Sharks in Brazil test positive for cocaine, say scientists

Sharks off the coast of Brazil have been found to test positive for cocaine, marking the first time the drug has been detected in free-ranging sharks. The study conducted by scientists at a research foundation in Brazil examined 13 Brazilian sharpnose sharks in the waters near Rio de Janeiro. Cocaine was found in the liver and muscle tissue of all 13 specimens. The small size and limited habitat of the species make them more vulnerable to contamination. The researchers believe that sewage discharges and illegal drug production are the primary causes of cocaine pollution in the sea. The concentration of cocaine in muscle tissue was three times higher than in the liver, and female sharks had higher concentrations than males. Although the effects on shark health are unknown, previous studies have shown that cocaine can harm other animals. The researchers also suspect that crustaceans, fish, and other prey of the sharks may also be contaminated. The implications for human health are difficult to establish, but the presence of cocaine in sharks raises concerns as they are commonly consumed by humans in Brazil and other countries. The researchers plan to conduct further studies on different species of sharks and rays to assess cocaine accumulation and its effects.