Marinas create physical and biotic conditions distinct from those in natural habitats which can facilitate the establishment of non-indigenous species (NIS) in coastal ecosystems. Using a series of images spanning nine years, we detected the introduction and followed the expansion of the NIS Tubastraea coccinea and T. tagusensis populations at a recreational marina in a region of Southeastern Brazil where sun-corals are rarely found on natural substrates. Because sun corals are known to reduce diversity in natural invaded environments, we evaluated how different densities of sun-corals affected the benthic community. Overall, the NIS populations have grown exponentially from 2010 to 2019 inside the marina, occupying up to 60% of the available space. However, the population growth in the breakwater stopped in 2016. Local variation in the population growth across the marina might be associated with the high phytoplankton biomass and larval retention inside the marina, which are results of the lower hydrodynamics. The expansion of sun-coral coverage did not significantly affect the richness of benthic communities but was associated with a reduction of the native bryozoan Amathia brasiliensis , the overall abundance of mobile crustaceans, and an increase in the area covered by the exotic bryozoan S. errata. The fast substitution of a native ecosystem engineer for a NIS suggests signs of invasion meltdown associated with the expansion of Tubastraea spp.

中文翻译：

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入侵珊瑚 Tubastraea spp。人工栖息地的人口增长及其对底栖生物多样性的影响

码头创造了不同于自然栖息地的物理和生物条件，可以促进非本土物种 (NIS) 在沿海生态系统中的建立。使用跨越九年的一系列图像，我们检测到了 NIS Tubastraea coccinea 和 T. tagusensis 种群在巴西东南部地区的一个休闲码头的引入和扩张，那里的天然基质上很少发现太阳珊瑚。由于已知太阳珊瑚会减少自然入侵环境的多样性，因此我们评估了不同密度的太阳珊瑚如何影响底栖群落。总体而言，从 2010 年到 2019 年，NIS 数量在码头内呈指数级增长，占据了可用空间的 60%。然而，防波堤的人口增长在 2016 年停止了。整个码头人口增长的局部变化可能与高浮游植物生物量和码头内的幼虫滞留有关，这是较低流体动力学的结果。太阳珊瑚覆盖范围的扩大并未显着影响底栖群落的丰富度，但与本土苔藓虫 Amathia brasiliensis 的减少、移动甲壳类动物的总体丰度以及外来苔藓虫 S. errata 覆盖面积的增加有关. 本地生态系统工程师对 NIS 的快速替代表明与 Tubastraea spp 扩张相关的入侵崩溃迹象。太阳珊瑚覆盖范围的扩大并未显着影响底栖群落的丰富度，但与本土苔藓虫 Amathia brasiliensis 的减少、移动甲壳类动物的总体丰度以及外来苔藓虫 S. errata 覆盖面积的增加有关. 本地生态系统工程师对 NIS 的快速替代表明与 Tubastraea spp 扩张相关的入侵崩溃迹象。太阳珊瑚覆盖范围的扩大并未显着影响底栖群落的丰富度，但与本土苔藓虫 Amathia brasiliensis 的减少、移动甲壳类动物的总体丰度以及外来苔藓虫 S. errata 覆盖面积的增加有关. 本地生态系统工程师对 NIS 的快速替代表明与 Tubastraea spp 扩张相关的入侵崩溃迹象。