Microplastic pollution in a rapidly changing world: Implications for remote and vulnerable marine ecosystems

Alice A Horton,David K.A Barnes

doi:10.1016/j.scitotenv.2020.140349

Alice A Horton, David K.A Barnes

Open Access

https://doi.org/10.1016/j.scitotenv.2020.140349

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Abstract

Ecosystems in remote regions tend to be highly specific, having historically evolved over long timescales in relatively constant environmental conditions, with little human influence. Such regions are amongst those most physically altering and biologically threatened by global climate change. In addition, they are increasingly receiving anthropogenic pollution. Microplastic pollution has now been found in these most remote places on earth, far from most human activities. Microplastics can induce complex and wide-ranging physical and chemical effects but little to date is known of their long-term biological impacts. In combination with climate-induced stress, microplastics may lead to enhanced multi-stress impacts, potentially affecting the health and resilience of species and ecosystems. While species in historically populated areas have had some opportunity to adapt to mounting human influence over centuries and millennia, the relatively rapid intensification of widespread anthropogenic activities in recent decades has provided species in previously ‘untouched’ regions little such opportunities. The characteristics of remote ecosystems and the species therein suggest that they could be more sensitive to the combined effects of microplastic pollution, global physical change and other stressors than elsewhere. Here we discuss how species and ecosystems within two remote yet contrasting regions, coastal Antarctica and the deep sea, might be especially vulnerable to harm from microplastic pollution in the context of a rapidly changing environment.

Highlights

Plastic waste has become a highly abundant and growing problem across global environments, as a result of increasing plastic manufacture, A.A
Since the early 1970s we have been aware of the presence of microplastics within the environment (Buchanan, 1971; Carpenter and Smith, 1972)
Plastic pollution is most evident near urban centres, there is growing evidence of microplastics reaching remote and so called ‘pristine’ environments, including polar sea ice and snow, deep sea sediments and remote alpine regions (Allen et al, 2019; Bergmann et al, 2019; Peeken et al, 2018; Van Cauwenberghe et al, 2013)

Summary

Introduction

Plastic waste has become a highly abundant and growing problem across global environments, as a result of increasing plastic manufacture, A.A. Plastics can act as a vector for organism transport, which could introduce non-native species and disease (Kirstein et al, 2016; Reisser et al, 2014) Despite these potential effects it is important to note that, with a few exceptions (Gray and Weinstein, 2017; Jemec et al, 2016), the majority of laboratory studies have not found microplastics to be inherently toxic with acute exposure. Biome-specific and range-restricted species are the least likely to be able to adapt or migrate in the face of external environmental pressures (Malcolm et al, 2006) Within diverse communities, it is often the rare and geographically restricted species which are key to supporting ecosystem function and processes. In comparison to the growing research efforts on microplastics in other environments, these regions have received little attention to date with respect to microplastic contamination (Fig. 1)

Coastal Antarctica and Southern Ocean Islands

Deep sea

Microplastics contribute to multi-stress impacts

How to assess change?

Findings

Long-term implications and outlook