Why have Brazilian sharks tested positive for cocaine?
Al Jazeera
Study finds people using the drug are causing large quantities to leak into the sea.
Thirteen Brazilian sharpnose sharks caught off Rio de Janeiro have tested positive for cocaine, marine biologists who carried out the tests have reported.
High concentrations of cocaine were found in the sharks’ muscles and livers by researchers at the Rio de Janeiro-based Oswaldo Cruz Foundation.
Benzoylecgonine was also detected in the same sharks. Benzoylecgonine is one of the byproducts produced when cocaine is consumed.
The 13 sharks were three males and 10 females, five of which were pregnant. All the sharks were captured from fishing boats off the coast of the state of Rio de Janeiro from September 2021 to August last year.
Samples were taken from the sharks, and the concentration of cocaine was found to be more than 100 times those previously reported in any other aquatic animals, according to the study.
