Chillean Seabass Facts

Taxonomy

• The Patagonian Toothfish, Dissostichus eleginoides, is sold under the trade names Chilean sea bass in the USA and Canada; Merluza negra in Argentina, Peru and Uruguay; Legine australe in France; Mero, in Japan and Bacalao de profundidad in Chile.

Species of Commercial Interest

• Chillean Seabass constitutes two species, Dissostichus eleginoides (the Patagonian toothfish), as well as a close relative, the Antarctic toothfish (Dissostichus mawsoni).

 

Distribution

• Seabass are typically found in the cold, temperate waters of the southern Atlantic, Pacific & Indian Oceans between depths of 45-3,850 meters (148-12,631 feet). Commercially-exploited stocks are found off southern Chile, Patagonia, the Falkland Islands, South Georgia Island, and Macquarie Island in the remote Southern Ocean.

Biology

• Chilean seabass is a slow-growing, deepwater fish that reproduces late in life, traits that make it vulnerable to overfishing. Both species have natural lifespans of several decades and are slow-growing species with low fecundity. They are not found in water colder than 2°C and lacks antifreeze. The average weight of a commercially caught Patagonian toothfish is 7–10 kg (15–22 lb), depending on the fishery, with large adults occasionally exceeding 100 kilograms (220 lb). They are thought to live up to fifty years and to reach a length up to 2.3 m (7.5 ft). 
• Patagonian toothfish are thought to reach sexual maturity at 9-10 years of age and about 90-100 cm in length. Eggs are few and both eggs and larvae are large, characteristics shared with most Antarctic fishes and indicative of a relatively large maternal investment in each egg. Spawning occurs in deep water (around 1,000m) during the austral winter, producing pelagic eggs and larvae. Larvae switch to a demersal habitat at around 100mm (1 year old) and inhabit relatively shallow water (<300m) until 6–7 years of age, when they begin a gradual migration into deeper water. As larvae, they feed primarily on krill, moving to a more piscivorous (fish-eating) diet as they grow larger and move to shallow water. There, they consume the most abundant suitably sized local prey. 
• With increasing size and habitat depth, the diet diversifies and includes more scavenging of squid, fish, and crustaceans (Antarctic bay shrimp). In turn, toothfish constitute a small part of the diets of sperm whales, southern elephant seals, and colossal squid.

Sustainability

• IUCN Red List Status: Not Evaluated (NE)

• MBA Seafood Watch:

• The Southern Ocean where Chilean seabass live is vast and remote. Enforcement is difficult and illegal fishing is common. In addition, the fishing methods used to catch Chilean seabass cause more problems: bottom trawling can damage seafloor habitat, and miles of baited longline gear can fatally hook and drown endangered albatross and other seabirds. For these reasons, most Chilean seabass should be avoided. 
• Consumers wishing to purchase MSC-certified Chilean seabass must be very careful. All restaurants and grocery stores that sell MSC products are required to have the MSC "Chain of Custody" certification. Legitimate purveyors should be able to produce this document when consumers ask. If the certificate is not available, assume the fish is not certified and don't make the purchase.

Potential Health Concerns

• Environmental Defense Fund has issued a consumption advisory for Chilean seabass for due to high levels of mercury.