Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Envisat radar surveillance protects endangered prehistoric fish

18.11.2005


A satellite surveillance zone within the southern Indian Ocean is helping protect the endangered Patagonian toothfish from pirate fishing vessels.



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.

Only French-owned ships are authorised to fish in the combined French Southern and Antarctic Territories EEZ, mostly working out of the French territory of Réunion Island, around 3000 kilometres west of Kerguelen. However this region has proved increasingly popular with pirate vessels intent on defying the law.

Réunion is the second largest producer of Patagonian toothfish behind Chile. So the toothfish is very important to it, earning in the region of 40 to 60 million euros for its economy annually. However in recent years the toothfish has fallen prey to illegal uncontrolled fishing. It is estimated that pirate vessels have been fishing up to 26 000 tonnes a year – nearly four times the legal quota.

In the last few years authorities have introduced measures to limit illegal fishing in the EEZ, defend France’s economic interests, protect ecosystems and stamp French sovereignty on their territorial waters. A surveillance system using French naval vessels has achieved some success, however the number of vessels fishing illegally continued to rise, and they proved adept at slipping through the surveillance net.

The EEZ totals nearby one million square kilometres of ocean – too great an area for naval vessels to police effectively. So the French maritime authority turned to satellite surveillance – employing ESA’s Envisat satellite in conjunction with Canada’s Radarsat-1.

The radar sensors aboard these spacecraft can monitor the region during both day and night and in all weathers, including cloudy conditions. The metal corners of ships make good radar reflectors, sending back distinctive signal echoes. Using the two spacecraft together means updated images become available daily, downlinked to a dedicated ground station located on Kerguelen Island.

"Kergulen is a remote and inaccessible place, but it has the advantage of being at the centre of the area we want to survey," explained Philippe Schwab, Technical director of CLS. "New images are received in real time, then automatically processed to discriminate radar echoes from vessels in the zone. Each vessel is then sent with its position via a satellite link to the French authorities on Réunion, where they are analysed to identify legal and illegal vessels.

"Authorised vessels are mandated to have an Argos satellite transmitter aboard, so they can be located and identified. Vessel positions are sent to the French authorities by CLS, the Argos system operator. Argos positions are then matched with radar echoes to discriminate illegal vessels, whose locations are then sent for action to French Navy patrol boats."

The system has been operational since February 2004. It had an early success on 25 June 2004 when French Navy patrol boat Albatross intercepted the Apache, a fishing vessel sailing under the Honduran flag. First identified southeast of Kerguelen Island, the operations centre on Reunion tracked the vessel for three days. The patrol boat fired a warning shot across its bow then boarded it to seize an illegal catch of 60 tonnes of Patagonian toothfish.

"Usually the system is more dissuasive than repressive," Schwab concluded. "Today, illegal fishing has almost disappeared. It seems that the unscrupulous fishermen have understood the efficiency of the system."

Satellites for ship detection

Satellite radar sensors detect ships well because their metal surfaces and sharp angles have a high signal return, in contrast to that of the surrounding water.

Envisat ASAR imagery is therefore being utilised for ship detection in a growing number of activities worldwide, including the protection of Icelandic fisheries through the Improving fisheries Monitoring through integrating Passive and Active Satellite-based Technologies (IMPAST) project run by the European Commission’s Joint Research Centre (EC-JRC).

Mariangela D’Acunto | alfa

More articles from Ecology, The Environment and Conservation:

nachricht Upcycling 'fast fashion' to reduce waste and pollution
03.04.2017 | American Chemical Society

nachricht Litter is present throughout the world’s oceans: 1,220 species affected
27.03.2017 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Fighting drug resistant tuberculosis – InfectoGnostics meets MYCO-NET² partners in Peru

28.04.2017 | Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

 
Latest News

Wireless power can drive tiny electronic devices in the GI tract

28.04.2017 | Medical Engineering

Ice cave in Transylvania yields window into region's past

28.04.2017 | Earth Sciences

Nose2Brain – Better Therapy for Multiple Sclerosis

28.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>