High selectivity with the SELTRA sorting box

The Fisheries Conservation team in BIM assesses a range of gear modifications to reduce unwanted catches and address requirements under the EU landing obligation. In this blog post, I highlight one of our most successful gear trials – the SELTRA sorting box. 


I am part of the Fisheries Conservation team (in BIM—Ireland’s Seafood Development Agency). We work closely with Ireland’s fishing industry to investigate new fishing-gear technology to reduce unwanted catches in Irish trawl fisheries.  Currently, our main focus is to provide options for Irish fishermen to address EU landing obligation requirements.

Typically we organise our work around priorities within the industry and legislative requirements (e.g.  the EU landing obligation). The Nephrops (Dublin Bay prawn) fishery is currently Ireland’s largest demersal trawl fishery and a large part of our work has focused on this.  All of our gear trials are carefully planned and are typically based on what is practical and achievable in five to ten days at sea.

One of our most successful gear trials in the Nephrops fishery is the SELTRA sorting box (Figure 1).  The trial compared the SELTRA against a standard trawl and the results showed reductions in whiting, haddock and dogfish of 57, 91 and 93%, respectively, and a 9% improvement in Nephrops catches.  Based on the results we have had numerous enquiries about the SELTRA and a number of fishermen have started using it.

Figure 1. Top: A two-dimensional representation of a typical otter trawl with the location of the SELTRA sorting box location (dashed circle).  Bottom: A diagrammatic representation of the SELTRA sorting box.

Our next project is to initiate a more systematic approach to developing tools for the fishing industry.  We are looking at the front of the trawl—the start of the catching process—to assess whether changes made here can reduce the herding efficiency of fish in Nephrops trawls.  Essentially, if fewer unwanted fish enter the net, there will be a reduction in the numbers of fish needing to escape or ending up on the sorting table thereby improving the trawl’s overall selectivity.

Interested individuals can check out more about the SELTRA and all of our gear trials on our web page— http://www.bim.ie/our-publications/fisheries/ and if you need to know anything more we are available on Twitter @BordIascMhara @MMcAodh

The new GearingUp website is a fantastic opportunity to bring all relevant gear trials together in one place, where anyone with an interest in fishing can check out what is available to make fisheries more environmentally sustainable. The information published on the GearingUp website will potentially allow fishers to assess what method/modification will be most suited to their needs.