The introduction and successful expansion of tropical species into temperate systems is being exacerbated by climate change, and it is particularly important to identify the impacts that those species may have, especially when habitat-forming species are involved. Seagrass meadows are key shallow coastal habitats that provide critical ecosystem services worldwide, and they are threatened by the arrival of non-native macroalgae. Here, we examined the effects of Halimeda incrassata, a tropical alga that has recently colonized the Mediterranean Sea, on epifaunal assemblages associated with Cymodocea nodosa seagrass meadows of Mallorca Island (Western Mediterranean Sea). This invasive macroalga is an ecological engineer and thus has a high potential of modifying native habitats. A seagrass meadow colonized by H. incrassata exhibited important changes on associated epifaunal assemblages, with an increase in abundance and diversity, particularly driven by higher abundances of Gammaridae, Polychaeta, Copepoda and Caprellidae. Given the key ecological contribution of epifauna to food webs, these alterations will likely have important implications for overall food web structure and ecosystem functioning of native ecosystems.

气候变化加剧了热带物种向温带系统的引入和成功扩张，确定这些物种可能产生的影响尤为重要，尤其是在涉及形成栖息地的物种时。海草草甸是重要的浅海栖息地，在全球范围内提供重要的生态系统服务，它们受到非本地大型藻类的威胁。在这里，我们检查了大头鱼，一种最近在地中海殖民的热带藻类，在与与结节藻马略卡岛（西地中海）的海草草地。这种侵入性大型藻类是一种生态工程师，因此具有改变原生栖息地的巨大潜力。被殖民的海草草地H. incrassata在相关的动物群落中表现出重要的变化，随着丰度和多样性的增加，特别是受到更高丰度的 Gammaridae、Polychaeta、桡足类和 Caprellidae 的驱动。鉴于表皮动物对食物网的关键生态贡献，这些变化可能会对原生生态系统的整体食物网结构和生态系统功能产生重要影响。