Millimeter-Sized Marine Plastics: A New Pelagic Habitat for Microorganisms and Invertebrates

Abstract

Millimeter-sized plastics are abundant in most marine surface waters, and known to carry fouling organisms that potentially play key roles in the fate and ecological impacts of plastic pollution. In this study we used scanning electron microscopy to characterize biodiversity of organisms on the surface of 68 small floating plastics (length range = 1.7–24.3 mm, median = 3.2 mm) from Australia-wide coastal and oceanic, tropical to temperate sample collections. Diatoms were the most diverse group of plastic colonizers, represented by 14 genera. We also recorded ‘epiplastic’ coccolithophores (7 genera), bryozoans, barnacles (Lepas spp.), a dinoflagellate (Ceratium), an isopod (Asellota), a marine worm, marine insect eggs (Halobates sp.), as well as rounded, elongated, and spiral cells putatively identified as bacteria, cyanobacteria, and fungi. Furthermore, we observed a variety of plastic surface microtextures, including pits and grooves conforming to the shape of microorganisms, suggesting that biota may play an important role in plastic degradation. This study highlights how anthropogenic millimeter-sized polymers have created a new pelagic habitat for microorganisms and invertebrates. The ecological ramifications of this phenomenon for marine organism dispersal, ocean productivity, and biotransfer of plastic-associated pollutants, remains to be elucidated.

Dangerous hitchhikers? Evidence for potentially pathogenic Vibrio spp. on microplastic particles

“…Recently the microbial community on marine plastics was targeted in several studies, highlighting the composition and diversity of plastic-attached microorganisms (Carson et al, 2013;Zettler et al, 2013;Oberbeckmann et al, 2014;Reisser et al, 2014;Amaral-Zettler et al, 2015;De Tender et al, 2015). Within the microbial community on the "Plastisphere" (Zettler et al, 2013) sequences related to the genus Vibrio, a group of bacteria also containing serious pathogens, were found (De Tender et al, 2015;Zettler et al, 2013).…”

Microfouling communities from pelagic and benthic marine plastic debris sampled across Mediterranean coastal waters

“…Once on the seabed, the process of colonization continues (Fortuño et al 2010, Demestre and Masó 2012, Sánchez et al 2013. Not only macroplastics but also microplastics are subject to microfouling (Reisser et al, 2014). During the SPURS-MIDAS (March-April 2013) oceanographic cruise in the North Atlantic subtropical gyre (Font et al 2014), neuston samples were collected in order to capture microplastics and see the degree of colonization by microorganisms.…”

“…Three recent papers address for the first time the characterization by SEM of the microfouling community on floating microplastics collected in three different areas: the North Atlantic (Zettler et al 2013), water around Australia (Reisser et al 2014) and the North Pacific Gyre (Carson et al 2013).…”

The vertical distribution of buoyant plastics at sea: an observational study in the North Atlantic Gyre

“…Their widespread occurrence at the sea surface may be shifting the distribution and abundance of marine populations due to (1) enhanced ocean drift opportunities and (2) damaging effects on biota and habitats. Plastics harbour organisms -such as fouling microorganisms, invertebrates, and fish -that can widely disperse via this new type of habitat, potentially entering non-native waters (Winston et al, 1997;Barnes, 2002;Thiel and Gutow, 2005;Zettler et al, 2013;Reisser et al, 2014). Plastic objects can also entangle or be ingested/inhaled by marine animals, leading to impacts such as starvation, death, and hepatic stress (Derraik, 2002;Browne et al, 2008;Gregory, 2009;Rochman et al, 2013;Watts et al, 2014).…”