Steves research focusses on abundance, distribution, and habitat use of seabirds and cetaceans, and human interaction with these species groups. Study areas range from the tropics to polar regions, with a focus on the North Sea. The main methodologies he uses, have been visual surveys, either by air or vessel, as well as passive acoustic monitoring. He has served the last years as a scientific advisor to the Dutch government, in particular in the ASCOBANS agreement. He is member of the ICES working group on marine mammal ecology (ICES WGMME), of OSPARs Marine Mammal Expert Group (OMMEG).and the joint CMS/ASCOBANS/ACCOBAMS Noise Working Group.