Natural and synthetic microfibers alter growth and behavior in early life stages of estuarine organisms

Abstract

Increasing shares of microfibers are being detected in environmental samples and a closer look to identify the risk associated with them using ecologically relevant endpoints, especially at sensitive early life stages, is needed. To assess exposure hazards, we used rope samples representative of fiber types ubiquitous in coastal systems, where microfibers are often the most common debris type found in the water column. To compare responses to natural vs. synthetic microfibers, we used rinsed “natural” cotton, polyester, and polypropylene microfibers (80-150 µm length, 8-20 µm width) created from the rope. Larval and juvenile estuarine indicator species Inland Silverside (Menidia beryllina) and mysid shrimp (Americamysis bahia), respectively, were exposed to these three microfiber types at three concentrations (3, 10, 30 particles/ml) along a 5-25 PSU salinity gradient to mimic estuarine conditions. Behavioral responses, growth, and ingestion were measured. The cotton microfibers were not detected in the digestive tracts of Silversides, however, both the polyester and polypropylene microfibers were detected in the Silversides’ stomach and gut lining. None of the fiber types were detected in mysid shrimps. Mysids exposed to cotton microfibers had fewer behavioral effects compared to Silversides, who responded more to cotton. Cotton exerted no effect on growth in Silversides but did cause reduced growth in the mysids at the two lower salinities. In contrast, polyester and polypropylene were identified to have a significant dose dependent effect on mysid and Silverside behavior as well as growth was affected in at least one of the three salinities at concentrations as low as 3 particles/ml. Cotton impacted both the organism’s behavior more at higher salinities, whereas polyester and polypropylene had more impacts at lower salinities. This raises concerns for microfiber impacts on estuarine ecosystems and the need for policies to limit microfiber production and outfall into the aquatic environment.

Polystyrene Plastic Particles Result in Adverse Outcomes for Hyalella azteca When Exposed at Elevated Temperatures

“…Behavioral studies were conducted using a DanioVision Observation chamber (Wageningen, The Netherlands) and integrated steady flow of water set to treatment temperature via chiller (TECO-US, Terrell, TX, USA). A 35 min LD (Light:Dark) cycle test was performed with alternating light and dark cycles of 5 min, following protocols described in Siddiqui et al [77,78]. After the exposure, HA was pipetted into randomized wells of 24-well plates (Corning Costar, Corning, NY, USA, 24-well Clear, Product Number 3524).…”

“…For correlation analysis, standard endpoints TDM (total distance moved) and thigmotaxis ("wall hugging", avoidance indicator), which describes the ratio of staying in the outer ("hiding") to inner ("boldness") behavior as described before by Segarra et al [51], and velocity were used. The further behavioral endpoints used were defined before [50,77,78].…”

Anthropogenic particle concentrations and fluxes in an urban river are temporally variable and impacted by storm events

“…AP have physical (Duis & Coors, 2016), chemical (Galloway et al, 2017; Rochman et al, 2014), and biological (Karbalaei et al, 2018; McCormick et al, 2014; Naidoo & Glassom, 2019; Siddiqui et al, 2023) impacts on organisms and may cause ecosystem‐wide effects (Galloway et al, 2017; Redondo‐Hasselerharm et al, 2020). AP can contain chemical additives (e.g., plasticizers, dyes, and flame retardants; Goodson et al, 2015; Oehlmann et al, 2009; Viganò et al, 2015) and can adsorb chemicals from the environment (Rochman et al, 2014) which may impact organisms ingesting these particles (Eerkes‐Medrano et al, 2015; Galloway et al, 2017; Katija et al, 2017; Lusher et al, 2013; McNeish et al, 2018).…”

Microfiber emission from a municipal wastewater treatment plant in Hungary

“…Since the toxicological effects of natural and microplastic fibers on aquatic organisms are comparable in a number of ways 13 – 15 , it would be necessary to investigate the emission of microplastic and natural fibers, as well as man-made cellulose fibers into the rivers. Prior to the discussion of natural and microplastic fibers in Athey and Erde’s critical review paper 16 , Ladewig et al 17 highlighted the potential of natural fibers to act as vectors of toxic compounds.…”

“…However, it should be noted that the effect of these fibers depends on a variety of factors, including their size, surface properties, adsorbed contaminants, life cycle, etc. 13 , 15 , 37 .…”