Occurrence and distribution of UV-filters and other anthropogenic contaminants in coastal surface water, sediment, and coral tissue from Hawaii

Abstract

The occurrence of UV-filters in the environment has raised concerns over potentially adverse impacts on corals. In this study, the concentrations of 13 UV-filters and 11 hormones were measured in surface seawater, sediment, and coral tissue from 19 sites in Oahu, Hawaii. At least eight UV-filters were detected in seawater, sediment, and coral tissue and total mass concentrations of all UV-filters were <750 ng L^-1, <70 ng g^-1 dry weight (dw), and <995 ng g^-1 dw, respectively. Four UV-filters were detected in water, sediment, and coral tissue at detection frequencies of 63-100%, 56-91%, and 82-100%, respectively. These UV-filter concentrations generally varied as follows: water, homosalate (HMS) > octisalate (OS) > benzophenone-3 (BP-3, also known as oxybenzone) > octocrylene (OC); sediment, HMS > OS > OC > BP-3; coral, OS ≈ HMS > OC ≈ BP-3. BP-3 concentrations in surface seawater were <10 ng L^-1 at 12 of 19 sites and highest at Waikiki beach (e.g., 10.9-136 ng L^-1). While BP-3 levels were minimal in sediment (e.g., <1 ng g^-1 dw at 18 of 19 sites), and ranged from 6.6 to 241 ng g^-1 dw in coral tissue. No quantifiable levels of 2-ethylhexyl 4-methoxycinnamate (also known as octinoxate) were recorded in surface seawater or coral tissues, but 5-12.7 ng g^-1 dw was measured for sediment at 5 of 19 sites. No hormones were detected in seawater or sediment, but 17α-ethinylestradiol was present in three corals from Kaneohe Bay. Surfactant degradation products were present in seawater, especially at Waikiki beach. These results demonstrate ubiquitous parts-per-trillion concentrations of UV-filters in surface seawater and is the first report of UV-filters in coral tissue from U.S.A. coastal waters. These data inform the range of environmentally-relevant concentrations for future risk assessments on the potential impacts of UV-filters on coral reefs in Oahu, Hawaii.

Keywords: Coral; Hormones; Octinoxate; Oxybenzone; Sunscreen; UV-filters.