Plastic pollution in a coral reef climate refuge: Occurrence of anthropogenic debris, microplastics, and plasticizers in the Gulf of Aqaba.

The Gulf of Aqaba in the northern Red Sea, considered a coral reef refuge from the negative effects of climate change, is however being subjected to increasing amounts of plastic contamination. We quantified the levels of benthic plastic debris, microplastics, and plasticizers within the coral reef's surrounding seawater and sediment over time. Our results indicate that the coral reefs of the GoA have relatively lower levels of plastic pollution compared to reefs in other regions. The measured benthic debris in the Red Sea reefs was found to be 0.093 ± 0.091 item/m and fell within the reported levels found in other tropical coral reefs, with boating and fishing materials being the most abundant type. Deep mesophotic reefs were found to have significantly higher levels of benthic plastic debris compared to the shallower reefs. Microplastic levels in the surrounding seawater of the reef were 0.516 ± 0.317 microplastics/m. These concentrations in the reef's surrounding waters are comparable to the levels observed in surface waters from the central Red Sea. The target plasticizers appeared infrequently in samples, and the concentrations for the majority of them were below the level of quantification (LOQ = 14.7 ng/l for water and 14.7 ng/g for sediment). The findings from this study provide a valuable scientific basis for shaping regional policies and implementing management strategies aimed at controlling and mitigating plastic pollution. Such policies can ensure the long-term protection of the reefs in the northern Red Sea, turning them into a secure coral refuge shielded from both global and local anthropogenic stressors.