• 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 physical properties and fishing performance between biodegradable PLA and conventional PA trammel nets in grey mullet (Mugil cephalus) and red-lip mullet (Liza haematocheila) fishery 

      Yu, Mengjie; Tang, Yanli; Min, Minghua; Herrmann, Bent; Cerbule, Kristine; Liu, Changdong; Dou, Yilin; Zhang, Liyou (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-09-16)
      Marine plastic pollution and continuous capture of marine animals, so-called “ghost fishing”, by abandoned, lost, or otherwise discarded fishing gear (ALDFG) are global concerns. This study investigated whether biodegradable polylactic acid (PLA) monofilaments can be used to replace conventionally used non-biodegradable polyamide (PA) in trammel net fishery for limiting ALDFG associated effects. It ...
    • 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 ...
    • CREELSELECT—A method for determining the optimal creel mesh: Case study on Norway lobster (Nephrops norvegicus) fishery in the Mediterranean Sea 

      Brčić, Jure; Herrmann, Bent; Mašanović, Marina; Šifner, Svjetlana Krstulović; Škeljo, Frane (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-03-31)
      In the laboratory, we investigated which sizes of <i>Nephrops</i> (<i>Nephrops norvegicus</i>) could pass through the meshes of different size and shape to establish a predictive model for the creels size selectivity. Predictions agreed well with the results from experimental fishing, demonstrating the reliability of this simple method. <i>Nephrops</i> minimum target size is 20 mm carapace length ...
    • Does soak time influence the effect of artificial light on catch efficiency in snow crab (Chionoecetes opilio) pot fishery? 

      Cerbule, Kristine; Herrmann, Bent; Grimaldo, Eduardo; Grimsmo, Leif; Karlsen, Junita D. (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-12-09)
      In the Barents Sea commercial snow crab (Chionoecetes opilio) fishery, an increase in catch efficiency of the conical pots is important for the profitability of the industry. Light emitting diodes (LEDs) have previously been tested for increasing catch efficiency of the snow crab pots. These earlier experiments have shown varying results ranging from large increase in snow crab catches to no ...
    • Does the efficiency of a counter-herding device depend on seabed contact? 

      Melli, Valentina; Krag, Ludvig Ahm; Herrmann, Bent; Karlsen, Junita Diana; Feekings, Jordan (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-07-06)
      To prevent unwanted fish bycatch from entering the trawl, we modified a counter-herding device, FLEXSELECT, developed for a Northeast Atlantic <i>Nephrops</i> (<i>Nephrops norvegicus</i>) trawl fishery. FLEXSELECT, which was designed to direct fish away from the trawl by means of sweeping ropes in the herding area, has been shown to be highly effective on both roundfish and flatfish species. However, ...
    • Dredge selectivity in a Mediterranean striped venus clam (Chamelea gallina) fishery 

      Petetta, Andrea; Herrmann, Bent; Virgili, Massimo; Bargione, Giada; Vasapollo, Claudio; Lucchetti, Alessandro (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-02-15)
      The striped venus clam Chamelea gallina is the target of a large fleet of hydraulic dredgers, which represent an important fishing sector in terms of income and landings in the Mediterranean Sea. Although there is information on the catch rates, impact and discards related to this fishery, the size selection process carried out by the dredge during trawl under commercial conditions is practically ...
    • Effect of a lateral square-mesh panel on the catch pattern and catch efficiency in a Mediterranean bottom trawl fishery 

      Bonanomi, Sara; Brcic, Jure; Herrmann, Bent; Notti, Emilio; Colombelli, Alessandro; Moro, Fabrizio; Pulcinella, Jacopo; Sala, Antonello (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-03-31)
      The current legal codends used in Mediterranean bottom trawl fisheries are at high risk of retaining undersized individuals of several commercial fish species. This entails that codends alone are unable to provide the desired exploitation pattern. A simple technological measure that potentially can provide higher release efficiency of undersized fish are Square-Mesh Panels (SMPs). SMPs are often ...
    • 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 ...
    • Effect of artificial lights on catch efficiency and capture patterns in Asian paddle crab (Charybdis japonica) gillnet fishery 

      Yu, Mengjie; Herrmann, Bent; Cerbule, Kristine; Liu, Changdong; Zhang, Liyou; Tang, Yanli (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-07-22)
      The gillnet fishery targeting Asian paddle crab (Charybdis japonica) is an important commercial fishery in the Yellow Sea of China. However, low catch rates represent a challenge, and solutions for improving the catch efficiency are crucial for economical sustainability in this fishery. Therefore, we tested whether the use of artificial fishing lights could improve gillnet catch performance. ...
    • Effect of Bait Type and Bait Size on Catch Efficiency in the European Hake Merluccius merluccius Longline Fishery 

      Sistiaga, Manu Berrondo; Herrmann, Bent; Rindahl, Lasse; Tatone, Ivan (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-02-21)
      We investigated the effect of bait type and bait size on the catch ef fi ciency of a demersal longline fi shery targeting European Hake Merluccius merluccius in the North Sea. Automation of the labor-intensive processes onboard fi shing vessels requires fi nding alternatives to the traditional bait used in the fi shery (i.e., whole European Pilchard Sardina pilchardus ). Of the six ...
    • Effect of Codend Circumference on the Size Selection of Square-Mesh Codends in Trawl Fisheries 

      Sala, Antonello; Herrmann, Bent; De Carlo, Francesco; Lucchetti, Alexandro; Brcic, Jure (Peer reviewed; Journal article; Tidsskriftsartikkel, 2016-07-29)
      It is well established that increasing mesh number in the circumference of a diamond-mesh trawl codend can reduce size selection for round fish, whereas selection for flat fish species is unaffected. This effect has also been documented in Mediterranean trawl fisheries. In contrast, no information is available with regard to the effect of increasing mesh number in the circumference of square-mesh ...
    • Effect of codend mesh sizes on the size selectivity and exploitation pattern of cocktail shrimp (Trachypenaeus curvirostris) in shrimp trawl fishery of the South China Sea 

      Yang, Bingzhong; Herrmann, Bent (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-08-29)
      This study aims at improving fishery management by testing and comparing the size selectivity and exploitation pattern of diamond-mesh codends, with mesh sizes ranging from 25 to 54 mm, for cocktail shrimp (Trachypenaeus curvirostris) in the South China Sea (SCS). Beginning from 25 mm, the minimum mesh size regulated by the shrimp trawl fishery industry, we investigated how the mesh sizes of ...
    • Effect of Extension Piece Design on Catch Patterns in a Mediterranean Bottom Trawl Fishery 

      Petetta, Andrea; Herrmann, Bent; Virgili, Massimo; Li Veli, Daniel; Brinkhof, Jesse; Lucchetti, Alessandro (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-05-18)
      The catch composition of bottom trawls is commonly refined and improved through changes in codend design. Measures like reducing the number of meshes in codend circumference or turning diamond netting by 90 degrees are well known to improve the size selectivity of fish species with rounded cross-sectional shape. Based on this we speculated whether the same measures, if applied in other parts of ...
    • 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 ...
    • Effect of gillnet twine thickness on capture pattern and efficiency in the Northeast-Arctic cod (Gadus morhua) fishery 

      Brinkhof, Ilmar; Herrmann, Bent; Larsen, Roger B.; Brinkhof, Jesse; Grimaldo, Eduardo; Vollstad, Jørgen (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-04-15)
      Gillnets are among the most common fishing gears worldwide. They are often made of thin twine, which is prone to wear and tear, limiting the lifespan of the gillnet. This increases gillnet turnover, and consequently increased risk of gear discarding, gear loss, ghost fishing and marine pollution. This might be mitigated by increasing twine thickness, and thereby breaking strength. However, the ...
    • Effect of grid section design on trawl size selectivity 

      Sistiaga, Manu; Herrmann, Bent; Brinkhof, Jesse; Larsen, Roger B. (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-06-12)
      Sorting grids are introduced in trawl fisheries to improve size selectivity and reduce the variability of results obtained with sorting devices constructed of netting e.g., codends. Grids are rigid or semi-rigid structures where the bar spacing defines the sizes of fish that can pass through. However, for size selection to occur, fish need to be oriented towards the grid in specific ways, which ...
    • The effect of grid size on catch efficiency and by-catch in the demersal trawl fishery for Norway pout (Trisopterus esmarkii) 

      Brinkhof, Jesse; Grimaldo Vela, Eduardo Enrique; Herrmann, Bent; Pettersen, Hermann (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-09-05)
      Norway pout (Trisopterus esmarkii) is caught with large trawls with small meshed codends, inevitably causing the fishery to have large by-catch issues. To reduce the amount of by-catch, a rigid sorting grid was made compulsory in 2010. However, there is still a severe by-catch issue, as well as the loss of target species because of the grid. A possible cause might be clogging of the grid, which could ...
    • Effect of ground gear modification on bycatch of rays in mediterranean bottom trawl fishery 

      Fakıoğlu, Y.E.; Özbilgin, H.; Gökçe, G.; Herrmann, Bent (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-03-28)
      Bycatch of rays and skates in towed fishing gears represents one of the major threats to these relatively slow-growing marine species. The objective of this study was to modify ground gear in a bottom trawl fishery to increase the escape of these species during towing without associated loss of target catch. Sea trials were carried out with a research vessel in Mersin Bay, North-eastern Mediterranean. ...