Exposure to pharmaceutical contaminants in stranded wild dolphins of the Western Mediterranean

Pharmaceutical contamination in aquatic ecosystems is a growing concern for marine biodiversity and human health. We have detected six different non-steroideal anti-inflamatory drugs (carprofen, ibuprofen, ketoprofen, phenylbutazone, diclofenac and flunixin), five antibiotics (florfenicol, enrofloxacin, ciprofloxacin, oxytetracycline and trimethoprim), acetaminophen and caffeine in liver samples from 13 bottlenose dolphins (Tursiops truncattus) and 14 striped dolphins (Stenella coeruleoalba) inhabiting the western Mediterranean Sea and stranded in the coast of Valencian Community (Spain) between 2010 and 2024. To our knowledge, this study is the first documentation of some of these pharmaceuticals in wild marine-mammal tissues. Our results confirm the presence of these contaminants in the Mediterranean marine ecosystem and their incorporation into the top predator level, likely mainly through the food chain. These pollutants could cause physiological alterations in exposed individuals and may represent a potential risk for population health and resilience under chronic exposure scenarios. Potential sources of such contamination include domestic wastewater and discharges from large cruise ships, as well as open aquaculture plants, highlighting the need for enhanced monitoring and awareness to mitigate the impact of pharmaceutical contamination in marine mammals and advocate for effectively protecting marine biodiversity and human health.