The spread of non-indigenous species (NIS) via shipping, particularly through biofouling, poses a major challenge to marine biodiversity and ecosystem functioning. Current biofouling management relies heavily on chemical antifouling coatings and maintenance practices, which have associated environmental costs and highlight the need for cost-effective and environmentally sustainable management. Here, we evaluated the potential application of non-chemical, stress-based approaches for biofouling mitigation. Using controlled experiments, we quantified survival responses of three invasive ascidian species: the tropical origin Microcosmus exasperatus and Phallusia nigra, and the temperate origin Styela plicata, under extreme heat exposure (36, 38, 40 °C; 20, 40, 60 min). Additionally, we tested air exposure effects (3, 6, 12, 24 h) on S. plicata under different environmental conditions. Survival and recovery were analyzed using generalized linear models and contingency analyses. Thermal exposure revealed strong species-specific tolerance differences; M. exasperatus exhibiting the highest resilience and S. plicata the lowest. Survival decreased significantly with increasing temperature and exposure duration; with all species showing complete mortality under the most extreme treatments, indicating a shared upper thermal limit. Air exposure revealed that S. plicata mortality was strongly influenced by environmental conditions, increasing under outdoor and summer conditions, particularly under longer exposures. Our findings indicate that stress-based treatments offer effective, non-chemical methods for reducing biofouling. Linking species-specific physiological thresholds to treatment conditions offers a generalizable framework for developing sustainable biofouling control interventions to mitigate marine bioinvasions.
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