Biogeographical transition zones are important areas to investigate evolutionary ecological questions but long-term population monitoring is needed to obtain a better understanding of ecological processes that govern populations variations in such edge environments. The southernmost Brazilian rocky reefs are the southern limit of distribution for 96% of the tropical ichthyofauna of the western Atlantic. The Arvoredo Marine Biological Reserve is the only nearshore no-take marine protected area (MPA) located in this transition zone. Our main objective was to investigate how the populations of rocky reef fish species vary in density and biomass in space and over time, inside and outside the Arvoredo MPA. We present results based on a 9-year (2008 to 2017) underwater visual censuses monitoring study to evaluate density and biomass of key fish species. Variations in density and biomass were detected for most species. Factors and mechanisms that may have influenced spatial variation are habitat structural complexity and protection from fisheries. Temporal variations, otherwise, may have been influenced by the species proximity to their distributional limit, in synergy with density-dependent mechanisms and stochastic winter temperature oscillations. The MPA harbor higher density and biomass for most species. However, a prominent temporal decline in recruitment for Epinephelus marginatus calls in question the MPA continuous effectiveness. This article is protected by copyright. All rights reserved.

中文翻译：

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生物地理气候过渡区岩礁鱼类密度和生物量的时空变化：巴西南部海岸唯一近岸禁捕海洋保护区内外九年的趋势

生物地理过渡区是研究进化生态问题的重要领域，但需要长期的种群监测才能更好地了解在这种边缘环境中控制种群变化的生态过程。巴西最南端的岩礁是西大西洋 96% 热带鱼群分布的南部界限。Arvoredo 海洋生物保护区是位于该过渡区的唯一近岸禁捕海洋保护区 (MPA)。我们的主要目标是调查在 Arvoredo MPA 内部和外部，岩礁鱼类种群在空间和时间上的密度和生物量如何变化。我们根据为期 9 年（2008 年至 2017 年）的水下视觉普查监测研究提供结果，以评估关键鱼类的密度和生物量。大多数物种都检测到密度和生物量的变化。可能影响空间变化的因素和机制是栖息地结构的复杂性和渔业保护。否则，时间变化可能受到接近其分布极限的物种的影响，与密度依赖机制和随机冬季温度振荡协同作用。MPA 为大多数物种提供更高的密度和生物量。然而，Epinephelus marginatus 招募的显着时间下降令人质疑 MPA 的持续有效性。本文受版权保护。版权所有。否则，时间变化可能受到接近其分布极限的物种的影响，与密度依赖机制和随机冬季温度振荡协同作用。MPA 为大多数物种提供更高的密度和生物量。然而，Epinephelus marginatus 招募的显着时间下降令人质疑 MPA 的持续有效性。本文受版权保护。版权所有。否则，时间变化可能受到接近其分布极限的物种的影响，与密度依赖机制和随机冬季温度振荡协同作用。MPA 为大多数物种提供更高的密度和生物量。然而，Epinephelus marginatus 招募的显着时间下降令人质疑 MPA 的持续有效性。本文受版权保护。版权所有。本文受版权保护。版权所有。本文受版权保护。版权所有。