Scalloped Hammerhead Shark (Sphyrna lewini) karenr10 / iNaturalist An antidepressant widely used to treat depression and anxiety was found in the brains of hammerhead sharks caught off the coast of Rio de Janeiro. The discovery, made by researchers at the Federal University of Rio de Janeiro (UFRJ), expands the evidence that drug residues are reaching the oceans and reaching species that occupy the top of the food chain. ? Also follow Terra da Gente on Instagram The study identified the presence of sertraline, an active ingredient present in several antidepressants, in the brain tissue of hammerhead sharks of the species Sphyrna lewini and Sphyrna zygaena, both classified as critically endangered. The animals analyzed were accidentally caught in fishing nets in the regions of Recreio dos Bandeirantes, Barra da Tijuca and Copacabana and sent to the researchers through a partnership with local fishermen. According to the authors, the discovery is part of research carried out by the EcoShark Project, which has been monitoring the health of sharks on the coast of Rio de Janeiro since 2018 and investigating the presence of emerging contaminants in elasmobranchs — a group that includes sharks and rays. See more news from Terra da Gente, on g1: FINDINGS: Park in the interior of SP reveals two new beetles and an insect seen only once in 60 years BUTANTAN: Unpublished study reveals the venom genes of the island jararaca FLAGRANT: Jaguar is caught on the prowl for capybara in broad daylight in the Pantanal How does an antidepressant reach the ocean? Medicine can end up in the ocean Freepik The path starts at home. After being ingested, sertraline is metabolized by the body and part of the medication is eliminated in the urine. This waste goes to the sewage system. As conventional treatment systems were not designed to completely remove pharmaceutical compounds, part of these molecules remain in the water and end up reaching rivers and the sea. See what's trending on g1 today:
Antidepressant is found in the brains of hammerhead sharks off the coast of Brazil
Scalloped Hammerhead Shark (Sphyrna lewini) karenr10 / iNaturalist An antidepressant widely used to treat depression and anxiety was found in the brains of hammerhead sharks caught off the coast of Rio de Janeiro. The...
In the marine environment, these contaminants can be absorbed directly by fish and invertebrates or enter the food chain. As sharks are top predators, they end up accumulating substances present in their prey throughout their lives, a phenomenon known as bioaccumulation. The researchers highlight that sertraline's affinity for fat-rich tissues and the nervous system may explain its detection in the brains of animals. What does the discovery mean? Hammerhead Shark (Sphyrna zygaena) goflowers / iNaturalist Despite the finding, the authors themselves make an important caveat: the presence of sertraline in the brains of sharks does not mean, in itself, that the medication has altered their behavior or physiology. The study demonstrates that there was exposure and bioaccumulation of the substance, but the effects of this contamination on animals still need to be investigated. The researchers recall that laboratory experiments have already shown that sertraline can cause behavioral changes in zebrafish, such as reduced activity and impaired learning. However, they emphasize that it is not yet known whether these effects also occur in sharks, whose neurochemistry presents different characteristics from those observed in bony fish. "What we still don't know — and this is the question that the EcoShark Project tries to answer — is what these compounds do to elasmobranchs", write the researchers in the scientific dissemination article published by the platform The Conversation. A warning beyond sharks For the authors, the result goes beyond the conservation of hammerhead sharks. The discovery reinforces the need to expand the monitoring of pharmaceutical contaminants in marine environments, modernize sewage treatment systems and invest in research into the effects of these compounds on aquatic fauna. Although the study represents an important step towards understanding the presence of medicines in the marine environment, the researchers emphasize that further work is still needed to assess whether continuous exposure to sertraline can cause changes in the health or behavior of these large predators. VIDEOS: Highlights Terra da Gente See more content about nature on Terra da Gente
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