Ecotoxicological Effects of Four Commonly Used Organic Solvents on the Scleractinian Coral Montipora digitata

• Published in: Toxics (Basel) 2023-04, Vol.11 (4), p.367
• Main Authors: Di Mauro, Valentina, Kamyab, Elham, Kellermann, Matthias Y, Moeller, Mareen, Nietzer, Samuel, Luetjens, Laura H, Pawlowski, Sascha, Petersen-Thiery, Mechtild, Schupp, Peter J
• Format: Article
• Language: English
• Subjects: Aquariums; biomarker; Coral reefs; Corals; Dimethyl sulfoxide; Dimethylformamide; Ecological effects; Ecotoxicology; Ethanol; Fluid filters; Hydrophobicity; Methanol; Montipora digitata; Morphology; Mortality; Organic solvents; Organisms; Oxidative stress; Pesticides; Physiology; Polycyclic aromatic hydrocarbons; Salinity; Seawater; Solvent effect; Solvents; Standardized tests; Stress response; Sulfoxides; sunscreen; Temperature; Toxicity; Toxicity testing; Turbidity; Ultraviolet filters; UV-filter
• ISSN: 2305-6304; 2305-6304
• DOI: 10.3390/toxics11040367

Organic solvents are often used in aquatic toxicity tests to facilitate the testing of hydrophobic or poorly water-soluble substances such as ultraviolet (UV) filters, pesticides, or polycyclic aromatic hydrocarbons (PAHs). Knowledge of intrinsic effects (i.e., measured as standardized and non-standardized endpoints) of such carrier solvents in non-standardized organisms (i.e., corals), is critical to regulatory processes. Therefore, we exposed the reef-building coral to the most commonly used carrier solvents ethanol, methanol, dimethyl sulfoxide, and dimethylformamide in the range of 10-100 µL L for 16 days. The effects on mortality, photobiological, morphological, and oxidative stress markers were evaluated. In our study, all solvents resulted in significant morphological and/or oxidative stress responses, but not in mortality. Moreover, ethanol led to a rapid increase in turbidity, thus questioning its suitability as a carrier solvent in aquatic studies in general. Based on our observations, we could rank the solvent effects as follows: dimethylformamide < dimethyl sulfoxide ≈ methanol ≤ ethanol, with dimethylformamide showing the least and ethanol the most pronounced effects. We conclude that the use of solvents in toxicity studies with corals, particularly by examining non-standardized (e.g., morphological, physiological) endpoints, should be taken with caution and requires further elaboration.