Impacts of microplastics on growth and health of hermatypic corals are species-specific

• Published in: Environmental pollution (1987) Vol. 254; no. Pt B; p. 113074
• Main Authors: Reichert, Jessica, Arnold, Angelina L., Hoogenboom, Mia O., Schubert, Patrick, Wilke, Thomas
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01-11-2019
• Subjects: Long-term exposure; Microcosm; Microplastic; Photosynthesis; Polyethylene; Reef-building corals; Long-term exposure; Polyethylene; Microplastic; Reef-building corals; Photosynthesis; Microcosm
• ISSN: 0269-7491; 1873-6424
• DOI: 10.1016/j.envpol.2019.113074

Coral reefs are increasingly affected by the consequences of global change such as increasing temperatures or pollution. Lately, microplastics (i.e., fragments < 5 mm) have been identified as another potential threat. While previous studies have assessed short-term effects caused by high concentrations of microplastics, nothing is known about the long-term effects of microplastics under realistic concentrations. Therefore, a microcosm study was conducted and corals of the genera Acropora, Pocillopora, Porites, and Heliopora were exposed to microplastics in a concentration of 200 particles L−1, relating to predicted pollution levels. Coral growth and health, as well as symbiont properties were studied over a period of six months. The exposure caused species-specific effects on coral growth and photosynthetic performance. Signs of compromised health were observed for Acropora and Pocillopora, those taxa that frequently interact with the particles. The results indicate elevated energy demands in the affected species, likely due to physical contact of the corals to the microplastics. The study shows that microplastic pollution can have negative impacts on hermatypic corals. These effects might amplify corals' susceptibility to other stressors, further contributing to community shifts in coral reef assemblages.
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•Microplastics had species-specific impacts on tropical reef-building corals.•Microplastics can cause reduced growth, health, and alter photosynthetic performance.•Density and chlorophyll contents of photosymbionts were not affected by microplastics.•Species-specific effects might promote community shifts in coral reefs.
Microplastics have species-specific impacts on tropical reef-building corals, potentially promoting community shifts in coral reefs.