The papers collected together in this special issue of Aquatic Conservation: Marine and Freshwater Ecosystems emanate from a symposium held in April 2006, to celebrate the career of Professor John Croxall CBE FRS on his retirement from the British Antarctic Survey (Figure 1).
John Croxall graduated with a first-class degree in Zoology from Oxford University in 1968. He undertook his PhD on marine invertebrate ecology at the Leigh Marine Laboratory of the University of Auckland, before returning to the UK to take up a position with the Oiled Seabird Research Unit at the University of Newcastle. Although John had long been a keen amateur ornithologist, this position initiated what was to become a long and distinguished career as a professional seabird ornithologist.
John left Newcastle in 1976 to lead a newly formed marine vertebrate programme with the British Antarctic Survey. With John at its head, Ian Boyd and the late Peter Prince running the seals and bird sections respectively, the BAS Birds & Seals Group (as it was universally known) rapidly established itself as a leading group in the world. Working from the small research station on Bird Island, South Georgia, this group re-established long-term monitoring of albatross and fur seal populations, undertook fundamental research on the reproductive and feeding biology of a wide range of seabirds, and pioneered many innovative techniques. This was a golden age of primary research into seabird and marine mammal ecology, and it produced a revolution in our knowledge of how seabirds live and where they go at sea when not on the breeding grounds.
Early work at Bird Island concentrated on detailed studies of food and feeding in a range of seabirds as well as Antarctic fur seals Arctocephalus gazella and ground-breaking work on their foraging behaviour at sea. The latter required significant technical innovation, and both seabirds and fur seals were fitted with increasingly sophisticated loggers recording dive depth and position at sea. Perhaps the most innovative development was that of an artificial nest for albatrosses that continuously recorded the weight of the