• Alternative bait trials in the Barents Sea snow crab fishery 

      Araya-Schmidt, Tomas; Olsen, Leonore; Rindahl, Lasse; Larsen, Roger B.; Winger, Paul D. (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-05-13)
      Commercial harvesting of snow crab (<i>Chionoecetes opilio</i>) in the Barents Sea started in 2012 by Norwegian fishing vessels. This new fishery has significant bait requirements, representing an emerging conservation challenge. In this study, we evaluate the performance of five alternative (natural) baits manufactured from the waste stream of existing and sustainably managed harp seal (<i>Pagophilus ...
    • Assessing the impact of buffer towing on the quality of Northeast Atlantic cod (Gadus morhua) caught with a bottom trawl 

      Brinkhof, Jesse; Larsen, Roger B.; Herrmann, Bent; Olsen, Stein Harris (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-05-28)
      The dense aggregations of Northeast Atlantic cod (Gadus morhua) in the Barents Sea have led to a new fishing practice termed “buffer towing.” In this fishery, many trawlers redeploy the trawl directly after taking the catch onboard in an attempt to secure a continuous supply of fish and avoid any unnecessary stops during processing. If the approximate desired amount of fish is caught or exceeded ...
    • Bycatch reduction in the deep-water shrimp (Pandalus borealis) trawl fishery by increasing codend mesh openness 

      Jacques, Nadine; Cerbule, Kristine; Pettersen, Hermann; Herrmann, Bent; Ingólfsson, Ólafur; Sistiaga, Manu Berrondo; Larsen, Roger B.; Brinkhof, Jesse; Grimaldo, Vela Eduardo; Brčić, Jure; Lilleng, Dagfinn (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-08-03)
      In most trawl fisheries, drag forces tend to close the meshes in large areas of diamond mesh codends, negatively affecting their selective potential. In the Barents Sea deep-water shrimp (Pandalus borealis) trawl fishery, selectivity is based on a sorting grid followed by a diamond mesh codend. However, the retention of juvenile fish as well as undersized shrimp is still a problem. In this study, ...
    • Bycatch reduction in the deep-water shrimp (Pandalus borealis) trawl fishery with a large mesh top panel 

      Cerbule, Kristine; Jacques, Nadine; Pettersen, Hermann; Ingólfsson, Ólafur Arnar; Herrmann, Bent; Grimaldo, Eduardo; Larsen, Roger B.; Brinkhof, Jesse; Sistiaga, Manu; Lilleng, Dagfinn; Brčić, Jure (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-04-08)
      In the Northeast Atlantic deep-water shrimp (Pandalus borealis) trawl fishery, the bycatch of juvenile fish and shrimp represents a problem. This study evaluated if inserting a 200 mm mesh size top-panel in the last three sections of the tapered upper belly section of the trawl could reduce bycatch of juveniles while maintaining the catch efficiency for deep-water shrimp. The bycatch species ...
    • Bycatch reduction in the Norwegian deep-water shrimp (Pandalus borealis) fishery with a double grid selection system 

      Larsen, Roger B.; Herrmann, Bent; Sistiaga, Manu Berrondo; Brinkhof, Jesse; Grimaldo, Eduardo (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-08-25)
      Trawlers targeting Deep-water Shrimp (<i>Pandalus borealis</i>) in the North Atlantic use a Nordmøre sorting grid ahead of a small-meshed codend. Based on experimental fishing, the effect of adding a 9 mm spaced release grid behind the mandatory 19 mm spaced Nordmøre sorting grid, was determined. The performance in terms of size selection of the release grid and the two grids combined were assessed ...
    • Can a large-mesh sieve panel replace or supplement the Nordmøre grid for bycatch mitigation in the northeast Atlantic deep-water shrimp fishery? 

      Jacques, Nadine; Herrmann, Bent; Larsen, Roger B.; Sistiaga, Manu Berrondo; Brčić, Jure; Gökçe, Gökhan; Brinkhof, Jesse (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-07-26)
      The Nordmøre grid is the principle bycatch mitigation device in many shrimp trawl fisheries. However, in several of these fisheries, bycatch is a problem because small sized fish can pass through the grid and enter the codend together with the targeted shrimp. One such fishery is the Northeast Atlantic deep-water shrimp (<i>Pandalus borealis</i>) fishery, where the use of a Nordmøre grid is mandatory. ...
    • Can biodegradable materials reduce plastic pollution without decreasing catch efficiency in longline fishery? 

      Cerbule, Kristine; Grimaldo, Eduardo; Herrmann, Bent; Larsen, Roger B.; Brčić, Jure; Vollstad, Jørgen (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-03-23)
      Longlining is a widely used fishing method. During longline fishing, some of the snoods connecting the hooks to the mainline are often lost at sea. Since snoods are made of nylon or polyester, lost snoods contribute to marine plastic pollution. Replacing nylon or polyester with a new material made of biodegradable plastics can potentially reduce macro- and microplastic pollution that is caused by ...
    • Can vertical separation of species in trawls be utilized to reduce bycatch in shrimp fisheries? 

      Larsen, Roger B.; Herrmann, Bent; Brcic, Jure; Sistiaga, Manu; Cerbule, Kristine; Nielsen, Kåre Nolde; Jacques, Nadine; Lomeli, Mark Joseph Max; Tokac, Adnan; Cuende, Elsa (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-03-26)
      Several shrimp trawl fisheries use a Nordmöre sorting grid to avoid bycatch of fish. However, small fish can pass through the grid. Therefore, the retention of juvenile fish often remains an issue during shrimp trawling. We investigated the vertical distribution of deepwater shrimp (<i>Pandalus borealis</i>) and dominant bycatch species at the point where the Nordmöre grid section is installed. This ...
    • Catch and release patterns for target and bycatch species in the Northeast Atlantic deep-water shrimp fishery: Effect of using a sieve panel and a Nordmøre grid 

      Larsen, Roger B.; Herrmann, Bent; Sistiaga, Manu Berrondo; Brinkhof, Jesse; Santos, Juan (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-12-21)
      The Nordmøre grid and the sieve panel are two of the main devices used to reduce fish bycatch in trawl fisheries targeting shrimp species. However, even when using such devices, some small-sized fish enter the codend of the trawl together with the targeted shrimp. Therefore, bycatch reduction remains a problem in some shrimp fisheries. One such fishery is the Northeast Atlantic deep-water shrimp ...
    • Catch Efficiency of Groundgears in a Bottom Trawl Fishery: A Case Study of the Barents Sea Haddock 

      Larsen, Roger B.; Herrmann, Bent; Brinkhof, Jesse; Grimaldo, Eduardo; Sistiaga, Manu Berrondo; Tatone, Ivan (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-10-10)
      The catch efficiency of two types of groundgear—a conventional rockhopper and a new type of groundgear called the semicircular spreading gear (SCSG)—was investigated through experimental fishing for Haddock Melanogrammus aeglefinus conducted in the Barents Sea. A retainer bag was attached behind the footrope of the trawl, and the number of fish that were overrun by the trawl was compared with the ...
    • Catch pattern and size selectivity for a gear designed to prevent fish injuries during the capture process in a North-East Atlantic demersal trawl fishery 

      Herrmann, Bent; Sistiaga, Manu; Larsen, Roger B.; Brinkhof, Jesse; Gjøsund, Svein Helge; Jacques, Nadine; Santos, Juan (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-11-04)
      In the North-East Atlantic demersal trawl fishery targeting cod and haddock, the interest on fishing gear designs that preserve fish quality and welfare has grown. However, the gear configurations tested so far imply practical challenges, therefore, more user-friendly designs are still sought by the industry. For a new design to be considered, it needs to have size selective properties that are at ...
    • Coincident mass occurrence of gelatinous zooplankton in Northern Norway 

      Knutsen, Tor; Hosia, Aino; Falkenhaug, Tone; Skern-Mauritzen, Rasmus; Wiebe, Peter H.; Larsen, Roger B.; Aglen, Asgeir (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-05-23)
      In autumn 2015, several sources reported observations of large amounts of gelatinous material in a large north Norwegian fjord system, either caught when trawling for other organisms or fouling fishing gear. The responsible organism was identified as a physonect siphonophore, Nanomia cara, while a ctenophore, Beroe cucumis, and a hydromedusa, Modeeria rotunda, were also registered in high abundances ...
    • Combination of a sorting grid and a square mesh panel to optimize size selection in the North-East Arctic cod (Gadus morhua) and redfish (Sebastes spp.) trawl fisheries 

      Sistiaga, Manu Berrondo; Herrmann, Bent; Grimaldo, Eduardo; Larsen, Roger B.; Olsen, Leonore; Brinkhof, Jesse; Tatone, Ivan (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-12-27)
      Sorting grids and square mesh panels are the two most-applied technical devices to supplement codend size- and species-selection in demer- sal trawls. In the Barents Sea gadoid fishery, the compulsory size-selectivity system comprises a mesh section with a sorting grid followed by a diamond mesh codend. We tested the size-selective performance of a new sorting section that comprised a sorting grid ...
    • Comparison of fishing efficiency between biodegradable PBSAT gillnets and conventional nylon (PA) gillnets 

      Grimaldo, Eduardo; Herrmann, Bent; Su, Biao; Føre, Heidi Moe; Vollstad, Jørgen; Olsen, Leonore; Larsen, Roger B.; Tatone, Ivan (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-01-19)
      Gillnets made of a new biodegradable resin (polybutylene succinate co-adipate-co-terephthalate (PBSAT) were tested under commercial fishing conditions to compare their fishing performance with that of conventional nylon (PA) nets. The relative catch efficiency between the two gillnet 15 types was evaluated over the entire winter fishing season for cod (<i>Gadus morhua</i>) in northern Norway. The ...
    • Comparison of the efficiency and modes of capture of biodegradable versus nylon gillnets in the Northeast Atlantic cod (Gadus morhua) fishery 

      Cerbule, Kristine; Herrmann, Bent; Grimaldo, Eduardo; Larsen, Roger B.; Savina, Esther; Vollstad, Jørgen (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-04-01)
      Modern gillnets are usually made of nylon with high breaking strength, suitable elasticity and durability making them an efficient fishing gear. Lost, abandoned, or discarded gillnets at sea cause plastic pollution and can continue capturing marine animals over long periods of time. Biodegradable materials are being developed to replace nylon in gillnets. However, biodegradable gillnets have shown ...
    • Could green artificial light reduce bycatch during Barents Sea Deep-water shrimp trawling? 

      Larsen, Roger B.; Herrmann, Bent; Sistiaga, Manu Berrondo; Brčić, Jure; Brinkhof, Jesse; Tatone, Ivan (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-03-31)
      The Nordmøre grid is widely used in shrimp trawls to reduce the bycatch of fish species. However, small-sized fish species and juveniles still pass through the grid and enter the codend, along with the targeted shrimp. This bycatch of small fish has a negative impact on the ecosystem due to increased fish mortality, and leads to additional sorting work onboard. Some small-sized fish that enter the ...
    • Effect of a quality-improving codend on size selectivity and catch patterns of cod in bottom trawl fishery 

      Brinkhof, Jesse; Herrmann, Bent; Larsen, Roger B.; Veiga-Malta, Tiago (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-02-26)
      A new codend concept developed and tested exhibited significantly improved quality of caught cod (<i>Gadus morhua</i>) compared to that of the conventional codend used in the Barents Sea bottom trawl fishery. However, the design of the new quality-improving codend raised concerns about its size selectivity and the possibility that higher retention probability could negatively impact the catch pattern ...
    • The Effect of Buffer Towing on Quality Aspects of Frozen and Thawed Atlantic Cod (Gadus Morhua) 

      Esaiassen, Margrethe; Jensen, Tonje Kristin; Eilertsen, Venil T.; Larsen, Roger B.; Olsen, Stein Harris; Tobiassen, Torbjørn Inge (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-11-16)
      A large part of the Northeast Atlantic cod caught with trawls is landed frozen, processed, and sold thawed. Many trawlers have adapted a fishing practice termed ‘buffer towing’, causing probability for poor exsanguination and fillet redness. Here, the effect of buffer towing upon color and hemoglobin concentration in cod loin section is studied, and the development of TVB-N during chilled storage ...
    • Effect of Codend Design and Postponed Bleeding on Hemoglobin in Cod Fillets Caught by Bottom Trawl in the Barents Sea Demersal Fishery 

      Jensen, Tonje Kristin; Tobiassen, Torbjørn Inge; Heia, Karsten; Møllersen, Kajsa; Larsen, Roger B.; Esaiassen, Margrethe (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-08-03)
      Previous studies have reported that cod caught using a newly developed dual sequential codend showed significant reduction in external catch-related damage compared to cod caught by a conventional codend. In this study, it was investigated whether this new codend affects residual blood in cod fillets and/or mitigates the effect of postponed bleeding. Residual blood was assessed by measuring ...
    • Effect of gear design on catch damage on cod (Gadus morhua) in the Barents Sea demersal trawl fishery 

      Brinkhof, Jesse; Herrmann, Bent; Sistiaga, Manu; Larsen, Roger B.; Jacques, Nadine; Gjøsund, Svein Helge (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-08-18)
      Damage incurred during the catch process is an indicator of the overall quality of fish and fish welfare. Because catch quality is difficult to improve once it has deteriorated, it is important to preserve quality during the catch process. Atlantic cod (<i>Gadus morhua</i>) is the most important species in the Barents Sea bottom trawl fishery. Bottom trawling is a non-benign fishing method, and it ...