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Habitat use patterns of franciscana dolphins (Pontoporia blainvillei) off southern Brazil in relation to water depth

  • Daniel Danilewicz (a1) (a2), Eduardo R. Secchi (a3) (a2), Paulo H. Ott (a1) (a4) (a2), Ignacio B. Moreno (a1), Manuela Bassoi (a3) (a5) (a2) and Márcio Borges-Martins (a1) (a6)...

Abstract

The patterns of habitat use by the franciscana dolphins (Pontoporia blainvillei) along its distribution are poorly known. This study investigates the patterns of habitat use with respect to depth for 181 individuals of different age, size, gender and reproductive condition off Rio Grande do Sul, southern Brazil. The results reveal that franciscanas are very homogeneously distributed according to depth. Individuals from all lengths utilize nearly the entire range of depths of the surveyed area. Larger or older animals do not use deeper waters than younger animals, indicating that body size and age are not limiting factors for franciscanas that occupy deeper or offshore waters. Gestation seems to not cause a change in the distribution of females. Although the sex-ratio of the overall data did not vary from 1:1 in different depth intervals, a small-scale comparison between the northern and southern coast demonstrated the existence of some kind of sexual segregation. Franciscana by-catch in Rio Grande do Sul is not sustainable and it is agreed that management procedures are needed. Nevertheless, the available data on species distribution do not allow the designing of a protected area in order to minimize the by-catches of a particular sex/reproductive class.

Copyright

Corresponding author

Correspondence should be addressed to: D. Danilewicz, Grupo de Estudos de Mamíferos Aquáticos do Rio, Grande do Sul (GEMARS), Rua Felipe Neri, 382/203, Porto Alegre 90440-150, Brazil email: daniel.danilewicz@gmail.com

References

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American Society of Mammalogy (1961) Standardized methods for measuring and recording data on the smaller cetaceans. Journal of Mammalogy 42, 471476.
Bassoi, M. (1997) Feeding of franciscana, Pontoporia blainvillei (Gervais and D'Orbigny, 1844), accidentally caught in coastal gillneting in southern Brazil. Bs dissertation. Universidade do Rio Grande, Rio Grande, Brazil.
Bordino, P. (2002) Movement patterns of franciscana dolphin (Pontoporia blainvillei) in Bahia Anegada, Buenos Aires, Argentina. Latin American Journal of Aquatic Mammals 1, 7176.
Bordino, P., Thompson, G. and Iñiguez, M. (1999) Ecology and behaviour of the franciscana (Pontoporia blainvillei) in Bahía Anegada, Argentina. Journal of Cetacean Research and Management 1, 213222.
Bowyer, R.T. (2004) Sexual segregation in ruminants: definitions, hypotheses, and implications for conservation and management. Journal of Mammalogy 85, 10391052.
Brownell, R.L. Jr (1984) Review of reproduction in platanistid dolphins. Report of the International Whaling Commission 6, 149158.
Corcuera, J., Monzon, F., Crespo, E.A., Aguilar, A. and Raga, J.A. (1994) Interactions between marine mammals and the coastal fisheries of Necochea and Claromecó (Buenos Aires Province, Argentina). Report of the International Whaling Commission 15, 283290.
Cremer, M.J. and Simões-Lopes, P.C. (2005) The occurrence of Pontoporia blainvillei (Gervais & d'Orbigny) (Cetacea, Pontoporiidae) in an estuarine area in southern Brazil. Revista Brasileira de Zoologia 22, 717723.
Crespo, E.A., Harris, G. and González, R. (1998) Group size and distribution range of the franciscana, Pontoporia blainvillei. Marine Mammal Science 14, 845849.
Danilewicz, D. (2003) Reproduction of female franciscana (Pontoporia blainvillei) in Rio Grande do Sul, southern Brazil. Latin American Journal of Aquatic Mammals 2, 6778.
Danilewicz, D., Claver, J.A., Pérez Carrera, A.L., Secchi, E.R. and Fontoura, N.F. (2004) Reproductive biology of male franciscanas (Pontoporia blainvillei) (Mammalia: Cetacea) from Rio Grande do Sul, southern Brazil. Fishery Bulletin 102, 581592.
Emlem, S.T. and Oring, L.W. (1977) Ecology, sexual selection, and the evolution of mating systems. Science 197, 215223.
Heithaus, M.R. (2001) Predator–prey and competitive interactions between sharks (Order Selachii) and dolphins (Suborder Odontoceti): a review. Journal of Zoology 253, 5368.
Heithaus, M.R. and Dill, L.M. (2002) Food availability and tiger shark predation risk influence bottlenose dolphin habitat use. Ecology 83, 480491.
Hohn, A., Chivers, S.J. and Barlow, J. (1985) Reproductive maturity and seasonality of male spotted dolphins, Stenella attenuata, in the eastern tropical Pacific. Marine Mammal Science 1, 273293.
IUCN (2008) IUCN Red List of Threatened Species: A Global Species Assessment. Gland, Switzerland and Cambridge, UK: IUCN. Pontoporia blainvillei. Available from http://www.iucnredlist.org/search/details.php/41761/all (accessed September 2008).
Kinas, P.G. (2002) The impact of incidental kills by gillnets on the franciscana dolphin (Pontoporia blainvillei) in southern Brazil. Journal of Marine Science 70, 409421.
Mann, J., Connor, R.C., Barre, L.M. and Heithaus, M.R. (2000) Female reproductive success in bottlenose dolphins (Tursiops sp.): life history, habitat, provisioning, and group size effects. Behavioral Ecology 11, 210219.
Moreno, I.B., Ott, P.H. and Danilewicz, D. (1997) Análise preliminar do impacto da pesca artesanal costeira sobre Pontoporia blainvillei no litoral norte do Rio Grande do Sul, sul do Brasil. In Proceedings of the 2nd Workshop for the Coordination of Research and Conservation of Franciscana in the Southwestern Atlantic, Buenos Aires, Argentina, 1997, pp 3141.
Norris, K.S. and Dohl, T.P. (1980) Behavior of the Hawaiian spinner dolphin, Stenella longirostris. Fishery Bulletin 77, 821849.
Ott, P.H. (1994) Estudo da ecologia alimentar de Pontoporia blainvillei (Gervais; D'Orbigny 1844) (Cetacea, Pontoporiidae) no litoral norte do Rio Grande do Sul, Sul do Brasil. BSc dissertation. Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
Ott, P.H. (1998) Análise das capturas acidentais da toninha, Pontoporia blaivillei, no litoral norte do Rio Grande do Sul, sul do Brasil. MSc dissertation. Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil.
Ott, P.H. and Danilewicz, D. (1998) Presence of franciscana dolphins (Pontoporia blainvillei) in the stomach of a killer whale (Orcinus orca) stranded in southern Brazil. Mammalia 62, 605609.
Ott, P.H., Secchi, E.R., Moreno, I.B., Danilewicz, D., Crespo, E.A., Bordino, P., Ramos, R., Di Beneditto, A.P., Bertozzi, C., Bastida, R., Zanelatto, R., Perez, J. and Kinas, P.G. (2002) Report of the working group of fishery interactions. Latin American Journal of Aquatic Mammals 1, 5564.
Perrin, W.F. and Donovan, G.P. (1984) Report of the workshop. Report of the International Whaling Commission 6, 124.
Pinedo, M.C. (1994) Impact of incidental fishery mortality on the age structure of Pontoporia blainvillei in southern Brazil and Uruguay. Report of the International Whaling Commission 15, 261264.
Pinedo, M.C. and Hohn, A. (2000) Growth layer patterns in teeth from the franciscana, Pontoporia blainvillei: developing a model for precision in age estimation. Marine Mammal Science 16, 127.
Pinedo, M.C., Praderi, R. and Brownell, R.L. Jr (1989) Review of the biology and status of the franciscana, Pontoporia blainvillei. In Perrin, W.F., Brownell, R.L. Jr., Kaya, Z. and Jiankang, L. (eds) Biology and conservation of river dolphins. Occasional Papers of the IUCN Species Survival Commission, pp. 4651.
Praderi, R. (1985) Relaciones entre Pontoporia blainvillei (Mammalia: Cetacea) e tiburones Selachii) de aguas Uruguaias. Comunicaciones de Zoologia del Museo de Historia Natural de Montevideo 11, 119.
Praderi, R. (1986) Comentarios sobre la distribución de Pontoporia blainvillei en aguas del Rio de La Plata. In Proceedings of the 1st Reunión de Trabajo de Expecialistas en Mamiferos Acuaticos de América del Sur, Buenos Aires, Argentina, 1984, pp. 206214.
Praderi, R., Pinedo, M.C. and Crespo, E.A. (1989) Conservation and management of Pontoporia blainvillei in Uruguay, Brazil and Argentina. In Perrin, W.F., Brownell, R.L. Jr., Kaya, Z. and Jiankang, L. (eds) Biology and conservation of river dolphins. Occasional Papers of the IUCN Species Survival Commission, pp. 5256.
Rodriguez, D., Rivero, L. and Bastida, R. (2002) Feeding ecology of the franciscana (Pontoporia blainvillei) in marine and estuarine waters of Argentina. Latin American Journal of Aquatic Mammals 1, 7794.
Rosas, F.C.W., Monteiro-Filho, E.L.A. and Oliveira, M.R. (2002) Incidental catches of franciscana (Pontoporia blainvillei) on the southern coast of São Paulo state and the coast of Paraná state, Brazil. Latin American Journal of Aquatic Mammals 1, 161167.
Santos, M.C.O. and Netto, D.F. (2005) Killer whale (Orcinus orca) predation on a franciscana dolphin (Pontoporia blainvillei) in Brazilian waters. Latin American Journal of Aquatic Mammals 4, 6972.
Secchi, E.R., Zerbini, A.N., Bassoi, M., Dalla Rosa, L., Moller, L.M. and Rocha-Campos, C.C. (1997a) Mortality of franciscanas, Pontoporia blainvillei, in coastal gillnetting in southern Brazil. Report of the International Whaling Commission 47, 653658.
Secchi, E.R., Dalla Rosa, L., Bassoi, M. and Barcellos, L. (1997b) Uma alternativa para minimizar o impacto da pesca costeira de emalhe sobre a população de toninhas, Pontoporia blainvillei (Cetacea, Pontoporiidae), no sul do Brazil. In Proceedings of the 7th Congresso Latino-Americano sobre Ciências do Mar, Santos, SP, 1997. Associação Latino-Americana dos Profissionais de Ciências do Mar, pp. 428429.
Secchi, E.R., Ott, P.H. and Danilewicz, D. (2003a) Effects of fishing by-catch and the conservation status of the franciscana dolphin, Pontoporia blainvillei. In Gales, N., Hindell, M. and Kirkwood, R. (eds) Marine mammals: fisheries, tourism and management issues. Collingwood, Australia: CSIRO Publishing, pp. 174191.
Secchi, E.R., Danilewicz, D. and Ott, P.H. (2003b) Applying the phylogeographic concept to identify Franciscana dolphin stocks: implications to meet management objectives. Journal of Cetacean Research and Management 5, 6168.
Secchi, E.R., Kinas, P.G. and Muelbert, M. (2004) Incidental catches of franciscana in coastal gillnet fisheries in the Franciscana Management Area III: period 1999–2000. Latin American Journal of Aquatic Mammals 3, 6168.
Secchi, E.R. (2006) Modelling the population dynamics and viability analysis of franciscana (Pontoporia blainvillei) and Hector's dolphins (Cephalorynchus hectori) under the effects of bycatch in fisheries, parameter uncertainty and stochasticity. Doctoral thesis, University of Otago. Dunedin, New Zealand.
Siciliano, S., Di Beneditto, A.P. and Ramos, R.M.A. (2002) A toninha, Pontoporia blainvillei (Gervais & d'Orbigny, 1844) (Mammalia, Cetacea, Pontoporiidae), nos estados do Rio de Janeiro e Espírito Santo, costa sudeste do Brasil: caracterizações dos habitats e fatores de isolamento das populações. Boletim do Museu Nacional.(Zoologia) 476, 115.
Wells, R.S., Scott, M.D. and Irvine, A.B. (1987) The social structure of free-ranging bottlenose dolphins. In Enoways, H.H. (ed.) Current mammalogy. Volume 1. New York: Plenum Press, pp. 247305.

Keywords

Habitat use patterns of franciscana dolphins (Pontoporia blainvillei) off southern Brazil in relation to water depth

  • Daniel Danilewicz (a1) (a2), Eduardo R. Secchi (a3) (a2), Paulo H. Ott (a1) (a4) (a2), Ignacio B. Moreno (a1), Manuela Bassoi (a3) (a5) (a2) and Márcio Borges-Martins (a1) (a6)...

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