Greynurse Shark, Carcharias taurus Rafinesque 1810


Other Names: Blue Nurse Shark, Grey Nurse Shark, Nuss Shark, Sand Shark, Sand Tiger, Sand Tiger Shark, Sandtiger Shark, Shovel-nosed Shark, Spotted Ragged Tooth, Spotted Ragged-tooth

Grey Nurse Sharks, Carcharias taurus, at South Solitary Island, New South Wales. Source: Dave Harasti / http://www.daveharasti.com/. License: All rights reserved

Summary:

A large, robust slow-swimming shark with a flattened conical snout, two similarly-sized dorsal fins, the mouth extending beyond the eyes and jaws with rows of protruding dagger-like teeth. Greyish-brown above, paler below, sometimes with scattered spots or blotches. Often seen hovering just above the bottom in large sandy gutters and caves.

Greynurse Sharks are one of the most endangered marine fishes in Australia. Once thought to be man-eaters, their numbers rapidly declined up until the 1990's, due to a combination of commercial fishing, spearfishing and protective beach meshing, especially on the east coast. 

Although considered harmless, Greynurse Sharks may attack if provoked.

Beautiful video footage of Greynurse Sharks at the Cod Grounds near Byron Bay.

Heaps of Greynurse Sharks at North Rock, Broughton Island, New South Wales.

So many Greynurse Sharks! Filmed around Big Seal Island, Seal Rocks, New South Wales.

The Greynurse Sharks of Looking Glass Cave at Broughton Island, near Port Stephens, New South Wales.

Video of the removal of emtanglements from Greynurse Sharks in the Solitary Islands Marine Park, near Coffs Harbour, New South Wales.

Video of a Greynurse Shark at Montague Island, New South Wales. 

Video of a large male Greynurse Shark filmed at Montague Island, New South Wales.

Video of intrauterine cannibalism on Greynurse Shark embryos.

Greynurse Sharks at 9 Mile Reef northern New South Wales.


Cite this page as:
Dianne J. Bray, Carcharias taurus in Fishes of Australia, accessed 20 Nov 2018, http://fishesofaustralia.net.au/home/species/3285

Greynurse Shark, Carcharias taurus Rafinesque 1810

More Info


Distribution

Historically widespread in most subtropical and warm temperate seas, except for the Eastern Pacific, and previously recorded from all Australia states except Tasmania - at depths to 190 metres. Grey nurse sharks often aggregate in deep sandy gutters.

Although historically known from around Australia (except Tasmania), Greynurse Shark numbers have been severely reduced by overfishing and protective beach meshing, especially on the eastern and southern coasts.

The species is extremely rare in Victorian, South Australian and Northern Territory waters. 

Once common in Port Phillip Bay, Greynurse Sharks have now all but disappeared from Victorian waters. They were indiscriminately killed in the past, including during the latter half of the nineteenth century in Victoria when a bounty was placed on them.

Features

Vertebrae: 156-186 (precaudal 80-97); Jaw teeth (upper) 16 to 17-1-13:3-1-16 or 17; Jaw teeth (lower) 15 to 17-3-1:1-3-15 to 17. 
Snout length to mouth 3.2-4.7% TL; teeth usually with 1 cusplet on either side of the main cusp.
A large shark with a short pointed snout, small eyes, spike-like teeth that are easily seen, two dorsal fins and a similarly-sized anal fin. The first dorsal fin arises behind the middle of the body and is closer to the pelvic fin than to the pectoral fins; caudal fin with a small ventral lobe and a pronounced sub-terminal notch.

Size

Females mature at 9 or 10 years of age and grow to about 3.2 m TL. Males mature at 6 or 7 years of age and reach about 2.7 m TL.

Colour

Pale brown or greyish-brown above, paler below, sometimes with scattered dark brownish spots and blotches that fade with growth.

Feeding

Carnivore - feeds on a wide range of bony fishes, smaller sharks and rays, squids, crabs and lobsters.

Biology

Greynurse Sharks are aplacental viviparous (ovoviviparous), meaning that although the young are born alive, they are not nourished via a placenta. 

After the largest developing embryos have absorbed their yolk sac, they feed on other eggs produced by the mother (embryonic oophagy), then on the other smaller embryos (intra-uterine cannibalism or adelphophagy) in the uterus.

The embryos develop teeth at about 10 cm, and the largest embryo in each side of the uterus feeds on the remaining eggs, and then on its smaller siblings.
After a gestation period of 9-12 months, females usually produce only two pups once every two years. At birth the pups measure about a metre in length. This means that Greynurse Shark populations recover very slowly from overfishing.

Video showing intrauterine cannibalism in Greynurse Shark embryos.

Fisheries

Greynurse sharks have been fished throughout their range in the past, by commercial and recreational fishers, spearfishers, and also in protective beach nets. Although now completely protected, they are still caught incidentally, especially by trap and line fishers. 

Conservation

  • EPBC Act 1999: Vulnerable
  • EPBC Act 1999: Critically Endangered (east coast population)
  • EPBC Act 1999: Vulnerable (west coast population)
  • IUCN Red List : Vulnerable (Worldwide)
  • IUCN Red List: Critically Endangered (East coast of Australia subpopulation)
  • IUCN Red List: Near Threatened (Western Australia subpopulation)

The Greynurse Shark was the first shark to be protected in the world when the New South Wales Government declared it a protected species in 1984. Studies have shown that there is little genetic diversity between individuals in eastern Australia, making this population vulnerable to extinction.

In addition to the Greynurse Shark listing under the EPBC Act, the species is protected in coastal waters of Tasmania, South Australia, Victoria and Western Australia. The species is also protected in the coastal waters of New South Wales and Queensland with exemptions or a defence to prosecution for shark control programs for bather protection (e.g. beach meshing and/or drumlining).

Department of the Environment. 2014. Recovery Plan for the Greynurse Shark (Carcharias taurus). 49 pp. 

Remarks


Similar Species


Etymology


Species Citation

Carcharias taurus Rafinesque, 1810, Caratteri di alcuni nuovi generi e nuove specie di animali e piante della Sicilia: 10, pl. 14(1). Type locality: Sicily

Author

Dianne J. Bray

Greynurse Shark, Carcharias taurus Rafinesque 1810

References


Bansemer, C. 2009. Population biology, distribution, movement patterns and conservation requirements of the grey nurse shark (Carcharias taurus Rafinesque 1810) along the east coast of Australia. University of Queensland. St Lucia, Queensland Australia. 143 pp.

Bansemer, C. & Bennett, M. 2010. Retained fishing gear and associated injuries in the east Australian grey nurse sharks (Carcharias taurus): Implications for population recovery. Marine and Freshwater Research 61(1): 97–103.

Bansemer, C.S. & Bennett, M.B. 2011. Sex- and maturity-based differences in movement and migration patterns of grey nurse shark, Carcharias taurus, along the eastern coast of Australia. Marine and Freshwater Research 62: 596–606.

Cavanagh, R.D., Kyne, P.M., Fowler, S.L., Musick, J.A. & Bennett, M.B. (eds) 2003.The Conservation Status of Australian Chondrichthyans: Report of the IUCN Shark Specialist Group Australia and Oceania Regional Red List Workshop. The University of Queensland, School of Biomedical Sciences, Brisbane, Australia. x + 170pp.

Coleman, N. 1980. Australian Sea Fishes South of 30ºS. Lane Cove, NSW : Doubleday Australia Pty Ltd 309 pp. (as Odontaspis taurus)

Compagno, L.J.V. 1984. FAO Species Catalogue. Sharks of the World. An annotated and illustrated catalogue of shark species known to date. Hexanchiformes to Lamniformes. FAO Fisheries Synopsis No. 125. Rome : FAO Vol. 4(1) pp. 1-249 (as Eugomphodus taurus)

Compagno, L.J.V. 2001. Sharks of the World. An annotated and illustrated catalogue of shark species known to date. Bullhead, mackerel and carpet sharks (Heterodontiformes, Lamniformes and Orectolobiformes). Rome : FAO, FAO Species Catalogue for Fisheries Purposes No. 1 Vol. 2 269 pp. 

Compagno, L.J.V. & Niem, V.H. 1998. Family Odontaspididae. pp. 1264-1267 in Carpenter, K.E. & Niem, V.H. (eds). The Living Marine Resources of the Western Central Pacific. FAO Species Identification Guide for Fisheries Purposes. Rome : FAO Vol. 2 687-1396 pp.

Compagno, L.J.V., Dando, M. & Fowler, S. 2005. A Field Guide to the Sharks of the World. London : Collins 368 pp.

Department of the Environment. 2014. Recovery Plan for the Grey Nurse Shark (Carcharias taurus). 49 pp. 

Dudley, S.F.J. 1997. A comparison of the shark control programs of New South Wales and Queensland (Australia) and KwaZulu-Natal (South Africa). Ocean and Coastal Management 34: 1–27.

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Krogh, M. 1994. Spatial, seasonal and biological analysis of sharks caught in the New South Wales protective beach meshing programme. Australian Journal of Marine and Freshwater Research 45: 1087–1106.

Kuiter, R.H. 1993. Coastal Fishes of South-eastern Australia. Bathurst : Crawford House Press 437 pp.

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Last, P.R. & Stevens, J.D. 2009. Sharks and Rays of Australia. Collingwood : CSIRO Publishing Australia 2, 550 pp.

Macbeth, W.G., Vandenberg, M. & Graham, K.J. 2008. Identifying Sharks and Rays; a Guide for Commercial Fishers. Sydney : New South Wales Department of Primary Industry 71 pp.

Otway, N.M., Bradshaw, C. & Harcourt, R. 2004. Estimating the quasi-extinction of the Australian grey nurse shark (Carcharias taurus) population using deterministic age- and stage-classified models. Biological Conservation 119: 341–350.

Otway, N.M. & Burke, A.L. 2004. Mark-recapture population estimate and movements of grey nurse sharks. New South Wales Fisheries Final Report Series No.63. NSW Fisheries Office of Conservation, Nelson Bay, NSW.

Otway, N.M., Burke, A.L., Morrison, N.S. & Parker, P.C. 2003. Monitoring and identification of NSW critical habitat sites for conservation of grey nurse sharks. New South Wales Fisheries Final Report Series No. 47. NSW Fisheries Office of Conservation, Nelson Bay, NSW. 62 pp.

Otway, N.M. & Ellis, M.T. 2011. Pop-up archival satellite tagging of Carcharias taurus: movements and depth/temperature-related use of south-eastern Australian waters. Marine and Freshwater Research 62: 607–620

Otway, N.M., Storrie, M.T., Louden, B.M. & Gilligan, J.J. 2009. Documentation of depth-related migratory movements, localised movements at critical habitat sites and the effects of scuba diving for the east coast grey nurse shark population. Final report for the Department of Environment, Water, Heritage and the Arts, Canberra. 88 pp.

Pepperell, J.G. 1992. Trends in the distribution, species composition and size of sharks caught by gamefish anglers off south-eastern Australia, 1961–90. Australian Journal of Marine and Freshwater Research 43: 213–225.

Pogonoski, J.J., Pollard, D.A. & Paxton, J.R. 2002. Conservation Overview and Action Plan for Australian Threatened and Potentially Threatened Marine and Estuarine Fishes. Canberra : Environment Australia 375 pp.

Rafinesque, C.S. 1810.Caratteri di alcuni Nouvi Generi e Nouve Specie di Animali e Piante della Sicilia con varie Osservazioni sopra i Medesimi. Palermo 105 pp. 20 pls

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White, W. 2008. Shark Families Heterodontidae to Pristiophoridae. pp. 32-100 in Gomon. M.F., Bray, D.J. & Kuiter, R.H (eds). Fishes of Australia's Southern Coast. Sydney : Reed New Holland 928 pp.

Young, M.A.L., S. Foale & D.R. Bellwood. 2014. Impacts of recreational fishing in Australia: historical declines, self-regulation and evidence of an early warning system. Environmental Conservation, available on CJO2014. doi:10.1017/S0376892914000046. 

Quick Facts


CAAB Code:37008001

Conservation:EPBC Critically Endangered (E coast); EPBC Vulnerable (WA only)

Conservation:Fully protected in Australia

Conservation:IUCN Critically Endangered (E Aust); Near Threatened (WA)

Danger:Potentially dangerous if provoked

Depth:0-190 metres

Max Size:320 cm TL

Species Maps

CAAB distribution map