Impacts of Discarded Plastic Bags on Marine Assemblages and Ecosystem Functioning

Abstract

The accumulation of plastic debris is a global environmental problem due to its durability, persistence, and abundance. Although effects of plastic debris on individual marine organisms, particularly mammals and birds, have been extensively documented (e.g., entanglement and choking), very little is known about effects on assemblages and consequences for ecosystem functioning. In Europe, around 40% of the plastic items produced are utilized as single-use packaging, which rapidly accumulate in waste management facilities and as litter in the environment. A range of biodegradable plastics have been developed with the aspiration of reducing the persistence of litter; however, their impacts on marine assemblages or ecosystem functioning have never been evaluated. A field experiment was conducted to assess the impact of conventional and biodegradable plastic carrier bags as litter on benthic macro- and meio-faunal assemblages and biogeochemical processes (primary productivity, redox condition, organic matter content, and pore-water nutrients) on an intertidal shore near Dublin, Ireland. After 9 weeks, the presence of either type of bag created anoxic conditions within the sediment along with reduced primary productivity and organic matter and significantly lower abundances of infaunal invertebrates. This indicates that both conventional and biodegradable bags can rapidly alter marine assemblages and the ecosystem services they provide.

Optimization of an Appropriate Technology Based Process for Converting Waste Plastic in to Liquid Fuel via Thermal Decomposition

“…As these bags float and cover the seabed, research has proven that they are depleting organic matter, reducing the amount of chlorophyll generated by biomass producing organisms and altering physicochemical characteristics associated with nutrient cycling. The same consequences have been reported for compostable or biodegradable bags (Gross, 2013;Green, et al, 2015). Consequently, this alteration in ecosystems is posing a physical barrier to mass and energy exchange across the sediment-water interface, driving the system to a different balance point (Green, et al, 2015).…”

“…This allows the plastic to eventually make its way to the oceans, where 80% of all waste is plastic (Barnes et al, 2016;Green, et al, 2015). An estimated 5.25 trillion pieces of plastic, weighing 270,000 tons have been reported to be present at sea (Joshi and Seay, 2016).…”

“…Additionally, the degradation of plastic is dependent on the amount of UV light reaching the particles and the abundance of oxygen. Therefore, as plastic sinks deeper into the ocean, the time taken to degrade is increased from hundreds to thousands of years (Barnes et al;Gross, 2013;Green, et al, 2015), further augmenting the negative consequences on marine life.…”

“…Most of the plastic that enters the ocean consists of single use items, like low density polyethylene, linear low-density polyethylene and high density polyethylene carrier bags (Barnes et al, 2016;Green, et al;. As these bags float and cover the seabed, research has proven that they are depleting organic matter, reducing the amount of chlorophyll generated by biomass producing organisms and altering physicochemical characteristics associated with nutrient cycling.…”

Micro-and macro-plastics in marine species from Nordic waters

“…For example, ghost fishing negatively impacts marine wildlife (Stelfox et al, 2016) and ALDFG can negatively impact benthic communities. Macroplastics can also lead to anoxic conditions within the sediment (Mordecai et al, 2011;Green et al, 2015) and can thereby affect the benthic community. Plastics can also provide habitats for many species, for example can floating plastic support diverse communities of marine biota including invertebrates and microbial communities (Barnes & Milner, 2005;Kiessling et al, 2015).…”