Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Envisat fishes up facts behind Chilean giant squid invasion

23.03.2004


Masses of large ocean-going squid have inundated the shores of Southern Chile, alarming local fishermen who fear these carnivorous invaders could threaten fish stocks. Envisat has helped account for their otherwise mysterious arrival.


This beached jumbo flyung squid is a mysterious deep sea visitor to the Chilean coastline, one of hundreds making a surprise appearance during February 2004, alarming local fishermen. But Envisat AATSR data has shed light on the mystery.

Credits: Mariscope Chilena



These jumbo flying squid – Dosidicus gigas is their Latin name – are some of the largest known squids on the planet: the ones here measure between 70 to 150 centimetres in length, although specimens have been known to reach more than three metres. Making their home in the open ocean, they rise to the surface at night to aggressively feed on small fish using barbed suckers.

In the final days of February more than 200 of the squid were washed up on the beaches around Ancud, on the northern coast of the island of Chiloé in southern Chile. Further incursions have since taken place towards Calbuco, on the inner side of the Chacao channel and towards the southern part of the island along the coast, up to Castro in the middle of the big island of ’Los Lagos’ region of the country. Strandings have also been reported in more northerly areas such as Chile’s VIII region.


Wondering why these deepwater animals unexpectedly made it to coastal waters is a matter of more than just scientific interest. Thousands of Chileans earn their livelihood from fishing in this part of the country, and these voracious cephalopods are known to prey on commercial fish including hake, sardines and anchovies. The squid themselves are a delicacy in some parts of the world but there is no local tradition of catching or consuming them.

But an explanation for the incursions was available – from 800 km away in space. Envisat’s Advanced Along Track Scanning Radiometer (AATSR) instrument works like a space-based thermometer, taking the temperature of land and sea as it orbits the Earth. It can measure sea surface temperature (SST) to an accuracy of 0.3 degrees centigrade at a spatial resolution of one square km.

A Chilean team is currently working with AATSR SST results in combination with ocean colour data from another Envisat instrument, the Medium Resolution Imaging Spectrometer (MERIS). Chile’s national fish farming association Salmon Chile has co-founded a pilot scheme with oceanography firm Mariscope Chilena, investigating the feasibility of a satellite-based early warning system for harmful phytoplankton blooms – explosive growths of sometimes toxic marine algae.

"The AATSR results show the appearance of the squid was connected with changes in the water mass conditions off the coast of Southern Chile in recent weeks," says Dr Cristina Rodríguez-Benito of Mariscope Chilena.

This part of the Chilean coast, like most western continental coasts, is subject to upwellings – cold, nutrient-rich waters rise from the oceans depths as prevailing winds blow warmer surface waters away. The phenomenon supports rich fisheries. But the AATSR data reveal that a coastal upwelling that typically influencing the waters between Chiloé and the mainland was not seen in the last week of February.

"This caused an influx of warmer water, between 0.5 and 1.5 degrees, and also squid, which are attracted to steep temperature and salinity gradients in the sea where they find their food," adds Rodríguez-Benito. "The squid ended up in a lens of cold water between warmer masses, and this carried them into the inner Gulf of Ancud area.

"The resulting decrease in water temperature can also have a direct effect on aquaculture, because the metabolic systems of fish species are very sensitive to such changes. Envisat’s AATSR data registered a decrease of up to 3ºC.

"Even more important than temperature is the indication of the entrance of a water mass poor in oxygen that could be the reason for the losses already registered in some aquaculture sites.


"We are interested in such events as part of our main project because temperature gradients are often where new phytoplankton blooms occur. But the possibility of being able to predict these phenomena would be very useful also to the fishing industry."

The team plans to present their experiences of using Envisat data in this way to a conference this month of the Chilean Civil Protection Organisation.

Frédéric Le Gall | ESA
Further information:
http://www.esa.int/esaSA/SEMVNJYV1SD_earth_0.html

More articles from Ecology, The Environment and Conservation:

nachricht Global threat to primates concerns us all
19.01.2017 | Deutsches Primatenzentrum GmbH - Leibniz-Institut für Primatenforschung

nachricht Reducing household waste with less energy
18.01.2017 | FIZ Karlsruhe – Leibniz-Institut für Informationsinfrastruktur GmbH

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: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

New Study Will Help Find the Best Locations for Thermal Power Stations in Iceland

19.01.2017 | Earth Sciences

Not of Divided Mind

19.01.2017 | Life Sciences

Molecule flash mob

19.01.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>