The Threat of Bis(2-Ethylhexyl) Phthalate in Coastal and Marine Environments: Ecotoxicological Assays Using Tropical Species from Different Trophic Levels

Plastic and plasticizer pollution has been a concern worldwide over the past decade. Bis(2-ethylhexyl) phthalate (DEHP) is the most produced plasticizer and has been detected in coastal and marine ecosystems. This study aimed to assess the toxicity of acute exposure (24, 48, 72, and 96 h) to DEHP concentrations (0.045–6.00 mg·L −1 ) on marine and estuarine tropical species from distinct trophic levels. The lethality and sublethal responses were assessed on two microorganisms and three invertebrates, independently. The microorganisms—the microalga Tetraselmis sp. and the microbial consortium MP001—showed high tolerance and a density-rising tendency during exposure to DEHP. Among the invertebrates, the mortality of the brine shrimp Artemia sp. and the amphipod Apohyale media rose with increasing DEHP concentrations. However, A. media was more sensitive across time since its lethality reached 100% in almost all DEHP concentrations from 72 h. The dark false mussel Mytilopsis leucophaeata was the most tolerant invertebrate: no significant lethality (≤20%) was observed exclusively from 72 h of exposure to DEHP at intermediate–high concentrations. Artemia sp. and M. leucophaeata presented sublethal responses that seem to be good endpoints for ecotoxicological assays. These results reinforce evidence of DEHP contamination risks for tropical coastal ecosystems, as well as suggest candidate species for its biodegradation.