标题：AZFP论文：楚科奇海东北部北极鳕在环境驱动因素下的时空动态分布
Abstract
The Chukchi Sea pelagic ecosystem continues to undergo dramatic oceanographic changes associated with reductions in sea ice and increasing temperatures over the last decades. Impacts of these changes on polar cod (Boreogadus saida), an iceassociated pelagic fish that constitutes a key energetic link between lower and upper trophic levels, remain uncertain. Here, we use 4 years (2016–2019) of high-resolution acoustic and oceanographic data from the Chukchi Ecosystem Observatory to characterize temporal patterns in polar cod densities and identify its environmental drivers in years with contrasting sea ice and temperature conditions. Polar cod densities were 2–16 times greater with peaks occurring 14–60 days earlier in years with early sea ice retreat and higher water temperatures (2017 and 2019). The variance to mean relationship showed a decrease in variance for larger abundances in warmer years. Increased densities occurring earlier in the summer are attributed to a combination of earlier and increased transport of polar cod eggs and larvae from spawning areas, enhanced local primary and secondary production, and increased growth rates of fish due to higher temperatures. Earlier sea ice retreat and increases in temperature could temporarily benefit polar cod production in the NE Chukchi Sea but potential changes in prey quality, mismatch between polar cod and its prey, and increased competition with boreal fish species could have detrimental effects on polar cod populations with further warming. Such effects on polar cod populations could propagate through pelagic Arctic food webs impacting higher trophic levels and human communities.
Keywords: Acoustic backscatter · Polar cod · Chukchi Sea · Arctic pelagic ecosystem
摘要：
楚科奇海远洋生态系统在过去几十年中继续经历着与海冰减少和气温升高相关的巨大海洋学变化。这些变化对极地鳕鱼（Boreogadus saida）的影响尚不确定，极地鳕鱼是一种与冰有关的远洋鱼类，在低营养级和高营养级之间构成了关键的能量联系。在这里，我们使用楚科奇生态系统观测站4年（2016-2019）的高分辨率声学和海洋学数据来表征极地鳕鱼密度的时间模式，并确定其在海冰和温度条件对比的年份中的环境驱动因素。极地鳕鱼密度高出2-16倍，峰值出现在海冰提前退缩和水温升高的年份（2017年和2019年）的14-60天前。方差与均值的关系表明，在温暖的年份，丰度越大，方差越小。夏季早些时候出现的密度增加是由于极地鳕鱼卵和幼虫从产卵区的运输提前和增加，当地初级和次级生产增强，以及温度升高导致鱼类生长速度加快。海冰的早期退缩和温度的升高可能会暂时有利于楚科奇海东北部的极地鳕鱼生产，但随着进一步变暖，猎物质量的潜在变化、极地鳕鱼与其猎物之间的不匹配以及与北方鱼类物种的竞争加剧可能会对极地鳕鱼种群产生不利影响。这种对极地鳕鱼种群的影响可能会通过北极远洋食物网传播，影响更高的营养水平和人类群落。
关键词：AZFP，鱼类和浮游动物声学剖面仪，声学后向散射·极地鳕鱼·楚科奇海·北极远洋生态系统
