Climate change and condition of herring (Clupea harengus) explain long-term trends in extent of skipped reproduction

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• 作者：Georg H. Engelhard and Mikko Heino
• 关键词：Skipping reproduction ; Size and condition ; Climate ; Current and future reproduction ; Spawning migration costs and risks
• 刊名：Oecologia
• 出版年：2006
• 出版时间：October, 2006
• 年：2006
• 卷：149
• 期：4
• 页码：593-603
• 全文大小：322 KB

文摘

It is commonly assumed that iteroparous fish, once mature, normally reproduce in all consecutive seasons. Recent work has suggested, however, that in Norwegian spring-spawning herring—a population that undertakes extensive spawning migrations—almost one in two adults may skip their second spawning migration. Why should herring not return to spawn the year after first spawning, but instead wait an extra year? For herring, participation in distant, energetically costly, and risky spawning migrations will only pay off in terms of fitness if individuals are sufficiently large, and in sufficient condition, to both successfully migrate and spawn. Changes in the environment and individual condition should therefore affect the likelihood of skipped spawning. This paper describes long-term changes in the extent to which the second reproductive season is skipped in this herring population. These are shown to be linked to the size and condition of herring as first-time spawners, and to climatic factors possibly related to food availability. The findings corroborate the hypothesis that skipped reproduction results from trade-offs between current and future reproduction, growth and survival.