The population dynamics of fish in northern lakes is strongly influenced by climatic factors. In this study, we investigated whether there is a link between the late 1980s climate regime shift in Europe and the collapse of vendace (Coregonus albula) population at the same time in Lake Peipsi. Until the end of the 1980s, vendace was very abundant in the lake, but then its catches sharply declined. This decline inspired investigations into the extreme weather events preceding the vendace collapse using data on daily water temperatures and ice phenology together with commercial fishery statistics since 1931 and test catch data since 1986. We identified using advanced statistical methods that the hot summer of 1988, which was accompanied by a severe cyanobacterial bloom and extensive fish kill, and the subsequent non-permanent ice cover and early ice-offs in 1989 and 1990 in Lake Peipsi were the main reasons for the disappearance of vendace from catches in 1991. Moreover, a negative correlation appeared between catches of the predatory pikeperch (Sander lucioperca) and vendace. Predation pressure as well as fish habitat degradation caused by lake eutrophication may contribute to the instability of the vendace population too. Our study showed that extreme weather events such as heat waves in summer and non-permanent ice-cover in winter in consecutive years may have long-lasting harmful effects on the population abundance of cool-water fish species such as vendace whose eggs usually develop under an ice cover in north-temperate lakes.

中文翻译：

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1980 年代后期气候制度转变如何影响对温度敏感的鱼类种群动态：北温带大型湖泊中的 Vendace（Coregonus albula）案例研究

北方湖泊鱼类种群动态受气候因素影响较大。在这项研究中，我们调查了 1980 年代后期欧洲气候制度的转变与 Peipsi 湖同时期的白头翁（Coregonus albula）种群的崩溃之间是否存在联系。直到 1980 年代末，湖中的白鲑鱼非常丰富，但随后其捕获量急剧下降。这种下降激发了使用每日水温和冰物物候数据以及自 1931 年以来的商业渔业统计数据和自 1986 年以来的测试捕获数据对旺达斯崩塌前的极端天气事件进行调查。我们使用先进的统计方法确定了 1988 年炎热的夏季，伴随着严重的蓝藻大量繁殖和大量鱼类死亡，1989 年和 1990 年 Peipsi 湖的非永久性冰盖和早期冰层是 1991 年白鲑鱼从捕捞量中消失的主要原因。此外，捕食性梭鲈 (Sander lucioperca) 的捕捞量之间出现负相关和旺达斯。捕食压力以及湖泊富营养化引起的鱼类栖息地退化也可能导致白鲑种群的不稳定。我们的研究表明，极端天气事件，如夏季的热浪和冬季的连续多年非永久性冰盖，可能对通常在低温下产卵的白鲟等冷水鱼类的种群丰度产生长期的有害影响。北温带湖泊中的冰盖。