ESR 11:233-243 (2010)  -  DOI:

Humpback whales within the Brazilian breeding ground: distribution and population size estimate

Artur Andriolo1,3,*, Paul G. Kinas2,3, Márcia H. Engel3, Cristiane C. Albuquerque Martins3, Anne M. Rufino2

1Departamento de Zoologia, Instituto de Ciências Biológicas, Universidade Federal de Juiz de Fora, Campus Universitário,
36036-900 Juiz de Fora, MG, Brazil
2Laboratório de Estatística Ambiental, Instituto de Matemática Estatística e Fisica, Universidade Federal do Rio Grande,
96200-970 Rio Grande, RS, Brazil
3Instituto Baleia Jubarte, Rua Barão do Rio Branco 26, 45900-000 Caravelas, BA, Brazil

ABSTRACT: 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.

KEY WORDS: Megaptera novaeangliae · Aerial survey · Abundance estimate · Breeding ground · South Atlantic Ocean

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Cite this article as: Andriolo A, Kinas PG, Engel MH, Albuquerque Martins CC, Rufino AM (2010) Humpback whales within the Brazilian breeding ground: distribution and population size estimate. Endang Species Res 11:233-243.

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