Aerial survey, an abundance index for young bluefin
Young Bluefin tuna likes the Gulf of Lions, where it spends most of its time through the year, excepted during the spawning season (May-July). The Gulf of Lions is a highly productive area, where small pelagics are an important resources for Bluefin.
Bluefin tuna are detected with other megafauna species, such as fin whales, sperm whales, pilot whales, common, Risso and bottlenose dolphins, mobula rays, sunfish... But our main target is definitely Bluefin, which can cluster into very large schools, the "football pitch" !
Ifremer is in charge of producing an abundance index based on this survey, which is used in the stock assessment of Bluefin tuna at ICCAT. Axes of research within this survey are correcting the index of abundance for the availability of tuna in the Gulf of Lions (PROMPT project) and using images from the plane for automatic detection of the marine megafauna in the Gulf of Lions.