Black Marlin

RECREATIONAL FISHERY

The Cairns-Lizard Is. fishery targets large females of 450kg+ ("Thousand Pounders") associated with the spawning/pre-spawning aggregation fished by the commercial fishery. The gamefishery occurs at the same time as the longline fishery (September-December) on the outside of the coral reefs but within several kilometres, often hundreds of metres, of the reef crests. Light-tackle fishing for 10-40kg fish occurs from July to October at Pixie Reef, Dunk Island and Cape Bowling Green. Fishing for 20-50kg fish off Cape Moreton peaks in January-February. More than 90% of the black marlin caught by the gamefishery in Queensland are tagged with numbered, scientific tags (supplied by the Fisheries Research Institute of NSW) and released (Figure 7). The modal size of fish caught in northern-central NSW is 25-120kg with the peak season occurring January-March. Larger fish are caught further south off Bermagui, mostly around March.

Figure 7. Annual records of the number of black marlin tagged in the Lizard Is., Cairns, Townsville and Brisbane regions.

Angler clubs located in eastern Australia reported landing approximately 600 marlin (predominantly black marlin) in 1988/89. Larger numbers of fish (>90% caught in Qld.) are tagged and released. During 1989/90, 974 black marlin were recorded as tagged in Qld., 77 in NSW and 13 in WA. The total number of black marlin tagged from the inception of the NSW Gamefish Tagging Program (covering all Australian waters) in 1974 until July 1992 was 19,423 fish (Table 2). There is no routine collection of catch data from the recreational fishery even though all gamefishing clubs are affiliated with state and national organisations which are well situated to promote the value of routine monitoring of member fishing activities.

An effective system for the protection of small fish is afforded by clubs' procedures for allocating tagging points during competitive angling. Tagging points are allocated irrespective of fish weight but any fish to be weighed must weigh heavier than a fixed minimum weight to accrue better than tagging points. This minimum weight is usually set at the top end of the weight range of fish normally encountered on the fishing ground.

Black marlin being tagged.

The recapture rates of black marlin do not vary significantly between fishing grounds. Recapture rates vary from 0.40% to 1.08% where all fish are considered and 0.15-0.76% where short-term (<90days) local (<100km) recaptures are excluded.

Table 2. Number of black marlin tagged under the FRI Gamefish tagging program by year and location.

Recreational fishing links

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Last updated - 28 October 98

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