Macro- and microplastics affect cold-water corals growth, feeding and behaviour

Abstract

Plastic contamination is now recognized as one of the most serious environmental issues for oceans. Both macro- and microplastic debris are accumulating in surface and deep waters. However, little is known about their impact on deep marine ecosystems and especially on the deep-sea reefs built by emblematic cold-water corals. The aim of this study was to investigate whether plastics affected the growth, feeding and behaviour of the main engineer species, Lophelia pertusa. Our experiments showed that both micro- and macroplastics significantly reduced skeletal growth rates. Macroplastics induced an increased polyp activity but decreased prey capture rates. They acted as physical barriers for food supply, likely affecting energy acquisition and allocation. Inversely, microplastics did not impact polyp behaviour or prey capture rates, but calcification was still reduced compared to control and in situ conditions. The exact causes are still unclear but they might involve possible physical damages or energy storage alteration. Considering the high local accumulation of macroplastics reported and the widespread distribution of microplastics in the world ocean, our results suggest that plastics may constitute a major threat for reef aggradation by inhibiting coral growth, and thus jeopardise the resilience of cold-water coral reefs and their associated biodiversity.

Long-term aquaria study suggests species-specific responses of two cold-water corals to macro-and microplastics exposure

“…Corals used for this study were selected from L. pertusa and M. oculata colonies collected live from the Lacaze-Duthiers Canyon, in the northwestern Mediterranean Sea (42°32'72"N, 03°25'28"E) at 540 m water depth in July 2012 by the Remotely Operated Vehicle (ROV) Super Achille on the R/V Minibex (COMEX Company). Plastic debris have been observed in this location over the years (Fiala-Medioni et al, 2012;Chapron et al, 2018). Sampled corals were transferred onboard to aerated 30 L seawater tanks maintained at a constant temperature of 13°C using a chiller.…”

“…The experimental design is similar to the one published earlier by Chapron et al (2018). The experiment consisted in three independent semi-closed flumes maintained in the dark at °C ± 0.5 °C in a thermoregulated room (for microplastics, control and macroplastics exposures; Fig.…”

“…The impact of microplastics on health is challenging to assess from in situ observations, although some studies have found evidence of tropical corals being contaminated by toxic plastic chemical additives (such as phthalic acid esters; Saliu et al, 2019). Most studies use aquarium experiments and strong negative impacts have been highlighted in a variety of marine taxa (Sussarellu et al, 2016;Tang et al, 2018) including tropical (Hall et al, 2015;Reichert et al, 2018) and deep-sea corals (Chapron et al, 2018). This body of evidence suggests that microplastics represent an equivalent (if not greater) threat than macroplastics to marine communities.…”

“…Macro-and microplastics have been reported in remote deep-sea coral provinces (La Beur et al, 2019) and macroplastic films have been observed to partially obstruct CWC reefs as they can be trapped in the corallite branches (Angiolillo et al, 2015). In short-term experiments (2.5 months), macroplastics were recently shown to impact the growth and prey capture rates, therefore, effecting colony health and survival of L. pertusa (Chapron et al, 2018). Those results, however, were restricted to one species (i.e., L. pertusa) and no data is available for long-term exposure.…”

Toxicity of Microplastics and Nanoplastics in Mammalian Systems

“…Plastic wastes are persistent environmental pollutants. Larger pieces of plastic wastes present well-publicized ecological problems in terms of physical entanglement and entrapment [3], physical barriers for food supply [4], and digestive tract congestion. The smaller plastic pieces, particularly their miniaturized forms that are less than 5 mm in size, are generally termed microplastics (MPs) [5].…”