|Scientific Name:||Callorhinchus milii|
|Species Authority:||Bory de Saint-Vincent, 1823|
|Red List Category & Criteria:||Least Concern ver 3.1|
|Assessor(s):||Reardon, M., Walker, T.I. & Francis, M.P. (SSG Australia & Oceania Regional Workshop, March 2003)|
|Reviewer(s):||Kyne, P.M. & Cavanagh, R.D. (Shark Red List Authority)|
The holocephalan Callorhinchus milii is relatively abundant and is caught as byproduct in fisheries of Southern Australia and New Zealand. In southern Australia, commercial catch rates have been stable for the past 20 years, while fishing effort is reducing and a Total Allowable Catch (TAC) was implemented during 2002. On-board monitoring over the past 25-year period indicates the change in the number of animals caught per unit of fishing effort was not statistically significant. A three-mile closure of all Victorian waters to shark fishing provides a large refuge for the species in southern Australia. In New Zealand TACs have been in place since 1986 and the CPUE trend increased during 1989 to 2001. As a result, the total TAC increased from 619 to 1,040 tonnes over this time period. The species is most abundant off the east coast of the South Island. This fishery appears to be stable with populations likely to be above the biomass required to provide the maximum sustainable yield. The species has relatively high biological productivity; maximum age of 15 years, matures relatively early and continues to lay eggs over several weeks each year. No contraction of range or fragmentation of the population has occurred.
|Range Description:||The assessment assumes a single genetic stock in southern Australia and a separate single genetic stock in New Zealand.|
Native:Australia (South Australia, Tasmania, Victoria, Western Australia); New Zealand (North Is., South Is.)
|FAO Marine Fishing Areas:||
Indian Ocean – eastern; Pacific – southwest
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||In southern Australia, C. milii is most abundant in Bass Strait and during the egg-laying period enters large estuaries and bays (e.g., American River Kangaroo Island and parts of the West Coast in South Australia, and Port Phillip Bay and Western Port Bay in Victoria) (Last and Stevens 1994). In New Zealand it is most abundant on the east coast of the South Island. No contraction of range or fragmentation of the population has occurred.|
|Habitat and Ecology:||C. milii is oviparous laying leathery egg cases in pairs in shallow water that may take up to 10 months to hatch (Last and Stevens 1994, Smith 2001). It is a seasonal breeder with females moving to shallower habitats to lay eggs (Francis 1997, Last and Stevens 1994, Reardon 2001, Smith 2000). Eggs are laid over several weeks each year. Juveniles remain in the shallow habitats for up to three years, which may make them vulnerable to trawl capture in New Zealand (Francis 1997). C. milii appears to be sexually segregated as males and females are often caught separately by commercial fishermen (T. I. Walker, unpublished data). C. milii has relatively high biological productivity. Maturity occurs relatively early at 70 cm fork length (FL) for females, and 50 cm FL for males. Maximum age has been estimated as nine years from ageing using growth increments in dorsal fin spines (T. I. Walker, unpublished data) and 15 years from a tag return (Francis 1997, Annala et al. 2002).|
C. milii is caught both commercially and recreationally in southern Australia and New Zealand. The sports fishery in New Zealand is currently recovering. The flesh is of good quality and is sold in seafood markets as whitefish fillets (Last and Stevens 1994).
C. milii is captured as byproduct from targeting M. antarcticus with gillnets of 6-6½" mesh-size off South Australia, Victoria and Tasmania. During 1970-2001 the catch of C. milii from the Southern Shark Fishery varied 4-118 tonnes (carcass weight), 2% of the total catch of all shark species (Walker et al. 2002). There is some targeting of females inshore by recreational fishers during the egg-laying period.
Small quantities are taken as byproduct in the South East Trawl Fishery, which targets a range of quota teleost species with demersal trawl nets off New South Wales, eastern Victoria and eastern Tasmania. The catch from this sector was 22 tonnes during 2002.
In southern Australia, commercial catch rates have been stable for the past 20 years, while fishing effort is reducing (Walker et al. 2002). On-board monitoring over the past 25-year period indicates the number of animals caught per unit of fishing effort declined to 67%; the change is not statistically significant (Walker et al. in press).
In New Zealand, the species is most abundant off the east coast of the South Island. The fishery appears to be stable with populations likely to be above the biomass required to provide the maximum sustainable yield (Annala et al. 2002).
|Conservation Actions:||Australia and New Zealand both have TAC limits in place for the elephant fish. In New Zealand, there is a recreation bag limit of 20 fish per day. Part of its range incorporates areas closed to shark fishing and marine protected areas. A three-mile closure of all Victorian waters to shark fishing provides a large refuge for the species in southern Australia.|
Allison, F.R. and Coakley, A. 1973. The two species of Gyrocotyle in the elephant fish, Callorhynchus milii (Bory de Saint-Vincent, 1823). Journal of the Royal Society of New Zealand 3: 381–392.
Annala, J.H., Sullivan, K.J., O'Brien, C.J., Smith, N.W.M. and Varian, S.J.A. (eds). 2002. Report from the Fishery Assessment Plenary, May 2002: Stock assessments and yield estimates. Wellington, Ministry of Fisheries.
Coakley, A. 1971. The biological and commercial aspects of the elephant fish. I. The commercial fishery. New Zealand Marine Department Fisheries Technical Report 76.
Coakley, A. 1973. A study in the conservation of elephant fish (Callorynchus milii, Bory) in New Zealand. New Zealand Marine Department Fisheries Technical Report 126.
Francis, M.P. 1997. Spatial and temporal variation in the growth rate of elephantfish (Callorhinchus milii). New Zealand Journal of Marine and Freshwater Research 31: 9–23.
Gorman, T.B.S. 1963. Biological and economic aspects of the elephant fish Callorhinchus milii Bory in Pegasus Bay and the Canterbury Bight. New Zealand Marine Department Fisheries Technical Report 8
IUCN. 2003. 2003 IUCN Red List of Threatened Species. www.iucnredlist.org. Downloaded on 18 November 2003.
IUCN SSC Shark Specialist Group. Specialist Group website. Available at: http://www.iucnssg.org/.
Last, P.R. and Stevens, J.D. 2009. Sharks and Rays of Australia. Second Edition. CSIRO Publishing, Collingwood.
McClatchie, S. and Lester, P. 1994. Stock assessment of the elephantfish (Callorhinchus milii). New Zealand Fisheries Assessment Research Document 94/6
Reardon, M.B. 2001. Seasonality and microanatomy of spermatophore formation in a holocephalan, the elephant fish, Callorhynchus milii. Honours Thesis (BSc). Department of Zoology. Melbourne, University of Melbourne
Smith, R. 2001. The reproductive biology of the female elephant fish, Callorhynchus milii, with particular reference to the oviducal gland. Honours Thesis (BSc). Department of Zoology. Melbourne, University of Melbourne
Walker, T.I., Hudson, R.J., and Gason, A.S. 2005. Catch evaluation of target, byproduct, and bycatch species in the shark fishery of south-eastern Australia. Journal of Northwest Atlantic Fishery Science 35: 505‒530.
Walker, T.I., Taylor, B.L., and Hudson, R.J. 2002. Southern shark catch and effort 1970–2001 report to Australian Fisheries Management Authority. 47 pp. July 2002. Marine and Freshwater Resources Institute: Queenscliff, Victoria, Australia.
|Citation:||Reardon, M., Walker, T.I. & Francis, M.P. (SSG Australia & Oceania Regional Workshop, March 2003) 2003. Callorhinchus milii. The IUCN Red List of Threatened Species. Version 2015.2. <www.iucnredlist.org>. Downloaded on 30 July 2015.|