A collaborative experiment between Nofima and Nergård Havfiske AS has shown that pumping from the trawl’s cod-end is gentler for the fish than lifting the complete catch onto the deck.
Results show that the survival rate and quality are both higher.
Experiments onboard the trawler J. Bergvoll in May have shown that pumping is considerably more gentle than pulling up onto the ramp, and that survival rates of 80-100%, depending on species, can be achieved.
Nofima says that fish caught by trawling should be kept alive in tanks for 5-6 hours, long enough for blood to be removed from the white muscles.
“This is the first time vacuum pumping has been used to get the fish onboard from the cod-end on a trawler. Pumping ensures that the fish are in contact with water all the time, and they are not subject to gravity. Using this method means that the quality, and thus also the price, of trawl-caught fish are at least as good as those of line-caught fish,” said Kjell Midling from Nofima and head of the Norwegian Centre of Excellence for Capture-based Aquaculture.
The opportunities offered by new technology in the trawler industry are being studied in a project financed by the Norwegian Seafood Research Fund (FHF). Several shipowners are considering installing pumping facilities when refurbishing old boats or building new ones.
Nofima is taking the collaboration further with Nergård Havfiske AS, ship designers, equipment manufacturers, and pump suppliers to ensure that trawl-caught fish is of the highest possible quality.
“Knowledge about live fish is crucial for the future of the trawler industry. The new technology is based on 25 years of experience about what the fish can withstand, and the conditions necessary for survival. This will determine how the new technology is implemented,” added Mr Midling.
