Scientific name: |
Xiphias gladius |
Other names: |
broadbill, broadbill swordfish, paea, espadon (France), mekajiki (Japan) |
Swordfish is a worst choice fish. A better alternative is albacore or skipjack tuna.
Swordfish is a highly migratory species of broadbill fish and an important oceanic predator found worldwide in temperate, tropical and subtropical seas. The management responsibility for this species, as with other Western Pacific migratory fish, lies with an international body: the Western and Central Pacific Fisheries Commission (WCPFC). However, the Ministry for Primary Industries is responsible for upholding WCPFC rules in New Zealand waters, with catch limits set under the quota management system. Swordfish are targeted and caught as a bycatch in the northern bigeye and southern bluefin tuna longline fisheries.
here are concerns over the uncertainty about the stock assessments, catch limits and state of the stocks, plus the potential for serial depletion of large swordfish. Swordfish are caught as bycatch in tuna longline fisheries. The bigeye target tuna longline fishery also captures turtles, including leatherback, a vulnerable threatened species. It also has an estimated capture of 593 seabirds a year including vulnerable threatened Gibson’s and Antipodean albatross, and near-threatened southern Buller’s albatross. An estimated 623 seabirds a year are caught in the southern bluefin tuna target fishery, including white-capped albatross and Buller’s albatross. This fishery also catches about 100 fur seals annually and vulnerable shark species like porbeagle, mako and thresher sharks.
Not certified under any scheme.
Main markets are the US (90%) then Japan and Australia. Swordfish export value was $5.7m in 2015.
Asssessment output
No regional or fishing method difference.
| Score: | C |
| Population size: | Unknown – South Pacific migratory population. |
| Annual catch limit: | Limit set at 885 tonnes since 2004. |
| Recorded catch: | Latest reported annual landings of 577 tonnes in 2013-14. The average sex ratio of swordfish caught in the longline fishery over the last 20 years was 3 times as many females compared to males. |
| Stock trends: | According to stock assessment in 2013, current total biomass levels are 44-68 %Bo and spawning biomass is 27-55% (range of key model runs). Following a period of continuous decline, the southwest Pacific swordfish biomass has recently increased. But an alternative Australian model indicates a decline. |
| MSY Status: | Recent catches are considered to be around the BMSY level. |
| The Ministry of Primary Industries assessment plenary report includes: |
“Overfishing is About as Likely as Not to be occurring”. “Fishing mortality increased substantially from 1995 to present.” “Projections based on the model that used Hawaii growth predict further increases in stock size at current fishing mortality levels. However, using the Australian growth the stock is About as Likely as Not to decline.” (MPI 2015, p498-502). |
| Score: | C |
| Distribution: | Swordfish are found worldwide in temperate, subtropical and tropical waters. They are present in New Zealand year round, from the Kermadecs to Foveaux Strait. |
| Maximum age (years): | 20+. New otolith-based research indicates fish live longer and grow more slowly than previous estimates. |
| Age at sexual maturity: | 1 year males, 10 years females |
| Growth rate: | Medium |
| Reproductive output: | Medium |
| Age exploited: | ? |
| Ability to recover: | Moderate |
| Score: | B |
| Fishing method(s): | Swordfish is caught as bycatch in tuna longline fisheries around the North Island. About 62% of swordfish are caught in the target bigeye tuna fishery and 17% in the Southern bluefin tuna fishery. About 13% is targeted. |
| Habitat damage: | No benthic impact |
| Habitat of particular significance: | Hasn’t been defined in New Zealand. |
| Bycatch: | Various sharks are caught in the longline fishery and, combined, make up over 90% of the bycatch by number. |
| Ecological effects: | Excessive removal of this large predator species can have considerable ecological implications. |
| Score: | E |
| Bycatch: | A number of other species are also caught in the tuna longline fisheries, including New Zealand fur seals, marine mammals, sharks, seabirds and turtles. The observed rate of turtle captures are one per year but, given level of observer coverage, actual numbers could be 10-40 times this. In the bigeye tuna fishery an estimated four New Zealand fur seal captures occur per year (based on the last 5 years) and 593 seabirds a year including vulnerable threatened Gibson’s and Antipodean albatross, and near-threatened southern Buller’s albatross (includes cryptic mortality). In the southern bluefin tuna fishery, an estimated 623 seabirds are caught and an estimated 100 fur seals a year (based on the last 5 years). Vulnerable threatened sharks, like porbeagle, mako and thresher sharks, are also caught. |
| Score: | A |
| Management component: | Single species of a western South Pacific stock, but the stock structure in the Pacific is uncertain. |
| Score: | D |
| Quota Management Species: | Yes, in 2004 |
| Catch limits: | Yes |
| Management plan: | Highly Migratory Species management plan for 2010-15 is out of date, and has yet to be reviewed and replaced. There is no operational plan and the old management plan lacks key environmental standards. The National Plans of Action on Seabirds and Sharks are more relevant but they are slow to be implemented. There is no international management plan and the Western and Central Pacific Fisheries Commission (WCPFC) has yet to apply effective measures to prevent over-fishing. |
| Stock assessment: | An assessment in 2013 by the WCPFC. No separate New Zealand assessment. |
| Research: | Limited, with no current directed research on swordfish. |
| Observer coverage: | About 21.4% of sets are observed but it is biased towards larger vessels. Observer coverage for small vessels is only 5.97% annually over last 5 years. |
Fisheries map
Taken from the Ministry for Primary Industries’ Plenary report for fisheries management.
References
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