Scientists have discovered significant traces of cocaine in 13 Brazilian sharpnose sharks off the coast of Rio de Janeiro, with concentrations up to 100 times higher than previously observed in other marine species. This unprecedented finding has raised concerns about the impact of human drug use and waste on marine life. Potential sources of contamination include untreated sewage from drug users and illegal drug labs. Researchers are particularly worried about the possible health effects on sharks, including increased aggression, impaired hunting abilities, and reproductive issues. The study underscores the broader issue of pharmaceutical waste contaminating aquatic ecosystems. Further research is needed to understand the full impact of these contaminants on marine life.