Although the ability to detect and respond to chemical cues is essential in most animals, we know very little of how the chemical sense will be affected by the rapid environmental changes we face today. The overall goal of this research project is to provide improved understanding of the combined impacts of climate change and pollutants on the chemosensory system of marine organisms, focusing on ecologically and economically important crustaceans. Using a combination of behavioural investigations and electrophysiological techniques will identify interference with the chemosensory system on all levels from neuron to behaviour.The project is divided into three objectives:- To study impacts of multiple stressors from climate change (ocean acidification, temperature and salinity) and pollutants on chemically mediated behaviour, such as feeding, establishment of dominance status and mating.- To identify impacts of multiple stressors on odour detection, performing electrophysiological studies.- To investigate the plasticity of the chemosensory system and its ability to adapt to environmental change, using Idothea baltica populations locally adapted fully marine or brackish waters in reciprocal transplant experiments.The results from this project will help us identify risks and better predict consequences of climate change and will be important assessment criteria for policymakers and authorities when developing coastal management, mitigation strategies and legislation. The high complementarity of the research training will expand my scientific competence and allow me to establish my very own, unique research profile. I will learn and test new approaches and bring together competence and collaborative work from different scientific fields and countries. Thus, this research project will be a significant step in my research career in order to reach a mature, independent research position.