Function Part Discussion

Small nets (15-30cm wide): 20% boost to fishing
Medium nets (30cm-4m wide): 50% boost to fishing
Large nets (+4m): 100% boost to fishing

Whiter and firmer fish fillet
“We have analysed and compared fish caught by long-lining and fish from trawler catches. This has shown that line-caught fish has a whiter flesh and gives a firmer fillet. The most important reasons for the better flesh quality of line-caught fish are better bleeding out and less compression damage,” says researcher Bjørn Tore Rotabakk of Nofima Mat.
Both the compression damage and the poor bleeding out are caused because trawling brings up from five to twenty tons of fish onto the deck each time, while with long-lining the fish are brought on board one by one. Researchers and sensory assessors at Nofima Mat in Stavanger have carried out chemical, technical and sensory analyses in order to assess fish quality.
Taste assessors have judged the fish on colour, texture, smell, splitting and surface, while chefs at the Gastronomic Institute have assessed the flavour. The conclusion of both groups is that line-caught fish has a much higher quality.

Lower CO2 consumption
Østfoldforskning has been responsible for creating a complete environmental audit for line-caught cod. Their analyses show the carbon audit for finished products, which indicates that for each kilo of fish products sold to the consumer there are emissions of 2.35 kilos of CO2 equivalents.
“We have made thorough analyses of line-caught fish and these have been compared with previous data from trawler fishing, including from a recent Icelandic study. This study shows that trawler-caught cod accounts for more than three times the greenhouse gas emissions and energy consumption of line-caught cod. We see that even with very careful estimates, the energy consumption of long-line fishing in Norwegian waters is half that of trawling in the same waters,” explains researcher Erik Svanes of Østfoldforskning.
A survey from Norwegian waters shows that in terms of fuel consumption, an autoline vessel uses 0.32 litres of diesel per kilo of round fish, a normal trawler 0.58 litres and a factory trawler 0.72 litres. All three examples are for fishing far offshore. Coastal fishing with shorter transport distances will naturally have a lower diesel consumption. Coastal fishing using seines, nets or jigs gives a diesel consumption of 0.21 litres per kilo of round fish. Coastal long-lining gives an even lower consumption, about 0.18 litres of fuel per kilo of product delivered to the consumer.
“But the big problem for coastal fishing is that the coastal cod is a threatened species, so it is primarily deep sea fishing that has been assessed in this project,” says Svanes. He adds that another problem with fishing with nets is that it is not unusual to lose the gear, which then remains lying on the bottom. This means that fish continue to swim into the net, causing a great deal of fish mortality over a long period.