Broadbill swordfish inhabit all Australian waters beyond the edge of the continental shelf (Ref. 6390).

Stock structure: There is little information on stock structure of broadbill swordfish in the Pacific Ocean although 2 hypotheses are currently proposed. The first identifies a single stock which is distributed throughout the Pacific but has local areas of high abundance. The second proposes 3 stocks based on the regional centres of high abundance in the north-western, south-western and eastern Pacific (Ref. 30449). There is no information on stock structure in Indian Ocean broadbill swordfish.

Commercial fishery: Broadbill swordfish do not represent a commercial fishery for Australian fishers. They are significant bycatch of pelagic longlining in the East Coast Tuna Fishery but are not normally targeted because of difficulties in marketing the species. The main target species of the longline fishery are yellowfin tuna (Thunnus albacares) and bigeye tuna ().

About 90 t of broadbill swordfish were caught by domestic tuna longline vessels in 1989-90. Most of the catch was taken from the Tasman Sea in waters off southern New South Wales and eastern Victoria. Fishing trials have shown that broadbill swordfish can be targeted at night by using squid baits set at shallow depths. The attachment of ‘lightsticks’ to the baits is reported to significantly increase the catch rate of broadbill swordfish.

Most of the broadbill swordfish caught off the east coast weigh less than 100 kg. They are headed and gutted on board the fishing vessel and sold as fresh chilled product on the domestic fresh fish market. Broadbill swordfish are popular amongst Sydney consumers but health regulations have caused a reduction in supply in recent years. Broadbill swordfish sold in New South Wales must be individually tested for mercury content. The larger fish are likely to exceed the limit, which is lower than the amount specified for other States. Much of the broadbill swordfish landed is therefore sold through Brisbane and Melbourne markets.

The Japanese longline fleet catches large numbers of broadbill swordfish throughout the Pacific and Indian oceans. Japanese longline vessels have operated near the eastern and western coasts of Australia since the 1950s. These vessels are normally between 35 m and 45 m in length and set approximately 3000 hooks per day on mainlines which are 70-110 km long. Within the Australian Fishing Zone the most productive areas are in the east, off southern Queensland and surrounding Lord Howe Island. Significant catches are also taken south of Norfolk Island, in the Coral Sea off north Queensland and off north-western Australia. Catches from north-eastern and north-western waters are mainly bycatch of vessels fishing for yellowfin tuna. Significant catches of broadbill swordfish are also recorded by Japanese longliners targeting bigeye tuna off south-western Australia from October to April each year. As at 1993, the annual Japanese catch of broadbill swordfish from the Australian Fishing Zone normally ranged between 700 t and 1000 t.

Recreational fishery: Broadbill swordfish are popular sport and gamefish in the eastern Pacific Ocean, particularly off California, Ecuador, Peru and northern Chile (Ref. 9742). In these areas basking broadbill swordfish are targeted using trolled whole fish or flesh baits.

For many years, rare catches of small broadbill swordfish have been reported by anglers in Australian waters. However, it was not until June 1989 that a broadbill swordfish was landed that qualified for record status under international game fishing regulations. A number of fish weighing in excess of 50 kg have since been caught from southern New South Wales waters. The Game Fishing Association of Australia’s record for a broadbill swordfish is 106 kg for a fish caught off Eden in May 1991. The larger fish landed by anglers in Australia have all been caught on baits drifted at night near the edge of the continental shelf.

Resource status: Stock assessments based on Japanese longline catch rates indicate that Pacific stocks of broadbill swordfish are not over-exploited (Ref. 30449). However, the data used for these assessments are incomplete for the period since 1980. Also Ref. 2334.