Tracking Dietary Sources of Short- and Medium-Chain Chlorinated Paraffins in Marine Mammals through a Subtropical Marine Food Web

Abstract

Our previous study revealed an elevated accumulation of short-chain chlorinated paraffins (SCCPs) and medium-chain chlorinated paraffins (MCCPs) in marine mammals from Hong Kong waters in the South China Sea. To examine the bioaccumulation potential and biomagnification in these apex predators, we sampled the dietary items of marine mammals and tracked the sources of SCCPs and MCCPs through a marine food web in this region. Sixteen fish species, seven crustacean species, and four mollusk species were collected, and the main prey species were identified for two species of marine mammals. Concentrations of ∑SCCPs and ∑MCCPs in these collected species suggested a moderate pollution level in Hong Kong waters compared to the global range. Lipid content was found to mediate congener-specific bioaccumulation in these marine species. Significantly positive correlations were observed between trophic levels and concentrations of ∑SCCPs or ∑MCCPs (p < 0.05). Trophic magnification factors for ∑SCCPs and ∑MCCPs were 4.29 and 4.79, indicating that both of them have trophic magnification potentials. Elevated biomagnification of SCCPs and MCCPs from prey species to marine mammals was observed. This is the first report of dietary source tracking of SCCPs and MCCPs in marine mammals. The elevated biomagnification between prey and marine mammals raises environmental concerns about these contaminants.

Environmental Risks of Medium-Chain Chlorinated Paraffins (MCCPs): A Review

“…Field-derived BMFs for MCCPs were reported by Houde et al11 and Zeng et al56 BMFs reported by Houde et al11 were generally below one. Field-derived BMFs reported by Zeng et al56 were above one but questionable (TableS9, SI).TMF No bioaccumulation of MCCPs was found in the food webs studied by Houde et al11 , NIVA57,58,59 and Huang et al60 Miljodirektoratet 61 and Zeng et al56 otherwise, calculated trophic magnification factors above one, which would indicate an increase in the chemical concentration in the biota with increasing trophical level. However, the TMFs in both studies were derived from concentrations in different tissues and are therefore questionable.…”

Status of short-chain chlorinated paraffins in matrices and research gap priorities in Africa: a review

“…SCCP concentration in fish samples from Zhubi Reef and Yongshu Reef ranged from 37.9 to 20.200 ng/g lipid weight (lw) and 75.7-25.400 ng g −1 lw, with ∑SCCP concentration of 3700 ± 6000 ng g −1 lw and 5200 ± 7340 ng g −1 lw, respectively. Different studies have shown that the lipid content is a crucial factor affecting SCCP bioaccumulation in marine environment (Yuan et al 2012;Ma et al 2014b;Zeng et al 2017a). In contrast, the obtained results were different from those of Pearl River Estuary, where lipid level was not the predominant influencing factor for SCCP concentration in marine organism (Huang et al 2019).…”

“…According to Houde et al (2008), SCCPs released during production and use have entered water bodies and have been transferred to sediment and aquatic organisms resulting in bioaccumulation through the food chain. Globally, bioaccumulation and trophic magnification of SCCPs have been studied (Houde et al 2008;Li et al 2017a;Ma et al 2014b;Sun et al 2017;Zeng et al 2017a). In the aquatic environment, SCCPs are more likely to be adsorbed in sediment since they have low water solubility and high carbon partition coefficients (Environment Canada 2008).…”

Measurable Levels of Short‐Chain Chlorinated Paraffins in Western Hudson Bay Fishes but Limited Biomagnification from Fish to Ringed Seals

“…Higher δ 15 N values in Greenland cod could explain the higher concentrations of these particular SCCPs compared to most other species. Although a previous study in lake trout from the Great Lakes also did not find any correlations between SCCP levels and fish length, weight, age, lipid content, or trophic level (Saborido Basconcillo et al, 2015), recent studies found biomagnification of SCCPs in fish in Liaodong Bay, in a marine food web in the South China Sea, and from oysters to crabs in the Pearl River estuary in China (Huang et al, 2017, 2019; Zeng et al, 2017), as well as biomagnification potential in a food web of the Baltic Sea (de Wit et al, 2020).…”