Abstract:
Pharmaceutical and personal care products (PPCPs) are emerging contaminants characterized by their pseudo-persistence at low concentrations and potential toxicity to marine organisms. While PPCPs have been widely documented globally, their presence and biological impacts in the Red Sea remain understudied, despite increasing contamination risks associated with rapid coastal and aquaculture development under Saudi Arabia’s Vision 2030. Marine sponges are proposed bioindicators and bioremediators of pollution due to their high filtration and retention capacity, yet their ability to accumulate and withstand chronic exposure to PPCPs is not well understood. The Red Sea sponge Stylissa carteri provides an ideal model for evaluating PPCP dynamics due to its abundance, sessility, and bioaccumulation potential. This study examines the distribution and effects of targeted PPCPs in S. carteri through (1) field collections of seawater and sponge tissue along a gradient from an aquaculture effluent site in the central Red Sea, and (2) a 14-day laboratory exposure to environmentally relevant concentrations of ciprofloxacin. Field surveys revealed widespread, low-level PPCP contamination in seawater, dominated by caffeine and paracetamol. Paracetamol accumulated disproportionately in sponges, whereas caffeine, ciprofloxacin, fluoxetine and carbamazepine exhibited low or inconsistent uptake. Antioxidant activity and lipid peroxidation were highest at the nearest-to-shore and offshore reefs, respectively. Interpretations of biochemical responses are limited by confounding environmental factors. Under experimental conditions, no significant physiological or biochemical responses were observed, suggesting S. carteri tolerated environmentally relevant concentrations of ciprofloxacin. Lipid peroxidation only increased in experimental groups relative to pre-exposure groups, likely reflecting handling stress. Overall, S. carteri displays compound-specific uptake and biological resistance, indicating potential adaptation to chronic low-level contamination. Additionally, S. carteri may not be a robust bioindicator of PPCP pollution, despite its high uptake of paracetamol. This research provides baseline knowledge on chemical contamination in Red Sea reefs, underscores the need for multi-species and multi-endpoint monitoring, and highlights the potential of sponges as bioremediation tools.

Bio:
Sofia is originally from New York and earned her bachelor's of biology at Cornell University. Prior to arriving at KAUST, she worked with the Coral Restoration Foundation to help restore the reefs of the Florida Keys. Sofia is now a Master's student in marine science conducting ecotoxicology research in the Biodiversity and Ecosystem Management Lab.