Fishermen and scientists have spent the past two months trialing a new type of selective fishing gear, and the results are now in! “Push-up traps” help fishermen catch more target species and less bycatch, while providing safer working conditions for fishermen working alone.
Despite the harsh Swedish winter, scientists and fishermen have been collaborating to test the design and function of the “push-up” trap, essentially a fish-bag on floats. They wanted to know whether this new type of selective fishing gear fitted with a sorting grid and which catches fish live, could:
- Continue to catch the target species – whitefish.
- Reduce catch and injury of sensitive species, e.g. Arctic char, brown trout and undersized whitefish.
- Be used by fishermen working alone.
To test this, GAP2 scientist Dr Alfred Sandström worked with two fishermen upon the icy waters of Lake Vättern to submerge two traps in different parts of the lake, and monitor their catch every two to seven days. The data has not yet been analysed in full, but Dr Alfred Sandström commented upon the results so far:
“The traps have certainly reduced the catch of non-target species. Over the two months’ fishing period, we only caught one individual of a sensitive species (an Arctic char, which we managed to release alive). Indeed, overall we caught 80% whitefish, with the rest of the catch comprising common species such as pike, bream, perch and roach.
We couldn’t have conducted this experiment without the fishermen; their involvement was absolutely critical to the trials being conducted. But I think that they are pleased with the results”.
Patrik Grönlind, one of the fishermen involved in trialing the trap commented:
“We’re now considering if we want to use this trap again. We are very satisfied with the selectivity and the catch. On some occasions, the catch was so big that it was difficult to handle the gear! Thus, we would very much like to try a larger version of the gear in the future, preferably in other locations and seasons to make sure that it works well in all situations. We also believe that there is certain small technical adjustments that can be made to make it work even better, particularly when the weather conditions are difficult in the winter.
You can read more about the beginning stages of the experiment here. But early winter conditions made the work much more demanding than initially expected. Heavy snowfall, strong winds and thick ice rendered every single trip grueling, and even damaged one of the traps. However, one unexpected boon was the use of the traps to provide live whitefish to the new Lake Vättern aquarium in Motala. You can see a video of the fish here!
Looking to the future, scientists will present the fully analysed results to the local fishermen at the beginning of 2013. The fishermen will then discuss whether they want to continue testing the traps and similar gear next year.