Evaluating the effects of inorganic UV filter titanium dioxide nanoparticles (nano-TiO2) on early life stages of scleractinian coral Acropora tumida

Abstract

The extensive use of sunscreen products has led to an increase in the amount of UV filters being detected in marine ecosystems. While the hazards associated with organic UV filters are relatively well-studied, the effects of inorganic UV filters like nano‑titanium dioxide (nano-TiO₂) on corals remain unclear. This study investigated the effects of nano-TiO₂ UV filters on the fertilization success, embryonic development, and larval survival of the branching coral species Acropora tumida. Our results indicated that nano-TiO₂ concentrations ranging from 0.01 mg/L to 10 mg/L had no significant impact on coral fertilization success or embryonic development. However, high concentrations of 5 and 10 mg/L nano-TiO₂ significantly reduced larval survival probability compared to control after 4 days exposure. Based on our results, the current environmental concentrations of TiO₂ are unlikely to pose serious threats on coral fertilization and larval survival.

Keywords: Coral fertilization; Coral reefs; Early embryonic development; Ecotoxicology; Nano-titanium dioxide; Sunscreen filter.