Microplastic ingestion decreases energy reserves in marine worms

Abstract

The indiscriminate disposal of plastic to the environment is of concern. Microscopic plastic litter (<5 mm diameter; 'microplastic') is increasing in abundance in the marine environment, originating from the fragmentation of plastic items and from industry and personal-care products [1]. On highly impacted beaches, microplastic concentrations (<1mm) can reach 3% by weight, presenting a global conservation issue [2]. Microplastics are a novel substrate for the adherence of hydrophobic contaminants [1], deposition of eggs [3], and colonization by unique bacterial assemblages [4]. Ingestion by indiscriminate deposit-feeders has been reported, yet physical impacts remain understudied [1]. Here, we show that deposit-feeding marine worms maintained in sediments spiked with microscopic unplasticised polyvinylchloride (UPVC) at concentrations overlapping those in the environment had significantly depleted energy reserves by up to 50% (Figure 1). Our results suggest that depleted energy reserves arise from a combination of reduced feeding activity, longer gut residence times of ingested material and inflammation.

Marine microplastics spell big problems for future generations

“…The impacts of plastic ingestion in laboratory studies include gut blockage and physical injury, oxidative stress, altered feeding behavior (7,8), and reduced energy allocation (9), with knock-on effects for growth and reproduction (5). Transfer to tissues of plastics associated with chemicals, many of which possess endocrinedisrupting activity (10), adds to the potential toxicity of ingested particles through activation of signal transduction pathways relevant to hormone action.…”

“…Sediment-dwelling worms exposed to sediments contaminated with PVC microparticles had increased gut transit times and reduced lipid accumulation (8). Similarly, planktonic copepods exposed to micropolystyrene for prolonged periods had reduced food consumption, resulting in reduced reproductive output (9).…”

Microplastics present pollution puzzle

“…In a complementary study from Thompson's laboratory, lugworms raised in sediment containing 5% polyvinyl chloride ate less, showed increased inflammation, and also suffered a 50% drop in energy reserves, as measured by levels of carbohydrates, proteins, and fats in their bodies (18). And ongoing work from Rochman's laboratory found that when a fish called the Japanese medaka (Oryzias latipes) was fed environmentally relevant levels of polyethylene marine debris, it experienced liver stress and signs of endocrine disruption (19).…”

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

“…Furthermore, it has also been found impacts on oyster reproduction after microplastic exposure (Sussarellu et al, 2015). For lugworm, several studies have found effects on their feeding activity after microplastic exposure; exposure to polyvinylchloride (PVC) (Wright et al, 2013) or polystyrene ) that reduced their feeding activity (number of casts produced). This reduction in feeding activity was also found in another laboratory test looking at the biodegradable polylactic acid (PLA) as well as HDPE and PVC.…”

“…Welden & Cowie 2016 Wright et al 2013 Note: * Intended to be used as an example species -Needs to be carefully considered with further research. ** As far as we know.…”