Innovative ways to catch premium white fish

Fishing, Fish, Discards, Net

Fisheries Innovation Scotland (FIS) has been working on fishing technology that could allow fishers to catch prime quality fresh fish.

As part of a FIS commissioned project (FIS025), researchers at Marine Scotland Science have been investigating the potential for a whitefish trap fishery on the West Coast of Scotland. With this project nearing its completion (April 2020), we caught up with Marine Scotland’s Jim Mair, the lead Gear Technician spearheading this work, to find out whether this might prove to be a viable method for harvesting and monitoring whitefish.

Fishing for ideas

The idea to improve a trap to harvest whitefish in this way originated 10 years ago when Jim and other Marine Scotland scientists were working on a large EU funded project. The research sought to investigate the survivability of fish once escaped from the cod end during the towing process. To complete this research, the team needed to collect unharmed fish to be used as a control for experiments. With long-line methods causing too much damage to the fish, they started to look for other methods and bought a trap from Norway. 

Jim explains that whilst diving and noticing the trap wasn’t working as well as it should, a couple of ideas for adjustments came to him.

“I took it [the Norwegian trap] underwater and watched it to see what was happening and then I remembered that I used to use a trap that I designed myself to catch bait… I grabbed a couple of ideas off that, introduced them and then we started to get really good results.”

Bringing design ideas to the surface

Jim’s lightbulb moment underwater resulted in two particular design changes. Firstly, Jim realised that by baiting the trap in a particular way he could continue to attract more fish. This combined with the addition of an extra compartment to reduce the number of escapees, Jim ‘upcycled’ a number of traps from old ones which he now uses for trials.

Although Jim’s design is novel, there are similar traps out there and on a much bigger scale. For example, Jim explains that in Newfoundland, USA, there is a group of fishermen using their own form of benthic traps to catch cod. Similar projects such as this have helped Jim refine his own design and develop ideas for where the project might go in the future.

The design also has added benefits for the environment. Unlike trawling, the traps remain in one place on the seabed with enough buoyancy to keep it upright. This means it causes little damage to the seabed, making it an extremely low-impact method of fishing.

80 kilos

Impressed by the results of the trials so far, Jim thinks “you couldn’t beat the quality of the fish” the traps produce. Fish are ‘harvested’ rather than ‘pursued’ and its design means less damage to the catch when hauled out. Although the project targets whitefish, they have also shown to be effective in catching other species such as shellfish. In one trap alone Jim managed to catch 12 lobsters: “I’ve never seen that many lobsters in one trap in my life!”

With preliminary results showing so much promise, Jim hopes to use cameras to record fish behaviour inside traps to see what differences things such as mesh size may make to the size of fish caught.

Is it commercially viable?

Although these traps are showing a lot of promise, Jim doesn’t believe that this type of fishing will ever overtake or compete with trawling.

However, it is possible that it could be a viable alternative for large crab boats for part of the year, by utilising their expert knowledge of fishing areas and the movement of fish to provide an extra income alongside crabbing.

However, Jim believes the nets should be limited to off-shore use, and with additional precautions to avoid bycatch issues, ensuring marine predators such as seals do not become trapped.

What does the future hold?

Could this method of fishing provide viable work for fishermen and be used commercially? As a small-scale fishing endeavour, Jim thinks that to make it a success, fishermen would need to work closely with restaurants to develop a high-end market for trap caught fish, such as has been developed in Newfoundland. Given the success of similar initiatives in other parts of the world, Jim is very hopeful that a profitable fishery could be developed on the West Coast of Scotland.

Jim hopes that in future he can answer more questions about the trap’s potential application and suitability indifferent locations. In Jim’s words: “I am just touching the edge of what’s possible in new ways of catching premium fish.”

This blog article was originally published as Innovative ways to catch premium white fish by Fisheries Innovation Scotland.