05);降水对双拖和围网作业方式鲣CPUE分别存在极其显著性(P<0.001)和显著性(P<0.05)影响,且影响趋势较为一致,即这2种作业方式中高CPUE出现在较为适宜的降水范围内,然而降水对鲣的延绳钓CPUE的影响并不显著;SSS和SST对鲣的3种作业方式CPUE影响显著(P<0.05)。因此,在今后分析环境因子对渔业CPUE的影响效果时,建议将降水放入常规海洋环境因子中。

Skipjack tuna(Katsuwonus pelamis)is widely distributed in tropical and subtropical waters around the world and is a key target species in global tuna fishery.The abundance of its resources is influenced by various marine environmental factors.In order to explore the mechanisms by which precipitation affects the distribution and variation of resources in different K.pelamis stocks,based on the data from the pair trawl fishery in Mauritanian waters during 2017−2019,data from the purse seine fishery from the Western and Central Pacific Ocean during 2018−2020,and data from the longline fishery recorded on the IATTC website during 2010−2020,combining with environmental data such as precipitation,sea surface salinity(SSS)and sea surface temperature(SST),we analyzed the spatiotemporal distribution of catch per unit effort(CPUE)for three different fishing methods of skipjack tuna and its relationship with environmental factors such as precipitation by Generalized Additive Model(GAM).The findings indicate that month significantly influenced the CPUE of skipjack tuna for pair trawl and longline fishing methods(P<0.05).Latitude also had a significant effect on all the three fishing methods(P<0.05).Precipitation exhibited an extremely significant effect(P<0.001)on the CPUE of skipjack tuna for pair trawl fishing method and a significant effect(P<0.05)for purse seine fishing method.The trend of this effect was relatively consistent,with higher CPUE occurring within a more suitable range of precipitation.However,the effect of precipitation on the CPUE of skipjack tuna for longline fishing method was not significant.Sea surface salinity and sea surface temperature also had significant effects on the CPUE of skipjack tuna for all the three fishing methods(P<0.05).Hence,when analyzing the effects of environmental factors on fishery CPUE in the future,it is recommended to include precipitation in conventional marine environmental factors.