Long-term site fidelity and residency patterns of bottlenose dolphins (Tursiops truncatus) in the Tramandaí Estuary, southern Brazil


  • Amanda Baron Di Giacomo Universidade Federal do Espírito Santo
  • Paulo Henrique Ott Grupo de Estudos em Mamíferos Aquáticos do Rio Grande do Sul (GEMARS)




Population size, Residence patterns


The occurrence of common bottlenose dolphins (Tursiops truncatus) in Tramandaí Estuary, southern Brazil, is described based on a photo-identification study conducted between January 2009 and February 2010. A total of 128 survey days were conducted with an average observation effort of 2.6 hours per day (SD = 0.6). Approximately 2050 photographs were taken from a shore land location at the mouth of the estuary. A total of nine dolphins were identified, including three calves. The dolphins were observed during all seasons, with a greater frequency during fall (79.3% of the days) and winter (60.7% of the days). The summer presented the lowest occurrence (2.4% of the days) of dolphins. During the entire study period, the maximum number of individuals sighted in any given day ranged from one to seven (average = 2.8 dolphins; SD = 1.35; n = 51). The residence indices, based on the resighting frequency of dolphins during the study period, ranged from 0.02 to 0.24 (average = 0.13; SD = 0.08; n = 9). However, most of the animals (67%) were resighted in over five months during a year and could be classified as residents. Longterm site fidelity was detected by resightings of four dolphins for over 18 years. These data combined reinforce the importance of the Tramandaí Estuary for the common bottlenose dolphins in the region and highlight the need for local conservation efforts to guarantee the long-term persistence of these coastal populations.

Author Biography

Amanda Baron Di Giacomo, Universidade Federal do Espírito Santo

Laboratório de Nectologia


Ananias, S.M.A., Jesus, A.H. and Yamamoto, M.E. (2008) Recorrência e fidelidade espacial do boto-cinza Sotalia guianensis na enseada do Curral, Pipa/RN, avaliada através da fotoidentificação. Pages 61-77 in Jesus, A.H., Medeiros, P.I.A.P. and Silva, F.J.L. (Orgs) Boto-cinza Sotalia guianensis: Pesquisa e conservação no nordeste do Brasil. Edições UERN, Rio Grande do Norte, Brazil.

Aragones, L.V., Jefferson, T.A. and Marsh, H. (1997) Marine mammal survey techniques applicable in developing countries. Asian Marine Biology 14: 15–39.

Avila, T.R., Pedrozo, C.S. and Bersano, J.G.F. (2009) Variação temporal do zooplâncton da Praia de Tramandaí, Rio Grande do Sul, com ênfase em Copepoda. Iheringia, Série Zoologia 99(1): 18-26. http://dx.doi.org/10.1590/S0073-47212009000100003

Daura-Jorge, F.G. and Simões-Lopes, P.C. (2011) Lobomycosis-like disease in wild bottlenose dolphins Tursiops truncatus of Laguna, southern Brazil: monitoring of a progressive case. Diseases of Aquatic Organisms 93: 163-170. http://dx.doi.org/10.3354/dao02291

Daura-Jorge, F.G., Cantor, M., Ingram, S.N., Lusseau, D. and Simões-Lopes, P.C. (2012) The structure of a bottlenose dolphin society is coupled to a unique foraging cooperation with artisanal fishermen. Biology Letters 8(5): 702-705. http://dx.doi.org/10.1098/rsbl.2012.0174

Dawson, S., Wade, P., Slooten, E. and Barlow, J. (2008) Design and field methods for sighting surveys of cetaceans in coastal and riverine habitats. Mammal Review 38: 19-49. http://dx.doi.org/10.1111/j.1365-2907.2008.00119.x

Defran, R.H., Shultzand, G.M. and Weller, D.W. (1990) A technique for the photographic identification and cataloging of dorsal fins of the bottlenose dolphin (Tursiops truncatus). Report of the International Whaling Commission(Special Issue) 12: 53-55.

Fruet, P.F., Kinas, P.G., Da Silva, K.G., Di Tullio, J.C., Monteiro, D.S., Dalla Rosa, L., Estima, S.C. and Secchi, E.R. (2010) Temporal trends in mortality and effects of bycatch on common bottlenose dolphins, Tursiops truncatus, in southern Brazil. Journal of the Marine Biological Association of the United Kingdom 91: 1-12. http://dx.doi.org/10.1017/S0025315410001888

Fruet, P.F., Secchi, E.R., Di Tullio, J.C and Kinas, K.P. (2011) Abundance of bottlenose dolphins, Tursiops truncatus (Cetacea: Delphinidae), inhabiting the Patos Lagoon estuary, southern Brazil: Implications for conservation. Zoologia 28(1): 23–30. http://dx.doi.org/10.1590/S1984-46702011000100004

Fruet, P.F., Secchi, E.R., Daura-Jorge, F., Vermeulen, E., Flores, P.A.C., Simões-Lopes, P.C., Genoves, R.C., Laporta, P., Di Tullio, J.C., Freitas, T.R.O., Dalla Rosa, L., Valiati, V.H., Beheregaray, L.B. and Möller, L.M. (2014) Remarkably low genetic diversity and strong population structure in common bottlenose dolphins (Tursiops truncatus) from coastal waters of the Southwestern Atlantic Ocean. Conservation Genetics 15(4):879-895. http://dx.doi.org/10.1007/s10592-014-0586-z

Gunnlaugsson, T. and Sigurjónsson, J. (1990) A note on the problem of false positives in the use of natural marking data for abundance estimation. Report of the International Whaling Commission (Special Issue) 12: 143-145.

Hoffmann, L.S. (2004) Um estudo de longa duração de um grupo costeiro de golfinhos Tursiops truncatus (Montagu, 1821) (Cetacea, Delphinidae) no sul do Brasil: aspectos de sua biologia e bioacústica. Ph.D. Thesis. Universidade Federal do Rio Grande do Sul. Porto Alegre, Brazil. 259 pp.

Mattos, P.H., Dalla Rosa, L. and Fruet, P.F. (2007) Activity budgets and distribution of bottlenose dolphins (Tursiops truncatus) in the Patos Lagoon estuary, southern Brazil. Latin American Journal of Aquatic Mammals 6(2): 161-169. http://dx.doi.org/10.5597/lajam00121

Milmann, L.C. (2011) Ecologia alimentar do boto, Tursiops truncatus (Montagu, 1821), no litoral norte do Rio Grande do Sul, sul do Brasil. Bachelor Thesis. Universidade Estadual do Rio Grande do Sul/Universidade Federal do Rio Grande do Sul. Imbé, Brazil. 59 pp.

O’Brien, J.M., Berrow, S.D., Ryan, C., McGrath, D., O’Connor, I., Pesante, G., Burrows, G., Massett, N., Klötzer, V. and Whooley, P. (2010) A note on long-distance matches of bottlenose dolphins (Tursiops truncatus) around the Irish coast using photo-identification. Journal of Cetacean Research and Management 11(1): 69–74.

Peterson, D., Hanazaki, N. and Simões-Lopes, P.C. (2008) Natural resource appropriation in cooperative artisanal fishing between fishermen and dolphins (Tursiops truncatus) in Laguna, Brazil. Ocean & Coastal Management 51: 469-475. http://dx.doi.org/10.1016/j.ocecoaman.2008.04.003

Pryor, K., Lindbergh, J., Lindbergh, S. and Milano, R. (1990) A dolphin-human fishing cooperative in Brazil. Marine Mammal Science 6(1): 77-82. http://dx.doi.org/10.1111/j.1748-7692.1990.tb00228.x

Ramos, L.A. and Vieira, J.P. (2001). Composição específica e abundância de peixes de zonas rasas dos cinco estuários do Rio Grande do Sul, Brasil. Boletim do Instituto de Pesca 27(1): 109–121.

Schwarzbold, A. and Schäfer, A. (1984) Gênese e morfologia das lagoas costeiras do Rio Grande do Sul, Brasil. Amazoniana 9: 87-104.

Shane, S.H., Wells, R.S. and Würsig, B. (1986) Ecology, behavior and social organization of the bottlenose dolphin: a review. Marine Mammal Science 2(1): 34-63. http://dx.doi.org/10.1111/j.1748-6692.1986.tb00026.x

Siciliano, S. (1994) Review of small cetaceans and fishery interactions in coastal waters of Brazil. Report of the International Whaling Commission (Special Issue) 15: 241-250.

Silva, C.P. (1982) Ocorrência, distribuição e abundância de peixes na região estuarina de Tramandaí, Rio Grande do Sul. Atlântica 5: 49-66.

Simões-Lopes, P.C. (1991) Interaction of coastal populations of Tursiops truncatus (Cetacea, Delphinidae) with the mullet artisanal fisheries in Southern Brazil. Biotemas 4(2): 83-94.

Simões-Lopes, P.C. (1995) Ecologia comportamental do delfim,

Tursiops truncatus (Montagu, 1821) durante as interações com a pesca artesanal de tainhas (Mugil spp.) no sul do Brasil. Ph.D. Thesis. Pontifícia Universidade Católica do Rio Grande do Sul. Porto Alegre, Brazil. 200 pp.

Simões-Lopes, P.C., Fabian, M.E. and Menegheti, J.O. (1998) Dolphin interactions with the mullet artisanal fisheries on southern Brazil: a qualitative and quantitative approach. Revista Brasileira de Zoologia 15(3): 709-726. http://dx.doi.org/10.1590/S0101-81751998000300016

Simões-Lopes, P.C. and Fabian, M.E. (1999) Residence patterns and site fidelity in bottlenose dolphins, Tursiops truncatus(Montagu) (Cetacea, Delphinidae) off Southern Brazil. Revista Brasileira de Zoologia 16(4): 1017-1024. http://dx.doi.org/10.1590/S0101-81751999000400012

Van Bressem, M-F., Van Waerebeek. K., Reyes, J.C., Félix, F., Echegaray, M., Siciliano, S., Di Beneditto, A.P., Flach, L., Viddi, F., Avila, I.C., Herrera, J.C., Tobón, I.C., Bolaños Jimenez, J., Moreno, I.B., Ott, P.H., Sanino, G.P., Castineira, E., Montes, D., Crespo, E., Flores, P.A.C., Haase, B., Mendonça de Souza, S.M.F., Laeta, M. and Fragoso, A.B.

(2007). A preliminary overview of skin and skeletal diseases and traumata in small cetaceans from South American waters. Latin American Journal of Aquatic Mammals 6: 7-42. http://dx.doi.org/10.5597/lajam00108

Wells, R.S. and Scott, M.D. (1999) Bottlenose dolphin Tursiops truncatus (Montagu, 1821). Pages 137-182 in Ridgway, S.H. and Harrison, S.R.(Eds) Handbook of Marine Mammals, Volume 6: The second book of dolphins and porpoises. Academic Press, San Diego, CA, USA.

Wells, R.S. and Scott, M.D. (2009) Bottlenose dolphins. Tursiops truncatus and T. aduncus. Pages 249-255 in Perrin, W.F., Würsig, B. and Thewissen, J.G.M. (Eds) Encyclopedia of Marine Mammals. 2.ed. San Diego: Academic Press, USA.

Wilson, B., Reid, R., Grellier, K., Thompson, P. and Hammond, P.S. (2004) Considering the temporal when managing the spatial: A population range expansion impacts protected areas-based management for bottlenose dolphins. Animal Conservation 7: 331-338.


Würsig, B. and Jefferson, T.A. (1990) Methodology of photoidentification for small cetaceans. Report of the International Whaling Commission (Special Issue) 12: 43-52.

Würsig, B. and Würsig, M. (1977) The photographic determination of group size, composition, and stability of coastal porpoises (Tursiops truncatus). Science 198: 755-756. http://dx.doi.org/10.1126/science.198.4318.755

Zappes, C.A., Andriolo, A., Simões-Lopes, P.C. and Di Beneditto, A.P.M. (2011) ‘Human-dolphin (Tursiops truncatus Montagu, 1821) cooperative fishery’ and its influence on cast net fishing activities in Barra de Imbé/Tramandaí, southern Brazil. Ocean & Coastal Management 54: 427-432. http://dx.doi.org/10.1016/j.ocecoaman.2011.02.003