Zachy Hennessey
October 7, 2024

I’m no expert, but I don’t think it’s healthy for fish to swim around in a cocktail of laxatives, antidepressants and cholesterol meds.

Well, assuming my instincts are correct, the gilled creatures of the northern Red Sea aren’t feeling so hot right now: A new study conducted by researchers at Tel Aviv University and its affiliated Steinhardt Museum of Natural History has uncovered some pretty alarming levels of pharmaceutical contamination in coral reefs in the Gulf of Eilat.

The study, published in the journal Environmental Pollution, detected traces of 10 common medications in coral samples collected from both shallow and deep sites.

The detected drugs would be found on a wide span of shelves in your local pharmacy: antibiotics, blood pressure medications, antiplatelet agents, calcium channel blockers, laxatives, proton pump inhibitors, statins and antidepressants.

Gulf of Eilat corals steeped in drug cocktail, scientists warn
It may look like a brain, but this reef doesn’t need antidepressants. Photo by Prof. Noa Shenkar/Tel Aviv University

The research team analyzed 96 reef-building stony corals and collected samples from shallow depths of 5-12 meters and deeper sites of 30-40 meters, beyond recreational diving limits.

Every single coral sample, regardless of depth, contained traces of pharmaceuticals. Most alarmingly, sulfamethoxazole, an antibiotic used to treat respiratory and urinary tract infections, was found in 93% of the sampled corals.

“We were surprised to find an extensive presence of medications even in the deep-water corals — which usually escape contaminations affecting corals in shallower areas,” said Prof. Noa Shenkar, one of the study’s lead researchers.

“What does the presence of pharmaceuticals in corals actually mean? Clearly, the corals did not receive a prescription for antibiotics from their doctor,” she said. “These medications are taken by humans to affect a certain receptor or biological pathway, and they can also impact other organisms.”

Gulf of Eilat corals steeped in drug cocktail, scientists warn
Prof. Noa Shenkar engaging in the thrilling act of scuba research. Photo by Prof. Noa Shenkar/Tel Aviv University

She elaborated: “Previous studies, conducted by both our lab and others, have revealed many examples of this negative impact: estrogen from birth control contraceptive pills induces female features in male fish, impairing reproduction in certain species; Prozac makes some crabs aggressive and reckless; and antidepressants damage the memory and learning abilities of squids.”

Shenkar said there is no reason to believe that corals are immune to such effects.

“For instance, if our pharmaceuticals should disrupt the spawning synchrony of coral populations, it would take us a long time to notice the problem, and when we do, it might be too late.”

The presence of these human drugs in marine life raises serious concerns about ecological impacts of pharmaceuticals.

“Clearly these medications save lives, and we have no intention of requesting people to reduce their use,” said Shenkar. “However, we must develop new sewage treatment methods that can effectively handle pharmaceutical compounds. Also, each of us must dispose of old medications in ways that do not harm the environment.

“Ultimately, these drugs come back to us.”

Hopefully we can get our act together and stop pumping our med-filled wastewater into the ecosystem. In the meantime, I guess we can start advising depressed and constipated fish to make their way over to the Gulf of Eilat and start licking the coral.

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