SIGNAL aims to contribute to the Priority Domain Green Transition, aligned with the European Green Deal. For this it will develop innovative and cost-effective solutions to diagnose and monitor chemical pollution. Aquatic ecosystems worldwide are under immense pressure from chemical pollution and multiple anthropogenic stressors, causing losses of water quality, biodiversity, ecological integrity and the benefits these ecosystems provide. Major sources of potentially highly hazardous contaminants, including emerging substances, originate from their incomplete removal in wastewater treatment plants (WWTPs). The effluents released hinder water reuse (circular economy) and the conservation and recovery of ecosystems, but WWTPs toxicological efficiency is seldom evaluated. Despite the European legislative framework (e.g. Water Framework Directive, Marine Strategy Framework Directive, Nature Restoration Law), most aquatic systems still lack regular monitoring to spot and manage ecological quality. Similarly, ecosystem restoration actions are seldom evaluated for ecological integrity or expected recovery success. This occurs because the biological methods recommended for diagnosing and monitoring are expensive, cumbersome and time-consuming, and often lack sensitivity to detect detrimental effects at low concentrations and establish timely protection actions. This is the case of standard aquatic ecotoxicity assays based on apical endpoints (e.g. mortality or reproduction), often involving collecting data from multiple environmental compartments, heavy analytical chemistry for contaminant detection, assessment of taxonomy and trait-based characteristics, and molecular sequencing. This is not at all feasible to routinely provide early-warning indications suitable to prioritise deeper assessments and areas of urgent intervention, pinpointing the urgent need for sensitive and practical biological effects methods, affordable as routine, able to detect integrated effects of complex mixtures, in a multistressor context and a changing climate influencing abiotic factors that are key to the physiology of animals, e.g. carbon dioxide and oxygen levels, temperature, nitrate and phosphate levels. In such mixtures, chemicals can interact in organisms causing synergistic or antagonistic effects, not detected in evaluations of single chemicals. Our vision is that Vibrational Raman Spectroscopy (RS) can be applied to evaluate these effects and diagnose the ecological quality of water and ecosystem health. It allows the acquisition of large amounts of data in very little time, with low analytical costs, producing qualitative and quantitative assessments of the chemical composition and molecular structure of the samples, i.e. molecular fingerprints for subsequent chemometric analysis to generate the diagnostic fingerprint. Initially employed in materials sciences, it has recently been employed to characterise biological samples and investigate biological processes involved in health and disease. Our team made the first application of this technology to the diagnosis of ecological quality, a proof-of-concept, and diatom profiling. The overall aim of SIGNAL is to develop monitoring and evaluation methods based on this application. This innovative idea was previously worked up to TRL3 in projects of the team addressing aquatic effects monitoring and toxicological evaluation for wastewater reuse. SIGNAL is set to further develop its application into practical, routine diagnosis of water quality and ecosystem health, using different target species (e.g. zebrafish embryos, snails, diatoms) and site-specific monitoring. The RS data will be acquired under experimental designs addressing the most relevant ecotoxicological challenges in controlled laboratory experiments and in real exposure scenarios, to increase development up to TRL4 to TRL5 (functionality in lab and real scenarios). The ultimate beneficiaries would be stakeholders in the environmental and water sectors, industry, environmental agencies and the public. The end product can be easily incorporated into regular analytical labs at a low cost. Overall, the goal is to develop an innovative method, generating high data about ecosystem health status, supporting the implementation of sustained and quick surveillance of pollution, as enshrined in international and national policy documents. In line with this, three of the 10 Ocean Decade Challenges (ODC) are directly related to pollution and consider a source-to-sea approach, bridging UN SD Goals 6 and 14 (related to water and ocean, respectively). These ODC include the mapping of contaminants and their impacts to understand the effects of multiple stressors and develop solutions to monitor, protect, manage and restore ecosystems and their biodiversity under changing environmental, social and climate conditions, and ensure capacity development. These are also reflected in the National ENEI and EREI 2030 and the S3 Norte 2027.
