Green sea urchins (Strongylocentrotus droebachiensis) as potential biomonitors of metal pollution near a former lead-zinc mine in West Greenland.

In this study, metal accumulation in green sea urchins (Strongylocentrotus droebachiensis) was investigated near the former Black Angel lead-zinc mine in Maarmorilik, West Greenland. Sea urchins (n = 9-11; 31-59 mm in diameter) were collected from three stations located at < 1 km, 5 km, and 12 km (reference site) away from the former mine site, respectively. After collection, tissue of the sea urchins was divided into gonads and remaining soft parts (viscera) before subjected to chemical analyses. Focus was on eight elements found in elevated concentrations in the mine waste (iron, copper, zinc, arsenic, silver, cadmium, mercury and lead). Sea urchins at the mine site contained significantly more copper, mercury and lead compared with the reference site for both the gonads and viscera, while the latter also contained significantly more iron, zinc and silver. Arsenic and cadmium were not significantly elevated in sea urchins at the mine site. Most elements were found in higher concentrations in the viscera compared with the gonads. For comprehensive monitoring of metal pollution at mine sites, a diverse selection of monitoring organisms is necessary. The study shows that green sea urchins accumulate selected metals and can be used as a monitoring organism for mining pollution, at least for iron, copper, zinc, silver, mercury and lead. However, the results also show that green sea urchins are less likely to reflect small environmental changes in loading of most metals (except iron, copper and silver) and for arsenic compared to suspension feeders such as blue mussels.