Abstract Global declines in elasmobranchs have been observed. Conservation measures such as area closures and fisheries prohibitions have been put in place to support the recovery of vulnerable species. However, the effectiveness of such measures is rarely evaluated in the context of other factors that may affect population abundance. This study investigates the effectiveness of management measures using 1) General additive mixed model derivative changes, taking into account environmental factors that may affect population stochasticity and 2) an age-structured density dependent population dynamic model. The Raja undulata (undulate ray) 2009 targeted fisheries prohibition was used as a case study. Potential beneficial responses on sympatric species Raja clavata (thornback ray) were modelled. A significant increase in abundance was observed in both IUCN red list species during the ban. Surface seawater temperature had a marginal effect on the abundance of both species. The prohibition was in place for an insufficient length of time for long lasting effects to be detected on skate length. The population dynamic model indicated that the increase in abundance was only possible when combining the fisheries ban with increased juvenile discard survival. Our results indicate that species conservation measures may not only have positive effects on the species in question, but also on species with a niche overlap. Nonetheless, due to ongoing fishing for other species, the full potential of fisheries prohibitions may not be realised. For real benefits to be assessed, evaluation of bans should take place once a steady state is observed.

中文翻译：

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在不断变化的世界中评估溜冰鞋管理措施的有效性

摘要 已经观察到弹性分支的全球下降。已经采取了诸如关闭区域和禁止渔业等保护措施，以支持脆弱物种的恢复。然而，很少在可能影响种群丰度的其他因素的背景下评估此类措施的有效性。本研究使用 1) 一般加性混合模型导数变化，考虑可能影响人口随机性的环境因素和 2) 年龄结构密度依赖人口动态模型来调查管理措施的有效性。Raja undulata (undulate ray) 2009 年有针对性的渔业禁令被用作案例研究。对同域物种 Raja clavata（刺背鳐）的潜在有益反应进行了建模。在禁令期间，在两个 IUCN 红色名录物种中观察到丰度显着增加。地表海水温度对两种物种的丰度都有边际影响。禁令的实施时间不够长，无法检测到对冰鞋长度的长期影响。种群动态模型表明，只有将渔业禁令与增加的幼鱼丢弃存活率相结合时，才有可能增加丰度。我们的结果表明，物种保护措施不仅可能对相关物种产生积极影响，而且可能对生态位重叠的物种产生积极影响。尽管如此，由于对其他物种的持续捕捞，渔业禁令的全部潜力可能无法实现。为了评估真正的好处，一旦观察到稳定状态，就应该对禁令进行评估。