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ABSTRACT: A toxicity test was developed to examine the effects of metal contaminants on the sensitiveearly life history stages of the common Antarctic echinoid Sterechinus neumayeri (Meissner).Embryos and larvae of the sea urchin were exposed to the metals copper, cadmium, zinc and lead,and the effects of each metal on development to hatched blastulae after 6 to 8 d, and to 2-arm pluteiafter 20 to 23 d were monitored. These metals are common in Antarctic marine environments and areoften found at elevated levels at sites subject to anthropogenic inputs. For all metals tested, the longtermtest to the 2-arm pluteus stage was more sensitive than the short-term test. Copper was themetal most toxic to developing embryos and larvae of S. neumayeri with EC50s of 11.4 µg l–1 and1.4 µg l–1 following 6 to 8 d and 20 to 23 d exposure respectively. Exposure to cadmium at concentrationsgreater than 2 mg l–1 caused a significant decrease in the proportion of embryos developing normallyto hatched blastulae (EC50 = 6.9 mg l–1) and concentrations greater than 0.2 mg l–1, caused adecrease in normal 2-arm plutei. EC50 values calculated for zinc were 2230 and 326.8 µg l–1 for theshort- and long-term tests respectively. Lead had no effect on development of embryos following 7 dexposure at all concentrations tested (up to 3.2 mg l–1). As the concentration of Cu shown to inhibitdevelopment of S. neumayeri is similar to levels found at impacted sites in Antarctic nearshore environments,results of this study indicate that this metal may have an impact on the development of S.neumayeri. The sensitivity of S. neumayeri to copper and cadmium in tests based on development tohatched blastulae (6 to 8 d) are generally comparable to results of tests on echinoids from tropical andtemperate regions that use development to 2-arm plutei (2 to 4 d) as the end-point. However, theAntarctic species is more sensitive to copper and cadmium than the tropical and temperate species ifthe tests are continued to the same stage of development, the pluteus larva (20 to 23 d for the Antarcticspecies). Comparing the tolerance of a key developmental stage common to all planktotrophic seaurchins may be more ecologically relevant than simply comparing exposure over a fixed period oftime, because for an embryo to survive to adulthood it must successfully complete all developmentstages. This is the first reported evidence that Antarctic species could be more sensitive to contaminantsthan species from warmer regions.
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