| Summary | Patagonian toothfish (Dissostichus eleginoides) are a species of fish endemic to the Southern Hemisphere, largely found around subantarctic islands and the southern tip of South America (in general north of 60S). The Antarctic toothfish (D. mawsoni) is a separate species, found at higher latitudes around Antarctica (largely south of 60S). Both species are sold on the market as "Chilean sea bass." Commercial Patagonian toothfish fisheries exist off of the coast of Argentina and Chile and around most subantarctic islands, including the Falkland/Malvinas, Macquarie (AU EEZ), Heard and McDonald (AU EEZ), Kerguelen Island (FR EEZ), Crozet Island (FR EEZ), Prince Edward and Marion Islands (South Africa EEZ) and South Georgia. |
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| Project | SESMAD |
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| Subtype | Natural Resource Unit |
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| Sector | |
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| Biotic | Yes |
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| Explanation | |
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| Commons Aggregation | Population |
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| Explanation | Patagonian toothfish (Dissostichus eleginoides) are a species of fish with a broad circum-Antarctic distribution, largely found off the tip of South America and around subantarctic islands, including Macquarie Island and the Heard and McDonald Islands. There appear to be distinct populations in the South Indian Ocean (including fish found around the Heard and McDonald Islands, Crozet, Kerguelen, Prince Edward and Marion Islands), the South Atlantic (including fish found around South Georgia, North Scotia Ridge), the Patagonian Shelf, and a distinct stock off Macquarie (see Collins et al. 2010, Appleyard 2002, Appleyard 2004). |
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| Commons Boundaries | Somewhat unclear boundaries (2) |
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| Explanation | Depending on the toothfish population, boundaries are more or less clear. For example, boundaries for the Macquarie Island stock appear fairly clear since the vast majority of toothfish spend their whole lifecycle in the water around Macquarie Island (based on genetics and tag-recapture studies in which mover than 99% of recaptures were from the Macquarie population; MSC 2012). Note that at Macquarie, there is some movement of toothfish between the Southern and Northern fishing grounds; as well as a smaller but limited movement into areas governed by CCAMLR. For other toothfish stocks, the boundaries are less clear. For example, the South Indian Ocean population appears to occupy a rather large range over the Kerguelen Plateau and out to the Prince Edward Islands, but the boundaries of this population's distribution are still unknown (see Collins et al. 2010 and references therein). |
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| Commons Indicator | ["Status of species targeted by fisheries"] |
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| Explanation | |
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| Commons Unit Size | Medium (3) |
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| Explanation | Toothfish can reach a weights greater than 200 kg and lengths over 2.3 meters (see e.g., Collins et al. 2010). The size of captured fish are, however, somewhat smaller and are generally gear-dependent. Trawl fishers tend to capture younger smaller fish (around 1 meter in length); while longline operators capture older larger fish (< one meter in length). |
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| Environmental Medium | Oceanic |
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| Explanation | |
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| Inter Annual Predictability | Moderate (2) |
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| Explanation | Most know Patagonian toothfish populations have been targeted in commercial fisheries on an annual basis since the mid to late 1990s and can predictably be caught from year to year. Genetic, otolith chemistry and parasite fauna studies all suggest that there are distinct populations of toothfish (one in the South Indian Ocean, one in the Atlantic sector, one off of Patagonia, and one around Macquarie; See Collins et al. 2010 and references therein). Further, tag-recapture studies indicate that most individual toothfish within a stock stays close by from year to year. For example, in the Heard and McDonald Islands (HIMI) fishery, 99% of recaptured toothfish were caught within 30 km of where they were tagged 1-3 years prior (Williams et al. 2002). However, in most stocks there are individuals that also exhibit vast travels. For example, in the HIMI fishery, some fish were recaptured up to 1850 km away (on the Crozet Plateau; Williams et al. 2002). |
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| Intra Annual Predictability | Low (1) |
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| Explanation | Note that most toothfish fisheries operate in a limited window of time (usually over the course of a few months), thus the scientific information on toothfish is largely based on an annual snapshot with very little information gathered about toothfish during the rest of the year. As a result, there are still major gaps in the life history knowledge of toothfish. For example, for many populations, their reproductive and spawning cycle (which usually happens in the winter between June and September, while some fisheries only operate in the summer) is not well understood. For some populations of toothfish, their reproductive cycle involves spawning migrations and there is increasing evidence that mature individuals may not spawn every year (i.e. exhibiting skip spawning). Despite these gaps in their intrannual cycle, tag-recapture studies suggest that most toothfish stay close by to where they were caught (e.g., in the HIMI fishery 99% of recaptured tagged fish were caught within 30km of where they were first caught and tagged 1-3 years prior), some individual fish travel great distances (e.g., in the HIMI fishery, some fish traveled up to 1850 km from where they were caught; see Collins et al. 2010 and references therein). |
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| Commons Renewability | Renewable (1) |
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| Explanation | Toothfish are a renewable resource, but are still subject to overexploitation because of their life history characteristics (e.g., slow growth, long-lived, later to mature). |
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| Productivity | Poorly productive (1) |
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| Explanation | Toothfish are not a highly productive fish. Like many deep dwelling fish, their life history characteristics make them vulnerable to overexploitation. They grow relatively slowly, live up to 50 years and mature later in life (10-13 years of age for females; 6-10 years for males). There is also evidence that toothfish may not spawn every year, leading to lower overall fecundity (see Collins et al. 2010 and references therein). Many populations are able to support small commercial fisheries (e.g., 1000-3000 tonnes/year), while others were quickly overexploited in the mid 1990s and early 200s from IUU fishing and have yet to recovery (e.g., BANZARE Bank; McKinlay et al. 2008). |
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| Commons Accessibility | Somewhat accessible (2) |
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| Explanation | The fish are accessible as a result of the availability of ocean-going vessels that can process and store Patagonian toothfish for eventual sale on international markets (especially the US and Japan). |
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| Commons Heterogeneity | Moderate (2) |
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| Explanation | Patagonian toothfish have a broad circum-Antarctic distribution, but they appear to have a patchy rather than continuous distribution with distinct and potentially isolated populations. Populations seem to be concentrated around islands (e.g., South Georgia) and banks (e.g., Kerguelen Plateau) with the vast deep areas of the Southern Ocean acting to isolate and restrict these populations (see Collins et al. 2010 and references therein). Macquarie Island Patagonian Toothfish tend to be concentrated in two fishing grounds around Macquarie Island; the Aurora Trough and Macquarie Ridge. None of these fishing grounds are within the Macquarie Island Marine Park. |
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| Commons Mobility | Medium (2) |
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| Explanation | Toothfish are capable of moving between large distances, but the vast majority tend to be resident in a small area, with some but limited movements to nearby areas (see Collins et al. 2010 and references therein). For example, 99% of the fish tagged and recaptured around the Heard and McDonald Islands were found (1-3 years later) within 30 km of where they were originally tagged. However, some fish were found more than 1800 km away (Williams et al. 2002). |
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| Commons Spatial Extent | |
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| Explanation | Patagonian toothfish are distributed throughout the Southern Ocean and are concentrated around sea mounts, continental shelves and islands. There are several different stocks including those found around Macquarie Island and HIMI. Individual toothfish are for the most part residents of a relatively small geographical area although some undergo extensive migrations (MSC 2012)
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| Technical Substitute | No |
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| Explanation | |
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