Marine protected areas rescue a sexually selected trait in European lobster

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...海洋保护区（Marine Protected Areas, MPAs）目前在全球范围内愈发广泛地被布设，以维持并修复已枯竭的物种种群。然而，尽管学界已明确保护区可带来诸多积极效应，但针对其能否保护物种种群的交配模式与第二性征的实证研究仍寥寥无几。对于欧洲龙虾（Homarus gammarus）的雄性个体而言，其螯足尺寸相较于体型的比值与雄性交配成功率呈正相关，推测该性状处于性选择作用之下。与此同时，高强度的笼捕渔业会对雄性个体的大螯足施加负向选择压力。因此，海洋保护区本应能够缓解这一矛盾的选择压力，保留拥有大螯足的雄性个体。本研究通过对比挪威南部3对海洋保护区及其邻近捕捞区域内雌雄龙虾的螯足尺寸，对这一假说展开了验证。本研究发现，与捕捞区域内体型相当的雄性龙虾相比，保护区内的雄性龙虾螯足尺寸最大可高出8%，由此为海洋保护区能够拯救……