Hostname: page-component-cd9895bd7-gxg78 Total loading time: 0 Render date: 2024-12-19T00:43:28.517Z Has data issue: false hasContentIssue false

Trends in cetacean sightings along the Galician coast, north-west Spain, 2003–2007, and inferences about cetacean habitat preferences

Published online by Cambridge University Press:  06 July 2010

Graham J. Pierce*
Affiliation:
Instituto Español de Oceanografía, Centro Oceanográfico de Vigo, PO Box 1552, 36200, Vigo, Spain School of Biological Sciences, University of Aberdeen, Tillydrone Avenue, Aberdeen AB24 2TZ, UK
Mara Caldas
Affiliation:
CEMMA, Apartado 15, 36380 Gondomar, Pontevedra, Spain
Jose Cedeira
Affiliation:
CEMMA, Apartado 15, 36380 Gondomar, Pontevedra, Spain
M. Begoña Santos
Affiliation:
Instituto Español de Oceanografía, Centro Oceanográfico de Vigo, PO Box 1552, 36200, Vigo, Spain
Ángela Llavona
Affiliation:
CEMMA, Apartado 15, 36380 Gondomar, Pontevedra, Spain
Pablo Covelo
Affiliation:
CEMMA, Apartado 15, 36380 Gondomar, Pontevedra, Spain
Gema Martinez
Affiliation:
Departamento de Fisica Aplicada, Edificio de Ciencias Experimentales, Campus Lagoas Marcosende, Universidad de Vigo, 36310 Vigo (Pontevedra), Spain
Jesus Torres
Affiliation:
Departamento de Fisica Aplicada, Edificio de Ciencias Experimentales, Campus Lagoas Marcosende, Universidad de Vigo, 36310 Vigo (Pontevedra), Spain
Mar Sacau
Affiliation:
Instituto Español de Oceanografía, Centro Oceanográfico de Vigo, PO Box 1552, 36200, Vigo, Spain
Alfredo López
Affiliation:
CEMMA, Apartado 15, 36380 Gondomar, Pontevedra, Spain
*
Correspondence should be addressed to: G.J. Pierce, School of Biological Sciences, University of Aberdeen, Tillydrone Avenue, Aberdeen AB24 2TZ, UK email: [email protected]

Abstract

Since mid-2003, systematic monthly sightings surveys for cetaceans have been carried out in Galicia (north-west Spain) from observation points around the coastline, with the aim of providing baseline data on cetacean distribution and habitat use to underpin future conservation measures. Here we summarize results for September 2003 to October 2007. The most frequently recorded species were the bottlenose dolphin (Tursiops truncatus, seen during 10.7% of observation periods), common dolphin (Delphinus delphis, 3.7%), harbour porpoise (Phocoena phocoena, 1.6%), Risso's dolphin (Grampus griseus, 0.4%) and short-finned pilot whale (Globicephala melas, 0.2%). The three most common species showed different distribution patterns along the coast. In terms of habitat preferences, bottlenose dolphins were seen to be associated with more productive areas (areas with higher chlorophyll-a concentrations) where the continental shelf was wider while both common dolphins and harbour porpoises were seen most frequently in less productive areas where the continental shelf is narrowest. Possible reasons for differences in habitat use include differing diets. In Galician waters, all three main cetacean species feed primarily on fish that are common in shelf waters, and in the case of blue whiting (the most important species in the stomach contents of common and bottlenose dolphins) abundant also on the slope. All three cetaceans feed on blue whiting while scad is important in diets of common dolphin and porpoise. It is also possible that porpoises do not use areas frequented by bottlenose dolphins in order to avoid aggressive interactions. Retrospective evaluation of the sampling regime, using data from the 2500 observation periods during 2003–2007 suggests that the overall sightings rates for all species (taking into account observation time and between-site travel time) would be higher if average observation duration was increased to at least 40 minutes. On the other hand, confidence limits on sightings rates stabilized after around 1000 observation periods, suggesting that the number of sites visited or the frequency of visits could be substantially reduced.

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

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Alonso, J.M., López, A., González, A.F. and Santos, M.B. (2000) Evidence of violent interactions between bottlenose dolphin (Tursiops truncatus) and other cetacean species in NW Spain. European Research on Cetaceans 14, 105106.Google Scholar
Bejder, L., Samuels, A., Whitehead, H., Gales, N., Mann, J., Connor, R., Heithaus, M., Watson-Capps, J., Flaherty, C. and Krutzen, M. (2006) Decline in relative abundance of bottlenose dolphins exposed to long-term disturbance. Conservation Biology 20, 17911798.CrossRefGoogle ScholarPubMed
Cendrero, O. (1993) Note on findings of cetaceans off northern Spain. Boletin del Instituto Español de Oceanografía 9, 251255.Google Scholar
Charnov, E.L. (1976) Optimal foraging: the marginal value theorem. Theoretical Population Biology 9, 129136.CrossRefGoogle ScholarPubMed
Evans, P.G.H. and Hammond, P.S. (2004) Monitoring Cetoceans in European waters. Mammol Review 34, 131156.Google Scholar
González, A.F., López, A., Guerra, A. and Barreiro, A. (1994) Diets of marine mammals stranded on the northwestern Spanish Atlantic coast with special reference to Cephalopoda. Fisheries Research 21, 179191.CrossRefGoogle Scholar
Hastie, G.D., Wilson, B., Tufft, L.H. and Thompson, P.M. (2003) Bottlenose dolphins increase breathing synchrony in response to boat traffic. Marine Mammal Science 19, 7484.CrossRefGoogle Scholar
Lahaye, V., Bustamante, P., Law, R.J., Learmonth, J.A., Santos, M.B., Boon, J.P., Rogan, E., Dabin, W., Addink, M.J., López, A., Zuur, A.F., Pierce, G.J. and Caurant, F. (2007) Biological and ecological factors related to trace element levels in harbour porpoises (Phocoena phocoena) from European waters. Marine Environmental Research 64, 247266.CrossRefGoogle ScholarPubMed
López, A. and Rodriguez Folgar, A. (1995) Agresión de arroás (Tursiops truncatus) a toniña (Phocoena phocoena). Eubalaena 6, 2327.Google Scholar
López, A., Santos, M.B., Pierce, G.J., González, A.F., Valeiras, X. and Guerra, A. (2002) Trends in strandings and by-catch of marine mammals in north-west Spain during the 1990s. Journal of the Marine Biological Association of the United Kingdom 82, 513521.CrossRefGoogle Scholar
López, A., Pierce, G.J., Santos, M.B., Gracia, J. and Guerra, A. (2003a) Fishery by-catches of marine mammals in Galician waters: Results from on-board observations and an interview survey of fishermen. Biological Conservation 111, 2540.Google Scholar
López, A., Cedeira, J.M., Caldas, M., Carril, R., Solla, P. and Llavona, A. (2003b) Monitorización de las poblaciones de cetáceos en la plataforma de Galicia (NW Spain). Thalassas 19, 111112.Google Scholar
López, A., Pierce, G.J., Valeiras, X., Santos, M.B. & Guerra, A. (2004). Distribution patterns of small cetaceans in Galician waters. Journal of the Marine Biological Association of the United Kingdom 84, 283294.CrossRefGoogle Scholar
Mattson, M.C., Thomas, J.A. and St Aubin, D. (2005) Effects of boat activity on the behavior of bottlenose dolphins (Tursiops truncatus) in waters surrounding Hilton Head Island, South Carolina. Aquatic Mammals 31, 133140.Google Scholar
Murphy, S., Herman, J., Pierce, G.J., Rogan, E. and Kitchener, A. (2006) Taxonomic status and geographical cranial variation of common dolphins (Delphinus) in the eastern north Atlantic. Marine Mammal Science 22, 573599.CrossRefGoogle Scholar
Nowacek, S.M., Wells, R.S. and Solow, A.R. (2001) Short-term effects of boat traffic on bottlenose dolphins, Tursiops truncatus, in Sarasota Bay, Florida. Marine Mammal Science 17, 673688.CrossRefGoogle Scholar
Pierce, G.J., Santos, M.B., Murphy, S., Learmonth, J.A., Zuur, A.F., Rogan, E., Bustamante, P., Caurant, F., Lahaye, V., Ridoux, V., Zegers, B.N., Mets, A., Addink, M., Smeenk, C., Jauniaux, T., Law, R.J., Dabin, W., López, A., Alonso Farré, J.M., González, A.F., Guerra, A., García-Hartmann, M., Reid, R.J., Moffat, C.F., Lockyer, C. and Boon, J.P. (2008) Bioaccumulation of persistent organic pollutants in female common dolphins (Delphinus delphis) and harbour porpoises (Phocoena phocoena) from western European seas: geographical trends, causal factors and effects on reproduction and mortality. Environmental Pollution 153, 401415.CrossRefGoogle ScholarPubMed
Redfern, J.V., Ferguson, M.C., Becker, E.A., Hyrenbach, K.D., Good, C., Barlow, J., Kaschner, K., Baumgartner, M.F., Forney, K.A., Ballance, L.T., Fauchald, P., Halpin, P., Hamazaki, T., Pershing, A.J., Qian, S.S., Read, A., Reilly, S.B., Torres, L. and Werner, F. (2006) Techniques for cetacean-habitat modelling. Marine Ecology Progress Series 310, 271295.CrossRefGoogle Scholar
Ridoux, V., Lafontaine, L., Bustamante, P., Caurant, F., Dabin, W., Delcroix, C., Hassani, S., Meynier, L., da Silva, V.P., Simonin, S., Robert, M., Spitz, J. and Van Canneyt, O. (2004) The impact of the ‘Erika’ oil spill on pelagic and coastal marine mammals: combining demographic, ecological, trace metals and biomarker evidences. Aquatic Living Resources 17, 379387.CrossRefGoogle Scholar
Santos, M.B., Pierce, G.J., López, A., Martínez, J.A., Fernández, M.T., Ieno, E., Mente, E., Porteiro, C., Carrera, P. and Meixide, M. (2004) Variability in the diet of common dolphins (Delphinus delphis) in Galician waters 1991–2003 and relationship with prey abundance. International Council for the Exploration of the Sea CM 2004/Q:09.Google Scholar
Santos, M.B., Fernández, R., López, A., Martínez, J.A. and Pierce, G.J. (2007) Variability in the diet of bottlenose dolphin, Tursiops truncatus (Montagu), in Galician waters, NW Spain, 1990–2005. Journal of the Marine Biological Association of the United Kingdom 87, 231242.CrossRefGoogle Scholar
Sini, M.I., Canning, S.J., Stockin, K.A. and Pierce, G.J. (2005) Bottlenose dolphins around the Aberdeen harbour, north-east Scotland: a study of habitat utilization and the potential effects of boat traffic. Journal of the Marine Biological Association of the United Kingdom 85, 15471554.CrossRefGoogle Scholar
Stockin, K.A., Lusseau, D., Binedell, V., Wiseman, N. and Orams, M.B. (2008) Tourism affects the behavioural budget of the common dolphin Delphinus sp. in the Hauraki Gulf, New Zealand. Marine Ecology Progress Series 355, 287295.CrossRefGoogle Scholar
Torres, L.G., Read, A.J. and Halpin, P. (2008) Fine-scale habitat modeling of a top marine predator: do prey data improve predictive capacity? Ecological Applications 18, 17021717.Google Scholar
Valavanis, V.D., Pierce, G.J., Zuur, A.F., Palialexis, A., Saveliev, A., Katara, I. and Wang, J. (2008) Modelling of essential fish habitat based on remote sensing, spatial analysis and GIS. Hydrobiologia 612, 520.CrossRefGoogle Scholar
Varela, M., Diaz del Rio, G., Alvarez-Ossorio, M.T. and Costas, E. (1991) Factors controlling phytoplankton size class distribution in the upwelling area of the Galician continental shelf northwest Spain. Scientia Marina 55, 505518.Google Scholar
Vieites, D.R., Nieto-Roman, S., Palanca, A., Ferrer, X. and Vences, M. (2004) European Atlantic: the hottest oil spill hotspot worldwide. Naturwissenschaften 91, 535538.Google Scholar
Visser, F., Hartman, K.L., Rood, E.J.J., Hendriks, A.J.E., Zult, D.B., Wolff, W.J., Huisman, J. and Pierce, G.J. (in press) Risso's dolphin alters daily resting pattern in response to whale watching at the Azores. Marine Mammal Science.Google Scholar