Marine protected areas (MPAs) are increasingly implemented worldwide to maintain and restore depleted populations. However, despite our knowledge on the myriad of positive responses to protection, there are few empirical studies on the ability to conserve species’ mating patterns and secondary sexual traits. In male European lobsters (Homarus gammarus), the size of claws relative to body size correlates positively with male mating success and is presumably under sexual selection. At the same time, an intensive trap fishery exerts selection against large claws in males. MPAs could therefore be expected to resolve these conflicting selective pressures and preserve males with large claws. We explored this hypothesis by contrasting claw size of males and females in three pairs of MPAs and nearby fished areas in southern Norway. By finding that male lobsters have up to 8% larger claws inside MPAs compared to similarly sized males in fished areas, our study provides evidence that MPAs rescue a secondary sexual trait. Recovery from harvest selection acting on claws is the most likely explanation; however, the higher abundance of lobster inside MPAs does not rule out a plastic response on claw size due to increased competition. Regardless of the underlying cause, our study demonstrates (a) the value of protected areas as a management tool for mitigating fisheries‐induced evolution and (b) that MPAs help maintaining the scope for sexual selection in populations with vulnerable life histories and complex mating system.

中文翻译：

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海洋保护区拯救欧洲龙虾的性选择特征


世界范围内越来越多地建立海洋保护区（MPA），以维持和恢复枯竭的种群。然而，尽管我们了解无数对保护的积极反应，但关于保护物种交配模式和第二性征的能力的实证研究却很少。在雄性欧洲龙虾（ Homarus gammarus ）中，爪子的大小相对于身体大小与雄性交配成功率呈正相关，并且可能受到性选择的影响。与此同时，密集的诱捕渔业对雄性的大爪鱼进行了选择。因此，海洋保护区有望解决这些相互冲突的选择压力，并保护拥有大爪子的雄性。我们通过对比挪威南部三对海洋保护区和附近捕鱼区的雄性和雌性爪子大小来探索这一假设。我们的研究发现，与捕捞区域中类似大小的雄性龙虾相比，海洋保护区内的雄性龙虾的爪子大 8%，这为海洋保护区拯救了第二性征提供了证据。最可能的解释是从作用于爪子的收获选择中恢复。然而，海洋保护区内龙虾数量较多，并不排除由于竞争加剧而对爪子尺寸产生塑料反应。无论根本原因如何，我们的研究表明（a）保护区作为缓解渔业引起的进化的管理工具的价值，以及（b）海洋保护区有助于维持具有脆弱生活史和复杂交配系统的种群的性选择范围。