Macrofouling communities and the degradation of plastic bags in the sea: anin situexperiment

Abstract

The increasing amount of plastic littered into the sea may provide a new substratum for benthic organisms. These marine fouling communities on plastic have not received much scientific attention. We present, to our knowledge, the first comprehensive analysis of their macroscopic community composition, their primary production and the polymer degradation comparing conventional polyethylene (PE) and a biodegradable starch-based plastic blend in coastal benthic and pelagic habitats in the Mediterranean Sea. The biomass of the fouling layer increased significantly over time and all samples became heavy enough to sink to the seafloor. The fouling communities, consisting of 21 families, were distinct between habitats, but not between polymer types. Positive primary production was measured in the pelagic, but not in the benthic habitat, suggesting that large accumulations of floating plastic could pose a source of oxygen for local ecosystems, as well as a carbon sink. Contrary to PE, the biodegradable plastic showed a significant loss of tensile strength and disintegrated over time in both habitats. These results indicate that in the marine environment, biodegradable polymers may disintegrate at higher rates than conventional polymers. This should be considered for the development of new materials, environmental risk assessment and waste management strategies.

Degradation of plastics and plastic-degrading bacteria in cold marine habitats

“…Slow degradation of large plastic fragments and generation of microplastic is caused by UV radiation and mechanical forces and is a facilitating factor in the transfer of plastic over long distances (Thevenon et al 2014 ). Depending on its density, plastic accumulates in the water column of central convergence zones and floats at the surface (Cózar et al 2014 ; Pauli et al 2017 ) or sinks to the sea floor after loading with biotic and abiotic dissolved compounds (Bergmann and Klages 2012 ; Derraik 2002 ). At the same time, there occurs settlement of the biomass on floating plastic, which is called biofouling (van Sebille et al 2016 ) (Fig.…”

“…Therefore, sunken or floating plastic wastes are not free of the influence of microorganisms. Despite the fact that microorganisms can colonize all plastic that is introduced to the marine environment (De Tender et al 2015 ; Eich et al 2015 ; Pauli et al 2017 ; Rummel et al 2017 ), a limited number of studies have been conducted on the interactions between plastic and marine microbiota (Bryant et al 2016 ; Harrison et al 2011 ). Unfortunately, the precise mechanisms of the bacterial attachment on the plastic surface are poorly known.…”

The Levels of Plastic-associated Heterotrophic Bacteria on Three Different Types of Plastics

“…The initiation of this mechanism, which is formed by microorganisms, which develops in all kinds of materials, and which is defined as "biofouling", is the attachment of gram negative bacteria to the environment, and then diatoms, protozoa and invertabrates are added to this structure. The long-term permanence of plastics in the marine ecosystem and the transport of bacteria and other microorganisms due to currents causes them to reach different marine areas as invasive species (Zettler et al, 2013;Pauli et a., 2017;Gündoğdu et al, 2017;Hodgson et al, 2018;Rech et al, 2018). These structures formed on plastics increase the weight of micro-macroplastics, and cause them to be transported from surface to bottom in aquatic ecosystems (Kaiser et al 2017;Kooi et al, 2017).…”

Urbanization and Waterborne Pathogen Emergence in Low-Income Countries: Where and How to Conduct Surveys?

“…During these travels, they will be degraded and fragmented, creating micro-and nanoparticles. The impacts of the degradation of plastic debris on biodiversity are still poorly known [93][94][95], but plastics can be easily colonized by microorganisms and biofilms [96,97]. They can play a major role in the transfer of organisms from one place to another [98][99][100][101][102][103].…”