Species-specific bioassays reveal spatial variation in chemical contamination of green sea turtles

The rapid increase of anthropogenic activity at shipping ports and surrounding coastal areas has been correlated with higher chemical contamination entering the surrounding marine environment. Chemical contaminants in marine environments can lead to significant health problems for green turtles (Chelonia mydas), especially when these contaminants accumulate in their foraging grounds. This study examined the exposure and toxicological effects of chemical contaminants on green turtle cells using a species-specific cell viability assay. Using the QuEChERs extraction, organic contaminants were extracted from 60 blood samples collected from green turtles in three foraging locations: Port Curtis, and two reefs (Heron Reef and Hoskyn-Fairfax Reefs) within the Capricorn Bunker Group of the outer Great Barrier Reef. Blood extracts were tested for cytotoxicity against primary green turtle fibroblast cells using an in vitro resazurin bioassay to assess cell viability. Extracts from Gladstone and Heron Reef indicated significant chemical contamination, at levels high enough to cause adverse health effects of green turtles. Very low toxicity values at the Hoskyn-Fairfax Reefs location indicate its potential to be established as a reference site for the southern Great Barrier Reef.