The Antarctic toothfish (''Dissostichus mawsoni''), also known as the Antarctic cod, is a large, black or brown

fish A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can ...

found in very cold (even subzero) waters of the

Southern Ocean The Southern Ocean, also known as the Antarctic Ocean, comprises the southernmost waters of the world ocean, generally taken to be south of 60th parallel south, 60° S latitude and encircling Antarctica. With a size of , it is the seco ...

near Antarctica. It is the largest species of

bony fish Osteichthyes ( ; ), also known as osteichthyans or commonly referred to as the bony fish, is a Biodiversity, diverse clade of vertebrate animals that have endoskeletons primarily composed of bone tissue. They can be contrasted with the Chondricht ...

in the Southern Ocean, feeding largely on smaller fishes and

crustacea Crustaceans (from Latin meaning: "those with shells" or "crusted ones") are invertebrate animals that constitute one group of arthropods that are traditionally a part of the subphylum Crustacea (), a large, diverse group of mainly aquatic arthrop ...

ns, and, in turn, preyed on by

orca The orca (''Orcinus orca''), or killer whale, is a toothed whale and the largest member of the oceanic dolphin family. The only extant species in the genus '' Orcinus'', it is recognizable by its black-and-white-patterned body. A cosmopol ...

s, other

toothed whale The toothed whales (also called odontocetes, systematic name Odontoceti) are a parvorder of cetaceans that includes dolphins, porpoises, and all other whales with teeth, such as beaked whales and the sperm whales. 73 species of toothed wha ...

s, and seals. It is caught for food and marketed as Chilean sea bass together with its sister species, the more northerly Patagonian toothfish (''D. eliginoides''). Often mistakenly called "Antarctic cod", the Antarctic toothfish is a species in the ( Nototheniidae), a

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

of fishes abundant in

subantarctic The sub-Antarctic zone is a physiographic region in the Southern Hemisphere, located immediately north of the Antarctic region. This translates roughly to a latitude of between 46th parallel south, 46° and 60th parallel south, 60° south of t ...

waters.

Name and taxonomy

The common name "toothfish" refers to the two rows of teeth in the upper jaw, thought to give it a shark-like appearance. The genus name ''Dissostichus'' is from the Greek (twofold) and ''stichus'' (line) and refers to the presence of two long

lateral line The lateral line, also called the lateral line organ (LLO), is a system of sensory organs found in fish, used to detect movement, vibration, and pressure gradients in the surrounding water. The sensory ability is achieved via modified epithelia ...

s that enable the fish to sense prey. The species name, ''mawsoni'', honors the Australian geologist

Douglas Mawson Sir Douglas Mawson (5 May 1882 – 14 October 1958) was a British-born Australian geologist, Antarctic explorer, and academic. Along with Roald Amundsen, Robert Falcon Scott, and Sir Ernest Shackleton, he was a key expedition leader during ...

who led the 1911–1914 Australasian Antarctic Expedition that explored the Antarctic coast and obtained the species'

type Type may refer to: Science and technology Computing * Typing, producing text via a keyboard, typewriter, etc. * Data type, collection of values used for computations. * File type * TYPE (DOS command), a command to display contents of a file. * ...

specimen. The Antarctic toothfish was first formally described in 1937 from the English

ichthyologist Ichthyology is the branch of zoology devoted to the study of fish, including bony fish (Osteichthyes), cartilaginous fish (Chondrichthyes), and jawless fish (Agnatha). According to FishBase, 35,800 species of fish had been described as of March 2 ...

John Roxborough Norman John Roxborough Norman (1898, Wandsworth, London – 26 May 1944, Berkhamsted, Hertfordshire) was an English ichthyologist. He started as a clerk in a bank. His lifetime affliction with rheumatic fever began during his military service during the ...

with the type locality given as off MacRobertson Land at 66°45'S, 62°03'E in Antarctica.

Description

Fully grown, antarctic toothfish, (like their warmer-water relatives, the Patagonian toothfish, ''D. eleginoides'') may grow to more than in length and 135 kg in mass, twice as large as the next-largest Antarctic species of fishes. Being large, and consistent with the unstructured

food web A food web is the natural interconnection of food chains and a graphical representation of what-eats-what in an ecological community. Position in the food web, or trophic level, is used in ecology to broadly classify organisms as autotrophs or he ...

s of the ocean (i.e., big fish eating little fish regardless of identity, even eating their own offspring), the Antarctic toothfish has been characterized as a voracious predator. Furthermore, by being by far the largest midwater fish in the Southern Ocean, it is thought to fill the ecological role that

sharks Sharks are a group of elasmobranch cartilaginous fish characterized by a ribless endoskeleton, dermal denticles, five to seven gill slits on each side, and pectoral fins that are not fused to the head. Modern sharks are classified within the ...

play in other oceans. As an adaptation to that role, the Antarctic toothfish is one of only five notothenioid species that, as adults, are neutrally buoyant. This buoyancy is attained at 100–120 cm in length and enables them to spend time above the bottom without wasting energy.Yukhov, V.L. (1971). The range of ''Dissostichus mawsoni'' Norman and some features of its biology. ''Journal of Ichthyology'' 11: 8–18. Both bottom-dwelling and mid-water prey are, therefore, available to them. Most other notothenioid fish and the majority of all Antarctic fishes, including smaller toothfish, are confined to the bottom. Coloring is black to olive brown, sometimes lighter on the undersides, with a mottled pattern on body and fins. Small fish blend in very well among the

benthic The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from the Ancient Greek word (), meaning "the depths". ...

sponge Sponges or sea sponges are primarily marine invertebrates of the animal phylum Porifera (; meaning 'pore bearer'), a basal clade and a sister taxon of the diploblasts. They are sessile filter feeders that are bound to the seabed, and a ...

s and

coral Corals are colonial marine invertebrates within the subphylum Anthozoa of the phylum Cnidaria. They typically form compact Colony (biology), colonies of many identical individual polyp (zoology), polyps. Coral species include the important Coral ...

s. The species has a broad head, an elongated body, long

dorsal Dorsal (from Latin ''dorsum'' ‘back’) may refer to: * Dorsal (anatomy), an anatomical term of location referring to the back or upper side of an organism or parts of an organism * Dorsal, positioned on top of an aircraft's fuselage The fus ...

and

anal fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported o ...

s, large

pectoral fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish aquatic locomotion, swim. Apart from the tail or caudal fin, fish fins have no direct connection with the vertebral column ...

s, and a rudder-like

caudal fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported only ...

. They typically move slowly, but are capable of speed bursts that may elude predatory seals.

Feeding ecology

Over the continental shelf, Antarctic toothfish feed on

shrimp A shrimp (: shrimp (American English, US) or shrimps (British English, UK)) is a crustacean with an elongated body and a primarily Aquatic locomotion, swimming mode of locomotion – typically Decapods belonging to the Caridea or Dendrobranchi ...

('' Nauticaris'' spp.) and small fish, principally another neutrally buoyant nototheniid, the Antarctic silverfish (''Pleuragramma antarcticum''). This loosely schooling species is also a major prey of Adélie (''Pygoscelis adeliae'') and emperor penguins (''Aptenodytes forsteri''), Weddell seals (''Leptonychotes weddellii'') and Antarctic minke whales (''Balaenoptera bonaerensis''). Therefore, competition for prey among toothfish and these other mesopredators (middle

trophic level The trophic level of an organism is the position it occupies in a food web. Within a food web, a food chain is a succession of organisms that eat other organisms and may, in turn, be eaten themselves. The trophic level of an organism is the ...

predators) could be very important. The large Antarctic toothfish are eaten by

sperm whale The sperm whale or cachalot (''Physeter macrocephalus'') is the largest of the toothed whales and the largest toothed predator. It is the only living member of the Genus (biology), genus ''Physeter'' and one of three extant species in the s ...

s (''Physeter macrocephalus''),

killer whale The orca (''Orcinus orca''), or killer whale, is a toothed whale and the largest member of the oceanic dolphin family. The only extant species in the genus '' Orcinus'', it is recognizable by its black-and-white-patterned body. A cosmopolit ...

s (''Orcinus orca''), Weddell seals, and possibly colossal squid (''Mesonychoteuthis hamiltoni''). Toothfish that are dwelling on the bottom, particularly those caught during the summer on the

continental slope A continental margin is the outer edge of continental crust abutting oceanic crust under coastal waters. It is one of the three major zones of the ocean floor, the other two being deep-ocean basins and mid-ocean ridges. The continental margi ...

, eat mainly

grenadiers A grenadier ( , ; derived from the word ''grenade'') was historically an assault-specialist soldier who threw hand grenades in siege operation battles. The distinct combat function of the grenadier was established in the mid-17th century, when ...

(Macrouridae), but also feed on other smaller fish species and skates (''Raja'' spp.). They also feed on the colossal squid. Antarctic toothfish have been caught to depths of 2200 m, though based on commercial fishing effort, few occur that deep.Hanchet, S.M.; Rickard, G.J.; Fenaughty, J.M.; Dunn, A.; and Williams, M.J.H. (2008). Hypothetical life cycle for Antarctic toothfish (''Dissostichus mawsoni'') in the Ross Sea region. CCAMLR Sci. 15:35–53.

Aging and reproduction

Aging data indicate Antarctic toothfish are relatively fast-growing when young, but then growth slows later in life. They reach about one-third of maximum size after 5 years, and half maximum by 10 years, after which growth slows considerably. To grow fast when small is an adaptation of most

predatory fish Predatory fish are hypercarnivorous fish that actively prey upon other fish or aquatic animals, with examples including shark, billfish, barracuda, alligator gar, tuna, dolphinfish, walleye, perch and salmon. Some omnivorous fish, such as t ...

, e.g., sharks, so as not to be small for very long. The maximum age recorded so far has been 48 years. Antarctic toothfish take a long time to mature (13 years for males, 17 years for females) and once mature may not

spawn Spawn or spawning may refer to: * Spawning, the eggs and sperm of aquatic animals Arts, entertainment and media * Spawn (character), a fictional character in the comic series of the same name and in the associated franchise ** ''Spawn: Armageddon' ...

every year, though the actual spawning interval is unknown. Only a few Antarctic toothfish with mature eggs have ever been caught, meaning knowledge is sparse about fecundity.Hanchet, S.M. (2010) Updated species profile for Antarctic toothfish (''Dissostichus mawson''i). CCAMLR WG-FSA-10/24. Hobart, Australia. They spawn sometime during winter.Brooks, C.M.; Ashford, J.R. (2008) Spatial distribution and age structure of the Antarctic toothfish (''Dissostichus mawsoni'') in the Ross Sea, Antarctica. CCAMLR WG-FSA-08-18. Hobart, Australia. Large, mature, older fish have been caught among the

seamount A seamount is a large submarine landform that rises from the ocean floor without reaching the water surface (sea level), and thus is not an island, islet, or cliff-rock. Seamounts are typically formed from extinct volcanoes that rise abruptly a ...

s of the Pacific-Antarctic Ridge, a location thus thought to be important for spawning. Smaller, subadult Antarctic toothfish tend to concentrate in shallower waters on the continental shelf, while a large portion of the older fish are found on in the continental slope. This sequestering by size and age could be another adaptation for small fish to avoid being eaten by large ones. The recruitment potential of Antarctic toothfish, a measure of both fecundity and survival to spawning age, is not known.

Anatomy and physiology

The Antarctic toothfish has a lightweight, partially

cartilaginous Cartilage is a resilient and smooth type of connective tissue. Semi-transparent and non-porous, it is usually covered by a tough and fibrous membrane called perichondrium. In tetrapods, it covers and protects the ends of long bones at the joints ...

skeleton, lacks a

swim bladder The swim bladder, gas bladder, fish maw, or air bladder is an internal gas-filled organ (anatomy), organ in bony fish that functions to modulate buoyancy, and thus allowing the fish to stay at desired water depth without having to maintain lift ...

, and has fatty deposits which act as a stored energy source, particularly during spawning. This fat also makes large toothfish neutrally buoyant. Many toothfish caught over the seamounts are very depleted of fat, and this is thought perhaps to be related to spawning and spawning migration, which are energy-demanding activities. It is not known what happens to these fat-depleted fish, including whether they reach, or how long it takes them to reach, breeding condition again; this ostensibly occurs upon returning to continental-slope waters. Antarctic toothfish have

vision Vision, Visions, or The Vision may refer to: Perception Optical perception * Visual perception, the sense of sight * Visual system, the physical mechanism of eyesight * Computer vision, a field dealing with how computers can be made to gain und ...

and

systems well adapted to find prey in low light levels.Eastman, JT; Lannoo, MJ. (2011). Divergence of brain and retinal anatomy and histology in pelagic Antarctic notothenioid fishes of the sister taxa ''Dissostichus'' and ''Pleuragramma''. Journal of Morphology 272:419-441. Since ice covers the surface of the ocean where Antarctic toothfish occur even in summer, these sensory specializations likely evolved to enable survival in the reduced light levels found under ice and in the Antarctic winter, as well as at deep depths. Antarctic toothfish also have a very well developed sense of smell, which is why they are easily caught by baited hooks and also scavenge the remains of penguins killed by other predators.

Cold adaptation

The Antarctic toothfish lives in subzero degree water below latitude 60°S. It is noteworthy, like most other Antarctic notothenioids, for producing antifreeze glycoproteins, a feature not seen in its closest relative, the Patagonian toothfish, which typically inhabits slightly warmer waters. The presence of antifreeze glycoproteins allows the Antarctic toothfish (and other notothenioids) to thrive in subzero waters of the Southern Ocean surrounding

Antarctica Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean (also known as the Antarctic Ocean), it contains the geographic South Pole. ...

. The Antarctic toothfish's voracious appetite also is important in coping with cold water. It is mainly caught in the

Ross Sea The Ross Sea is a deep bay of the Southern Ocean in Antarctica, between Victoria Land and Marie Byrd Land and within the Ross Embayment, and is the southernmost sea on Earth. It derives its name from the British explorer James Clark Ross who ...

in the austral summer, but has also been recorded from Antarctic coastal waters south of the

Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or approximately 20% of the water area of Earth#Surface, Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia (continent), ...

sector, in the vicinity of the

Antarctic Peninsula The Antarctic Peninsula, known as O'Higgins Land in Chile and Tierra de San Martin in Argentina, and originally as Graham Land in the United Kingdom and the Palmer Peninsula in the United States, is the northernmost part of mainland Antarctica. ...

, and near the

South Sandwich Islands The South Sandwich Islands () are a chain of uninhabited volcanic islands in the South Atlantic Ocean. They are administered as part of the British Overseas Territory of South Georgia and the South Sandwich Islands. The chain lies in the sub-A ...

Fishery and associated ecosystem

A fishery for Antarctic toothfish, managed by the

Convention for the Conservation of Antarctic Marine Living Resources The Convention on the Conservation of Antarctic Marine Living Resources, also known as the Commission for the Conservation of Antarctic Marine Living Resources, and CCAMLR, is part of the Antarctic Treaty System. The convention was opened for s ...

(CCAMLR), has existed since 1997. The existence of this fishery in the Ross Sea, the area where most Antarctic toothfish are caught, is very contentious - the main argument proposed for this is the lack of accurate population parameters, such as original stock size, fecundity, and recruitment. Moreover, the main fishing grounds are presumed by some researchers to cover the area through which the entire stock of Antarctic toothfish pass. Typically, the fishing season has finished in the area by the end of February and for the remainder of the year, much of the area is covered by sea ice, providing a natural impediment to fishing. This fishery is characterised by opponents as being a challenge to manage owing to the nature of benthic

longline fishing Longline fishing, or longlining, is a commercial fishing angling technique that uses a long ''main line'' with baited hooks attached at intervals via short branch lines called ''snoods'' or ''gangions''. Current spawning stock biomass for Antarctic toothfish in the Ross Sea Region is estimated to be at 75% of the pre-exploitation level (95% Bayesian probability interval 71–78%), well above the 50% target reference point. An independent study was reported to have detected the disappearance of large fish at the southern periphery of its range in the

McMurdo Sound The McMurdo Sound is a sound in Antarctica, known as the southernmost passable body of water in the world, located approximately from the South Pole. Captain James Clark Ross discovered the sound in February 1841 and named it after Lieutenant ...

and was postulated to be consistent with this apparent loss of large fish. However, more recent work has shown this was not the case in 2014. Some studies have reported that the prevalence of fish-eating killer whales has been apparently decreasing in the southern Ross Sea, foraging efficiency of

Weddell seal The Weddell seal (''Leptonychotes weddellii'') is a relatively large and abundant Earless seal, true seal with a Subantarctic, circumpolar distribution surrounding Antarctica. The Weddell seal was discovered and named in the 1820s during expediti ...

s is decreasing, and numbers of

Adélie penguin The Adélie penguin (''Pygoscelis adeliae'') is a species of penguin common along the entire coast of the Antarctic continent, which is the only place where it is found. It is the most widespread penguin species, and, along with the emperor peng ...

s (competitors for Antarctic silverfish) have been increasing. More recent studies have confirmed visual sightings of Weddell seals and Type-C killer whales holding and consuming large toothfish in the McMurdo Sound area and raise questions over the previously assumed importance of assumed dominance of Antarctic silverfish (''Pleuragramma antarcticum'') in the diet of Weddell seal and Type-C killer whales. These reports highlight the importance of managing this fishery in the best interests of the ecosystem by continuing to collect information on both Antarctic toothfish life history and the interaction of that species with predators and prey. An important research programme in this regard is the annual 'Shelf' survey carried out annually since 2012, which is designed to monitor the abundance of subadult Antarctic toothfish in areas where subadult-sized fish have been regularly found (e.g., in the southern Ross Sea) has been designed provide data to better estimate recruitment variability and provide an important early-warning signal of changes in toothfish recruitment. The project also is used for additional targeted data collection to better understand the lifecycle and ecosystem role of Antarctic toothfish. Research has provided evidence for long-distance migrations of type-C killer whales between the Ross Sea and New Zealand waters, indicating a much wider range that had been postulated by a number of scientists. One adult female type-C killer whale has been seen in both New Zealand waters and McMurdo Sound, Antarctica, and a high large proportion of type-C killer whales sighted in McMurdo Sound have scars caused by cookiecutter sharks that are currently assumed to be limited to north of 50°S. At the same time as this study was occurring, Italian whale experts at Terra Nova Bay, about 360 km north of Scott Base, deployed satellite transmitters on type-C killer whales to determine the whales' movements. Their results independently verified that type-C killer whales were commuting between Scott Base and the waters off Northland. The total catch of Antarctic toothfish in 2013–14 was 3820 tonnes; 3,320 tonnes of this were taken from the Ross Sea (FAO Statistical Divisions 88.1 and 88.2), with the remainder taken from other high seas areas within the CCAMLR convention area.

Management

The ecosystem approach to fishing is encapsulated in Article II of the CAMLR Convention. The ecosystem approach uses decision rules based on both population status targets and limit reference points, and incorporates uncertainty and ecosystem status in the calculation of these targets. Different reference points to account for the needs of dependent predators in the ecosystem are used depending on the location of the species in the food web. The ecosystem fisheries management approach by CCAMLR involves use of move-on rules to protect trophic interactions, and limit direct effects of fishing on fish bycatch, seabirds, and vulnerable marine ecosystems. Annually reviewed mitigation measures such as line weighting and streamer lines minimize seabird bycatch, which have resulted in a substantial reduction in accidental seabird mortalities in the CAMLR Convention Area. The 50% (target) and 20% (limit) reference points used by the CCAMLR decision rules exceed the requirements for target and limit reference points set by almost all national and international fisheries management organizations, even for species longer lived than toothfish. A wide study of many fisheries generally indicated that most reach maximum sustainable yield at 30–35% of their pre-exploitation abundances. CCAMLR uses a more conservative reference level to allow exploitation at a level where toothfish recruitment and the ecosystem in general is not appreciably impacted. This is required by Article II of the CAMLR Convention. A common misunderstanding of the CCAMLR decision rules is an assumption that the decline in population size will follow a clear trajectory from the starting year to a point 35 years later when the stock size will reach 50% of pre-exploitation levels and an assumption that no feedback occurs during each assessment. The catch limit, though, is recalculated based on all updated or revised data at each annual or biennial assessment. This approach is used to ensure that the 50% level will be approached slowly and enables an ongoing readjustment of catch levels as knowledge improves.

Environment and bycatch

CCAMLR imposes stringent environmental protection and

bycatch Bycatch (or by-catch), in the fishing industry, is a fish or other marine species that is caught unintentionally while fishing for specific species or sizes of wildlife. Bycatch is either the wrong species, the wrong sex, or is undersized or juve ...

mitigation measures to Antarctic toothfish fisheries, including: * Monitoring of daytime setting and movement of vessels from the fishery should any vessel catch more than three seabirdsCCAMLR CM 25-02, http://www.ccamlr.org/en/measure-25-02-2009 * Use of streamer lines during setting to keep birds away from baited hooks * Weighting of lines to ensure fast sink rates to prevent seabirds from accessing baited hooks * The use of bird exclusion devices to prevent birds from accessing hooks whilst lines are being hauled * Limitations on the release of fish offal overboard at the same time as setting and hauling of lines to avoid attracting seabirds: An additional requirement prohibits the dumping of all offal south of 60°S, the region where Antarctic toothfish are caughtCCAMLR CM 26-01, http://www.ccamlr.org/en/measure-26-01-2001 * Prohibition on the dumping of oil, plastic, garbage,

food waste The causes of food going uneaten are numerous and occur throughout the food system, during food production, production, food processing, processing, Food distribution, distribution, Grocery store, retail and food service sales, and Social clas ...

, poultry, eggs or eggshells, sewage, and ash by fishing vessels * Prohibition of the use of plastic packaging bands on fishing vessels Incidental mortality of seabirds as a result of fishing has fallen to near-zero levels in the CCAMLR convention area. No mortality of seabirds or marine mammals was recorded as a result of fishing for Antarctic toothfish in 2011–12 and only two seabirds (southern giant petrels ''Macronectes giganteus'') have been killed as a result of fishing in the Ross Sea since 1996/97.

Compliance

Compliance measures adopted by CCAMLR apply to all Antarctic toothfish fisheries. These include: * At-sea inspections of

fishing vessel A fishing vessel is a boat or ship used to fishing, catch fish and other valuable nektonic aquatic animals (e.g. shrimps/prawns, krills, coleoids, etc.) in the sea, lake or river. Humans have used different kinds of surface vessels in commercial ...

s * Vessel licensing * Port inspections of fishing vessels * Continuous reporting of fishing vessel positions via satellite-linked

vessel monitoring system Vessel Monitoring Systems (VMS) is a general term to describe systems that are used in commercial fishing to allow environmental and fisheries regulatory organizations to track and monitor the activities of fishing vessels. They are a key part of ...

s * Catch documentation scheme for toothfish, which tracks toothfish from the point of landing through to the final point of sale and requires verification and authorisation by government authorities at each step * The requirement to carry two scientific observers on each licensed vessel – including one from a member state other than the vessel flag

Sustainability

In November 2010, the

Marine Stewardship Council The Marine Stewardship Council (MSC) is a non-profit organisation which aims to set standards for sustainable fishing. Fisheries that wish to demonstrate they are well-managed and sustainable compared to the MSC's standards are assessed by a tea ...

(MSC) certified the Ross Sea Antarctic toothfish fishery as a sustainable and well-managed fishery. The certification is contentious, with many conservation groups protesting the certification due to the paucity of information needed to reliably manage the fishery, and that only eight of the 19 vessels in the fishery during the latest year for which data are publicly available were certified. During the 2013–14 season, vessels operating under the Marine Stewardship Certification landed 51.3% of all Antarctic toothfish from the Ross Sea Region (CCAMLR Subarea 88.1) and 64.7% of Antarctic toothfish from the Amundsen Sea sector (CCAMLR Subarea 88.2). The argument that only a portion of Antarctic toothfish is certified, the high price it commands, and the remote areas where a large proportion of the fish are caught have been advanced as an encouragement to illegal, unreported, and unregulated (IUU) fishing and mislabeling. A 2011 genetic study of MSC-labeled Antarctic toothfish found in markets revealed a significant proportion was not from the MSC-certified stock, and many were not toothfish at all. The MSC had conducted its own internal study, which found no evidence of mislabeling. The MSC conducts an annual audit of the fishery which includes sampling of certified product. Due to the challenges that faced toothfish management in the 1990s and early 2000s (e.g., IUU fishing, mislabeling, and inadequate data for management), consumer seafood guides such as Seafood Watch placed toothfish of both species (Chilean seabass) on their red, or "avoid", list; however, in light of up-to-date, internationally peer-reviewed scientific information, in April 2013, Seafood Watch upgraded the Ross Sea Antarctic toothfish fishery to a "good alternative". Following a comprehensive review in 2012, the Monterey Bay Aquarium revised its rating of Antarctic toothfish to 'good alternative'.

Greenpeace International Greenpeace is an independent global campaigning network, founded in Canada in 1971 by a group of environmental activists. Greenpeace states its goal is to "ensure the ability of the Earth to nurture life in all its diversity" and focuses its ...

added the Antarctic toothfish to its seafood red list in 2010. This approach is at variance with the high score given the fishery when it was granted certification by the MSC.