Natural history matters: Plastics in estuarine fish and sediments at the mouth of an urban watershed

Abstract

The extent to which small plastics and potentially associated compounds are entering coastal food webs, especially in estuarine systems, is only beginning to be realized. This study examined an estuarine reach at the mouth of urbanized Chollas Creek in San Diego, California to determine: 1) the extent and magnitude of microplastics pollution in estuarine sediments and fish, 2) the extent and magnitude of SVOC contamination in estuarine fish, and 3) whether fish preferentially ingested certain types of microplastics, when compared with the microplastic composition of creekbed sediments. Surface sediments (0-5 cm depth) contained about 10,000 small plastic pieces per m 2 , consisting mostly (90%) of fibers, and hard and soft pieces. Nearly 25% of fish contained small plastics, but prevalence varied with size and between species. Of the 25 types of small plastics found in sediment, fish preferred about 10 types (distinct colors and forms). Several SVOCs, both water soluble and sediment-associated compounds, were found in the two species of fish tested. This study revealed that a species' natural history may influence contamination levels, and warrants further study to better understand the pathways of plastics and associated contaminants into and throughout coastal food webs, and the potential health risks for small and/or low-trophic level organisms.

Distribution patterns of microplastics in subtidal sediments from the Sado river estuary and the Arrábida marine park, Portugal

“…Regarding the representativeness of MPs types, fragments were by far the most abundant one in the estuarine sediments (st1), in agreement with findings from other studies (Vianello et al, 2013;Talley et al, 2020;Haddout et al, 2021;Liong et al, 2021). Conversely, fibers were less abundant, but consistently spread throughout the six stations.…”

Evidence of microplastics in water and commercial fish from a high-altitude mountain lake (Lake Titicaca)

“…It has frequently been suggested that fish living in freshwater environments near urbanized regions have a higher risk of microplastic ingestion, and a direct relationship with the level of urbanization has been observed ( Silva-Cavalcanti et al, 2017 ; Souza, Corrêa & Smith, 2020 ; Galafassi et al, 2021 ). However, several studies present evidence that higher environmental concentrations of microplastics do not necessarily translate into higher ingestion by aquatic biota ( McNeish et al, 2018 ; Talley, Venuti & Whelan, 2020 ; Sembiring et al, 2020 ). Such is the case for our results because the microplastic numbers in the water were higher than in the stomachs.…”

“…Such is the case for our results because the microplastic numbers in the water were higher than in the stomachs. Life history may thus have an even more significant influence on the level of microplastic ingestion ( Talley, Venuti & Whelan, 2020 ). It is important to highlight here that more research is needed to obtain further information on microplastic ingestion by fish in Lake Titicaca.…”

Prevalence of microplastics, antibiotic resistant genes and microplastic associated biofilms in estuary - A review

“…The important sources of plastic pollution are agricultural mulching [59], sewage sludge disposal [60], wastewater treatment plants [61], informal landfills [62], and biowaste compost [63]. MPs are found in a variety of terrestrial environments, including home and garden soils [64], flood plain soils [65], remote high mountain soils [66], and industrial soils [67], as well as surface and deep ocean waters [68], lakes [69,70], mangroves [71], shorelines [72], and estuaries [73][74][75]. The studies conducted to examine the distribution of different sizes, forms, and types of MPs in estuaries across the world are presented in Table 1.…”