The identification of marine areas of importance for seabirds is a challenge, because it is often unclear how birds are using the different areas in which they occur. Species differ in habitat choice, foraging behaviour and feeding range, but also in tendencies to roost at sea or to utilise resting places closer to or even on land. Because the designation of marine protected areas (MPAs) for seabirds should bear relevance to the ecological importance of these regions, simple presence/absence information is not sufficiently accurate and could even be misleading. Large amounts of data have been collected to assess distribution patterns of seabirds around the world. Two sources of data are highlighted here: ship-based surveys and sensor data from instruments attached to individual birds. Recently developed protocols to systematically record seabird behaviour at sea during ship-based surveys and novel tracking technology that facilitate spatio-temporal quantification of space use and identification of behaviour will be evaluated in the context of MPA designations. We present some limitations of traditional techniques and exciting possibilities of new protocols and the latest generations of electronic devices attached to seabirds. These advanced approaches in data collection and spatial analysis will reveal important ecological information that will enhance our understanding of offshore seabird distribution and activity which can guide the designation of marine protected areas.