Bleaching and necrosis of staghorn coral (Acropora formosa) in laboratory assays: Immediate impact of LDPE microplastics

Abstract

The impact of low-density polyethylene (LDPE) microplastics (<100 mm; P100-A P100-B, P100-C, 100 e200 mm; P200, 200e500 mm; P500) on Acropora formosa was investigated. This study investigated the bleaching and necrosis extent of A. formosa caused by LDPE contamination via laboratory assay. The staghorn coral ingested the microplastics, resulting in bleaching and necrosis that concomitantly occurred with the release of zooxanthellae. P100-A experimentation was the worst case, showing bleaching by day 2 (10.8 ± 2.2%) and continued bleaching to 93.6% ± 2.0 by day 14 followed by 5.9 ± 2.5% necrosis. The overall results confirmed that the LDPE concentration impacts coral health. We highlighted that microplastics have been ingested and partially egested. Their presence showed either a direct or indirect impact on coral polyps via direct interaction or through photosynthesis perturbation due to microplastics that cover the coral surface.

Scleractinian corals incorporate microplastic particles: identification from a laboratory study

“…This behaviour is thought by Allen et al (2017) to have been triggered by the chemical composition of the microplastic particles. Uptake subsequently led to gut blockage and false satiation, a depletion of energy levels and ultimately to death in the form of bleaching (Wright et al 2013;Watts et al 2015;Hall et al 2015;Biquand et al 2017;Allen et al 2017;Okubo et al 2018;Hankins et al 2018;Rotjan et al 2019;Syakti et al 2019). A recent study revealed that ingested plastic microspheres were incorporated into the cells of the mesenterial filaments of specimens of the anthozoan genus Exaiptasia after entering the gastrovascular cavity, while migration into the tissue interface is thought to depend on particle size (Okubo et al 2020).…”

Interactive effects of microplastic pollution and heat stress on reef-building corals

“…Microplastic occurs in various shapes (most often in form of particles and fibers), polymer types (most commonly polyethylene and polypropylene) and highly variable concentrations spanning eight orders of magnitude from less than 0.0001 particles per L (Jensen et al, 2019) to more than 10,000 particles per L (Badylak et al, 2021). The effect of microplastic on corals ranges from low and moderate (Chapron et al, 2018;Mouchi et al, 2019;Reichert et al, 2019) to severe (Syakti et al, 2019;Tang et al, 2018) depending on the experimental approach and particle dose used. Corals actively ingest (Allen et al, 2017;Hall et al, 2015;Reichert et al, 2019) or passively catch particles by adherence (Corona et al, 2020;Martin et al, 2019).…”

Effects of Microplastics Exposure on the Acropora sp. Antioxidant, Immunization and Energy Metabolism Enzyme Activities

“…MPs negatively affect the photosynthesis activity of coral endosymbiontic microorganisms through reducing chlorophyll content and photochemical efficiency (Mao et al, 2018;Wu et al, 2019). Many studies to date have found that MPs could accumulate in an organism and cause endocrine disruption (Chapron et al, 2018;Syakti et al, 2019). It has been revealed that the reactive oxygen species (ROS) and antioxidant enzymes (SOD, CAT, and GSH) of coral are up-regulated after exposure to MPs (Chen et al, 2017;Tang et al, 2018;Dias et al, 2019).…”