Effects of temperature and food availability on larval cod survival: a model for behaviour in vertical gradients
Effects of temperature and food availability on larval cod survival: a model for behaviour in vertical gradients
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DOI：
10.3354/meps11326
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发表时间：
2015-06-08
影响因子：
2.5
通讯作者：
Fiksen, Oyvind
中科院分区：
文献类型：
--
作者：
Fouzai, Nadia;Opdal, Anders F.;Fiksen, Oyvind
由于生命早期阶段的高生存变异性，海洋生物资源的招募成功是可变的。提高我们对环境和生态因素如何相互作用并影响幼鱼生长和生存的理解是必要的，以便更好地预测年级强度和预期的生理和行为对气候变暖的反应。我们使用状态依赖的行为最优模型大西洋鳕鱼的幼虫Gadus morhua来分析与生长和生存相关的权衡。依赖温度的最大生长率和温度的垂直分布以及随机猎物可用性被用作机制建模框架的输入，该框架可以找到垂直迁移和觅食活动的最佳行为策略。适应度标准是在幼虫达到一定体型（15 mm）之前最大限度地提高生存概率。通过对最佳策略的模拟，详细描述了鳕鱼幼虫的捕食、生理、生长和生存。该模型表明，温度对存活的影响是复杂的。温度升高可能导致更快的生长和更高的存活率，但只有在有足够的食物的情况下。在恶劣的食物环境中，较高的温度使幼虫更容易被捕食，因为它们冒着更高的风险来满足它们的代谢成本。总的来说，这些结果表明，在气温升高和食物供应减少的气候变化情景下，大西洋鳕鱼的幼虫，特别是那些来自温暖水域的鳕鱼，可能会经历生存和补充的减少。
Recruitment success in living marine resources is variable due to high survival variability of early life stages. Improving our understanding of how environmental and ecological factors mechanistically interact and influence larval fish growth and survival is necessary to better predict year-class strength and expected physiological and behavioural responses to climate warming. We use a state-dependent optimality model for the behaviour of larval Atlantic cod Gadus morhua to analyse trade-offs related to growth and survival. Temperature-dependent maximum growth rates and vertical profiles of temperature and stochastic prey availability are used as inputs within a mechanistic modelling framework that finds optimal behavioural strategies of vertical migration and foraging activity. The fitness criterion used is maximization of survival probability until the larvae reach a given body size (15 mm). Detailed descriptions of predation, physiology, growth and survival of larval cod emerge from simulations of the optimal strategies. The model shows that the effect of temperature on survival is complex. Increasing temperature may lead to faster growth and higher survival, but only when there is sufficient food. In poor food environments, higher temperatures make larvae more susceptible to predation as they take higher risks to satisfy their metabolic costs. Overall, these results suggest that larval Atlantic cod, especially those from warmer-water stocks, may experience reduced survival and recruitment in climate-change scenarios that predict both elevated temperatures and reduced food supply.