Biomagnification of persistent organic pollutants from diets and microplastics to a seabird species (Sula sula)

The present study quantified plastic abundance in beach sand from the Xisha Islands and measured associated persistent organic pollutant (POP) concentrations. Sand contained moderate microplastic abundance (576 particles/kg) dominated by polypropylene (PP) fragments enriched with decabromodiphenyl ether (BDE 209) and decabromodiphenyl ethane (DBDPE). Red-footed boobies (Sula sula) and two prey species-Japanese scads (Decapterus maruadsi) and squids (Ommastrephidae) were also collected to quantify POP biomagnification. Polychlorinated biphenyls (PCBs) and Dichlorodiphenyltrichloroethane (DDTs) were the dominant POPs within the local food web. BDE 209 and DBDPE demonstrated unexpected biomagnification potential, and trophic-transfer analysis further suggested the existence of non-trophic exposure for these compounds. Congener-profile similarity further supported a plastic-linked, non-trophic exposure pathway. Approximately 2.6 g of POPs were estimated to be deposited annually via guano.