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Vol. 50 No. 3, 2011
Distribution and Status of the Guiana Dolphin Sotalia
guianensis (Cetacea, Delphinidae) Population in Babitonga Bay, Southern
Brazil
Marta J. Cremer1,2,*, Fernando A.S. Hardt1, Antonio J. Tonello Jr1, and Paulo Cesar Simões-Lopes2,3
1Laboratório
de Nectologia, Departamento de Ciências Biológicas, Univ. da Região de
Joinville, Caixa Postal 110, Cep 89240-000, São Francisco do Sul, Santa
Catarina, Brazil
2Programa de Pós-Graduação em Ciências Biológicas – Zoologia, Univ. Federal do Paraná, Curitiba, Brazil
3Laboratório de Mamíferos Aquáticos, Departamento de Ecologia e Zoologia, Univ. Federal de Santa Catarina, Florianópolis, Brazil
Marta J. Cremer, Fernando A.S. Hardt, Antonio J. Tonello Jr, and Paulo Cesar Simões-Lopes (2011) The Guiana dolphin Sotalia guianensis
is one of the most endangered small cetaceans in the southern Atlantic
Ocean. The population abundance and density of this species were
estimated in Babitonga Bay in 2000-2003. Sampling was random and
stratified, and a line transect method with distance sampling was
applied in an area of 160 km2. The total length of transects
covered was 1251.9 km, with 163 groups of dolphins recorded. Group
sizes varied 2-30 (mean, 5.3; SD, 5.6) individuals. Some areas were
preferred by the population, and area 3 was considered the core area of
S. guianensis in Babitonga Bay. The abundance was estimated to be 245
(95% confidence interval (CI): 142-422) individuals between Dec. 2000
and Nov. 2001, 186 (95% CI: 93-374) individuals between Apr. 2002 and
Feb. 2003, and 179 (95% CI: 93-344) individuals between Mar. and Dec.
2003, and the densities were estimated at 1.6 (95% CI: 1-2.7), 1.2 (95%
CI: 0.6-2.4), and 1.3 (95% CI: 0.5-3.4) individuals/km2, respectively. The highest density was recorded in the central area of the bay.
Key words: Abundance, Density, Group size, Sotalia guianensis, Southern Brazil.
*Correspondence: E-mail:marta.cremer@univille.net
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