Stenella frontalis

Taxonomy

Assessment Information

Geographic Range

Population

Habitat and Ecology

Threats

Conservation Actions

Bibliography

View Printer Friendly

Taxonomy [top]

Kingdom	Phylum	Class	Order	Family
ANIMALIA	CHORDATA	MAMMALIA	CETARTIODACTYLA	DELPHINIDAE

Scientific Name:

Stenella frontalis

Species Authority:

(G. Cuvier, 1829)

Common Name/s:

English	–	Atlantic Spotted Dolphin, Bridled Dolphin
French	–	Dauphin Tacheté De L'Atlantique
Spanish	–	Delfín Manchado Del Atlántico, Delfín Pintado

Synonym/s:

Stenella plagiodon Cope, 1866

Taxonomic Notes:

Recent genetic work suggests that the genus Stenella is paraphyletic, and it is likely that the Delphininae will be restructured in coming years (LeDuc et al. 1999). This species might move to a different genus.

Assessment Information [top]

Red List Category & Criteria:

Data Deficient ver 3.1

Year Assessed:

2008

Assessor/s:

Hammond, P.S., Bearzi, G., Bjørge, A., Forney, K., Karczmarski, L., Kasuya, T., Perrin, W.F., Scott, M.D., Wang, J.Y., Wells, R.S. & Wilson, B.

Reviewer/s:

Rojas-Bracho, L. & Smith, B.D. (Cetacean Red List Authority)

Justification:
Although the species is widespread, abundance has not been estimated for the mid- and eastern Atlantic. Bycatches in West Africa are of unknown scale and potentially large.

History:

1996	–	Data Deficient
1994	–	Insufficiently Known (Groombridge 1994)

Geographic Range [top]

Range Description:	This species is found only in the Atlantic Ocean, from southern Brazil to the United States (New England) in the west, and to the coast of Africa in the east (the exact limits off West Africa are not well known – Perrin 2002a,b). A discontinuity in the range of the species exists in the western South Atlantic Ocean (Moreno et al., 2005).
Countries:	Native: Angola; Antigua and Barbuda; Bahamas; Barbados; Belize; Benin; Brazil; Cape Verde; Cayman Islands; Colombia; Costa Rica; Côte d'Ivoire; Cuba; Dominica; Dominican Republic; Equatorial Guinea; French Guiana; Gabon; Gambia; Ghana; Guinea; Haiti; Honduras; Jamaica; Martinique; Mauritania; Mexico; Montserrat; Netherlands Antilles; Nicaragua; Panama; Portugal (Azores, Madeira); Puerto Rico; Saint Helena; Saint Lucia; Saint Vincent and the Grenadines; Senegal; Sierra Leone; Spain (Canary Is.); Togo; United States; Venezuela; Virgin Islands, British; Virgin Islands, U.S. Presence uncertain: Argentina; Bermuda; Cameroon; Canada; Congo; Congo, The Democratic Republic of the; Grenada; Guadeloupe; Guatemala; Guinea-Bissau; Guyana; Liberia; Morocco; Namibia; Nigeria; Sao Tomé and Principe; Suriname; Trinidad and Tobago; Turks and Caicos Islands; Uruguay; Western Sahara
FAO Marine Fishing Areas:	Native: Atlantic – western central; Atlantic – northeast; Atlantic – northwest; Atlantic – southeast; Atlantic – southwest; Atlantic – eastern central
Range Map:	Click here to open the map viewer and explore range.

Population [top]

Population:	Data from surveys in the 1990s were used to estimate abundance in the northern Gulf of Mexico at 30,947 (CV=27%), although NMFS considers this an underestimate due to survey limitations (Waring et al. 2006). There are no data available from West Africa, but the few records available suggest that it is either not abundant or that it has an offshore distribution there (Van Waerebeek et al. 2000). A geographically and possibly genetically isolated population may occur off southern Brazil from 21-33°S (Moreno et al. 2005).
Population Trend:	Unknown

Population:

Data from surveys in the 1990s were used to estimate abundance in the northern Gulf of Mexico at 30,947 (CV=27%), although NMFS considers this an underestimate due to survey limitations (Waring et al. 2006). There are no data available from West Africa, but the few records available suggest that it is either not abundant or that it has an offshore distribution there (Van Waerebeek et al. 2000). A geographically and possibly genetically isolated population may occur off southern Brazil from 21-33°S (Moreno et al. 2005).

Population Trend:

Unknown

Habitat and Ecology [top]

Habitat and Ecology:	Distribution is mostly over the offshore continental shelf, but these dolphins also inhabit deep oceanic waters. The species is known from far-offshore Gulf-stream waters and the mid-tropical Atlantic (Perrin et al. 1987). The large, heavily spotted form of the Atlantic spotted dolphin along the south-eastern and Gulf coasts of the United States inhabits the continental shelf, usually being found inside or near the 200 m isobath (within 250-350 km of the coast), but sometimes coming into very shallow water adjacent to the beach seasonally, perhaps in pursuit of migratory fish (Perrin et al. 1987). In the Bahamas, Atlantic spotted dolphins spend much time in shallow water (6-12 m) over sand flats. The smaller and less-spotted forms that inhabit more pelagic offshore waters and waters around oceanic islands are less well known in their habitat requirements (Perrin et al. 1994; Jefferson and Schiro 1997. In the north-central and western Gulf of Mexico. Atlantic spotted dolphins were consistently found in the shallowest waters on the continental shelf and along the shelf break within the 250-m isobath (Davis et al. 1998). In addition, the bottom depth gradient (sea floor slope) was less for Atlantic spotted dolphins than for any other species. A wide variety of epi- and mesopelagic fishes and squids, as well as benthic invertebrates, are taken by this species (Perrin et al. 1994). There are known to be some regional differences in diet.
Systems:	Marine

Habitat and Ecology:

Distribution is mostly over the offshore continental shelf, but these dolphins also inhabit deep oceanic waters. The species is known from far-offshore Gulf-stream waters and the mid-tropical Atlantic (Perrin et al. 1987). The large, heavily spotted form of the Atlantic spotted dolphin along the south-eastern and Gulf coasts of the United States inhabits the continental shelf, usually being found inside or near the 200 m isobath (within 250-350 km of the coast), but sometimes coming into very shallow water adjacent to the beach seasonally, perhaps in pursuit of migratory fish (Perrin et al. 1987). In the Bahamas, Atlantic spotted dolphins spend much time in shallow water (6-12 m) over sand flats. The smaller and less-spotted forms that inhabit more pelagic offshore waters and waters around oceanic islands are less well known in their habitat requirements (Perrin et al. 1994; Jefferson and Schiro 1997. In the north-central and western Gulf of Mexico. Atlantic spotted dolphins were consistently found in the shallowest waters on the continental shelf and along the shelf break within the 250-m isobath (Davis et al. 1998). In addition, the bottom depth gradient (sea floor slope) was less for Atlantic spotted dolphins than for any other species.

A wide variety of epi- and mesopelagic fishes and squids, as well as benthic invertebrates, are taken by this species (Perrin et al. 1994). There are known to be some regional differences in diet.

Systems:

Marine

Threats [top]

Major Threat(s):	No direct killing is known, other than occasional catches in small Caribbean dolphin fisheries, possible off West Africa and possibly in the Azores (Jefferson et al. 1993; Perrin et al. 1994). Incidental catches in fisheries are known for several areas of the range (Brazil, the Caribbean, off the east coast of the United States, and in Mauritania). Some are probably also taken incidentally in tuna purse seines off the West African coast (Van Waerebeek et al. 2000). There are no reliable estimates of the number of animals taken in any of these fisheries (Jefferson et al. 1993). Atlantic spotted dolphins are also captured incidentally in gillnets in Brazil and Venezuela (Zerbini and Kotas 1998). In Venezuela, the dolphin carcasses are used for shark bait and for human consumption (Perrin et al. 1994). Mignucci-Giannoni et al. (1999) found that the most common human-related causes observed in strandings were entanglement and accidental captures, followed by animals being shot or speared. Niero et al. (1999) reported that in 1995, a large number of Atlantic spotted dolphins washed ashore on the sandy beaches north of Nouakchott, the capital of Mauritania. Workers surveyed the coastline to assess the number of corpses and the cause of death, which was attributed to fishery interaction.

Major Threat(s):

No direct killing is known, other than occasional catches in small Caribbean dolphin fisheries, possible off West Africa and possibly in the Azores (Jefferson et al. 1993; Perrin et al. 1994).

Incidental catches in fisheries are known for several areas of the range (Brazil, the Caribbean, off the east coast of the United States, and in Mauritania). Some are probably also taken incidentally in tuna purse seines off the West African coast (Van Waerebeek et al. 2000). There are no reliable estimates of the number of animals taken in any of these fisheries (Jefferson et al. 1993). Atlantic spotted dolphins are also captured incidentally in gillnets in Brazil and Venezuela (Zerbini and Kotas 1998). In Venezuela, the dolphin carcasses are used for shark bait and for human consumption (Perrin et al. 1994). Mignucci-Giannoni et al. (1999) found that the most common human-related causes observed in strandings were entanglement and accidental captures, followed by animals being shot or speared. Niero et al. (1999) reported that in 1995, a large number of Atlantic spotted dolphins washed ashore on the sandy beaches north of Nouakchott, the capital of Mauritania. Workers surveyed the coastline to assess the number of corpses and the cause of death, which was attributed to fishery interaction.

Conservation Actions [top]

Conservation Actions:	The species is listed in Appendix II of CITES. Abundance and bycatch in fisheries off West Africa should be investigated.

Conservation Actions:

The species is listed in Appendix II of CITES.

Abundance and bycatch in fisheries off West Africa should be investigated.

Bibliography [top]

	Davis, R. W., Fargion, G. S., May, N., Leming, T. D., Baumgartner, M., Evans, W. E., Hansen, L. J. and Mullin, K. 1998. Physical habitat of cetaceans along the continental slope in the north-central and western Gulf of Mexico. Marine Mammal Science 14(3): 490-507. Jefferson, T. A. and Schiro, A. J. 1997. Distribution of cetaceans in the offshore Gulf of Mexico. Mammal Review 27: 27-50. Jefferson, T. A., Leatherwood, S. and Webber, M. A. 1993. Marine Mammals of the World: FAO Species Identification Guide. United Nation Environment Programme and Food and Agricultural Organization of the UN. Leduc, R. G., Perrin, W. F. and Dizon, A. E. 1999. Phylogenetic relationships among the delphinid cetaceans based on full cytochrome b sequences. Marine Mammal Science 15: 619-648. Mignucci-Giannoni, A. A., Pinto-Rodriguez, R., Velasco-Escudero, M., Montoya-Ospina, R. A., Jiminez-Marrero, N. M., Rodriguez-Lopez, M. A., Williams, E. H. and Odell, D. K. 1999. Cetaceans strandings in Puerto Rico and the Virgin Islands. Journal of Cetacean Research and Management 1(2): 191-198. Moreno, I. B., Zerbini, A. N. Danilewicz, D., Santos, M. O. S., Simoes-Lopes, P. C., Lailson Brito, J. and Azevedo, A. F. 2005. Distribution and habitat characteristics of dolphins of the genus Stenella (Cetacea: Delphinidae) in the southwest Atlantic Ocean. Marine Ecology Progress Series 300: 229-240. Niero, M., Grau, E., Lamarche, B. and Aguilar, A. 1999. Mass mortality of Atlantic spotted dolphins (Stenella frontalis) caused by a fishing interaction in Mauritania. Marine Mammal Science 15: 847-853. Perrin, W. F. 2002. Atlantic spotted dolphin Stenella frontalis. In: W. F. Perrin, B. Wursig and J. G. M. Thewissen (eds), Encyclopedia of Marine Mammals, pp. 49-51. Academic Press. Perrin, W. F. 2002. Stenella frontalis. Mammalian Species 702: 1-6. Perrin, W. F., Caldwell, D. K. and Caldwell, M. C. 1994. Atlantic spotted dolphin Stenella frontalis (G. Cuvier, 1829). In: S. H. Ridgway and R. Harrison (eds), Handbook of marine mammals, Volume 5: The first book of dolphins, pp. 173-190. Academic Press. 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(2): 99-170. Van Waerebeek, K., Ndiave, E., Djiba, A., Diallo, M., Murphy, P., Jallow, A., Camara, A., Ndiave, P. and Tous, P. 2000. A survey of the conservation status of cetaceans in Senegal, the Gambia and Guinea-Bissau. WAFCET - I Report. Waring, G. T., Josephson, E., Fairfield, C. P. and Maze-Foley, K. (eds). 2006. U.S. Atlantic and Gulf of Mexico marine mammal stock assessments - 2005. NOAA Technical Memorandum NMFS-NE, pp. 346 pp.. Zerbini, A. N. and Kotas, J. E. 1998. A note on cetacean bycatch in pelagic driftnetting off southern Brazil. Reports of the International Whaling Commission 48: 519-524.

Davis, R. W., Fargion, G. S., May, N., Leming, T. D., Baumgartner, M., Evans, W. E., Hansen, L. J. and Mullin, K. 1998. Physical habitat of cetaceans along the continental slope in the north-central and western Gulf of Mexico. Marine Mammal Science 14(3): 490-507.

Jefferson, T. A. and Schiro, A. J. 1997. Distribution of cetaceans in the offshore Gulf of Mexico. Mammal Review 27: 27-50.

Jefferson, T. A., Leatherwood, S. and Webber, M. A. 1993. Marine Mammals of the World: FAO Species Identification Guide. United Nation Environment Programme and Food and Agricultural Organization of the UN.

Leduc, R. G., Perrin, W. F. and Dizon, A. E. 1999. Phylogenetic relationships among the delphinid cetaceans based on full cytochrome b sequences. Marine Mammal Science 15: 619-648.

Mignucci-Giannoni, A. A., Pinto-Rodriguez, R., Velasco-Escudero, M., Montoya-Ospina, R. A., Jiminez-Marrero, N. M., Rodriguez-Lopez, M. A., Williams, E. H. and Odell, D. K. 1999. Cetaceans strandings in Puerto Rico and the Virgin Islands. Journal of Cetacean Research and Management 1(2): 191-198.

Moreno, I. B., Zerbini, A. N. Danilewicz, D., Santos, M. O. S., Simoes-Lopes, P. C., Lailson Brito, J. and Azevedo, A. F. 2005. Distribution and habitat characteristics of dolphins of the genus Stenella (Cetacea: Delphinidae) in the southwest Atlantic Ocean. Marine Ecology Progress Series 300: 229-240.

Niero, M., Grau, E., Lamarche, B. and Aguilar, A. 1999. Mass mortality of Atlantic spotted dolphins (Stenella frontalis) caused by a fishing interaction in Mauritania. Marine Mammal Science 15: 847-853.

Perrin, W. F. 2002. Atlantic spotted dolphin Stenella frontalis. In: W. F. Perrin, B. Wursig and J. G. M. Thewissen (eds), Encyclopedia of Marine Mammals, pp. 49-51. Academic Press.

Perrin, W. F. 2002. Stenella frontalis. Mammalian Species 702: 1-6.

Perrin, W. F., Caldwell, D. K. and Caldwell, M. C. 1994. Atlantic spotted dolphin Stenella frontalis (G. Cuvier, 1829). In: S. H. Ridgway and R. Harrison (eds), Handbook of marine mammals, Volume 5: The first book of dolphins, pp. 173-190. Academic Press.

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(2): 99-170.

Van Waerebeek, K., Ndiave, E., Djiba, A., Diallo, M., Murphy, P., Jallow, A., Camara, A., Ndiave, P. and Tous, P. 2000. A survey of the conservation status of cetaceans in Senegal, the Gambia and Guinea-Bissau. WAFCET - I Report.

Waring, G. T., Josephson, E., Fairfield, C. P. and Maze-Foley, K. (eds). 2006. U.S. Atlantic and Gulf of Mexico marine mammal stock assessments - 2005. NOAA Technical Memorandum NMFS-NE, pp. 346 pp..

Zerbini, A. N. and Kotas, J. E. 1998. A note on cetacean bycatch in pelagic driftnetting off southern Brazil. Reports of the International Whaling Commission 48: 519-524.

Citation:	Hammond, P.S., Bearzi, G., Bjørge, A., Forney, K., Karczmarski, L., Kasuya, T., Perrin, W.F., Scott, M.D., Wang, J.Y., Wells, R.S. & Wilson, B. 2008. Stenella frontalis. In: IUCN 2011. IUCN Red List of Threatened Species. Version 2011.2. <www.iucnredlist.org>. Downloaded on 10 February 2012.
Disclaimer:	To make use of this information, please check the <Terms of Use>.
Feedback:	If you see any errors or have any questions or suggestions on what is shown on this page, please fill in the feedback form so that we can correct or extend the information provided