At BIO he undertook research on the physical oceanography of coastal and shelf seas as well as investigating environmental effects on fish stocks. For 20 years he provided environmental reviews of the Northwest Atlantic for the North Atlantic Fisheries Organization (NAFO) and later for fisheries assessment groups in eastern Canada. While at the Institute of Marine Research in Bergen, Norway, he has continued his investigations into the effects of climate variability and change on marine ecosystems. He has led or been involved in several ESSAS related projects funded by the Norwegian Research Council including NESSAS, NORCAN, MENU, MENUII, and @eco.
He was chair of the ICES/GLOBEC Working Group on Cod and Climate Change (1998-2004), a co-author on the Arctic Climate Impact Assessment (ACIA) Marine System chapter to assess possible consequences of climate change on the Arctic (2001-2005), and a review editor for the 2015 IPCC Working Group II’s Chapter 6 on Ocean Processes. He is presently one of two co-chief editors for Deep-Sea Research II.