Carcharhinidae. Southern bluefin tuna >6.4kg Bigeye tuna >3.2kg Yellowfin tuna >3.2kg Swordfish >119cm LJFL / >18kg dressed Marlins >210cm LJFL

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1 SANBI IDentifyIt - Species Bronze Whaler - Carcharhinus brachyurus Family Carcharhinidae Geographic location / distribution Habitat: Bronze whalers are coastal-pelagic species, preferring inshore and offshore warm-temperate and tropical waters. They range from close inshore in the surf zone to far ofshore, from the sea surface to 400m depths. The adults prefer deeper waters of the continental shelf between Mozambique and the southern Cape while the juveniles are more common closer inshore off KZN. They are attracted inshore during the annual sardine run. It is thought that 2 separate populations exist in southern Africa, and that the inshore waters of the KwaZulu-Natal coast form the nursery grounds. Fishery Bronze whalers (or dusky sharks) are caught as bycatch in the pelagic shark longline fishery and in the tuna/swordfish longline fishery. They are also targeted by recreational linefishermen, and the newly born juveniles are commonly caught by shore anglers. Size limits Southern bluefin tuna >6.4kg Bigeye tuna >3.2kg Yellowfin tuna >3.2kg Swordfish >119cm LJFL / >18kg dressed Marlins >210cm LJFL Stock status The dusky shark has one of the lowest intrinsic rebound potentials among shark. Therefore, its exploitation should be conducted with extreme caution and under close monitoring. According to the Natal Sharks Board, each year approximately 117 of all sizes are caught. Catches tend to be the highest during June and July; at this time pregnant females and those which have recently pupped are common. Fisheries management Bronze whalers are managed as a bycatch in the tuna/swordfish in the large pelagic fishery, and which are managed by Regional Fisheries Management Organisations. South Africa is a member of ICCAT and a co-operating non-member of IOTC and CCSBT. Although RFMO's manage high seas fisheries, management recommendations and resolutions are implemented by South Africa through national legislation and permit conditions. The South African Shark fishery was actually banned at the end of 2009 but vessels are allowed to fish on an exemption permit in 2010/2011. The Tuna fishery is managed by a Total Allowable Effort (TAE), meaning that instead of setting a limit on the catch, a limit is set on the number of rights holders allowed to catch tuna. Currently there is a limit of 200 rights holders in SA (including pole and longline). Longlining is not a very selective form of fishing and many species are caught accidentally on the the hooks. Bycatch species in this fishery include: billfishes (swordfish, marlins etc), seabirds, turtles and sharks. Recent assessments show that eleven species of seabird, four species of turtle and 20 species of shark are caught incidentally by this fishery. The FAO estimates that approximately 28% of the catch is discarded. Local studies indicate that discards comprise approximately 22% of the catch. Bycatch restrictions therefore exist to protect vulnerable species like sharks: The bycatch of billfish cannot exceed 10% of the total tuna catch A precautionary catch limit of 25 seabirds has been set for tuna longline vessels, after which further management restrictions are enforced

2 Shark fins need to be landed with their trunks, with the fins not exceeding 5% of the weight of the trunk on foreign vessels according to ICCAT and IOTC, but 8% on SA vessels. Any Bigeye, Swordfish or Southern Bluefin tuna landed must be accompanies by the relevant RFMO (ICCAT, IOTC or CCSBT) catch statistical document. Maturity and Sizes Bonze whalers are born at a size of cm; reach maturity from cm, and will reach a maximum size over cm. Physical description Identifying characters snout moderately long and narrowly rounded, with small anterior nasal flaps first dorsal fin with bluntly pointed apex and short free rear tip, much larger than second dorsal or anal fins first dorsal fin originates over or behind free rear tip of pectorals second dorsal fin has short free tip and originates over or slightly behind the anal fin interdorsal ridge usually absent pectoral fins long, falcate and narrow-tipped striking bronzy or olive grey above, white below; no conspicuous marks on any of the fins; a moderately prominent white band on each flank Other similar species Carcharodon carcharias - Great White Shark Isurus oxyrinchus - Shortfin Mako Shark Prionace glauca - Blue Shark References Natal Sharks Board FAO fact sheets Fishery Resource Monitoring System Fact Sheets: ICCAT Tuna fact sheets. ICAT Manual. January FAO Fisheries and Aquaculture Department. Biological characteristics of tuna/individual species sheets. FI Institutional Websites. Text by Michel Goujon and Jacek Majkowski. In: FAO Fisheries and Aquaculture Department[online]. Rome. Updated 24 February [Cited 30 November 2010]. Website: Bronze Whaler Photo: fishindex.blogspot.com P hotographer: fishindex.blogspot.com Copy right/website: fishindex.blogspot.com

3 Bronze Whaler Photo: SFTEP / Rudie Kuiter / DiscoverLife Photographer: SFTEP / Rudie Kuiter / DiscoverLife Copyright/Website: SFTEP / Rudie Kuiter / DiscoverLife Bronze Whaler. Open Cage - Wikimedia Commons

4 Bronze Whaler Identification Copyright/Website: TRAFFIC Landed, headed & gutted without fins, the trunk can still be differentiated by black spots on a brown body. PHOTO: Nicola Okes Bronze Whaler Photo: Tassapon KRAJANGDARA and Supachai Photographer: P Tassapon KRAJANGDARA and Supachai Copy Copyright/Website: Tassapon KRAJANGDARA and Supachai

5 Bronze Whaler PHOTO: Kari Underhill Bronze Whaler Photo: Two Oceans Angling Club (*The TOAC works on a catch and release basis) Photographer: P Two Oceans Angling Club Copy Copyright/Website: Two Oceans Angling Club

6 Bronze Whaler Photo: Two Oceans Angling Club (*The TOAC works on a catch and release basis) Photographer: P Two Oceans Angling Club Copyright/Website: Two Oceans Angling Club Bronze Whaler Photo: Kari Underhill Photographer: Kari Underhill Copyright/Website: Kari Underhill Bronze Whaler Photo: Two Oceans Angling Club (*The TOAC works on a catch and Photographer: Two Oceans Angling Copyright/Website: Two Oceans Angling

7 release basis) Club Club Bronze Whaler Photo: OpenCage / Wikimedia Commons P hotographer: OpenCage Copy right/website: OpenCage / CC BY-SA 2.5 Bronze Whaler jaws Photo: D. Ross Robertson Photographer: D. Ross Robertson Copyright/Website: D. Ross Robertson / Public Domain

8 Bronze Whaler upper teeth Photo: D. Ross Robertson Photographer: D. Ross Robertson Copyright/Website: D. Ross Robertson / Public Domain Bronze Whaler lower teeth Photo: D. Ross Robertson Photographer: D. Ross Robertson Copyright/Website: D. Ross Robertson / Public Domain

9 General Shark Identification Copyright/Website: TRAFFIC Shark Trade Products Copy right/website: TRAFFIC Copyright All rights reserved.

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