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Hammerhead Sharks (Sphyrna Spp.)

I & I NSW Wild Fisheries research Program Hammerhead ( spp.) Exploitation Status undefined Three of hammerhead are harvested by the commercial line fishery and are also caught by the recreational gamefish fishery. Little information is available to specify exploitation status.

Scientific name Standard name comment

Sphyrna zygaena

Sphyrna lewini

Sphyrna mokarran

Sphyrna mokarran Image © Bernard Yau

Background The Australian distribution of the scalloped Three species of hammerhead sharks are found hammerhead covers all northern waters, in NSW waters, the smooth hammerhead extending south to ~34ºS latitude on each (Sphyrna zygaena), scalloped hammerhead coast (Sydney to Geographe Bay). Adult (S. lewini) and great hammerhead (S. mokarran). scalloped hammerheads inhabit deep waters The smooth hammerhead occurs south from adjacent to continental and insular shelves, in Coffs Harbour, and is the most abundant of the water depths ranging from the surface to at three species in NSW waters. It occurs over the least 275 m. Juveniles are often found close , from the surface to at least inshore, often in large migratory schools. Adult 60 m depth. females are rarely caught inshore. Scalloped hammerheads produce litters of 13 to 41 Smooth hammerheads attain a maximum pups after a 9-10 month gestation. Pupping length of 350 cm, with males maturing at about takes place between October and January in 250 cm, and females at about 265 cm. It is . likely that hammerhead sharks have at least a 2 year breeding cycle. All hammerheads give The great hammerhead inhabits tropical and birth to free-swimming live young. Smooth warm temperate waters. It is found on the hammerheads have 20 to 50 pups per litter, continental shelf north of Sydney, from inshore after a 10-11 month gestation. As the name to at least 80 m depth. It can grow to a length suggests, smooth hammerheads have a of 600 cm, though rarely more than 450 cm. very smooth, curved, leading profile to their Males mature at about 225 cm and females hammer. at about 210 cm. Litters of 6 to 33 pups are produced in summer in northern Australia. The great hammerhead is distinguished by a very tall first , a large 2nd dosral fin and a non-curved leading edge to their hammer.

status of fisheries resources in nsw, 2008/09 Hammerhead sharks | p 173 wild fisheries research program

The scalloped hammerhead and the smooth Historical Landings of Hammerhead Sharks hammerhead comprise the majority of NSW

commercial and recreational catches. Total 15 commercial hammerhead catch peaked in 1993/94 at 15.7 t. Annual commercial catches have averaged approximately 4 t in the last 5 years. Most hammerhead landings come 10 from the Ocean Trap and Line Fishery, with

smaller landings by the Ocean Trawl Fishery Landings (t) and occasionally by the Estuary General 5 Fishery. Between the 1970s and 2001, the total catch of hammerhead sharks by recreational gamefishing and protective beach meshing 0 remained at about 250 sharks per year. It was 90/91 92/93 94/95 96/97 98/99 00/01 02/03 04/05 06/07 08/09 estimated that over 95% of the recreational Financial Year gamefishing catches are tagged and released Commercial landings (including available historical alive. records) of hammerhead sharks for NSW from 1990/91 to 2008/09 for all fishing methods.

Additional Notes • This subgroup of pelagic sharks is readily identifiable by all stakeholders - the three Further Reading species can be differentiated by their teeth Chan, R.W.K. (2001). Biological studies on sharks and a notch in the middle of the head but caught off the coast of New South Wales. School of correct identification to species level by Biological Sciences. Sydney, University of New South fishers may be problematic. Wales. PhD Thesis. • Hammerhead sharks are a key secondary Compagno, L.J.V. (1984). Sharks of the World. An species in the Ocean Trap and Line Fishery. annotated and illustrated catalogue of sharks Reported landings have generally been less known to date. Part 2 - , FAO. than 10 t in recent years. Henry, G.W. and J.M. Lyle (2003). The National Recreational and Indigenous Fishing Survey. Final • The current observer program in the line Report to the Fisheries Research & Development fishery is providing additional information Corporation and the Fisheries Action Program on the composition of this group of species, Project FRDC 1999/158. NSW Fisheries Final Report however catches have been small. Series No. 48. 188 pp. Cronulla, NSW Fisheries. • There is a recreational bag limit of one Krogh, M. (1994). Spatial, seasonal and biological . analysis of sharks caught in the New South Wales protective beach meshing program. Australian Journal of Marine and Freshwater Research 45 (7): Catch 1087-1106. Recreational Catch of Hammerhead Sharks Last, P.R. and J.D. Stevens (2009). Sharks and Rays of Australia 2nd Edition. Melbourne, CSIRO. The annual recreational harvest of hammerhead Macbeth, W.G., P.T. Geraghty, V.M. Peddemors and sharks in NSW is likely to lie between 10 and C. Gray, A. (2009). Observer-based study of targeted 50 t. This estimate is based upon the results for large shark species in waters of the offsite National Recreational and off northern New South Wales. . Final report to the Indigenous Fishing Survey (Henry and Lyle, Northern Rivers Catchment Management Authority. 2003) and onsite surveys undertaken by Final Report Series 114. Cronulla, Industry & I & I NSW. Investment NSW - Fisheries: 82pp.

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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 (1): 213-225. Reid, D.D. and M. Krogh (1992). Assessment of catches from protective shark meshing off New South Wales beaches between 1950 and 1990. Australian Journal of Marine and Freshwater Research 43 (1): 283-296. Stevens, J.D. (1984). Biological Observations on Sharks Caught by Sport Fishermen Off New South Wales. Australian Journal of Marine and Freshwater Research 35 (5): 573-590. Walker, T.I. (1998). Can shark resources be harvested sustainably? A question revisited with a review of shark fisheries.Marine and Freshwater Research 49 (7): 553-572.

Please visit the CSIRO website, http://www.marine.csiro.au/caab/ and search for the species code (CAAB) 37 019004, 37 019001 and 37 019002, common name or scientific name to find further information.

© State of New South Wales through Industry and Investment NSW 2010. You may copy, distribute and otherwise freely deal with this publication for any purpose, provided that you attribute Industry and Investment NSW as the owner.

D disclaimer: The information contained in this publication is based on knowledge and understanding at the time of writing (April 2010). However, because of advances in knowledge, users are reminded of the need to ensure that information upon which they rely is up to date and to check currency of the information with the appropriate officer of Industry and Investment NSW or the user’s independent adviser.

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