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 ...

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 ...

The present study reports results of a small-scale preliminary experiment to evaluate whether lifting trawl doors and sweeps from the seabed can lead to a reduction of by-catch in the Northeast Arctic shrimp trawl fishery. We carried out a catch comparison and catch ratio analysis between two gear configurations: one with trawl doors and sweeps on the seabed (traditional rigging) and the other with ...

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 ...

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 ...

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 ...

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 ...

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 ...

The Nordmøre grid is regarded as an efficient bycatch reducing device and is used in various shrimp trawl fisheries globally. However, in some shrimp fisheries bycatch remains a problem that seriously impacts commercial trawl activities. This study tested and compared the performance of two versions of the Nordmøre grid in the Northeast Arctic Deepwater Shrimp (Pandalus borealis) fishery; a standard ...

The aim of this study was to provide practitioners working with trawl selectivity with general and easily understandable guidelines regarding the fish sampling effort necessary during sea trials. In particular, we focused on how many fish would need to be caught and length measured in a trawl haul in order to assess the selectivity parameters of the trawl at a designated uncertainty level. We also ...