標題：AZFP論文：楚科奇海東北部北極鱈在環(huán)境驅動因素下的時空動態(tài)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：
楚科奇海遠洋生態(tài)系統(tǒng)在過去幾十年中繼續(xù)經歷著與海冰減少和氣溫升高相關的巨大海洋學變化。這些變化對極地鱈魚（Boreogadus saida）的影響尚不確定，極地鱈魚是一種與冰有關的遠洋魚類，在低營養(yǎng)級和高營養(yǎng)級之間構成了關鍵的能量聯系。在這里，我們使用楚科奇生態(tài)系統(tǒng)觀測站4年（2016-2019）的高分辨率聲學和海洋學數據來表征極地鱈魚密度的時間模式，并確定其在海冰和溫度條件對比的年份中的環(huán)境驅動因素。極地鱈魚密度高出2-16倍，峰值出現在海冰提前退縮和水溫升高的年份（2017年和2019年）的14-60天前。方差與均值的關系表明，在溫暖的年份，豐度越大，方差越小。夏季早些時候出現的密度增加是由于極地鱈魚卵和幼蟲從產卵區(qū)的運輸提前和增加，當地初級和次級生產增強，以及溫度升高導致魚類生長速度加快。海冰的早期退縮和溫度的升高可能會暫時有利于楚科奇海東北部的極地鱈魚生產，但隨著進一步變暖，獵物質量的潛在變化、極地鱈魚與其獵物之間的不匹配以及與北方魚類物種的競爭加劇可能會對極地鱈魚種群產生不利影響。這種對極地鱈魚種群的影響可能會通過北極遠洋食物網傳播，影響更高的營養(yǎng)水平和人類群落。
關鍵詞：AZFP，魚類和浮游動物聲學剖面儀，聲學后向散射·極地鱈魚·楚科奇?！け睒O遠洋生態(tài)系統(tǒng)
