Since the beginning of toothfish fishing in the seas around Antarctica, the fish stock has declined as a result of illegal fishing, particularly in the southern Atlantic and Indian Ocean sectors of the Antarctic Ocean1, 2. The fishery is still within its limits of sustainable use, but careful management and monitoring is needed 3. In the Ross Sea area, which is managed and monitored by New Zealand agencies on behalf of the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) 4, stock estimates are uncertain, but it is thought that the stock has declined by between 5-20% since 1996 5.
The toothfish fishery is highly-regulated, and overseen by CCAMLR. This multi-government body is part of the Antarctic Treaty System. The aim of the Commission is to safeguard the environment and protect the integrity of the ecosystem of the seas surrounding Antarctica, and to conserve Antarctic marine living resources.
CCAMLR regulates the amount of toothfish that can be caught each year. New Zealand companies and vessels that want to target toothfish must apply to the Ministry of Fisheries for a permit, and there are very strict selection criteria. The number of New Zealand vessels granted access to fish in CCAMLR waters is decided by the Commission at its annual meeting. The current CCAMLR rules allow for a long-term reduction of the toothfish stock of up to 50% over the next 35 years 6.
Continued access for a vessel is based on its past performance in the fishery. Vessels granted access to fish in CCAMLR waters must adhere to strict conservation rules, undertake research work, and carry official observers so all activity is monitored. Conservation rules include seabird by-catch mitigation measures, such as fast-sinking weighted lines, and retention of offal on board.
Observers accompany vessels such as the San Aspiring on fishing voyages in the Antarctic. There are usually two observers on each vessel, one from the New Zealand Ministry of Fisheries, and one from another member country of CCAMLR. This allows 24-hour monitoring of fishing activity. The observers monitor fishing practices and catch, and make sure fishing vessels adhere to the strict conservation rules for fishing in the Antarctic, including storage and disposal of rubbish.
Observers also take part in ongoing research by
tagging and releasing fish, taking biological samples, and collecting specimens of fish and unusual or rare by-catch. The observers can retain specimens taken at sea, which are then sent to Te Papa for identification. In the case of the colossal squid, the Ministry of Fisheries observer and the skipper of the San Aspiring arranged for the specimen to be kept, with cooperation and ongoing logistical support from the fishing company Sanford Limited.
Studies of toothfish have been carried out at McMurdo Sound since the 1960s, before commercial toothfishing began in 1996 7, 8. Over almost 40 years an average of 200-500 toothfish were caught annually. However, after a rise in industrial fishing effort in the Ross Sea in 2003, catches at McMurdo declined rapidly and in 2007 only two toothfish were caught.
The study concluded that the trend indicated a contraction of the Ross Sea toothfish population northward as industrial fishing removed toothfish from the central stock. It was also noted that the numbers of fish-eating killer whales had dropped dramatically and the diet of penguins reflected the disappearance of a competitor.
1: Another one that didn't get away! - Australian Antarctic Magazine
2: Issues of Sustainability in the Southern Ocean Fishers - the Case of the Patagonian Toothfish
3: The Patagonian toothfish fishery in Flakland Islands' waters
4: Ministry of Fisheries Annual Report 2004/2005
5: Dissostichus SPP. (TOT) (Dissostichus mawsoni and Dissostichus eleginoides)
6: Finding the role of Antarctic toothfish in the Ross Sea ecosystem
7: Decline of Antarctic toothfish and its predators in McMurdo Sound and the Southern Ross sea, and recommendations for its restoration - Arthur L. DeVries and David Ainley
8: Decline of Antarctic toothfish and its predators in McMurdo Sound and the Southern Ross sea, and recommendations for its restoration - Arthur L. DeVries and David Ainley and Grant Ballard