MAR-ECO (2003 - 2010)was an international exploratory study of the animals inhabiting the northern mid-Atlantic. Scientists from 16 nations around the northern Atlantic Ocean participated in research of the waters around the mid-Atlantic Ridge from Iceland to the Azores. This data set is subset of the data collected, and comprises presence/absence records (sightings) for mammals and birds, collected in 2004 on R/V G.O. Sars. Skov,H, T. Gunnlaugsson, W.P. Budgell, J. Horne, L. Nøttestad, E. Olsen, H. Søiland, G. Víkingsson and G. Waring (2008) Small-scale spatial variability of sperm and sei whales in relation to oceanographic and topographic features along the Mid-Atlantic Ridge. Deep-sea Research II. 55: 254-268.