Trenngitter - eine Alternative zu den Trichternetzen in der Garnelenfischerei

Experimental fishing trials were conducted in the Elbe Estuary using an experimental 3 m-standard beamtrawl. To avoid the by-catch of fish, a sorting grid was used. The elliptical grid was constructed of 6 mm diameter stainless steel bars with a spacing of 13 mm between the bars and housed in a cylindrical frame of 400 mm diameter. It was installed in the extension piece just in front of the codend angled at 45°, with a fish outlet at the top. A series of 10 tows of 15 minutes duration at a towing speed of 3 kn was done. The catch of the main codend was compared with the catch separated by the sorting grid. This achieved a reduction of 56 % of plaice (Pleuronectes platessa), 75 % of flounder (Platichthys flesus), 99 % of whiting (Merlangius merlangus), 94 % of cod (Gadus morhua) and 49 % of smelt (Osmerus eperlanus) with a mean loss of 43 % of shrimps (Crangon crangon). English grid trials in the Humber estuary using a flapper set or guiding funnel in front of the sorting grid device demonstrated reasonable lower escapement rates for fish and shrimps.

Cartas enviadas por Karl Bouda a Justo Garate entre 1934 y 1946

9 cartas + 2 tarjetas postales (manuscritas) ; entre 330x225mm y 100x60mm

Cartas enviadas por Karl Bouda a Justo Garate entre 1947

14 cartas + 3 tarjetas postales (manuscritas y mecanografiadas) ; entre 210x295mm y 150x105mm

Cartas enviadas por Karl Bouda a Justo Garate entre 1948 y 1949

16 cartas + 1 tarjeta postal (manuscritas y mecanografiadas) ; entre 210x300mm y 150x105mm

Cartas enviadas por Karl Bouda a Justo Garate entre 1950 y 1972

14 cartas + 3 archivos con bibliografía (manuscritas y mecanografiadas) ; entre 210x300mm y 210x150mm