Global change is increasingly altering the structure and functioning of aquatic ecosystems through the combined action of chemical pollution, nutrient enrichment, temperature variations and other environmental stressors. Understanding how these pressures affect ecological functions and ecosystem services is essential to assess ecosystem resilience and to support effective management and conservation strategies.

In this study, we propose a multi-trophic ecotoxicological approach to evaluate the effects of global change on ecosystem services by integrating the responses of three key biological levels: decomposer bacteria, unicellular algae as primary producers, and echinoderm embryos as primary consumers.

Ecotoxicological assays were carried out under controlled conditions, comparing optimal scenarios with exposure scenarios characterized by the presence of chemical contaminants, temperature variations and their combined effects. Biological responses were assessed through endpoints such as abundance, bioluminescence, biomass, growth rate and mortality.

To translate ecotoxicological endpoints into ecosystem-scale implications, laboratory results were linked to ecological functions and ecosystem services using indicators derived from the scientific literature, with particular reference to regulating and supporting services. The comparison between exposed organisms and controls made it possible to estimate potential functional changes associated with the stressors considered.

By linking effects observed at the organism level to ecosystem processes, the proposed approach provides an integrated assessment of how global change factors may impair ecosystem services in aquatic environments. The study highlights the value of multi-trophic bioindicators as early-warning tools for detecting functional alterations and strengthening the understanding of the links between ecotoxicological stress and the provision of ecosystem services.