Microplastic Pollution in Deep-Sea Sediments From the Great Australian Bight

Abstract

Interest in understanding the extent of plastic and specifically microplastic pollution has increased on a global scale. However, we still know relatively little about how much plastic pollution has found its way into the deeper areas of the world's oceans. The extent of microplastic pollution in deep-sea sediments remains poorly quantified, but this knowledge is imperative for predicting the distribution and potential impacts of global plastic pollution. To address this knowledge gap, we quantified microplastics in deepsea sediments from the Great Australian Bight using an adapted density separation and dye fluorescence technique. We analyzed sediment cores from six locations (1-6 cores each, n = 16 total samples) ranging in depth from 1,655 to 3,062 m and offshore distances ranging from 288 to 356 km from the Australian coastline. Microplastic counts ranged from 0 to 13.6 fragments per g dry sediment (mean 1.26 ± 0.68; n = 51). We found substantially higher microplastic counts than recorded in other analyses of deepsea sediments. Overall, the number of microplastic fragments in the sediment increased as surface plastic counts increased, and as the seafloor slope angle increased. However, microplastic counts were highly variable, with heterogeneity between sediment cores from the same location greater than the variation across sampling sites. Based on our empirical data, we conservatively estimate 14 million tonnes of microplastic reside on the ocean floor.

Ingestion and Depuration of Microplastics by a Planktivorous Coral Reef Fish, Pomacentrus amboinensis

“…This suggests that microplastic ingestion, and potential effects on planktivorous fish like P. amboinensis, are strongly influenced by the amount of microplastics present in their environment (Ding et al, 2018;Roch et al, 2020). Thus, higher risk of biological contamination and subsequent effects are likely associated with environments that are more contaminated (Everaert et al, 2020), such as accumulation zones [e.g., gyres (Eriksen et al, 2013) and benthic habitats (Ogata et al, 2009;Barrett et al, 2020)], as well as areas adjacent to highly populated regions or areas of industrial and commercial fishery (Xue et al, 2020) interest. Similarly, our findings are consistent with predictions that microplastic body burdens will increase in marine fish along with projected increases in marine microplastic contamination (Jambeck et al, 2015;Geyer et al, 2017;Everaert et al, 2020), driven by the estimated 400% rise in annual plastic production by 2100 (Everaert et al, 2020).…”

The Effect of Wastewater Treatment Plants on Retainment of Plastic Microparticles to Enhance Water Quality—A Review

“…Plastic particles, even initially positively buoyant particles [58] [59], can sink through the water column to the ocean floor [60], where it is generally accepted that the ocean floor serves as a sink for marine plastic [61] [62]. There could be as many as 35 times more MP on the ocean floor than on the ocean's surface, amounting to 4.4 million tons of MP in the top 9 cm of sediment throughout the world's oceans [63]. Between 1.15 and 2.41 million tons of plastic waste enter the oceans every year from rivers [64], with an estimated 4.8 to 12.7 million tons of plastic waste entering the oceans from land via all methods of transport, as of 2010 [65].…”

Analysis of plastic waste reduction and recycling in Taiwan

“…In recent years, several studies have shown the impact of plastic microbeads on aquatic and marine environments (Barrett et al, 2020; Ng et al, 2018; Reimonn et al, 2019; Sharma and Chatterjee, 2017; Yu et al, 2018). These tiny materials, which are commonly made of PE, PP or polystyrene (PS), are used as special additives in the cosmetics and personal care products like facial cleansers.…”