Researchers raise concerns as medical compounds found in Eilat coral samples
Tel Aviv University team says trace pharmaceuticals in corals are compounding threats to marine ecosystems from climate change, pollution, overfishing
Sue Surkes is The Times of Israel's environment reporter
Traces of 10 common medications have been identified in coral samples in shallow and deep water sites in the Gulf of Eilat in southern Israel.
Sulfamethoxazole, an antibiotic used for respiratory and urinary tract infections, was found in 93 percent of corals tested.
The researchers from Tel Aviv University received a list of the most commonly used pharmaceuticals in Israel from Clalit Health Services. They then looked for 18 compounds in a sample of 96 reef-building stony corals representing two genera, Acropora and Favites. They did this in shallow sites (5-12 meters, or 16-40 feet deep) and in deeper sites beyond recreational diving limits (30-40 meters, or 98-130 feet).
Ten of the 18 compounds were found in the coral samples, including antibiotics, blood pressure medications, antiplatelet agents, calcium channel blockers, laxatives, proton pump inhibitors, statins, and antidepressants.
They entered the sea in sewage (apparently from neighboring countries), agricultural run-off and excretions from bathers.
Prof. Noa Shenkar of the university’s School of Zoology and Steinhardt Museum of Natural History, who led the study, said, “Humans take these medications to affect a certain receptor or biological pathway, and they can also impact other organisms.”
“Previous studies conducted by our laboratory and others have revealed many examples of this negative impact. Estrogen from 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.”
She continued, “There is no reason to believe that corals should be 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 did, it might be too late.”
“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, we must dispose of old medications in ways that do not harm the environment. Ultimately, these drugs come back to us. I know people who avoid medications, but when they eat a fish, they might unknowingly consume a ‘cocktail’ of drug residues absorbed by the fish from the marine environment.”
PhD student Gal Navon, who participated in the research, said, “Stony corals build coral reefs, and the types we studied are very common in the Gulf of Eilat. Coral reefs are a cornerstone of marine biodiversity. They provide food, shelter, and spawning sites to numerous species and support the human fishing and tourism industries. Today, this delicate ecosystem is under pressure due to climate change, pollution, and overfishing. Pharmaceuticals in coral tissues add another layer of concern, indicating that human activities even contaminate faraway marine environments.”
The study was carried out in cooperation with Prof. Dror Avisar’s hydrochemistry laboratory at TAU’s Porter School of Environment and Earth Sciences.
The results were published in the journal Environmental Pollution.
