基于最大熵模型的西北太平洋远东拟沙丁鱼和日本鲭栖息地差异

远东拟沙丁鱼Sardinops melanostictus和日本鲭Scomber japonicus作为西北太平洋的主要关联物种,研究其潜在栖息地分布以及对该海域环境变化响应的差异对管理和持续利用该渔业资源有重要的科学意义。本研究采用最大熵模型,利用2017~2021年盛鱼期(5~11月)在西北太平洋远东拟沙丁鱼和日本鲭的渔业数据,结合海表面温度 sea surface temperature, SST、海表面盐度 sea surface salinity, SSS、海表面高度 sea surface height, SSH、叶绿素浓度 chlorophyll-a, Chl-a、涡旋动能 eddy kinetic energy, EKE、不同水层温度(包括50m、100m、150m、200m),通过贡献率的大小分别筛选出各月对远东拟沙丁鱼和日本鲭排位前三的关键因子,根据二者对各月关键环境因子的响应曲线,获得各月关键因子对二者潜在栖息地的月间变化,最终模拟出二者在5~11月的潜在栖息地分布图。结果表示,远东拟沙丁鱼和日本鲭的潜在栖息地变动与实际作业位置具有一致性,随着月份的增加均呈现先向东北方向移动,在向西南方向折回的运动趋势,且二者各月潜在栖息地位置均大范围重叠。在6、8~10月影响二者适宜栖息地变动的关键因子均为SSH、SST、Chl-a,且适宜范围相差不大。5、7、11月影响二者适宜栖息地变动的关键因子有所不同,远东拟沙丁鱼5月的关键因子为SSH、EKE、SST,7月为SSH、SST、Chl-a,11月为EKE、SST、Chl-a,而日本鲭5月为SSH、EKE、Chl-a,7月为SST、Chl-a、SSS,11月为SSH、SST、Chl-a,各月环境因子的适宜范围不同。此外,随着月份增加日本鲭最适栖息地面积向北逐渐缩小,7和11月份面积最小,而远东拟沙丁鱼最适栖息地面积有增大趋势,11月份最适栖息地延伸到37°N以北的地区。该研究表明SSH、SST、Chl-a的变化对西北太平洋远东拟沙丁鱼和日本鲭潜在栖息地分布变化均有重要影响,而EKE、SSS是造成二者之间潜在栖息地分布变化差异的主要原因。

Differences in habitat distribution of Sardinops melanostictus and Scomber japonicus in the northwest Pacific based on a maximum entropy model

Sardinops melanostictus and Scomber japonicus, as the main associated species in the Northwest Pacific Ocean, are of great scientific significance for the management and sustainable use of fishery resources to study their potential habitat distribution and differences in response to environmental changes in this area. We used the fishery data of S.melanostictus and S. japonicus in the northwest Pacific Ocean from March to November in 2017~2021, combined with sea surface temperature (SST), sea surface salinity (SSS), sea surface height (SSH), chlorophyll-a (Chl-a), eddy kinetic energy (EKE), and water temperature at different depths (50m, 100m, 150m, 200m) to construct a maximum entropy model. According to the response curves of the two to the key environmental factors of each month, the inter-month changes of the key factors on the potential habitats of S. melanostictus and S. japonicus were obtained, and finally the S. melanostictus were simulated Map of potential habitat distribution from May to November for S. melanostictus and S. japonicus. The key factors affecting the change of suitable habitats from June and August to October were SSH, SST, and Chl-a, and their suitable ranges were not much different. The results show that the potential habitat changes of S. melanostictus and S. japonicus are consistent with the actual operating location, and with the increase of months, they all show a trend of moving first to the northeast and turning back in the southwest direction, and their potential habitat positions overlap widely in each month. The key factors affecting the change of suitable habitat in May, July and November are different. The key factors affecting the change of suitable habitat in May, July and November are different, the key factors of S. melanostictus are SSH, EKE, SST, the key factors in July are SSH, SST, Chl-a, the key factors in November are EKE, SST, Chl-a, while the key factors of S. japonicus are SSH, EKE, Chl-a in May, and the key factors in July are SST and Chl-a ,SSS, the key factors in November are SSH, SST, Chl-a, and the suitable range of environmental factors varies from month to month. In addition, as the number of months increases, the optimal habitat area of S. japonicus gradually decreases northward, with a minimum area in July and November, while the optimal habitat area of S. melanostictus tends to increase, extending to the area north of 37° north latitude in November. The study concluded the changes of SSH, SST and Chl-a have an important impact on the distribution of potential habitats of S. japonicus and S. melanostictus in the northwest Pacific Ocean, and EKE and SSS are the main reasons for the difference in the distribution of potential habitats.