Red List of South African Species

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Least Concern (LC)
Assessors: Stephanie Plön Claire Relton Vic Cockcroft
Contributors: Simon Elwen Ken Findlay Michael Meÿer
Reviewers: Shanan Atkins Matthew Child

Rationale

Stenella species have not been well studied in the assessment region and population size and trend estimates are unavailable. However, periodic but regular strandings suggest that there is no major population decline of these species. Additionally, Pantropical Spotted and Spinner Dolphins are considered to be abundant in the Indian Ocean. Although general pelagic threats may apply and annual takes of Stenella species occur in regions outside of the assessment region, no major threats were identified for these species; thus they are not considered conservation priorities. However, the potential emerging threat of a drift-net fishery requires monitoring. The listing as Least Concern is retained for S. attenuata, S. coeruleoalba and S. longirostris.

Regional population effects: No barriers to dispersal of these species have been identified, thus rescue effects are possible.

Distribution

Generally, Stenella species occur in tropical and subtropical waters, but the extent of their range is poorly known in many regions (Moreno et al. 2005). The Spinner Dolphin occurs throughout tropical and subtropical zones of the northern and southern hemisphere, where the broad limits of their range extend from approximately 40°N to 40°S. Stenella l. longirostris primarily inhabits waters around the oceanic islands of the tropical Atlantic and Indian Oceans, as well as the western and central Pacific, eastwards to about 145°W (Rice 1998). In the assessment region, it occurs on the east coast from Kosi Bay southwards possibly to 34°S, and is found in coastal and continental shelf zones.

Population trend

Trend

No estimates of abundance are available for Stenella species within the assessment region. No population research has been conducted on Spinner Dolphins within the assessment region and it is known only from strandings and incidental sightings. Spinner Dolphins are wide-ranging, occurring both in deep pelagic waters far from the coast, as well as around islands and banks. The population is very unlikely to be isolated and long distance movement is high probable. Additionally, movement between Mozambique and South Africa is expected. Model based estimates of generation time for the Pantropical Spotted Dolphin and Spinner Dolphin have been recorded at 23.1 years and 13.7 years, respectively (Taylor et al. 2007).

Threats

The offshore distribution of Stenella species within the region suggests that industrial activity is not a major threat, additionally MacLeod (2009) predicted that due to the tropical distribution of S. attenuata and S. longirostris, it is unlikely that these species would be negatively influenced by the effects of climate change. However, although it is largely undocumented, due to their diet and distribution, localized threats to these species include accidental bycatch and competition for prey resources associated with pelagic fisheries.

Spinner Dolphins have been recorded as bycatch in purse-seine, trawl and gillnet fisheries throughout their range (Donahue & Edwards 1996). Although the rate of bycatch is largely unrecorded, as the most abundant dolphin within the Indian Ocean, entanglement incidences of Spinner Dolphins is likely to be substantial in this region. Artisanal set nets off Mozambique have been identified as a specific threat to Spinner Dolphins. In the eastern Tropical Pacific mortality as a result of entanglement in purse-seine fisheries was estimates at 130,000 individuals in 1971 (Perrin et al. 1982), but more recently (1995) this rate of mortality declined to 1,100 animals (Hall & Lennert 1997).

Uses and trade

There is no trade of these species within South Africa, although in certain regions Stenella spp. are hunted for food and as bait for fisheries.

Conservation

No species-specific conservation initiatives have been identified for Stenella species within the assessment region, although S. attenuata, S. coeruleoalba and S. longirostris are all listed in Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), and are protected by national legislation under the Marine Living Resources Act (No. 18 of 1998).

Ship-based sighting surveys are recommended for the assessment region in order to determine general abundance, seasonality and distribution of Stenella species, and the pelagic zone of the temperate Agulhas Current should be specifically targeted. Additionally, investigations into the severity of threats and possible mitigation measures (including the use of alternative fishing gear technologies) associated with pelagic trawl, gillnet and purse-seine fisheries are required for these species. In response to the negative effects associated with fisheries bycatch of other dolphin species, Buscaino et al. (2009) suggest a collaborative response towards sustainable exploitation of oceanic resources, a decrease in the intensity of marine extraction and the establishment of protected areas.

Recommendations for managers and practitioners:
  • Accurate bycatch assessments in the pelagic trawl, gillnet and purse-seine fisheries.
  • Enforce regulations associated with deep water fisheries, including bycatch mitigation efforts.
  • Sightings data should be recorded during systematic monitoring of other marine species.
Research priorities:
  • Basic life history parameters, population size, structure and trends within the assessment region.
  • Bycatch assessments in pelagic fisheries, including a specific reassessment of the western Indian Ocean fisheries.
  • Taxonomic resolution of the Stenella genus.
  • Distribution and the identification of core concentration regions of these species within South African waters.
Encouraged citizen actions:
  • Use information dispensed by the South African Sustainable Seafood Initiative (SASSI) to make good choices when buying fish in shops and restaurants, e.g. wwfsa.mobi, FishMS 0794998795.
  • Report sightings on virtual museum platforms (for example, iSpot and MammalMAP) to help with mapping geographical distribution.
  • Report any stranding reports to the relevant local authorities.

References 

[@book{275,
 address = {Cambridge},
 author = {Skinner, J.D. and Chimimba, C.T.},
 publisher = {Cambridge University Press, United Kingdom},
 title = {The Mammals of the Southern African Subregion},
 year = {2005}
}
,@book{2062,
 address = {Lawrence, Kansas},
 author = {Rice, D.W.},
 publisher = {Society for Marine Mammalogy, Special Publication Number 4},
 title = {Marine Mammals of the World: Systematics and Distribution},
 year = {1998}
}
,@inbook{2474,
 address = {San Diego, California, USA.},
 author = {Perrin  and Thewissen },
 booktitle = {Minke Whales <i>Balaenoptera acutorostrata</i> and <i>B. bonaerensis</i>},
 editor = {Perrin, W.F. and Brownell, R.L},
 pages = {750–754},
 publisher = {Academic Press},
 title = {Encyclopedia of Marine Mammals},
 year = {2002}
}
,@electronic{2474,
 address = {www.marinemammalscience.org},
 author = {Committee on Taxonomy},
 publisher = {Society for Marine Mammalogy},
 title = {List of marine mammal species and subspecies},
 year = {2017}
}
,@techreport{2475,
 address = {La Jolla, California},
 author = {Taylor, B.L., Chivers, S.J., Larese, J. and Perrin, W.F.},
 title = {Generation length and percent mature estimates for IUCN assessments of cetaceans},
 year = {2007}
}
,@inbook{2476,
 address = {Amsterdam},
 author = {},
 booktitle = {Bryde’s Whales <i>Balaenoptera edeni/brydei</i>},
 editor = {Kato, H., and Perrin, W. F.},
 pages = {158--163 },
 publisher = {Academic Press},
 title = {Encyclopedia of marine mammals},
 year = {2009}
}
,@article{2476,
 author = {MacLeod, C.D. },
 journal = {Endangered Species Research },
 pages = {125--136},
 title = {Global climate change, range changes and potential implications for the conservation of marine cetaceans: a review and synthesis},
 volume = {7},
 year = {2009}
}
,@article{2762,
 author = {Sekiguchi, K., Klages, N.T.W. and Best, P.B.},
 journal = {South African Journal of Marine Science},
 pages = {843--861},
 title = {Comparative analysis of the diets of smaller odontocete cetaceans along the coast of southern Africa},
 volume = {12},
 year = {1992}
}
,@article{2762,
 author = {Findlay KP, Best PB, Ross GJB, Cockcroft VG.},
 journal = {South African Journal of Marine Science},
 pages = {237–270},
 title = {The distribution of small odontocete cetaceans off the coasts of South Africa and Namibia},
 volume = {12},
 year = {1992}
}
,@inbook{4161,
 author = {},
 booktitle = {Heaviside's dolphin <i>Cephalorhynchus heavisidii</i> (Gray, 1828)},
 editor = {Best, P.B. and Abernethy, R.B.},
 pages = {289--310},
 publisher = {Academic Press},
 title = {Handbook of marine mammals, Volume 5: The first book of dolphins},
 year = {1994}
}
,@article{8551,
 author = {Ross, G. J. B.},
 journal = {Annals of the Cape Provincial Museums (Natural History)},
 pages = {173--410},
 title = {The smaller cetaceans of the south east coast of southern Africa},
 volume = {15},
 year = {1984}
}
,@phdthesis{8551,
 author = {Findlay KP.},
 school = {University of Pretoria},
 title = {The distribution of cetaceans off the coast of South Africa and South West Africa/Namibia},
 year = {1989}
}
,@article{11140,
 author = {Dolar, M. L. L., Walker, W. A., Kooyman, G. L. and Perrin, W. F.},
 journal = {Marine Mammal Science},
 number = {1},
 pages = {1--19},
 title = {Comparative feeding ecology of spinner dolphins (<i>Stenella longirostris</i>) and Fraser's dolphins (<i>Lagenodelphis hosei</i>) in the Sulu Sea},
 volume = {19},
 year = {2003}
}
,@article{11144,
 author = {LeDuc, R.G., Perrin, W.F. and Dizon, A.E.},
 journal = {Marine Mammal Science},
 pages = {619--648},
 title = {Phylogenetic relationships among the delphinid cetaceans based on full cytochrome b sequences},
 volume = {15},
 year = {1999}
}
,@article{20729,
 author = {Barlow, J},
 journal = {Report of the International Whaling Commission, (Special Issue)},
 pages = {191--198},
 title = {Reproductive seasonality in pelagic dolphins (Stenella spp.): implications for measuring rates},
 volume = {6},
 year = {1984}
}
,@article{20729,
 author = {Kasuya, T.},
 journal = {Scientific Reports of the Whales Research Institute},
 pages = {107--138},
 title = {Effect of exploitation on reproductive parameters of the spotted and striped dolphins off the Pacific coast of Japan},
 volume = {36},
 year = {1985}
}
,@article{20729,
 author = {Hassani, S., Antoine, L. and Ridoux, V.},
 journal = {Journal of Northwest Atlantic Fishery Science},
 pages = {119--124},
 title = {Diets of albacore, <i>Thunnus alalunga</i>, and dolphins, <i>Delphinus delphis</i> and <i>Stenella coeruleoalba</i>, caught in the northeast Atlantic albacore drift-net fishery: a progress report},
 volume = {22},
 year = {1997}
}
,@article{20729,
 author = {Würtz, M. and Marrale, D.},
 journal = {Journal of the Marine Biological Association of the United Kingdom},
 pages = {571--578},
 title = {Food of striped dolphin, <i>Stenella coeruleoalba</i>, in the Ligurian Sea},
 volume = {73},
 year = {1993}
}
,@article{20729,
 author = {Archer, F. I. and Perrin, W. F.},
 journal = {Mammalian Species},
 pages = {1--9},
 title = {<i>Stenella coeruleoalba</i>},
 volume = {603},
 year = {1999}
}
,@article{20729,
 author = {Moreno, I. B., Zerbini, A. N. Danilewicz, D., Santos, M. O. S., Simoes-Lopes, P. C., Lailson Brito, J. and Azevedo, A. F.},
 journal = {Marine Ecology Progress Series},
 pages = {229--240},
 title = {Distribution and habitat characteristics of dolphins of the genus <i>Stenella</i> (Cetacea: Delphinidae) in the southwest Atlantic Ocean},
 volume = {300},
 year = {2005}
}
,@article{20729,
 author = {Donahue, M. A. and Edwards, E. F.},
 journal = {Southwest Fisheries Science Center Administrative Report},
 pages = {46 pp.},
 title = {An annotated bibliography of available literature regarding cetacean interactions with tuna purse seine fisheries outside of the eastern tropical Pacific},
 volume = {96-20},
 year = {1996}
}
,@article{20729,
 author = {Perrin, W. F., Warner, R. R., Fiscus, C. H. and Holts, D. B.},
 journal = {Fishery Bulletin},
 pages = {1077--1092},
 title = {Stomach contents of porpoise, <i>Stenella</i> spp., and yellowfin tuna, <i>Thunnus albacares</i>, in mixed-species aggregations},
 volume = {71},
 year = {1973}
}
,@article{20729,
 author = {Van Waerebeek, K., Gallagher, M., Baldwin, R., Papastavrou, V. and Al-Lawati-Samira, M.},
 journal = {Journal of Cetacean Research and Management},
 number = {2},
 pages = {167--177},
 title = {Morphology and distribution of the spinner dolphin, <i>Stenalla longirostris</i>, rough-toothed dolphin, <i>Steno bredanensis</i>, and melon-headed whale, <i>Peponocephala electra</i>, from waters off the Sultanate of Oman},
 volume = {1},
 year = {1999}
}
,@article{20729,
 author = {Cockcroft, V. G. and Krohn, R.},
 journal = {Reports of the International Whaling Commission, Special Issue},
 pages = {317--328},
 title = {Passive gear fisheries of the southwestern Indian and southeastern Atlantic oceans: an assessment of their possible impact on cetaceans},
 volume = {15},
 year = {1994}
}
,@article{20729,
 author = {Miyazaki, N.},
 journal = {Reports of the International Whaling Commission},
 pages = {621--631},
 title = {Catch statistics of small cetaceans taken in Japanese waters},
 volume = {33},
 year = {1983}
}
,@article{20729,
 author = {DeMaster, D. P., C. W. Fowler, S. L. Perry and M. F. Richlen},
 journal = {Journal of Mammalogy},
 number = {3},
 pages = {641--651},
 title = {Predation and competition: the impact of fisheries on marine mammal populations over the next one hundred years},
 volume = {82},
 year = {2001}
}
,@article{20729,
 author = {Reeves, R. R., McClellan, K., and Werner, T. B. },
 journal = {Endangered Species Research},
 pages = {71--97},
 title = {Marine mammal bycatch in gillnet and other entangling net fisheries, 1990 to 2011},
 volume = {20},
 year = {2013}
}
,@article{20729,
 author = {Buscaino G, Buffa G, Sara G, Bellante A, Tonello Jr AJ, Hardt FAS, Cremer MJ, Bonanno A, Cuttitta A, Mazzola S},
 journal = {Fisheries Science},
 pages = {537--544},
 title = {Pinger affects fish catch efficiency and damage to bottom gill nets related to bottlenose dolphins},
 volume = {75},
 year = {2009}
}
,@article{20729,
 author = {Fitch JE, Brownell RL.},
 journal = {Journal of the Fisheries Board of Canada},
 pages = {2561–2574},
 title = {Fish otoliths in cetacean stomachs and their importance in interpreting feeding habits.},
 volume = {25},
 year = {1968}
}
,@article{20729,
 author = {Fraser FC, Noble BA.},
 journal = {Investigations on Cetacea},
 pages = {147–164},
 title = {Variation of pigmentation in Meyer’s dolphin, <i>Stenella coeruleoalba</i> (Meyer)},
 volume = {2},
 year = {1970}
}
,@article{20729,
 author = {Hall MA, Boyer SD.},
 journal = {Reports of the International Whaling Commission},
 pages = {321–322},
 title = {Estimates of incidental mortality of dolphins in the eastern Pacific fishery for tropical tunas in 1987},
 volume = {39},
 year = {1989}
}
,@article{20729,
 author = {Hall MA, Lennert C.},
 journal = {Report of the International Whaling Commission},
 pages = {641–644},
 title = {Incidental mortality of dolphins in the eastern Pacific Ocean tuna fishery in 1995},
 volume = {47},
 year = {1997}
}
,@proceedings{20729,
 editor = {Hohn AA, Scott MD.},
 series = {5th Biennial Conference on the Biology of Marine Mammals},
 title = {Segregation by age and sex in schools of spotted dolphins in the eastern tropical Pacific.},
 year = {1983}
}
,@article{20729,
 author = {Kasuya T, Miyazaki N.},
 journal = {Mammals of the Seas. FAO Fish Ser. 5},
 pages = {21–37},
 title = {The stock of <i>Stenella coeruleoalba</i> off the Pacific coast of Japan.},
 volume = {4},
 year = {1982}
}
,@article{20729,
 author = {Kasuya T, Miyazaki N, Dawbin WH.},
 journal = {Scientific Reports of the Whales Research Institute, Tokyo},
 pages = {157–226},
 title = {Growth and reproduction of Stenella attenuata in the Pacific coast of Japan.},
 volume = {26},
 year = {1974}
}
,@phdthesis{20729,
 author = {Kroese M.},
 school = {University of Port Elizabeth},
 title = {Age, growth and reproductive biology of striped dolphins, <i>Stenella coeruleoalba</i> (Meyer, 1833) off the coast of southern Africa. M.Sc. Thesis.},
 year = {1993}
}
,@article{20729,
 author = {Mitchell E.},
 journal = {Canadian Journal of Zoology},
 number = {717–740},
 title = {Pigmentation pattern evolution in delphinid cetaceans: an essay in adaptive coloration.},
 volume = { 48},
 year = {1970}
}
,@article{20729,
 author = {Myrick A, Hohn AA, Barlow J, Sloan PA.},
 journal = {Fishery Bulletin U.S. },
 pages = {247–259},
 title = {Reproductive biology of female spotted dolphins, Stenella attenuata, from the eastern tropical Pacific},
 volume = {84},
 year = {1986}
}
,@article{20729,
 author = {Miyazaki N.},
 journal = {Reports of the International Whaling Commission (Special Issue)},
 pages = {343–353},
 title = {Further analyses of reproduction in the striped dolphin,<i> Stenella coeruleoalba </i>, off the Pacific coast of Japan.},
 volume = {6},
 year = {1984}
}
,@article{20729,
 author = {Norris KS, Würsig B, Wells RS, Würsig M, Brownlee SM, Johnson C, Solow J.},
 journal = {Fishery Bulletin U.S.},
 pages = {821–849},
 title = {The behaviour of the Hawaiian spinner dolphin, <i>Stenella longirostris<i/>},
 volume = {77},
 year = {1985}
}
,@article{20729,
 author = {Perrin WF, Coe JM, Zweifel JR.},
 journal = {Fishery Bulletin US},
 pages = {229–269},
 title = {Growth and reproduction of the spotted porpoise, <i>Stenella attenuata<i/>, in the offshore eastern tropical Pacific},
 volume = {74},
 year = {1976}
}
,@article{20729,
 author = {Perrin WF, Henderson JR.},
 journal = {Reports of the International Whaling Commission (Special issue)},
 pages = {417–430},
 title = {Growth and reproductive rates in two populations of spinner dolphins, <i>Stenella longirostris<i/>, with different histories of exploitation.},
 volume = {6},
 year = {1984}
}
,@article{20729,
 author = {Perrin, W.F., Smith, T.G. and Sakagawa, G.T.},
 journal = {Mammals of the Seas. FAO Fish },
 number = {4},
 pages = {67–83},
 title = {Status of populations of spotted dolphin, <i>Stenella attenuata</i>, and spinner dolphins, <i>Stenella longirostris</i>, in the eastern tropical Pacific},
 volume = {Ser.5},
 year = {1982}
}
,@electronic{20731,
 address = {www.iucnredlist.org},
 author = {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., and Wilson, B. },
 title = {<i>Stenella coeruleoalba</i>. In 'The IUCN Red List of Threatened Species'. Version 2012.2},
 year = {2008}
}
,@article{20733,
 author = {Cockcroft, V. G.},
 journal = {South African Journal of Wildlife Research},
 pages = {44--51},
 title = {Dolphin catches in the Natal shark nets, 1980-1988},
 volume = {20},
 year = {1990}
}
,@electronic{20733,
 address = {http://www.iucnredlist.org.},
 author = {IUCN (International Union for Conservation of Nature).},
 title = {<i>Stenella longirostris</i>},
 year = {2012}
}
,]
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