Finding the missing piece of the aquatic plastic pollution puzzle: Interaction between primary producers and microplastics

Abstract

Mounting evidence of global plastic pollution has prompted many studies of its potential effects on aquatic ecosystems. In particular, most research has focused on organismal responses to microplastics and the effects of microplastics when introduced as food. However, there has been far less research into the possible effects of microplastics on primary producers. In this review, we document the available evidence for possible effects from the literature and from a laboratory experiment using cyanobacteria and microplastic fragments. Our review shows that primary producer-microplastic interactions can alter algal photosynthesis, growth, gene expression, and colony size and morphology, possibly via adhesion and/or transfer of adsorbed pollutants from microplastics; and, these effects could be transferred up the food web, including to humans. We recommend that the effects of microplastics on primary producers be incorporated into microplastic research to better understand its full effects on freshwater and marine ecosystems. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made. Scientific Significance StatementA significant amount of plastic waste enters rivers, lakes, and oceans, where larger pieces eventually break down into smaller pieces called microplastics. Many researchers have investigated how these microplastics can be ingested by invertebrate and vertebrate animals and can lead to negative consequences for organisms and food webs. However, there is only a limited amount of research on how microplastics could alter growth patterns of primary producers, including micro-and macro-algae and aquatic plants. In this article, we summarize the available evidence from the literature and an experimental study to show that photosynthetic organisms do interact with microplastics, with measurable changes in their growth. Future research on microplastics should pay closer attention to possible influences of microplastics at the bottom of the aquatic food web. 91Limnology and Oceanography Letters 2, 2017, 91-104

Understanding How Microplastics Affect Marine Biota on the Cellular Level Is Important for Assessing Ecosystem Function: A Review

“…Adsorption was also observed in the colonial green algae Scenedesmus or seaweed Fucus vesiculosus (Bhattacharya et al 2010;Gutow et al 2016). Such results address the significance of primary producers interacting with microplastic (Yokota et al 2017). Green et al (2016) concluded that a reduction of macroalgal biomass can be responsible for the overall primary productivity of a sandy bottom ecosystem.…”

Quantifying ecological risks of aquatic micro- and nanoplastic

“…however, growth inhibition could occur due to adhesion, pollutant transfer or attenuation of light caused by presence of microplastics (Yokota et al, 2017). From these SSDs, a hazardous concentration (HC 5 ) of 1.67 mg/L (R 2 : 0.85, 95% confidence interval (95%CI): 0.086 -32.6 mg/L) was derived for microplastic.…”

Colonisation of plastic pellets (nurdles) by E. coli at public bathing beaches

“…Vibrio spp. are more likely to colonise plastics that already contain a biofilm compared with bare microplastics (Yokota et al, 2017), although whether E. coli similarly prefers to bind to an existing biofilm, or whether they can efficiently bind to uncolonised plastic debris remains unknown. The type of plastic, together with seasonal and spatial factors are important for promoting microbial colonisation of plastics in the open ocean (Kirstein et al, 2018), with evidence that bacteria more readily colonise plastics in low nutrient environments (Amaral-Zettler et al, 2015).…”