• Escape rate for cod (Gadus morhua) from the codend during buffer towing 

      Brinkhof, Jesse; Herrmann, Bent; Larsen, Roger B.; Sistiaga, Manu Berrondo (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-10-30)
      The high abundances of Northeast Arctic cod (Gadus morhua) in the Barents Sea have led to the development of a new fishing tactic called buffer towing. On factory trawlers, the trawl is deployed immediately after taking the catch onboard, a tactic used to ensure a continuous supply of fish is being processed. If the desired amount of fish is caught before the catch from the previous haul has been ...
    • External damage to trawl-caught Northeast arctic cod (Gadus morhua): Effect of codend design 

      Tveit, Guro Møen; Sistiaga, Manu Berrondo; Herrmann, Bent; Brinkhof, Jesse (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-02-22)
      The purpose of this study was to investigate the extent of external damage (gear marks, pressure injuries, ecchymosis and skin abrasion) present on trawl-caught cod (Gadus morhua) and to examine whether the extent of damage could be reduced by introducing changes in the gear. We tested whether changing the 2-panel knotted codend used by the Norwegian trawler fleet operating in the Barents Sea today ...
    • Ghost fishing efficiency by lost, abandoned or discarded pots in snow crab (Chionoecetes opilio) fishery 

      Cerbule, Kristine; Herrmann, Bent; Grimaldo, Eduardo; Brinkhof, Jesse; Sistiaga, Manu; Larsen, Roger B.; Bak-Jensen, Zita (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-07-07)
      Marine pollution by lost, abandoned or otherwise discarded fishing gear (ALDFG) often has negative impact on the ecosystem through plastic pollution and continuous capture of marine animals, so-called “ghost fishing”. ALDFG in pot fisheries is associated with high ghost fishing risk. The snow crab (Chionoecetes opilio) pot fishery is conducted in harsh weather conditions increasing the risk of ...
    • Improved bycatch reduction in the mixed demersal trawl fishery for Norway pout (Trisopterus esmarkii) 

      Grimaldo, Eduardo; Brinkhof, Jesse; Herrmann, Bent; Cerbule, Kristine; Grimsmo, Leif; Pettersen, Hermann (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 ...
    • Is there a limit to the potential effects of shortening lastridge ropes on the size selectivity of diamond mesh codends? 

      Sistiaga, Manu; Herrmann, Bent; Brinkhof, Jesse; Larsen, Roger B.; Santos, Juan; Stepputtis, Daniel; Brinkhof, Ilmar; Jacques, Nadine; Cerbule, Kristine; Petetta, Andrea; Cuende, Elsa; Kvalvik, Liz Beate Kolstad (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-02-21)
      Shortening codend lastridge ropes can be an effective fishing gear modification to improve the size selection properties in diamond mesh codends. Lastridge ropes attached to codend selvedges withstand the longitudinal forces created by the catch building up and therefore, prevent the codend meshes from closing. However, the extent to which the lastridge ropes should be shortened to maximize the ...
    • Make it simpler and better: T90 codend improves size selectivity and catch efficiency compared with the grid-and-diamond mesh codend in the Northeast Atlantic bottom trawl fishery for gadoids 

      Brinkhof, Jesse; Larsen, Roger B.; Herrmann, Bent (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-11-08)
      The use of a sorting grid followed by a size-selective codend with minimum 130 mm mesh size is compulsory in the Northeast Atlantic demersal trawl fishery targeting cod (Gadus morhua), haddock (Melanogrammus aeglefinus), and saithe (Polachius virens). However, sorting grids cause some disadvantages, which possibly can be solved by removing the grid and improving codend selectivity, thus making the ...
    • Managing size selectivity: the relevance of compulsory and alternative selection devices in the Northeast Atlantic bottom trawl fishery 

      Brinkhof, Jesse; Sistiaga, Manu; Herrmann, Bent; Grimaldo Vela, Eduardo Enrique; Larsen, Roger B. (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-10-14)
      Two decades of use of the compulsory selectivity gear configuration in the Northeast Atlantic bottom trawl fishery, which consists of a rigid sorting grid followed by a diamond mesh codend, have revealed problems with performance and efficiency. Size selectivity gear alternatives to this configuration are being pursued, and recent studies of codends with shortened lastridges have reported promising ...
    • New approach for modelling size selectivity in shrimp trawl fisheries 

      Larsen, Roger B.; Herrmann, Bent; Sistiaga, Manu Berrondo; Brinkhof, Jesse; Tatone, Ivan; Langård, Lise (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-07-10)
      In the deep sea trawl fishery targeting shrimp (Pandalus borealis) and other cold-water shrimp species, fishers often use a Nordmöre sorting grid ahead of a small mesh codend to avoid bycatch. However, small fish can pass through the grid and are subsequently retained in the codend. This makes shrimp size selection complex and the size-dependent curve for both the shrimp and the bycatch species often ...
    • Performance of the Nordmøre grid in shrimp trawling and potential effects of guiding funnel length and light stimulation 

      Larsen, Roger B.; Herrmann, Bent; Sistiaga, Manu Berrondo; Brinkhof, Jesse; Tatone, Ivan; Langård, Lise (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-07-31)
      The introduction of the Nordmøre grid to shrimp trawls has reduced the issue of bycatch to that of small-sized species and juveniles that are able to pass through the grid and enter the small-meshed cod end together with the targeted shrimp. This study estimated the size- and species-selective performance of the Nordmøre grid in the configuration most often applied by fishermen and made a preliminary ...
    • Potential for codends with shortened lastridge ropes to replace mandated selection devices in demersal trawl fisheries 

      Sistiaga, Manu; Brinkhof, Jesse; Herrmann, Bent; Larsen, Roger B.; Grimaldo, Eduardo; Cerbule, Kristine; Brinkhof, Ilmar; Jørgensen, Terje (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 

      Grimaldo, Eduardo; Herrmann, Bent; Brčić, Jure; Cerbule, Kristine; Brinkhof, Jesse; Grimsmo, Leif; Jacques, Nadine (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 ...
    • Quantification of bell-shaped size selectivity in shrimp trawl fisheries using square mesh panels and a sorting cone after a Nordmøre grid 

      Sistiaga, Manu Berrondo; Herrmann, Bent; Larsen, Roger B.; Brinkhof, Jesse (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-09-12)
      Shrimp trawlers in the Barents Sea use a Nordmøre sorting grid ahead of a small-mesh codend to avoid bycatch while catching shrimps efficiently. However, small fish can still pass through the grid to enter the codend, which increases their risk of being retained. In this study, we quantified the selectivity of a standard Nordmøre grid used together with one of two different codend designs, namely a ...
    • Quantification of gear inflicted damages on trawl-caught haddock in the Northeast Atlantic fishery 

      Sistiaga, Manu; Herrmann, Bent; Brinkhof, Jesse; Larsen, Roger B.; Jacques, Nadine; Santos, Juan; Gjøsund, Svein Helge (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-06-12)
      External damages are indicators of the overall quality of fish and fish welfare. Haddock is an important commercial species widespread in the North Atlantic, but few studies related to quality have been carried out on this species. We studied the levels of external damages on haddock captured with a demersal trawl in the Northeast Atlantic. Further, we investigated to what extent the compulsory ...
    • Sequential codend improves quality of trawlcaught cod 

      Brinkhof, Jesse; Olsen, Stein Harris; Ingólfsson, Ólafur Arnar; Herrmann, Bent; Larsen, Roger B. (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-10-10)
      Trawl-caught fish are frequently associated with deteriorated catch quality. This study presents a new dual sequential codend concept with the aim of improving the quality of trawl-caught fish by minimizing the frequency and severity of catch damage. During towing, the fish are retained in an anterior codend segment with the legislated mesh size. A quality improving codend segment, is attached to ...
    • 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 

      Larsen, Roger B.; Herrmann, Bent; Sistiaga, Manu Berrondo; Grimaldo, Eduardo; Tatone, Ivan; Brinkhof, Jesse (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 

      Larsen, Roger B.; Herrmann, Bent; Sistiaga, Manu Berrondo; Grimaldo, Eduardo; Brinkhof, Jesse; Tatone, Ivan (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 catch efficiency of bottom trawl with a double sorting grid and diamond mesh codend in the North-east Atlantic gadoid fishery 

      Brinkhof, Jesse; Larsen, Roger B.; Herrmann, Bent; Sistiaga, Manu (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-07-28)
      This study investigated the size selectivity and catch efficiency in the North-east Atlantic demersal trawl fishery targeting cod (<i>Gadus morhua</i>) and haddock (<i>Melanogrammus aeglefinus</i>). The use of a sorting grid followed by a size selective codend is compulsory in this fishery. Experimental fishing was conducted with a commercially rigged trawl, flexigrid section, and diamond-mesh codend. ...
    • Size selectivity and length-dependent escape behaviour of haddock in a sorting device combining a grid and a square mesh panel 

      Herrmann, Bent; Sistiaga, Manu Berrondo; Grimaldo, Eduardo; Larsen, Roger B.; Olsen, Leonore; Brinkhof, Jesse; Tatone, Ivan (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 ...
    • A study on the escape rate of Northeast Atlantic cod (Gadus morhua) and haddock (Melanogrammus aeglefinus) under the fishing line with two different ground ropes in the Barents Sea bottom trawl fishery and the influence of some biotic and abiotic factors on the efficiency during bottom trawling 

      Brinkhof, Jesse (Master thesis; Mastergradsoppgave, 2015-05-15)
      The aim of this study was to investigate the escapement under the fishing line for cod (Gadus morhua) and haddock (Melanogrammus aeglefinus) with the conventional rock-hopper gear and a new type of gear termed semicircular spreading gear (SCSG). The trials were conducted during November 2014 and February 2015 in the Barents Sea under varying environmental conditions. In order to catch the escapees ...
    • Understanding and predicting the effect of entrance cone diameters on the catch efficiency of snow crabs (Chionoecetes opilio) in conical pots 

      Cerbule, Kristine; Herrmann, Bent; Grimaldo Vela, Eduardo Enrique; Sistiaga, Manu; Brinkhof, Jesse; Vollstad, Jørgen (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-02-11)
      Conical pots with a plastic entrance cone on the top are a type of fishing gear used to harvest snow crabs (Chionoecetes opilio) in Arctic regions. In this study, we assessed the effect of pot entrance diameter on the catch efficiency of snow crabs. We used catch data collected during sea trials of pots with different entrance cone diameters, and we conducted laboratory experiments where morphological ...