A new study published in “Environmental Pollution,” a peer-reviewed scientific journal, detailed in their May 2026 issue a study done on 85 tested sharks in the Bahamas area that had drugs such as cocaine, caffeine and several different painkillers in one-third of the tested sharks.
The study was conducted by Natascha Wosnick, a biologist at the Federal University of Paraná in Brazil, which is a country where studies on sharks have been performed a number of times.
Researchers have concluded that the main contributor to this outcome is human pollution that accumulates in sewage pouring out into the ocean. As a result, sea creatures become exposed to both legal and illegal substances, which can be harmful to their health.
These findings are not the first of their kind, as researchers at the same university found high concentrations of cocaine in sharks off the coast of Brazil in a 2024 study. The difference is that the previous study focused on muscle tissue, whereas this one focused on blood samples.
The presence of drugs in the sharks’ bloodstreams indicates that these exposures were recent.
“The best part about the study is how this is going to capture everyone’s imagination because ‘Cocaine Bear’ was good, but ‘Cocaine Shark’ is a whole other thing,” said Melanie DeVore, a professor in the Department of Biology & Environmental Sciences.
Human pollution can affect the environment in damaging ways over time. The more harmful substances are found within marine life, the more aware people become of how human waste affects living creatures.
“As you move up in the food chain, and see that an apex predator, like a shark, has cocaine in its blood, it’s gonna trigger people’s attention,” DeVore said. “They’re gonna think, ‘If it’s that far in the food chain, we have a problem.’”
If harmful drugs are being found in sharks, who are at the top of the food chain, there is a high possibility that they are also affecting other sea creatures.
“What concerns me with the Brazilian study is finding the levels of drugs really bad in crustaceans,” DeVore said. “If you have cocaine impacting crustaceans, that can be devastating to the lobster in Bahama streets.”
Tourism in the Bahamas is another contributor to this outcome. From cruise lines to summer vacations, thousands of people visit this area.
“Yes, sharks are important, but right now, I would be going after the conch, lobster, grouper and snapper,” DeVore said. “People visit and they want conch salad or conch fritter, so if people are consuming this, the drug itself is in the tissues.”
Although harmful substances are largely found in areas like the Bahamas, marine life in Georgia is affected by other contaminants. The GCSU Bass Fishing Team takes the necessary precautions to learn about the risks of ingesting contaminated fish and how it is an increasing possibility.
“Around Georgia, the fish that have the highest bioaccumulation are striped bass and catfish because of their lifespans,” said Drew Bates, a junior environmental science and biology major and Bass Fishing Team member. “I’m eating two to three servings of these fish every week, but I don’t think it’s a big deal.”
The team is able to access information that tells them what is safe to eat and what is not.
“What’s really nice is that the state puts out a data sheet every year of the recommended dosage from different water bodies for mercury and lead, which is the main bioaccumulator that we care about in Georgia,” Bates said.
Brett Boswell, a junior environmental science major and fellow bass-fisher, reflects on the signs of pollution that they notice and how it is progressively getting worse.
“We see pollution everywhere we go,” Boswell said. “It is an increasing problem as the population increases. Companies do their part in minimizing sewage, but at the end of the day we can never really limit pollution.”
Ultimately, to help resolve the issue, people can become more aware of how they take part in these issues and understand the effects they have on marine life.
“This news kind of opens your eyes to some things you don’t think about every day, especially in waters, whether it’s close to home or around the world,” Boswell said.
For more information on this study, students can check out Wosnick’s research in the journal, “Environmental Pollution.” There is also a 2023 documentary called “Cocaine Sharks” on the Discovery Channel that investigates this same issue.