A unique approach to monitor stress in coral exposed to emerging pollutants

Didier Stien,Philippe Lebaron,Marion Yvin,Alice M S Rodrigues,Fanny Clergeaud,Evane Thorel,Marcelino Suzuki

doi:10.1038/s41598-020-66117-3

Abstract

Metabolomic profiling of the hexacoral Pocillopora damicornis exposed to solar filters revealed a metabolomic signature of stress in this coral. It was demonstrated that the concentration of the known steroid (3β, 5α, 8α) -5, 8-epidioxy- ergosta- 6, 24(28) - dien- 3- ol (14) increased in response to octocrylene (OC) and ethylhexyl salicylate (ES) at 50 µg/L. Based on the overall coral response, we hypothesize that steroid 14 mediates coral response to stress. OC also specifically altered mitochondrial function at this concentration and above, while ES triggered a stress/inflammatory response at 300 µg/L and above as witnessed by the significant increases in the concentrations of polyunsaturated fatty acids, lysophosphatidylcholines and lysophosphatidylethanolamines. Benzophenone-3 increased the concentration of compound 14 at 2 mg/L, while the concentration of stress marker remained unchanged upon exposition to the other solar filters tested. Also, our results seemed to refute earlier suggestions that platelet-activating factor is involved in the coral inflammatory response.

Highlights

Metabolomic profiling of the hexacoral Pocillopora damicornis exposed to solar filters revealed a metabolomic signature of stress in this coral
Used for skin protection against cancer, solar filters are regularly released in the sea from populated coastal zones or in sites dedicated to touristic activities including a bathing zone
An early article from Danovaro and coworkers[2] demonstrated that solar filters can induce coral bleaching by promoting viral infections

Summary

Introduction

Metabolomic profiling of the hexacoral Pocillopora damicornis exposed to solar filters revealed a metabolomic signature of stress in this coral. It has been shown that other ingredients in sunscreens and cosmetics exacerbate the toxicity of the UV filters OC and octinoxate[8], while Fel et al reported that many UV filters, including OC have little or no effect on corals[9]. Other groups have described the accumulation of UV filters in coral tissues[8,12,13] These data further increase the interest of studying coral response to pollutants. In the current context, where national legislations are evolving to promote more sustainable tourism while little is known on the impact of UV filters on coral, it was key to evaluate more solar filters and to introduce a practical reliable tool to quantify coral responses to pollutants, while considering the public health importance of sunscreens. Name Octocrylene Methylene bis-benzotriazolyl tetramethylbutylphenol Benzophenone-3 Butyl methoxydibenzoylmethane Diethylamino hydroxybenzoyl hexyl benzoate 2-Ethylhexyl salicylate Homosalate bis-Ethylhexyloxyphenol methoxyphenyl triazine Diethylhexyl butamido triazone

Methods

Results

Conclusion