The first aerial survey to estimate abundance of humpback whales (Megaptera novaeangliae) in the breeding ground off Brazil (Breeding Stock A)

In the Southern Hemisphere, humpback whales (Megaptera novaeangliae) were heavily exploited from both coastal stations and in pelagic waters all major ocean basins. About 200,000 taken after 1900, causing declines of populations to small percentages their pre-exploitation levels. The study presented here aimed investigate whale abundance Brazilian breeding ground, order provide information support further analysis population recovery. Between 25 August 2 September 2001, a fixed wing, flat window, aircraft was used survey transect lines along northern limit Bahia State (12°10’S), southern Espírito Santo (20°42’S). All on-effort sightings recorded estimated according standard distance sampling methodology (Burnham et al., 1980; Buckland 1993). Group sizes ranged between 1-5 mean group size 1.52 (±0.06). model that best fitted perpendicular data, based on minimum Akaike Information Criterion, hazard rate model. using uncorrected data 1,493 (CV=0.21) whales. Surface time correct estimates for gˆ(0), resulting correction factor 0.67 (±0.15). corrected each block combined result, increased estimate 2,229 (CV=0.31) individuals. this could be identify new areas appropriate whalewatching, monitor status dynamics off coast establishment protected areas.