Mitigation trials and recommendations to reduce seabird mortality in the pelagic icefish (Champsocephalus gunnari) fishery (Subarea 48.3)

Trials were conducted during the 2004/5 mackerel icefish (Champsocephalus gunnari) season in sub-area 48.3, to quantify seabird interaction with fishing operations, to trial different mitigation methods in an attempt to reduce seabird mortality caused by entanglement with the net and to collect baseline data on general seabird abundance while fishing.
Priority was placed on developing a new idea of binding the net with sisal string on shooting, in order to prevent it opening until it had sunk beneath the sea surface, and thereby reduce the chance of seabirds becoming entangled, while attempting to feed from the net. Observations suggest this technique to be highly efficient and adoption of this technique across the fleet is recommended.
The use of streamer lines during shooting and hauling of the net were also tested however due to low vessel speed this proved to be impractical and their use was discontinued.
In addition other ideas were considered and reviewed. These included reducing the size of the ‘dangerous’ 200mm net meshes to a safer 140mm, the use of additional weighting on the net body during hauling to reduce the amount of time that the net is on the surface, and the placing of a small-mesh ‘jacket’ on top of the dangerous meshes. Established techniques, such as cleaning the net and reducing offal discharge prior to shooting and hauling were also monitored.
Unfortunately only 39 trawls were completed and due to the small number of replications it was not possible to show significant difference between the treatments.