English
norskBlar i forfatter "Grimaldo, Eduardo"
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Improved bycatch reduction in the mixed demersal trawl fishery for Norway pout (Trisopterus esmarkii)
(Journal article; Tidsskriftartikkel; Peer reviewed, 2022-12-22)In this study, we compared the bycatch reduction capacity of a trawl fitted with a standard rigid sorting grid with that of a trawl fitted with a newly developed, flexible system called the Excluder. We conducted the fishing trials in the Norway pout (Trisopterus esmarkii) small-meshed trawl fishery in the North Sea. Catch data were analysed by species and length using the catch comparison and catch ... -
Increasing sustainability in food production by using alternative bait in snow crab (Chionoecetes opilio) fishery in the barents sea
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-02-17)The use of food grade wild-captured species as bait for other fisheries questions the sustainability of food production. In pot fisheries, bait is an important factor determining the effectiveness of the gear. In snow crab (Chionoecetes opilio) fishery, the pots are normally baited with squid (Illex sp.) and herring (Clupea harengus). This fishery uses substantial amounts of bait for each ... -
Modelling the effect of mesh size and opening angle on size selection and capture pattern in a snow crab (Chionoecetes opilio) pot fishery
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-12-18)Size selection in commercial snow crab (Chionoecetes opilio) pot fisheries is important for reducing on-board sorting and unintended mortality of undersized individuals. In this paper, we tested whether snow crab of various sizes geometrically could pass through diamond meshes of different sizes and opening angles, to estimate a model for predicting the effect of mesh size and mesh opening angle on ... -
MultiSEPT - Full scale tests of the semicircular spreading gear (SCSG)
(Research report; Forskningsrapport, 2013-06-24)This reportdescribes full scale tests at sea with the semi-circular spreading gear (SCSG). This activity is part of Work Package 3 (WP3: Development of new ground gear) of the MultiSEPT project. The spreading of the SCSG and rockhopper gear was measured by useof MARPORT distance sensors. Bottom contact was monitored by use of SCANMARtrawl sensors and by underwater cameras mounted in the headline ... -
Potential for codends with shortened lastridge ropes to replace mandated selection devices in demersal trawl fisheries
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-10-28)In many trawl fisheries, codend size selectivity is supplemented by adding selection devices to the gear. In the Barents Sea gadoid fishery, combining diamond mesh codends with sorting grids is compulsory. However, the use of grids increases the costs and complexity of the gear, causing discontent among fishermen and prompting researchers to seek alternative solutions. Lastridge ropes are ropes ... -
Prediction of potential net panel selectivity in mesopelagic trawls
(Journal article; Tidsskriftartikkel; Peer reviewed, 2022-07-17)The growing interest in harvesting mesopelagic fish species has increased the need for knowledge about how trawls should be designed for optimizing the catch efficiency of these resources. Since the net herding efficiency for small mesopelagic fish species is unknown, trawls targeting these species need to consider the potential net panel selectivity along the entire trawl body. Therefore, trawl ... -
Reducing plastic pollution caused by demersal fisheries
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-10-07)Marine microplastics generated by wear and tear of bottom trawls and demersal seines during their service life is a growing environmental concern that requires immediate attention. In Norway, these fishing gears account for more than 70 % of the landings of demersal fish species, but they are also the leading sources of microplastics generated by fisheries. Because these two fishing gears are widely ... -
Size selection of cod (Gadus morhua) and haddock (Melanogrammus aeglefinus) in the Northeast Atlantic bottom trawl fishery with a newly developed double steel grid system
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-02-06)In recent years, Norwegian fishermen have reported problems with fish accumulation in front of the mandatory sorting grids (Sort-X, Sort-V, and Flexigrid). These problems are associated with high fish entry rates and low water flow through the grid sections. In this study, we replaced the lifting panel in the original design of a sorting grid section (Sort-V) by another steel grid (“lower grid”) in ... -
Size selection of Greenland halibut (Reinhardtius hippoglossoides) in the Norwegian bottom trawl fishery with a newly developed double grid system
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017)Greenland halibut (<i>Reinhardtius hippoglossoides</i>) is a commercially important species in the northeast Atlantic trawl fishery. However, direct fishing for it is not allowed and it can only be harvested as bycatch. We investigated for the first time the size selection of Greenland halibut in a newly developed double steel grid system designed for the cod and haddock bottom trawl fishery. In ... -
Size selectivity and length-dependent escape behaviour of haddock in a sorting device combining a grid and a square mesh panel
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-10-04)Size selectivity of a new sorting section combining a sorting grid and a square mesh panel was tested for haddock (Melanogrammus aeglefinus) in the Barents Sea demersal trawl fishery. Sampling data for a wide size range enabled investigating the selection process for this species in detail, both for the grid and the square mesh panel. Contrary to earlier studies modelling size selectivity for grids ... -
Understanding the effect of design parameters on the filtration efficiency of trawls intended for commercial harvesting of zooplankton
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-11-01)A major challenge for the aquaculture sector is access to sustainable and cost-effective raw materials for feed. Copepods (Calanus spp.) have potential to meet this need for large volumes of marine raw materials to enable sustainable growth of aquaculture production worldwide. However, the lack of an energy- and catch-efficient trawl technology has limited the development of this fishery in the ... -
Use of biodegradable materials to reduce marine plastic pollution in small scale coastal longline fisheries
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-06-14)Pollution from lost, abandoned, or discarded fishing gear is recognized as a global nature conservation concern. Longlining with hooks is a commonly applied fishing method in fisheries around the world. The longline gear consists of a mainline with a number of baited hooks that are attached to it by thinner twine (snoods) which are often made of plastic material such as polyamide (nylon) or ... -
Use of semi-pelagic trawling for reducing bycatch in shrimp trawls. Trials onboard R/V Johan Ruud 02-06 February 2015
(Research report; Forskningsrapport, 2015)The present study evaluates whether lifting the trawl doors and sweeps from the seabed can reduce bycatch in shrimp trawl fisheries. We carried out a catch comparison and catch ratio analysis between two gear setups, one with the trawl doors and sweeps at the seabed (the traditional way) and the other with the doors and sweeps lifted. The study was carried out on American plaice. The results ...
