应用栖息地适宜性指数研究温台渔场小黄鱼的空间分布特征

Spatial distribution of Larimichthys polyactis in Wen-Tai fishing ground based on habitat suitability index

根据2015-2016年春、夏、秋、冬4个季节在温台渔场开展的渔业资源与栖息环境综合调查采集的生产数据,采用正态分布函数分别构建海水底层温度(sea bottom temperature, SBT)、海水底层盐度(sea bottom salinity, SBS)和水深(depth)与相对资源密度的适宜性指数(suitability index, SI),利用最小二乘法进行参数求解,利用提升回归树(boosted regression tree, BRT)模型确定各环境因子的权重,采用基于不同权重的算术平均法(arithmetic weighted model, AWM)建立栖息地适宜性指数(habitat suitability index, HSI)模型,并通过交叉验证检验模型精度。研究发现:各环境因子与SI间均呈现明显的正态关系;小黄鱼的最适栖息地存在明显的季节性变化,全年HSI高值区出现在春季和夏季,其次为秋季和冬季,春季高值区位于122°30′E以东,28°30′N以北海域,夏季高值区呈带状南下,秋季高值区位于122°00′E,28°00′N附近海域,冬季高值区北上,位于123°00′E,29°00′N附近海域。研究结果表明:在HSI模型中考虑权重后,该模型能够较好地反映温台渔场小黄鱼栖息地的分布和变化情况。

According to the investigated data of fishery resources and habitats of comprehensive survey on Wen-Tai fishing ground in four seasons in 2015-2016, using normal distribution function respectively the sea bottom temperature(SBT), sea bottom salinity(SBS), water depth, and by the relative density of resources suitability index(SI) were built, and by used the least squares parameter model, based on different weight arithmetic average method(AWM), the habitat suitability index(HSI) model was also built. According to the data of resource density, bottom temperature, bottom salinity and depth, the boosted regression tree(BRT) was also built used to evaluate the weight of each environmental variable in the HSI model, and the model accuracy was tested by cross validations. It was found that there was a significant normal relationship between environmental factors and SI. Larimichthys polyactis optimal habitat has an obvious seasonal change of habitats.The whole-year high value appeared in spring and summer, followed by autumn and winter, the spring high value area is located in east of 122°30′E, north of 28°30′N summer strip of south high value area, autumn high value area is located at 122°00′E, 28°00′N, winter high value area north is located 123°00′E, 29°00′N. The results showed that the model can positively reflect the distribution and variation of the habitat of the Larimichthys polyactis in the warm stage after considering the weight in the HSI model.