A global review on ecotoxicological studies concerning metal and metalloid contamination in Hammerhead Sharks.

Abstract

Sharks, are highly vulnerable to fishing pressures, a key factor in their global population decline. Chemical pollution, however, especially metal and metalloid contamination, poses significant additional risks. Of around 520 shark species, about 170 are threatened, including the Sphyrna genus (hammerheads). This review examines contamination in these sharks and its ecological and human health implications. A scientometric review indicates limited research, mainly on juveniles and only mercury contamination, with scarce data on other metals, life stages, and consumption thresholds. The findings also indicate a certain amount of Colonial Science concerning ecotoxicological Sphyrna spp. assessments. The expected link between ecotoxicological risks and Sphyrna spp. threat status remains inconclusive due to insufficient data. Notably, larger hammerhead species do not always exhibit higher contamination levels, suggesting that local environmental factors may influence contamination more than biological characteristics. More research is required to understand how environmental pressures impact shark vulnerability and inform conservation strategies.