Sharks under the influence of cocaine, shocking discovery by scientists

Increasing contamination of the seas and oceans has been an international concern for many years. However, the latest discovery by Brazilian scientists turned out to be the proverbial bucket of cold water – significant amounts of cocaine and its metabolites were found in the bodies of shortfin mako sharks caught off the coast of Rio de Janeiro. The presence of these toxic substances in the water poses a threat not only to marine fauna, but also to humans, which is of growing concern.

Cocaine sharks in Brazil

The world’s media has not escaped the paradoxical coincidence – in 2023. the horror film Cocaine Shark was released in theaters with the goal of entertaining crowds with an unrealistic vision of a drugged predator. Not a year later, the scientific publication Science of The Total Environment publishes a study about the first-ever case of cocaine identification in the bodies of Brazilian sharks. Could it be that reality has begun to follow in the footsteps of movie scripts?

Psychoactive toxicants in seawater are no exception to the rule. Scientists in Rio de Janeiro examined the bodies of 3 male and 10 female shortfin mako sharks(Rhizoprionodon lalandii) caught off the coast of southeastern Brazil between 2021 and 2023. Cocaine was found in all the tissue samples collected, and in 92 percent. additionally benzoylgonine, the main metabolite of cocaine. This means that the organisms of the predators processed the infamous drug and felt its effects. In doing so, the measured amounts of cocaine were up to 100 times higher than concentrations previously detected in other marine animals.

Cocaine in water and wastewater

It is not known how the sharks became intoxicated – it is speculated that drugs flushed down toilets may be the cause, but also whole packages of cocaine that end up in the sea due to the activities of smugglers. We also do not know what effects the psychoactive alkaloid will have on the future of the population, which spends its entire life in coastal waters. Most of the female sharks studied were pregnant.

The problem is significant because, as a 2023 report by the United Nations Office on Drugs and Crime (UNODC) points out, global cocaine consumption is on the rise, and 22 percent of cocaine users are in South America, where levels of urban wastewater treatment are far from accepted standards.

Other places around the world have also repeatedly identified psychoactive toxic substances in wastewater. Monitoring conducted between 2011 and 2017 in 37 countries showed the presence of cocaine in wastewater in the United States, Canada, Spain, Turkey and Poland. Additionally, in South America, cocaine has already been sampled from surface water.

The consequences of cocaine exposure for aquatic organisms can be catastrophic. Studies have shown that mollusks, crustaceans and bony fish experience reduced cell longevity, increased DNA fragmentation and disruption of protein structures that are crucial to basic life processes. Sharks, at the top of the food chain, are particularly vulnerable to the cumulative effects of cocaine contamination.

Other toxic substances in the water

Fish and seafood are, of course, also consumed by humans. If you add dangerous and toxic substances in drinking water, such as microplastics, taken from freshwater reservoirs, it turns out that no one in the world today is completely free of an extra dose of hormones, drugs and narcotics. Amphetamine and methamphetamine, for example, have already been detected repeatedly in European wastewater.

In 2022. Residents of coastal towns in the English counties of Hampshire and West Sussex have raised money to test coastal seawater. Analysis by two regional universities found as many as 50 controversial chemicals, including diabetes and hypertension drugs, nicotine and the aforementioned benzoylgonine.

In an interview with the BBC, Prof. Alex Ford of the University of Portsmouth confirmed that residues of drugs and illegal substances are regularly detected in the tissues of crabs and shrimp that later end up on our tables. It has also been proven that under the influence of antidepressants, sea creatures begin to move and behave differently, which can seriously disrupt the biological balance. What’s more penny-pinching, researchers are still finding toxic substances banned 30 years ago in the water in which we bathe and from which we get our food.

Researchers from Harvard Medical School add that of all the medicines we take, only a portion stays in the body and the rest is discharged into the sewage system. An additional problem is expired medicines, which end up in landfills or flushed down the toilet. It’s worth remembering that they can come back to us in the form of lunch, causing environmental havoc along the way.