The potential impact of increasing vessel traffic and coastal development has led to concerns regarding the future of the Brazilian humpback whale Megaptera novaeangliae population. Our objective was to monitor humpback whale abundance in the Brazilian coastal breeding grounds in order to provide information to support future conservation strategies for this species. To this end, a 4 yr series (2002 to 2005) of aerial surveys was implemented. Abundance was estimated using standard line-transect methods. Data were analyzed using the software DISTANCE 5.0. Perpendicular sighting data were modeled using (1) the uniform function with cosine and simple polynomial adjustments, (2) the half-normal function with cosine, and (3) the hazard-rate function with cosine and a simple polynomial series expansion. The model that best fitted the data was selected according to Akaike’s Information Criterion (AIC). We estimated the population off the Brazilian coast to be 6404 (CV = 0.11) ind. in 2005. Alternative scenarios are presented to permit the discussion of results obtained from different g (0) corrections (where g (0) is the probability of detecting an animal at distance 0). We confirmed what previous studies have shown, i.e. that the studied population is increasing, and it is expected that new areas will be occupied and conflicts of interests will arise. The results of this study support the Brazilian government’s stance against whaling and should be used in national and international debate to help solve conflicts of interest and to find non-lethal solutions
The study reviews the information available on the distribution patterns of bottlenose dolphins within the SWAO (04oN-56oS, 25oW-67oW) including the northern portion of Brazil, covering the period from 1894 to 2011.
8 January 2017 in Latin American Journal of Aquatic Mammals
The review compiles available information about the habitat use patterns of bottlenose dolphins within the SWAO, including temporal analysis of survey effort allocation, and spatial analysis indicating areas of resident or seasonally resident populations.