Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Searching for exotics in the shrimp nets

28.03.2012
Shrimp fishermen help biologist to monitor rare fish species

So far the shrimp fisherman Uwe Abken has had little interest in the bycatch in his nets. But recently the fisherman from the East Friesian town of Neuharlingersiel has been taking a closer look.

The fisherman and his deck hand have been recording which North Sea exotics and rare migratory fish get caught in their shrimp nets for the biologist Kai Wätjen from the Alfred Wegener Institute for Polar and Marine Research in the Helmholtz Association. This is a project with model character because fishermen, scientists and the environment benefit from the results.

Does the fish have a tiny spot behind its gills or is the spot missing? This will be the all important difference when shrimp fisherman Uwe Abken from the East Friesian town of Neuharlingersiel goes out on the North Sea to catch shrimps at the end of March with his cutter POLARIS. Because Abken and his deck hand Daniel Ahrens have agreed to examine their catch for rare fish species. The inquiry came from Kai Wätjen, Biologist at the Alfred Wegener Institute for Polar and Marine Research in the Helmholtz Association.

Together with the German 'Verband der kleinen Hochsee- und Küstenfischerei im Landesfischereiverband Weser-Ems' he is participating in the EU project GAP 2 (http://www.gap2.eu) the objective of which is to bring together fishermen and science to develop a sustainable fishing strategy. For this reason Kai Wätjen went fishing with Uwe Abken and another fisherman several times last autumn to get to know their everyday work and then develop a monitoring programme which is exactly tailored to suit the work rhythm of the fishermen.

Fifteen names of species are on the list prepared by Kai Wätjen for the shrimp fishermen: these include Red List calibres such as salmon and sea trout but also the lesser known representatives of the European Flora and Fauna Habitat Directive such as the allis shad, lamprey or twait shad – the herring-like species characterised by the small gill spot. “Some of the fish look very similar; even a specialist has to look closely“, says Kai Wätjen. The biologist has drawn up identification cards to help the fishermen if they experience difficulty and has given every cutter crew a camera with time stamp and GPS function. This is intended to enable fishermen to document rare or special catches quickly and simply.

The biologist primarily hopes for one thing from the cooperation with the shrimp fishermen: “To be able to realistically estimate the fish stock of these rare species in the Wadden Sea, we scientists need more data. The fishermen go fishing virtually daily from March to December. If they were able to document the migratory fish species and exotic species in their bycatch a huge sea area could be covered at little expense“, explains Kai Wätjen.
However, the scientist is not just relying on fishermen’s’ alert eyes, photos and catch records. Whenever Uwe Abken casts the nets, a data logger is activated which is attached to the beam trawl. “It measures the depth, water temperature and the salinity for every haul so that I can later reconstruct which fish species was caught at which water temperature“, says the biologist. Given a successful implementation of this method, it could be used later on in monitoring within the scope of the European Marine Strategy Framework Directive.

The cooperation also makes sense for the fishermen. They take a sample of around 400 shrimps every time they go fishing. The animals are then measured in the laboratory and examined for the anthracnose . Kai Wätjen: “Firstly we want to know how widespread the disease is and secondly find out where the large shrimps are in the catch area at which time and how the animals react to changes in the water temperature.“ A second advantage of this concomitant research: it could advance the certification of the Wadden Sear shrimp fishing according to the standard of the Marine Stewardship Council (MSC).

During the first test runs last autumn the shrimp fishermen primarily caught small twait shads and occasional river lampreys. Now in spring, when the sun is warming the Wadden Sea, the chance ought to increase of also finding the heat-loving migrants such as striped red mullet, sardine and sand smelt. “Perhaps we might even see species which have become rare such as the snake pipefish, the weever or thornback ray and whiptail stingray“, says Kai Wätjen. The latter used to be found regularly in the Wadden Sea.

The Alfred Wegener Institute conducts research in the Arctic and Antarctic and in the high and mid-latitude oceans. The Institute coordinates German polar research and provides important infrastructure such as the research icebreaker Polarstern and research stations in the Arctic and Antarctic to the national and international scientific world. The Alfred Wegener Institute is one of the 18 research centres of the Helmholtz Association, the largest scientific organisation in Germany.

Ralf Röchert | idw
Further information:
http://www.awi.de/en

More articles from Life Sciences:

nachricht Biophysicists reveal how optogenetic tool works
29.05.2020 | Moscow Institute of Physics and Technology

nachricht Mapping immune cells in brain tumors
29.05.2020 | University of Zurich

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Biotechnology: Triggered by light, a novel way to switch on an enzyme

In living cells, enzymes drive biochemical metabolic processes enabling reactions to take place efficiently. It is this very ability which allows them to be used as catalysts in biotechnology, for example to create chemical products such as pharmaceutics. Researchers now identified an enzyme that, when illuminated with blue light, becomes catalytically active and initiates a reaction that was previously unknown in enzymatics. The study was published in "Nature Communications".

Enzymes: they are the central drivers for biochemical metabolic processes in every living cell, enabling reactions to take place efficiently. It is this very...

Im Focus: New double-contrast technique picks up small tumors on MRI

Early detection of tumors is extremely important in treating cancer. A new technique developed by researchers at the University of California, Davis offers a significant advance in using magnetic resonance imaging to pick out even very small tumors from normal tissue. The work is published May 25 in the journal Nature Nanotechnology.

researchers at the University of California, Davis offers a significant advance in using magnetic resonance imaging to pick out even very small tumors from...

Im Focus: I-call - When microimplants communicate with each other / Innovation driver digitization - "Smart Health“

Microelectronics as a key technology enables numerous innovations in the field of intelligent medical technology. The Fraunhofer Institute for Biomedical Engineering IBMT coordinates the BMBF cooperative project "I-call" realizing the first electronic system for ultrasound-based, safe and interference-resistant data transmission between implants in the human body.

When microelectronic systems are used for medical applications, they have to meet high requirements in terms of biocompatibility, reliability, energy...

Im Focus: When predictions of theoretical chemists become reality

Thomas Heine, Professor of Theoretical Chemistry at TU Dresden, together with his team, first predicted a topological 2D polymer in 2019. Only one year later, an international team led by Italian researchers was able to synthesize these materials and experimentally prove their topological properties. For the renowned journal Nature Materials, this was the occasion to invite Thomas Heine to a News and Views article, which was published this week. Under the title "Making 2D Topological Polymers a reality" Prof. Heine describes how his theory became a reality.

Ultrathin materials are extremely interesting as building blocks for next generation nano electronic devices, as it is much easier to make circuits and other...

Im Focus: Rolling into the deep

Scientists took a leukocyte as the blueprint and developed a microrobot that has the size, shape and moving capabilities of a white blood cell. Simulating a blood vessel in a laboratory setting, they succeeded in magnetically navigating the ball-shaped microroller through this dynamic and dense environment. The drug-delivery vehicle withstood the simulated blood flow, pushing the developments in targeted drug delivery a step further: inside the body, there is no better access route to all tissues and organs than the circulatory system. A robot that could actually travel through this finely woven web would revolutionize the minimally-invasive treatment of illnesses.

A team of scientists from the Max Planck Institute for Intelligent Systems (MPI-IS) in Stuttgart invented a tiny microrobot that resembles a white blood cell...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Dresden Nexus Conference 2020: Same Time, Virtual Format, Registration Opened

19.05.2020 | Event News

Aachen Machine Tool Colloquium AWK'21 will take place on June 10 and 11, 2021

07.04.2020 | Event News

International Coral Reef Symposium in Bremen Postponed by a Year

06.04.2020 | Event News

 
Latest News

Black nitrogen: Bayreuth researchers discover new high-pressure material and solve a puzzle of the periodic table

29.05.2020 | Materials Sciences

Argonne researchers create active material out of microscopic spinning particles

29.05.2020 | Materials Sciences

Smart windows that self-illuminate on rainy days

29.05.2020 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>