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 Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery
20.01.2017 | GSI Helmholtzzentrum für Schwerionenforschung GmbH

nachricht Seeking structure with metagenome sequences
20.01.2017 | DOE/Joint Genome Institute

All articles from Life Sciences >>>

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

Helmholtz International Fellow Award for Sarah Amalia Teichmann

20.01.2017 | Awards Funding

An innovative high-performance material: biofibers made from green lacewing silk

20.01.2017 | Materials Sciences

Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery

20.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>