Tree trawler
Beam trawls or kurren are special bag-like bottom trawls for catching North Sea shrimp and flatfish (e.g. plaice or sole ) in the Wadden Sea. They are said to have been imported from China by the Dutch over 200 years ago . Other sources say she came directly from Keitel network from which in Prussia to fishing for the Haffen was used. They have only been in use at the Elbe estuary since 1814.
A 9.5 m long spar , the so-called Kurrbaum , keeps the opening of the net open under water. The fish or shrimp trawler pulls the net over the seabed using skid-like shoes . The lower edge of the net carries a 10.6 m long line (lead clay) , which is weighted with lead knots and which has recently been replaced by a chain wrapped with old rope (Schlatting) . Each end of the Kurrbaum carries iron balls and, as a sliding shoe on the sea floor, an iron, the Kurrclaw. The bottom rope under the net opening weighs down the trawler and triggers vibrations when gliding over the seabed. As a result, the crabs and flatfish startle from the ground and can be caught by the net. The fishermen themselves fill the net; it requires 22 kg of yarn, and its length is 17 m.
The WWF criticizes fishing with beam trawls, on the one hand, for the high energy consumption that is necessary for towing, and on the other hand, for the high load on the seabed and its inhabitants from the rollers and runners.
Even Greenpeace criticized the use of the beam trawl and other demersal trawls. Fisheries that use beam trawls plow the seabed, killing and destroying all fauna and flora living there. In addition, Greenpeace criticizes the very high bycatch that occurs with this fishing method. For 1 ton of shrimp, up to 15 tons of bycatch occur, for 1 kilogram of sole or plaice there are around 10 kilograms of bycatch. The bycatch is thrown back into the sea and does not survive, as the pressure of the other animals crushes the fish in the net or the swim bladder bursts. Greenpeace therefore categorizes the tree trawl fishing method as a destructive one.
The aspects criticized by WWF and Greenpeace also apply to a lesser degree in fisheries that work with so-called modified beam trawls that are considered sustainable.
Individual evidence
- ↑ History of shrimp fishing in Schleswig-Holstein ( memento of the original from February 27, 2013 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. - Section "Crab catching with beam trawls"
