Toxicity assessment for the wastes removed from the in-water ship’s surface cleaning activities using sea-urchin embryos

Abstract

This study was conducted to assess the toxicity of the wastes removed from ship’s surface by the in-water cleaning and water jet cleaning activities on the marine benthic animals. To evaluate the toxicity of wastes, sea urchin (Mesocentrotus nudus) embryos were used. Materials for this toxicity test were collected from the antifouling paint wastes removed by on dock water jet cleaning from the R/V EARDO and R/V ISABU, and also those from in-situ cleaning water (ICW) and filtered ICW (FICW) from the R/V EARDO and R/V ONNURI. Heavy metals and biocide contents in the wastes from cleaning operations and all the final stock solutions were analyzed. In the case of the R/V EARDO, the fertilization rate exposed on water jet samples were 79±5.8% at the 0.1% diluted solution, 2.3±1.4% and 0.2±0.5% at 1% and 10% solutions, respectively. The fertilization rate for ICW was 0% at 10% and 100% solution, but it was over than 90% at both the 0.1% and 1% solution. The fertilization rates on the ICW and the FICW were similar the EC50 values of fertilization rate for ICW and FICW were 2.7% and 3.1%, respectively. In the case of the R/V ISABU, fertilization rate was 0% exposed on the 10% solutionor less diluted solution from water jet samples. The concentration of copper in the water jet samples was higher at R/V ISABU than R/V EARDO, while those of copper and zinc were higher at R/V EARDO. Among the biocides, higher concentrations