Pollution of marine environments with microplastic particles (i.e. plastic fragments <5 mm) has increased rapidly during the last decades. As these particles are mainly of terrestrial origin, coastal ecosystems such as coral reefs are particularly threatened. Recent studies revealed that microplastic ingestion can have adverse effects on marine invertebrates. However, little is known about its effects on small-polyp stony corals that are the main framework builders in coral reefs. The goal of this study is to characterise how different coral species I) respond to microplastic particles and whether the exposure might II) lead to health effects. Therefore, six small-polyp stony coral species belonging to the genera Acropora, Pocillopora, and Porites were exposed to microplastics (polyethylene, size 37–163 μm, concentration ca. 4000 particles L⁻¹) over four weeks, and responses and effects on health were documented.

The study showed that the corals responded differentially to microplastics. Cleaning mechanisms (direct interaction, mucus production) but also feeding interactions (i.e. interaction with mesenterial filaments, ingestion, and egestion) were observed. Additionally, passive contact through overgrowth was documented. In five of the six studied species, negative effects on health (i.e. bleaching and tissue necrosis) were reported.

We here provide preliminary knowledge about coral-microplastic-interactions. The results call for further investigations of the effects of realistic microplastic concentrations on growth, reproduction, and survival of stony corals. This might lead to a better understanding of resilience capacities in coral reef ecosystems.

在过去的几十年中，微塑料颗粒（即小于5毫米的塑料碎片）对海洋环境的污染迅速增加。由于这些颗粒主要来自陆地，因此沿海生态系统（例如珊瑚礁）尤其受到威胁。最近的研究表明，摄入微塑料可能会对海洋无脊椎动物产生不利影响。然而，人们对它对珊瑚礁主要骨架建造者小息肉石质珊瑚的影响知之甚少。这项研究的目的是表征不同的珊瑚物种I）对微塑料颗粒的反应以及暴露是否可能II）导致健康影响。因此，六属于属小息肉石珊瑚品种鹿角，鹿角和滨在四个星期内暴露于微塑料（聚乙烯，尺寸37–163μm，浓度约4000颗粒L ^-1），并记录了其响应和对健康的影响。

研究表明，珊瑚对微塑料的反应不同。观察到清洁机制（直接相互作用，粘液产生）以及进食相互作用（即与肠系膜细丝的相互作用，摄食和排泄）。此外，记录了通过过度生长进行的被动接触。在所研究的六个物种中，有五个对健康产生了负面影响（即漂白和组织坏死）。

我们在这里提供有关珊瑚-微塑料相互作用的初步知识。研究结果要求进一步研究实际的微生物含量对石质珊瑚生长，繁殖和生存的影响。这可能会导致人们更好地了解珊瑚礁生态系统的复原力。