WASHINGTON (CN) – The National Marine Fishery Service has proposed that weaker hooks be used in the Gulf of Mexico to help bluefin tuna escape being incidentally caught by longline fishing boats.
The rule would require the use of thin gauge wires (less than 3.65 mm in diameter) which are likely to bend and straighten under the weight of the tuna.
Experimental fishing using the weaker tensile strength hook resulted in a nearly 57 percent reduction in by-catch of bluefin tuna.
The agency predicts a likely reduction in incidental by-catch from 285 fish per year to approximately 124 individuals, if the experimental results hold true in practical application.
Not only are larger fish more likely to escape from the weaker hooks before being hauled aboard, the hooks cause less damage to those fish meaning they are more likely to survive than those fish who have been caught and then released.
The weaker hooks did allow some, larger target fish – such as the yellowfin tuna – to escape. The agency argues that this may, over time, increase the size of target fish as smaller adults are removed from the breeding population.
The same may be true for the bluefin tuna the individual body mass of which, as well as the overall breeding population, have been in sharp decline since 1980.