ABSTRACT: Nursery area habitats such as estuaries are vital for the success of many fish populations. Climate change is altering conditions in these areas, which can thus impact the availability of suitable nursery habitat. The sandbar shark Carcharhinus plumbeus uses Chesapeake Bay (USA) as a nursery habitat during the summer months from birth up to 10 yr of age. To assess the impacts of climate change on juvenile sandbar sharks, we developed a habitat model using longline data collected from a fishery-independent survey within Chesapeake Bay. With this model, we projected contemporary and future distributions of suitable habitat for juvenile sandbar sharks in Chesapeake Bay under varying environmental regimes. Predicted suitable juvenile sandbar shark habitat was negatively impacted by future increases in temperature, but positively influenced by future decreases in dissolved oxygen. The latter trend was likely related to the habitat partitioning that occurs between different life stages. Changes in salinity had relatively small impacts. By end-of-century the projected amount of suitable bottom habitat decreased; however, when incorporating the entire water column, projected suitable habitat increased. This suggests that juvenile sandbar sharks may need to make a behavioral shift to avoid non-preferred conditions, which could alter their foraging ecology or refuge strategies. As nursery habitats change with climate change, it is crucial to understand how a species may be impacted during this vital life stage when trying to predict overall species success in the future.

中文翻译：

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鲨鱼苗圃栖息地对气候变化的敏感性

摘要：河口等苗圃地区的栖息地对于许多鱼类种群的成功至关重要。气候变化正在改变这些地区的条件，从而可能影响合适的苗圃栖息地的供应。沙洲鲨鱼Carcharhinus plumbeus在出生至10岁的夏季月份内，使用切萨皮克湾（美国）作为苗圃栖息地。为了评估气候变化对幼年沙洲鲨的影响，我们使用从切萨皮克湾独立于渔业的调查中收集的延绳钓线数据开发了栖息地模型。通过这种模型，我们预测了切萨皮克湾在不同环境条件下适合青少年沙洲鲨的栖息地的当代和未来分布。预测的合适的幼年沙洲鲨鱼栖息地受到未来温度升高的负面影响，但受到未来溶解氧下降的积极影响。后一种趋势可能与不同生命阶段之间发生的栖息地分区有关。盐度变化的影响相对较小。到本世纪末，合适的底部生境的预计数量减少了；但是，当将整个水柱合并时，预计的合适栖息地会增加。这表明，幼年沙洲鲨可能需要做出行为上的转变，以避免出现不利条件，这可能会改变其觅食生态或避难策略。随着苗圃栖息地随气候变化而变化，在预测未来总体物种成功时，了解物种在这一重要生命阶段可能受到的影响至关重要。