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Cetacean distribution and relative abundance in offshore Gabonese waters

Published online by Cambridge University Press:  28 July 2010

Marijke N. de Boer*
Affiliation:
Wageningen IMARES, Institute for Marine Resources and Ecosystem Studies, Postbus 167, 1790 AD Den Burg, The Netherlands
*
Correspondence should be addressed to: M.N. de Boer, Wageningen IMARES, Institute for Marine Resources and Ecosystem Studies, Postbus 167, 1790 AD Den Burg, The Netherlands email: marijke.deboer@wur.nl

Abstract

Information on cetaceans off Gabon in tropical West Africa is summarized from boat-based surveys carried out between 7 March and 7 August 2009. Thirteen cetacean species were positively identified comprising two baleen whale species, one sperm whale species and ten species of delphinid. Bryde's whale (Balaenoptera brydei) and humpback whale (Megaptera novaeangliae) were the most frequently encountered species. Cetaceans were found throughout a range of sea surface temperature between 20.5°C and 27.5°C and a wide range of depths with the majority of effort and sightings occurring seaward of the shelf break. Of particular interest from the study were the following: (1) Gabonese waters have a broad cetacean diversity, especially with a large and diversified delphinid community in the northern part of the study area; (2) the variations in oceanographic conditions within Gabonese waters are likely to result in a temporal variation in species composition; (3) the sightings of Atlantic spotted dolphin (Stenella frontalis) are the first at-sea sightings confirmed for these waters, although not unexpected given their distribution and abundant presence in surrounding waters; and (4) the poorly known Clymene dolphin (Stenella clymene) was sighted on four occasions in deep oceanic waters and was the most abundant cetacean. These are the first confirmed records of Clymene dolphins in Gabonese waters.

Type
Research Article
Copyright
Copyright © Marine Biological Association of the United Kingdom 2010

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References

REFERENCES

Best, P.B. (1977) Two allopatric forms of Bryde's whale off South Africa. Reports of the International Whaling Commission Special Issue 1, 1038.Google Scholar
Best, P.B. (2001) Distribution and population separation of Bryde's whale Balaenoptera edeni off southern Africa. Marine Ecology Progress Series 220, 277–89.CrossRefGoogle Scholar
Best, P.B. (2007) Whales and dolphins of the Southern African Subregion. Cape Town: Cambridge University Press.Google Scholar
Best, P.B. and Rickett, L.H. (1984) An assessment cruise for the South African inshore stock of Bryde's whales (Balaenoptera edeni). Reports of the International Whaling Commission, 34, 403423.Google Scholar
Budker, P. and Collignon, J. (1952) Trois campagnes balenières au Gabon: 1949–1950–1951. Bulletin de l'Institut d'Etudes Centrafricaines 3, 75100.Google Scholar
De Boer, M.N. (in press) First record of an anomalously white rough-toothed dolphin (Steno bredanensis) off tropical West Africa (Gabon) including notes on behaviour. Biodiversity Records.Google Scholar
Bost, C.A., Cotté, C., Bailleul, F., Cherel, Y., Charrassin, J.B., Guinet, C., Ainley, D.G. and Weimerskirch, H. (2009) The importance of oceanographic fronts to marine birds and mammals of the southern oceans. Journal of Marine Systems 78, 363376.CrossRefGoogle Scholar
Clapham, P.J. (2000) The humpback whale: seasonal feeding and breeding in a baleen whale. In Mann, J., Connor, R.C., Tyack, P.L. and Whitehead, H. (eds) Cetacean societies. Chicago, IL; University of Chicago Press, pp. 173196.Google Scholar
Collins, T., Cerchio, S., Pomilla, C., Loo, J., Carvalho, L., Ngouessono, S. and Rosenbaum, H.C. (2008) Revised estimates of abundance using mark-recapture data for breeding stock 1B: Gabon. Paper SC/60/SH28 presented to the IWC Scientific Committee, June 2008, Santiago, Chile, 17 pp.Google Scholar
Collins, T., Ngouessono, S. and Rosenbaum, H.C. (2004) A note on recent surveys for Atlantic humpback dolphins, Sousa teuszii (Kukenthal, 1892) in the coastal waters of Gabon. Paper SC/56/SM23 presented to the IWC Scientific Committee, June 2004, Sorrento, Italy, 6 pp.Google Scholar
Fertl, D., Jefferson, T.A., Moreno, I.B., Zerbini, A.N. and Mullin, K.D. (2003) Distribution of the Clymene dolphin Stenella clymene. MammalReview 33, 253271.Google Scholar
Findlay, K.P., Collins, T. and Rosenbaum, H.C. (2006) Environmental impact assessment and mitigation of marine hydrocarbon exploration and production in the Republic of Gabon. Report of the Wildlife Conservation Society, Bronx, NY, 166 pp.Google Scholar
Hoyt, E. (2005) Marine Protected Areas for whales, dolphins and porpoises—a world handbook for cetacean habitat conservation. London: Earthscan, 492 pp.Google Scholar
Jefferson, T.A. (1996) Morphology of the Clymene dolphin (Stenella clymene) in the northern Gulf of Mexico. Aquatic Mammals 22, 3543.Google Scholar
Jefferson, T.A., Curry, B.E., Leatherwood, S. and Powell, J.A. (1997) Dolphins and porpoises of West Africa: a review of records (Cetacea: Delphinidae, Phocoenidae). Mammalia 61, 87108.CrossRefGoogle Scholar
Johnston, D.W., Westgate, A.J. and Read, A.J. (2005) Effects of fine scale oceanographic features on the distribution and movements of harbour porpoises Phocoena phocoena in the Bay of Fundy. Marine Ecology Progress Series 295, 279293.CrossRefGoogle Scholar
Longhurst, A.R. (1962) A review of the oceanography of the Gulf of Guinea. Bulletin de l'Institute Africain Noire Serie A 24, 633663.Google Scholar
MacLeod, C.D. and Bennett, E. (2006) Pantropical spotted dolphins (Stenella attenuata) and other cetaceans around St Helena. Journal of the Marine Biological Association of the United Kingdom 87, 339344.CrossRefGoogle Scholar
Maigret, J. (1981) Rapports entre les cétacés et la pêche thonière dans l'Atlantique tropical oriental. Notes Africaines 171, 7784.Google Scholar
Maigret, J. (1994) Marine mammals and fisheries along the West African coast. Reports of the International Whaling Commission, Special Issue 15, 307316.Google Scholar
Odekunle, T.O. and Eludoyin, A.O. (2008) Sea surface temperature patterns in the Gulf of Guinea: their implications for the spatio-temporal variability of precipitation in West Africa. International Journal of Climatology 28, 15071517.CrossRefGoogle Scholar
Panigada, S., Notarbartolo di Sciara, G., Zanardelli Panigada, M., Airoldi, S., Borsani, J.F. and Jahoda, M. (2005) Fin whales (Balaenoptera physalus) summering in the Ligurian Sea: distribution, encounter rate, mean group size and relation to physiographic variables. Journal of Cetacean Research and Management 7, 137145.Google Scholar
Perrin, W.F. and Mead, J.G. (1994) Clymene dolphin Stenella clymene (Gray, 1846). In Ridgway, S.H. and Harrison, R. (eds) Handbook of marine mammals, Volume 5: the first book of dolphins. London: Academic Press, pp. 161171.Google Scholar
Perrin, W.F. and Van Waerebeek, K. (2007) The small cetacean fauna of the west coast of Africa and Macaronesia: diversity and distribution. Western African Talks on Cetaceans and their Habitats. Convention on the Conservation of Migratory Species of Wild Animals. UNEP/CMS-WATCH-Inf.6. Tenerife.Google Scholar
Perrin, W.F., Mitchell, E.D., Mead, J.G., Caldwell, D.K., Caldwell, M.C., van Bree, P.J.H. and Dawbin, W.H. (1987) Revision of the spotted dolphins, Stenella spp. Marine Mammal Science 3, 99170.CrossRefGoogle Scholar
Picanço, C., Carvalho, I. and Brito, C. (2009) Occurrence and distribution of cetaceans in São Tomé and Príncipe tropical archipelago and their relation to environmental variables. Journal of the Marine Biological Association of the United Kingdom 89, 10711076.CrossRefGoogle Scholar
Pomilla, C. and Rosenbaum, H.C. (2006) Estimates of relatedness in groups of humpback whales (Megaptera novaeangliae) on two wintering grounds of the Southern Hemisphere. Molecular Ecology 15, 25412555.CrossRefGoogle ScholarPubMed
Robineau, D., Vely, M. and Maigret, J. (1994) Stenella clymene (Cetacea, Delphinidae) from the coast of West Africa. Journal of Mammalogy 75, 766767.CrossRefGoogle Scholar
Reeves, R.R. and Mitchell, E. (1988) Killer whale sightings and takes by American pelagic whalers in the North Atlantic. Rit Fiskideildar 11, 723.Google Scholar
Rosenbaum, H.C. and Collins, T. (2004) Cetacean conservation and research in Gabon. Bronx, NY: Wildlife Conservation Society.Google Scholar
Rosenbaum, H.C. and Collins, T. (2006) The ecology, population characteristics and conservation efforts for humpback whales (Megaptera novaeangliae) on their wintering grounds in the coastal waters of Gabon. Bulletin of the Biological Society of Washington 12, 425433.Google Scholar
Rosenbaum, H.C., Pomilla, C., Mendez, M., Leslie, M.S., Best, P.B., Findlay, K.P., Minton, G., Ersts, P.J., Collins, T., Engel, M.H., Bonatto, S.L., Kotze, D.P.G.H., Meÿer, M., Barendse, J., Thornton, M., Razafindrakoto, Y., Nogouessono, S., Vely, M. and Kiska, J. (2009) Population structure of humpback whales from their breeding grounds in the South Atlantic and Indian Oceans. PLoS ONE 4(10): e7318. doi:10.1371/journal.pone.0007318.Google ScholarPubMed
Roy, C. (2004) Coastal upwelling in the Gulf of Guinea. In Robinson, A.R. and Brink, K.H. (eds) The sea—the global coastal ocean, interdisciplinary regional studies and synthesis, Volume 14, Part 2. Cambridge, MA: Harvard University Press, pp. 867874.Google Scholar
Siciliano, S., de Oliveira Santos, M.C., Vincente, A.F.C., Alvarenga, F.S., Zampirolli, E., Brito, J.L., Azevedo, A.F. and Pizzorno, J.L.A. (2004) Strandings and feeding records of Bryde's whales (Balaenoptera edeni) in south-eastern Brazil. Journal of the Marine Biological Association of the United Kingdom 84, 857859.CrossRefGoogle Scholar
Townsend, C.H. (1935) The distribution of certain whales as shown by logbook records of American whaleships. Zoologica 19, 150.Google Scholar
Van Waerebeek, K. (1997) Long-beaked and short-beaked common dolphin sympatric of central-west Africa. Paper SC/49/SM46 presented to the IWC Scientific Committee, October 1997, Bournemouth, UK, 4 pp.Google Scholar
Van Waerebeek, K. (2007) Conservation status of the Clymene dolphin in West Africa. Report CMS/ScC14/Doc.5 submitted at the 14th meeting of the CMS Scientific Council, Bonn, Germany, March 2007.Google Scholar
Weir, C.R. (2006a) Sightings of rough-toothed dolphins (Steno bredanensis) off Angola and Gabon, South-east Atlantic Ocean. Abstract submitted to the 20th Annual Conference of the European Cetacean Society, April 2006, Gdynia, Poland.Google Scholar
Weir, C.R. (2006b) First confirmed records of Clymene dolphin, Stenella clymene (Gray, 1850), from Angola and Congo, Southeast Atlantic Ocean. African Zoology 41, 297300.CrossRefGoogle Scholar
Weir, C.R. (2006c) Sightings of beaked whales (Cetacea: Ziphiidae) including first confirmed Cuvier's beaked whales Ziphius cavirostris from Angola. African Journal of Marine Science 28, 173–75.CrossRefGoogle Scholar
Weir, C.R. (2007) Occurrence and distribution of cetaceans off northern Angola, 2005/05. Journal of Cetacean Research and Management 9, 225239.Google Scholar
Weir, C.R. (2010) A review of cetacean occurrence in West African waters from the Gulf of Guinea to Angola. Mammal Review 40, 239.CrossRefGoogle Scholar
Weir, C.R. and Coles, P. (2007) Morphology of common dolphins (Delphinus spp.) photographed off Angola. Abstracts of the 17th Biennial Conference of the Society for Marine Mammalogy, Cape Town, South Africa, 29 November–3 December, 2007.Google Scholar
Weir, C.R., Collins, T., Carvalho, I. and Rosenbaum, H.C. (in press) Killer whales (Orcinus orca) in Angolan and Gulf of Guinea waters, tropical West Africa. Journal of the Marine Biological Association of the United Kingdom.Google Scholar
Whitehead, P.J.P. (1985) An annotated and illustrated catalogue of the herrings, sardines, pilchards, sprats, anchovies and wolf-herrings. In Whitehead, P.J.P. (ed.) Part 1. Chirocentridae, Clupeidae and Pristigasteridae. FAO Fisheries Synopsis Volume 7, 303 pp.Google Scholar
Yen, P.P.W., Sydeman, W.J. and Hyrenbach, K.D. (2004) Marine bird and cetacean associations with bathymetric habitats and shallow water topographies: implications for trophic transfer and conservation. Journal of Marine Systems 50, 7999.CrossRefGoogle Scholar