A study carried out by the project Eco Sharkcoordinated by Dr. Mariana Bata Alonso from UFRJ (Federal University of Rio de Janeiro), revealed the presence of antidepressants, specifically sertralineno hammerhead shark brain in Rio de Janeiro.
In an interview with CNN Brazilthe professor at the college’s Biophysics Institute explained that, since 2018, researchers have been collecting shark carcasses that are accidentally caught in fishing nets.
According to Mariana, the intention of the new study was to analyze and understand the effects of antidepressants and anxiolytics, as there was a 25% increase in the consumption of these drugs due to the Covid-19 pandemic.
This concern led the team to focus on “” (such as pharmaceuticals), going beyond the industrial waste and pesticides that they have been monitoring since 2018.
Different from that accumulate in the liver or muscles, sertraline showed selective behavior. The team analyzed five organs: brain, liver, muscle (meat), gills and the ampullae of Lorenzini.
“We found the contaminants in all the organs analyzed. However, the antidepressant showed a higher concentration in the brain. This reinforces that, as in humans, it is a substance that acts directly on psychological issues.
The scientific explanation for this is that sertraline is lipophilic (has an affinity for fat). As the brain is rich in lipids due to the myelin sheath, the medicine ends up preferentially accumulating there.
Dr. Mariana also explains that human consumption is the cause of the presence of this type of medicine in the brains of animals, but that the main flaw is in the sanitation system. About 1% of sertraline ingested by humans is excreted unchanged.
As the professor explains, current sewage treatment plants are unable to eliminate pharmaceuticals. The medicine does not stay in the water. It goes into the sediment, is ingested by shrimp, which are eaten by larger fish, until it ends up in the sharks’ diet.
Sharks, as the biologist reinforces, should not be seen as villains, but as vital indicators of the planet’s health.
“A sea without sharks, that’s where we have to worry. Because it will be a sea in total imbalance. And another thing is that it is serving as a flag, a sentinel, showing us what could happen to us, to the planet, to our health”, he stated.
The teacher also appeals to the population don’t eat dog meatremembering that “dogfish is a shark” and that these species (such as the hammerhead shark) are already critically endangered in Brazil. She also warns that in the toilet, as they go directly into the sea.
Understand the Eco Shark Project
The Shark Project can be understood as an environmental project aimed at conserving marine ecosystems with a special focus on sharks — not just as a species, but as a central piece of the balance of the oceans.
Sharks, despite the image often distorted by fear and popular culture, are natural regulators of the seas. They control populations of intermediate species, prevent imbalances in fauna and help maintain healthy coral reefs.
Without them, there is a cascade effect: certain species multiply uncontrollably, others disappear, and the entire ecosystem loses stability. EcoShark, in this sense, emerges as a direct response to the need to protect these “invisible engineers” of the ocean.
