浙江近岸海域春夏季剑尖枪乌贼栖息地分布变化规律

Habitat distribution change pattern of Uroteuthis edulis during spring and summer in the coastal waters of Zhejiang Province

摘要:

根据2014-2016年春夏季浙江沿岸海域拖网调查捕获的剑尖枪乌贼样本数据，结合提升回归树方法（boosted regression tree，BRT），确定不同的环境因子权重，利用算术平均法（arithmetic mean model，AMM）和几何平均法（geometric mean model，GMM）构建基于多因子的栖息地适宜性指数（habitat suitability index，HSI）模型进行分析。结果显示，春季剑尖枪乌贼栖息海域海表面温度（sea surface temperature，SST）、海表面盐度（sea surface salinity，SSS）、叶绿素a质量浓度（chlorophyll-a，Chl.a）和表层溶解氧质量浓度（dissolved oxygen，DO）的适宜范围分别为22~24℃、34~36、0.5~1.5 mg/m³和8~10 mg/L；而夏季对应的环境因子适宜范围分别为23~24℃、31~34、0.5~1.5 mg/m³和7~11 mg/L，季节差异较小；提升回归树分析结果表明，SST为环境因子中最重要的因子，其次分别为DO、Chl.a和SSS。剑尖枪乌贼栖息地适宜性指数的时空分布：春季HSI相对较低，且适宜栖息地主要出现在偏南部海域（27°N~29°N）；夏季的HSI相对较高，且在北部海域也发现较高的HSI值（30°N~31°N）。2种算法相比而言，GMM方法有着更低的赤池信息准则值（Akaike information criterion，AIC），因此更为适宜浙江沿岸剑尖枪乌贼的栖息地研究。浙江沿岸的剑尖枪乌贼最适栖息地的分布与海洋环境的变化以及海流等因素有着密切的关系。

Abstract:

According to the coastal survey of Zhejiang Province from 2014 to 2016, the Uroteuthis edulis was selected as target species, using boosted regression tree(BRT) to determine the weight of different environmental factors, and also utilize the arithmetic mean model (AMM) and geometric mean model (GMM) to construct the multifactor habitat suitability index (HSI) model. The results showed that the suitable range of sea surface temperature (SST), sea surface salinity (SSS), chlorophyll-a (Chl.a) and dissolved oxygen (DO) in spring for U. edulis habitat area was 22-24℃, 34-36, 0.5-1.5 mg/m³, 8-10 mg/L, respectively; the suitable range of SST, SSS, Chl.a and DO in summer for U. edulis was 23-24℃, 31-34, 0.5-1.5 mg/m³ and 7-11 mg/L, respectively, little seasonal variation was observed; the results of BRT showed that SST was the most important environmental factor, and the other factors ranked as DO, Chl.a and DO, respectively. The spatiotemporal distribution U.edulis is:HSI in spring is relatively low, and occurred in the southern area (27°N-29°N); in summer, HSI is relatively high and often occurred in the northern area (30°N -31°N). Compared with two different algorithms, GMM had lower AIC value than that of AMM, so GMM is more suitable for the habitat suitability study of U. edulis. The optimal habitat distribution of U. edulis in the coast of Zhejiang Province is closely related with some factors, such as the oceanographic variation and current change.