期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2016
卷号：113
期号：52
页码：15030-15035
DOI：10.1073/pnas.1525749113
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：SignificanceRapid anthropogenic trait changes in fish stocks is a highly publicized ocean conservation issue, yet the relative contributions of evolutionary and ecological dynamics are unknown. We present an integrative empirically based simulation model to determine the role of these contributions in the worlds largest cod stock. We quantitatively evaluate predictions with different density-dependent growth models using historical stock-specific data. The amount of evolution required for explaining observed maturation trends is small, yet with weakly density-dependent growth, critical for preventing stock collapse. The role of evolution in explaining trends is diminished when density-dependent growth is present. Our study reveals how interactions among evolution, ecology, and fisheries influence stock dynamics and harvest sustainability, emphasizing the need for integrated approaches to fisheries management. The relative roles of density dependence and life history evolution in contributing to rapid fisheries-induced trait changes remain debated. In the 1930s, northeast Arctic cod (Gadus morhua), currently the worlds largest cod stock, experienced a shift from a traditional spawning-ground fishery to an industrial trawl fishery with elevated exploitation in the stocks feeding grounds. Since then, age and length at maturation have declined dramatically, a trend paralleled in other exploited stocks worldwide. These trends can be explained by demographic truncation of the populations age structure, phenotypic plasticity in maturation arising through density-dependent growth, fisheries-induced evolution favoring faster-growing or earlier-maturing fish, or a combination of these processes. Here, we use a multitrait eco-evolutionary model to assess the capacity of these processes to reproduce 74 y of historical data on age and length at maturation in northeast Arctic cod, while mimicking the stocks historical harvesting regime. Our results show that model predictions critically depend on the assumed density dependence of growth: when this is weak, life history evolution might be necessary to prevent stock collapse, whereas when a stronger density dependence estimated from recent data is used, the role of evolution in explaining fisheries-induced trait changes is diminished. Our integrative analysis of density-dependent growth, multitrait evolution, and stock-specific time series data underscores the importance of jointly considering evolutionary and ecological processes, enabling a more comprehensive perspective on empirically observed stock dynamics than previous studies could provide.
