Prospects for the future of pink salmon in three oceans: From the native Pacific to the novel Arctic and Atlantic

While populations of other migratory salmonids suffer in the Anthropocene, pink salmon (Oncorhynchus gorbusca Salmonidae) are thriving, and their distribution is expanding both within their natural range and in the Atlantic and Arctic following introduction of the species to the White Sea in the 1950s. Pink salmon are now rapidly spreading in Europe and even across the ocean to North America. Large numbers of pink salmon breed in Norwegian rivers and small numbers of individuals have been captured throughout the North Atlantic since 2017. Although little is known about the biology and ecology of the pink salmon in its novel distribution, the impacts of the species' introduction are potentially highly significant for native species and watershed productivity. Contrasts between pink salmon in the native and extended ranges will be key to navigating management strategies for Atlantic nations where the pink salmon is entrenching itself among the fish fauna, posing potential threats to native fish communities. One key conclusion of this paper is that the species' heritable traits are rapidly selected and drive local adaptation and evolution. Within the Atlantic region, this may facilitate further establishment and spread. The invasion of pink salmon in the Atlantic basin is ultimately a massive ecological experiment and one of the first examples of a major faunal change in the North Atlantic Ocean that is already undergoing rapid changes due to other anthropogenic stressors. New research is urgently needed to understand the role and potential future impacts of pink salmon in Atlantic ecosystems.     

从连续到偶发：中华鲟在葛洲坝下发生小规模自然繁殖

中华鲟(Acipenser sinensis Gray)为国家一级重点保护野生动物,典型的溯河洄游产卵鱼类。历史上,中华鲟在长江上游及金沙江下游产卵,由于葛洲坝修建阻隔了其洄游通道,1981年以后在葛洲坝下形成了比较稳定的产卵场,1982―2013年,每年均有自然繁殖发生。由于其栖息生境退化,每年洄游进入长江的中华鲟繁殖亲本逐年减少,2013―2015年连续3年在已知葛洲坝下中华鲟产卵场未监测到中华鲟自然繁殖活动。2016年11―12月的野外监测发现,中华鲟在宜昌葛洲坝下已知产卵场发生了自然繁殖。其中底层网具采集到中华鲟鱼卵(卵膜)67粒、仔鱼22尾;解剖食卵鱼发现,10尾食卵鱼类共摄食中华鲟卵454粒;水下视频观测到5处中华鲟卵黏附底质位点。根据采集到的鱼卵发育期及采集位点推算,产卵时间为2016年11月24日凌晨,产卵场位于葛洲坝大江电厂以下约300 m的江段内,产卵日水温为19.7℃,流量为6610 m3/s,水位为39.7 m。