Recent and current research on Balearic shearwater on colonies and in Atlantic and Mediterranean areas

The Balearic shearwater Puffinus mauretanicus is the most threatened seabird in Europe. Several recent research and conservation programmes from different countries (Spain, Portugal, France, UK and Ireland), using various methodologies such as colony monitoring, at-sea surveys, tracking and coastal censuses, brought new information about the population status, behaviour and threats of the species. The global population can now be estimated in over 25,000 individuals, roughly twice than previous estimation. Mean extinction time is also revised to 70-80 years. For the first time, birds from Eivissa (i.e. the southern breeding population) were tracked and breeders appear to forage not only on the Iberian shelf and around breeding sites, but also in North African waters, seeking marine productive waters. During wintering, Balearic shearwaters appear to restrict their activity to few core areas off western Iberia or south-western Brittany. Some of the French coastal survey sites host large numbers of individuals (> 5,000 observed in Brittany in 2010) and should integrate the MPA network. Tracking surveys of breeders and of moulting adults caught-at-sea show that they can directly return to their breeding sites as early as 5 months before the beginning of the breeding season (egg laying, which takes place in early March). Data from observers onboard fishing vessels and questionnaires to fishermen show that bycatch is a big issue for the species in both the Mediterranean and the Atlantic area. Preliminary results suggest that Mediterranean bycatch mainly occur in longlining, whereas purse-seiners and trawlers could capture more birds in the NE Atlantic. Further work is required in order to obtain bycatch rates on a more representative fleet. The highly mobile Balearic shearwater is not attached to administrative boundaries and it is therefore essential to overcome legal limitations to provide its efficient protection. Transboundary programmes such as the Interreg FAME should be rapidly encouraged to provide efficient conservation measures for Puffinus mauretanicus.