Blar i forfatter "Sistiaga, Manu Berrondo"

Viser treff 21-28 av 28

    • Release efficiency and selectivity of four different square mesh panel configurations in the Basque mixed bottom trawl fishery 

      Cuende, Elsa; Arregi, Luis; Herrmann, Bent; Sistiaga, Manu Berrondo; Basterretxea, Mikel (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-01-28)
      Reduction of discards from the Basque mixed bottom trawl fishery is a challenge. To improve the selective properties of the gear used by the fleet and supplement codend size selection, a square mesh panel (SMP) installed in the upper panel of the trawl was introduced in 2006. However, recent studies have shown that the release efficiency of this SMP is low due to lack of contact between the fish and ...

    • 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 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 ...

    • Size selectivity of redfish (Sebastes spp.) in the Northeast Atlantic using grid-based selection systems for trawls 

      Herrmann, Bent; Sistiaga, Manu Berrondo; Larsen, Roger B.; Nielsen, Kåre Nolde (Journal article; Tidsskriftartikkel; Peer reviewed, 2013)
      Using experimental data and a model to predict size selection based on morphological data, we investigated size selection of redfish (Sebastes spp.) in the grid-based selection systems used in Northeast Atlantic trawls. We found that not all redfish make physical contact with the spacing between the bars in the sorting grids while they pass in the direction of the codend, and therefore the ...

    • Stimulating release of undersized fish through a square mesh panel in the Basque otter trawl fishery 

      Cuende, Elsa; Arregi, Luis; Herrmann, Bent; Sistiaga, Manu Berrondo; Onandia, Inigo (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-11-19)
      Discards of regulated species in the Basque mixed trawl fishery are a challenge. In 2006, a square mesh panel (SMP) was introduced in the fishery to increase the release efficiency of undersized fish. However, studies have shown that the selectivity in this fishery is based on codend selectivity and the release through the SMP is inefficient due to low contact between fish and the SMP. In order to ...

    • Understanding the Size Selectivity of Redfish (Sebastes spp.) in North Atlantic Trawl Codends 

      Herrmann, Bent; Sistiaga, Manu Berrondo; Nielsen, Kåre Nolde; Larsen, Roger B. (Journal article; Tidsskriftartikkel; Peer reviewed, 2012)
      The majority of trawl selectivity studies for the three redfish species of particular commercial importance in North Atlantic fisheries: Sebastes marinus, Sebastes mentella and Sebastes fasciatus, are based on data collected from diamond mesh codends with mesh sizes ranging from 88 mm to 147 mm. We demonstrate how results from these studies can be understood by morphological characteristics of ...

    • Use of semi-pelagic trawling for reducing bycatch in shrimp trawls. Trials onboard R/V Johan Ruud 02-06 February 2015 

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