Combined Effect of Salinity and Leachates of Environmental Plastics on the Copepod Nitokra spinipes

PAZOS, ROCÍO S.; NIU, ZHIYUE ; EVERAERT, GERT; CATARINO, ANA

Congreso; SETAC EUROPE 33RD ANNUAL MEETING; 2023

Plastic debris have reached approximately a volume of 8 million tons per year in the oceans and it is necessary to understand the effects on the communities that inhabit them. It is essential to consider that plastic litter comprise not only the polymer that makes them up, but also the various additives that are added during their manufacture and the chemicals that might be sorbed to them from the environment, that are often leached because of their persistence and durability. Coastal areas such as estuaries are transitional zones with natural salinity gradient, that can accumulate plastic litter, and because the release of leachates also depend on such environmental conditions, it is therefore important to assess combined stresses to understand the effects on organisms. The main goal of this study was to analyze the ecotoxicological effect of leachates from environmental and weathered plastics, in two brackish water conditions (two salinities), in a representative model species of planktonic organisms, the harpacticoid copepod Nitokra spinipes. Three different environmental samples of PVC, PE and PP collected in coastal areas from Belgium (North Sea) and Argentina (Río de la Plata estuary) were used for the leachates. The plastics were cut into small fragments (2.5cm) and the leachates (80g/L) were prepared in brackish water (BW, salinities of 7 and 15) following standardized method (22°C in dark, 7d, 80rpm). After 7 days the leachates were filtrated by 1 and 0.2µm pore size cellulose filters. The toxicity test to assess the mortality in the copepods was carried out for 96h following the ISO 14669 protocol, comparing the endpoint among the three polymers and using BW as control (0 % leachates), as well as a positive control using dodecanol. The results indicated a 32% of mortality at 24h caused by leachates (100% concentration) from PVC, being the mortality of 30% at the end of the experiment (p