A recent study conducted by researchers in Brazil has unveiled a startling discovery: sharks off the coast of Rio de Janeiro are found to have traces of cocaine in their systems. This revelation adds another layer of concern to the already prevalent fear of sharks in beach waters.
The investigation, published last week, involved thirteen sharks and revealed that all had remnants of cocaine in their livers and muscle tissues. Shockingly, the cocaine concentrations measured in these sharks were up to one hundred times greater than levels previously recorded in marine life.
“We were astounded,” said Rachel Ann Hauser Davis, a co-author of the study and biologist at Brazil’s Oswaldo Cruz Foundation. “Our excitement was in a negative sense, but it is groundbreaking research. This is the first time such data has been reported in any apex predator.”
This study is significant as it marks the first examination of cocaine presence in sharks, following previous research on smaller marine species like mollusks, crustaceans, and eels. The findings showed that the sharks had unfiltered cocaine in notably high concentrations, suggesting chronic exposure to the drug.
However, the scope of the study was limited to a small sample size, raising numerous questions regarding whether this cocaine exposure has detrimental effects on the sharks themselves or on humans consuming them.
Daniel Snow, a director at the University of Nebraska’s Aquatic Sciences Laboratory, expressed surprise that such findings were published based on just thirteen sharks. Over a decade ago, he was among the first to detect the illicit drug methamphetamine in Nebraska’s wastewater. “It’s not too far-fetched to think these chemicals ending up in aquifers could impact the aquatic organisms that inhabit them,” he noted.
The study was conceived early this year after scientists identified elevated cocaine levels in rivers within the Rio de Janeiro basin. Other marine experts had previously investigated the potential for Gulf of Mexico sharks to ingest cocaine from the numerous lost or discarded packets following a documentary titled “Cocaine Sharks” released in 2023.
The team of biologists from the Oswaldo Cruz Foundation, affiliated with Brazil’s Ministry of Health, aimed to test apex predators in those river basins. They analyzed the Brazilian shortfin mako, a relatively small shark species commonly consumed by local populations.
Hauser Davis proposed various hypotheses concerning how these marine animals came into contact with cocaine. One possibility is that it comes from illegal laboratories refining the substance or from drug traffickers losing or dumping packages in the ocean. However, she believes these account for only a small fraction of the drug found in marine environments.
“The primary source is likely from the excretion via urine and feces of people who consume cocaine,” she explained. Most wastewater treatment plants worldwide do not effectively filter out such substances, leading to their release into the ocean.
João Matias, a scientific analyst from the European Drug Agency, analyzed cocaine levels in wastewater across over a hundred cities, including those in Brazil. His findings indicated that cocaine concentrations in Brazilian wastewater were akin to those in European cities with the highest levels.
Still, Matias emphasized that the detected concentrations were not alarmingly high. Referring to the recent study, he stated, “It is essential to highlight that I am a hundred percent sure that the concentrations they found are very low.”
Tracy Fanara, an environmental engineer from Florida who led research for the “Cocaine Sharks” documentary, noted that cocaine is just one small component of a larger issue regarding pollutants in natural habitats. “Cocaine captivates people’s interest,” she said, “but we have antibiotics, antidepressants, pharmaceuticals, sunscreens, insecticides, and fertilizers—all these chemicals enter our ecosystem.”
Hauser Davis shared similar concerns, questioning why metal and pesticide contaminants rarely spark the same level of surprise or alarm when discovered. Despite this, she hopes her research will pave the way for further studies on cocaine presence in marine life.
“Our intention is to conduct similar studies on other sharks, rays, and even sea turtles,” she concluded.
A Brazilian shortfin mako was captured by researchers off the coast of Rio de Janeiro, drawing attention to this unexpected issue.
Image and News Source: https://www.infobae.com/america/the-new-york-times/2024/07/25/no-le-temes-a-los-tiburones-pues-ahora-consumen-cocaina/
