Perched between Africa, India, Australia and Antarctica, the windswept French territory of the Kerguelen Islands is one of the remotest places on Earth. Even so, fishing vessels are lured there by the prospect of catching one valuable species found in its surrounding waters the Patagonian toothfish, also known as Chilean sea bass, or else 'white gold' for the high prices it commands on the black market.
However a radar satellite surveillance system based on Envisat and Radarsat-1 imagery has cut the number of illegal fishing incursions in the vicinity of Kerguelen Island by nine-tenths. Run for the benefit of the French maritime authorities by the firm CLS (Collecte, Localisation Satellites), a subsidiary of the French space agency CNES, the system is up and running at a time when overfishing has left the 40-million-year-old Patagonian toothfish species on the verge of extinction.
Also found off South America, the toothfish has evolved anti-freeze components in its blood, making it one of a small number of species to colonise the sub-Antarctic waters of the Southern Ocean, playing an important role in the ecosystem there, providing sustenance to whales and seals.
Toothfish dwell in deep waters on the edge of coastal shelves and sea mounts. Individual toothfish can live for 40 years but take a decade to reach adulthood: their slow-maturing character makes them especially vulnerable to overfishing.
As toothfish numbers have crashed in heavily fished waters off Chile and Argentina, fishermen are increasingly drawn to Southern Ocean fisheries. However strict quotas have been set to preserve numbers. France maintains an economic exclusion zone (EEZ) extending 360 kilometres offshore from Kerguelen Island, along with its nearby Crozet and St-Paul Amsterdam territories.