Multiple impacts of microplastics can threaten marine habitat-forming species

Abstract

Microplastics are recognised as a potential global threat to marine ecosystems, but the biological mechanisms determining their impact on marine life are still largely unknown. Here, we investigated the effects of microplastics on the red coral, a long-lived habitat-forming organism belonging to the Corallium genus, which is present at almost all latitudes from shallow-water to deep-sea habitats. When exposed to microplastics, corals preferentially ingest polypropylene, with multiple biological effects, from feeding impairment to mucus production and altered gene expression. Microplastics can alter the coral microbiome directly and indirectly by causing tissue abrasions that allow the proliferation of opportunistic bacteria. These multiple effects suggest that microplastics at the concentrations present in some marine areas and predicted for most oceans in the coming decades, can ultimately cause coral death. Other habitat-forming suspension-feeding species are likely subjected to similar impacts, which may act synergistically with climate-driven events primarily responsible for mass mortalities.

Physisorption and Chemisorption Mechanisms Influencing Micro (Nano) Plastics-Organic Chemical Contaminants Interactions: A Review

“…The adverse effects of microplastics on fishes and large aquatic animals, zooplankton, phytoplankton, microalgae, crustaceans, and seabirds have been widely reported (Boerger et al, 2010;Kögel et al, 2019;Ma et al, 2020;Corinaldesi et al, 2021;Wang et al, 2021), at the population levels (e.g., fertility, mortality, growth and organismal development, feeding activity) (Zarfl et al, 2011;Sussarellu et al, 2016;Heindler et al, 2017;Mouchi et al, 2019;Chapron et al, 2020;Liu G. et al, 2020;Issac and Kandasubramanian, 2021), cellular (e.g., motility; cell fragmentation, membrane stability, apoptosis) (Von Moos et al, 2012;Han et al, 2020;Tallec et al, 2020), and molecular levels (e.g., mortality, gene expression, stress defense, and oxidative stress effects) (Balbi et al, 2017;Liu Z et al, 2018;Yu et al, 2018;Sendra et al, 2020;Capolupo et al, 2021). Corals readily ingest polypropylene microplastics upon exposure to plastic particles, resulting in a variety of biological implications ranging from feeding dysfunction to mucus formation and distorted gene expression (Corinaldesi et al, 2021). These multiple effects mean that microplastics, at the concentrations seen in some marine areas and expected for most oceans in the coming decades, could lead to the death and eventual extinction of corals.…”

Micro-Nano Plastic in the Aquatic Environment: Methodological Problems and Challenges

“…Experimental results have demonstrated the accumulation of 0.25 µm NPs in the intestine of Pecten maximus after 6 h of ingestion, and 24 nm NP in the whole body, indicating possible translocation across epithelial membranes [222]; however, the authors were cautious in confirming such claims. With the growing evidence of the MP and NP presence in the digestive system, liver and gills [62,64,197,202,[223][224][225][226][227][228][229][230][231][232], it is postulated that their presence may affect the physiological functioning of the organism, with more evidence coming on ubiquitous presence of MPs [233][234][235][236]. However, no conclusive proof exists on the extent to which the MPs-NPs affect different marine organisms, and much of the evidence emanates from laboratory exposure experiments that show impacts on feeding, oxidative stress, inflammations, and compromised reproductive capacities [237].…”

Microplastics: impacts on corals and other reef organisms

“…Where plastisphere communities differ from the those on natural surfaces, there is a potential that the presence of plastics may disrupt the microbially driven processes that occur. These may including, for example, disruption of biogeochemical processes [165][166][167], the dysbiosis of an organism's microbiome [102,103] or altered pathogen exposure [105,107,168,169]. The plastisphere may also play host to the early life stages of non-indigenous species (NIS) [170].…”

“…Larger plastic debris has been implicated in disease transmission and physical trauma resulting in susceptibility [ 100 , 101 ]. It is plausible that MPs also pose a threat, either through pathogen transmission, tissue damage or alteration of the coral microbiome [ 102 , 103 ], resulting in reduced fitness and susceptibility to disease. This includes the skeletal microbiome which is thought to play a critical role in the health of the colony [ 102 , 104 ].…”

“…Studies examining the ingestion and effects of MNPs on other anthozoa had similar results to those seen in scleractinia [ 44 , 103 , 122 ] but there needs to be more research done before we fully understand the impacts, including using environmentally relevant MNP types and concentrations and exposure periods. Being able to achieve this is reliant upon the development of internationally agreed standard methods which are able to accurately determine the levels and characteristics (e.g.…”