Water and Sediment Toxicity and Hazard Assessment of Dcoit Towards Neotropical Marine Organisms

Abstract

DCOIT is an effective antifouling biocide, which presence in the environment and toxicity towards non-target species has been generating great concern. This study evaluated the waterborne toxicity of DCOIT on marine invertebrates (i.e., survival of brine shrimp Artemia sp., and larval development of the sea-urchin Echinometra lucunter and the mussel Perna perna), as well as DCOIT spiked sediments toxicity on the fecundity rate of the copepod Nitrocra sp., and the mortality of the amphipod Tiburonella viscana. Data outcomes were used to calculate environmental hazards and risks, which were compared to their corresponding values obtained to temperate regions. The waterborne toxicity can be summarized as follows: Artemia sp (LC50-48h = 163 (135-169) µg/L), E. lucunter (EC50-36h = 33.9 (17-65) µg/L), P. perna (EC50-48h = 8.3 (7-9) µg/L). For whole-sediment toxicity, metrics were calculated for T. viscana (LC50-10d = 0.5 (0.1-2.6) µg/g) and Nitrocra sp, (EC50-10d = 0.2 (0.01-0.48) µg/g). The hazard of DCOIT was assessed for both tropical and non-tropical pelagic organisms. The PNEC for tropical species (0.19 µg/L) was 1.7-fold lower than that for non-tropical organisms (0.34 µg/L). In whole-sediment exposures, DCOIT presented a PNEC of 90 µg/g and the RQs were >1 for areas of constant input of DCOIT such as ports ship/boatyards, marinas, and maritime traffic zones of Korea, Japan, Spain, Malaysia, Indonesia, Vietnam, and Brazil. The presented data is important to support the establishment of policies and regulations for the booster biocides across the world.

Keywords: PNEC, Risk quotient, Sea-Nine, Biocide, Hazard, Antifouling