There is disturbing evidence of high mortality of salmon at sea. The need for a multidisciplinary study of contributing factors and appropriate action has been advocated for some time. As a result, the Atlantic Salmon Trust, organised a workshop under the chairmanship of Derek Mills to redress this situation, bringing together climatologists, oceanographers, planktonologists and marine and salmon biologists to clarify and discuss the environmental and biological issues affecting survival. Proposals are put forward for further research and collaboration.