Developmental Defects of In-Water Cleaning Wastewater on Resident Non-Target Organism

Abstract

In-water cleaning operation can result in the release of antifouling system to the surrounding coastal environment. The International Maritime Organization (IMO) recommend that not only biosecurity but also contaminant risks are appropriately managed in accordance with the 2015 Guidelines. To define the toxic effects of wastewater from in water hull cleaning on resident non-target organisms, we investigated the chemical concentrations and developmental toxicity on embryonic flounder, which is an organism sensitive to chemical contamination. The dominant inorganic metal was zinc in robot in-water cleaning wastewater (RICW). Fortyeight hours after exposure, the frequency percentage of malformation began to increase in embryos exposed to 50-fold dilution of RICW. We performed transcriptome sequencing to characterize the toxicological developmental effects of RICW exposure at the molecular level. The results of the analysis revealed significantly altered expression of genes associated with muscle cell, muscle contraction, lens development in camera-type eye, and nervous system development (cutoff P< 0.05) in embryonic flounder exposed to RICW. Although the toxicity of the malformation defects in embryos exposed to RICW decreased through the robot filter, it was confirmed that the effects of genetic level continued due to dissolved contaminants. These findings provide a greater understanding RICW effluent management practices to reduce impacts on non-target coastal organisms.