Microplastic pollution presents an emerging stressor of concern to coral reef ecosystems. The physical impact of corals ingesting microplastics has been well studied, but the chemical threat that microplastics may pose to these organisms has been understudied. The effect that microplastic-associated chemicals may have on coral reef health and reproduction has been unexplored. Therefore, the goal of this study was to determine if a difference exists between the effects of microplastics themselves and their associated chemicals on Montipora capitata fertilization rates. For this, gametes were exposed to either 4 types of 5 mm microplastic spheres (nylon, polypropylene, high-density polyethylene, or low-density polyethylene) at one of three concentrations (50, 100 or 200 particles per/L) or leachates from these same microplastics. The results showed that gamete fertilization was not impacted by plastic particles themselves, but leachates from these plastic particles heavily reduced fertilization rates for Montipora capitata. These findings are the first to show that microplastic-associated chemicals are an important stressor affecting coral reproduction. Thus, microplastic pollution might pose a threat to coral replenishment and persistence on coral reef ecosystems.

Primary Presenter: Keiko Wilkins, University of Hawaii at Manoa (keikow2@hawaii.edu)

Authors:

Robert Richmond, University of Hawaii at Manoa  (richmond@hawaii.edu)

Keiko Wilkins, University of Hawaii at Manoa  (keikow2@hawaii.edu)