Fish
Toothfish
Dissostichus · also called toothfishes, Chilean sea bass
Rebranded from an obscure Antarctic fish into “Chilean sea bass,” the toothfish became so commercially valuable so quickly that it triggered one of the most serious illegal fishing crises in modern ocean history. Slow-growing and long-lived, it survives the crushing cold of the Southern Ocean using natural antifreeze proteins in its own blood.
Overview
The toothfish, genus Dissostichus, is a slow-growing, long-lived predator of the Southern Ocean and sub-Antarctic waters, sometimes living over 30 years. Antifreeze glycoproteins in its blood prevent ice crystals from forming in the near-freezing water it inhabits.
A marketing name, and a fishing crisis
Rebranded as Chilean sea bass, demand surged and fuelled a wave of illegal, unregulated fishing in the 1990s and 2000s that seriously depleted populations. International management under a dedicated Antarctic conservation body, including satellite monitoring and strict quotas, has since brought illegal catches down significantly.
Status
Near Threatened but stable under current management — the species’ slow growth means any return to unsustainable fishing pressure would be difficult and slow to reverse.
Toothfish: common questions
Is Chilean sea bass actually a bass from Chile?
No, Chilean sea bass is simply a marketing name applied to toothfish, primarily to make the fish more commercially appealing to American consumers, and it is not biologically a bass at all, nor is its range limited to Chile, since toothfish are found broadly across the Southern Ocean and sub-Antarctic waters. The rebranding was a purely commercial decision that proved highly successful in boosting sales and demand, well before many consumers were aware of what the fish actually was.
Why did toothfish become the target of such a serious illegal fishing crisis?
Once demand surged following the successful Chilean sea bass rebranding, the high prices toothfish could command created a strong financial incentive for illegal, unregulated fishing vessels to target the species in the Southern Ocean, often operating outside proper catch limits and reporting requirements. Combined with the toothfish's slow growth and long lifespan, which make populations slow to recover from overfishing, this illegal fishing pressure pushed some stocks toward serious depletion before increased international enforcement measures brought illegal catches down significantly.
How is toothfish fishing managed today?
Toothfish fishing is now managed under an international body specifically established to conserve Antarctic marine living resources, which sets catch quotas, requires satellite-based vessel monitoring to track fishing activity, and coordinates enforcement among member countries to detect and deter illegal fishing. This internationally coordinated management approach has been credited with significantly reducing illegal toothfish catches compared with the crisis levels seen in previous decades.
Why does a toothfish need antifreeze proteins in its blood?
Toothfish live in some of the coldest ocean water on Earth, in and around the Southern Ocean surrounding Antarctica, where water temperatures can approach the freezing point of seawater, conditions that would cause damaging ice crystals to form within the tissues of most fish. Specialised antifreeze glycoproteins circulating in the toothfish's blood and body fluids bind to any forming ice crystals and prevent them from growing large enough to cause fatal cellular damage, an adaptation shared with several other Southern Ocean fish species.