Lumoled hook
Image: Fishtec Marine
Sliding weights discovery
In 2014 and 2015, seven Republic of Korea tuna longline vessels operating off South Africa and Western Australia discovered that new sliding weights improved the safety for seabirds and helped to address the safety concerns of crew.
Adding a weight near the hook, on tuna longline branchlines, helps to sink hooks quickly, so that seabirds eat fewer baits and less seabirds are caught.
However weighting hooks can sometimes be dangerous for crew. For example, when hauling the line back on board after the fishing period, sometimes a hooked fish will try and swim away, and this pulls the branchline tight. If the hook breaks off or comes out of the fish’s mouth, the weight can fly back towards the boat and crew.
New sliding weights are safer
The Korean vessels trialled the sliding weights and found that when a fish pulls the branchline tight and bites the hook off, the sliding weight slips off the branchline.
The fishing masters were satisfied that the sliding weights made it safer for seabirds and crew and didn’t affect fishing.
Who was involved
This project involved Sajo Industries, Dongwon Fisheries and Dongwon Industries, the Korean National Institute of Fishery Science, FitzPatrick Institute of African Ornithology and BirdLife South Africa.
Sliding weights are commercially available through two companies: