Evaluating the Synergistic Impacts of Climate Change-Related Thermal Stress and Oxybenzone Contamination in Artemia salina Nauplii.

Oxybenzone (benzophenone-3, BP-3), a widely used ultraviolet filter in sunscreens, has emerged as an environmental contaminant of concern because of its persistence and potential toxicity in aquatic ecosystems. Rising ocean temperatures associated with climate change may further exacerbate the effects of chemical pollutants on marine organisms. This study investigated the combined effects of thermal stress and oxybenzone exposure on Artemia salina nauplii under simulated climate-relevant conditions. Nauplii were exposed to BP-3 concentrations ranging from 0.1 to 1.5 µg/mL for 72 hours at 27 °C and 32 °C, and mortality and morphological alterations were assessed every 24 hours.

Mortality increased in a concentration-dependent manner at both temperatures. Lower LC₅₀ values observed at 32 °C after 24 and 48 hours indicated enhanced toxicity under elevated temperature conditions. Microscopic observations revealed reduced locomotor activity and abnormal body positioning in exposed nauplii, suggesting physiological stress. Overall, the results demonstrate that thermal stress can modulate the toxic effects of oxybenzone, highlighting the complex interactions between climate change and chemical pollution in aquatic environments. These findings highlight the importance of considering climate change-related stressors when evaluating contaminant impacts on marine organisms and underscore potential risks to aquatic ecosystem health in warming environments. Understanding these interactions is essential for improving ecological risk assessments and predicting the consequences of multiple environmental stressors on aquatic species in the context of global climate change.