My immediate reaction to this study was that if only sharks had more after school activities they wouldn’t be showing such predatory behavior. Here’s the study’s abstract:
Pharmaceuticals and illicit drugs are increasingly recognized as contaminants of emerging concern (CECs) in marine environments, particularly in areas undergoing rapid urbanization and tourism-driven development. Potential exposure to such contaminants, however, remains largely unexplored in The Bahamas. This study provides the first investigation into the occurrence of selected CECs (acetaminophen, benzoylecgonine, caffeine, carbamazepine, ciprofloxacin, citalopram, clindamycin, cocaine, diclofenac, fipronil, fluoxetine, nimesulide, piroxicam, sertraline, sulfamethoxazole, triclosan, trimethoprim, and tramadol) and their potential associations with physiological systemic health markers (triglycerides, total cholesterol, urea, phosphorus, and lactate) in the serum of five shark species sampled from nearshore habitats in Eleuthera Island, namely Galeocerdo cuvier (Tiger Shark), Carcharhinus limbatus (Blacktip Shark), Carcharhinus perezi (Caribbean Reef Shark), Ginglymostoma cirratum (Atlantic Nurse Shark), and Negaprion brevirostris (Lemon Shark). Serum samples were analyzed for CECs employing LC–MS/MS and for physiological markers by UV-Vis spectrophotometry. Four of the investigated CECs (diclofenac, cocaine, acetaminophen, and caffeine) were detected at varying concentrations in Caribbean Reef sharks, Atlantic Nurse sharks, and Lemon sharks, demonstrating their local environmental occurrence and bioavailability. Furthermore, sharks with detectable CECs exhibited triglyceride, urea, and lactate alterations in comparison to those where these contaminants were not detected. This represents the first report concerning CECs and potentially associated physiological responses in sharks from The Bahamas, pointing to the urgent need to address marine pollution in ecosystems often perceived as pristine.
Yes, I’m aware that’s not the point of the study. That it appeared in Environmental Pollution was my first hint. Still, it’s interesting.
Of note, the ones they found in the sharks are ones that are not usually given by injection. None of the ones given that way, IV or IM/SC, showed up. Of the ones that were positive they showed up in a minority of the sharks. Suggests some of the sharks were hanging around closer to people. The levels they detected appear to be about 1/000th of what would be therapeutic levels in people. Dont know if this is because they are consuming a lot or unable to break down and excrete the drugs they found.
Steve
None of the species they listed are particularly territorial rather they are nomadic. That sounds to me like it undermines the conclusion they’re drawing.
My recollection is that sharks are attracted to areas with human waste in the water, probably because smaller fish dine on it. But I’m not an ichthyologist, I’ve just seen all of the Jaws movies more than once. I do think terms like contaminants of emerging concern might be useful for general research purposes, but convey that there is an established concern where there may not be.