Acronym NA
Category
Fisheries
Title Uttesting av nye seleksjonsrister for trål - Testing of new selection grids for trawls Programme National Programme
Instrument (FP6)
Contact Type (FP7)
Strand (Interreg)
NA
Theme (FP7)
Activity Area (FP6)
Regional Area (Interreg)
Action (COST)
NA
Specific Programme (FP7)
NA
Funding source National Coordinator Manu Sistiaga Coordinator email manu.sistiaga@sintef.no
Coordinator institution
NA
Institutions involved
IMR - Institute of Marine Research (Norway) ,
UiT - The Arctic University of Norway (Norway) ,
Start year 2013 End year 2014 Funding (€) € 794,848 Website www.fhf.no/prosjekter/prosjektbasen/900944/ Summary The Northeast Arctic cod stock has been in exceptionally good condition in recent years, and solutions to limit and adapt the catch to the vessels' production capacity have come into focus. Spinners and trawlers in particular are experiencing a higher number of hauls with a large catch now than before, which can be a challenge both in terms of boarding, quality and HSE (health, environment and safety). In this connection, both the Research Council of Norway and FHF have invested in projects related to catch control. With regard to trawls, several relevant solutions have been found to limit the catch in the bag, but challenges have also been identified in using these devices in combination with the sorting grids that are mandatory in the fishery. Of the three grating systems that are allowed to be used today, only single grating and flexi grating are used by trawlers. Both systems have been shown to have satisfactory selection properties at moderate catches, but problems have been identified at high concentrations with fish, e.g. associated with reduced water flow as a result of the grate section. Underwater footage shows that the catch falls backwards in the extension until it tends to accumulate at the grate. A probable important reason for this is that the flow velocity is partly significantly reduced due to the various subsequent elements in a grating section (lifting panel, grating (s), guide panel and whistle balls). For single gratings, this has recently been demonstrated during experiments with full-scale grate sections in the test tank in Hirtshals (Gjøsund et al., 2013), for both two- and four-panel sections. For the catch sensors to work and the fishermen to be able to have control over how much fish is in the bag, the fish must pass through the grate section without building up. This presupposes i.e. that the flow rate is not significantly reduced but is maintained through the grate section. Catch limitation solutions based on hydrodynamic pressure also presuppose that the flow rate is maintained as best as possible in order to function well. In connection with this, the Directorate of Fisheries has organized a cruise where two new grate devices will be tested: A four-panel version of a single grate (the current version in the regulations is a two-panel construction), and a four-panel construction of single grate without lifting panel. The project is well adapted within FHF's priority: "Catch control / gear control, including species selection, size selection and catch quantity". All the institutions involved in the project (the Institute of Marine Research, the Norwegian College of Fisheries, the Directorate of Fisheries and SINTEF Fisheries and Aquaculture) have worked for several years to develop selection facilities for the Norwegian trawl fishery.
Keywords
Gear selectivity;
Cod;
Fish;
Fishing technology;
Trawling;
Marine Region
42
Barents Sea (27.I)
13
Northern North Sea (27.IVa)
41
Norwegian Sea (27.IIa)
14
Skagerrak, Kattegat (27.IIIa)
4
Marine Region Map
