The fishery overlaps with the breeding season of sooty shearwaters. Photo: Wikimedia Commons
A group representing quota owners of New Zealand deepwater fisheries estimates the number of seabirds captured have more than halved in the last decade.
Research by New Zealand Deepwater Group's Ben Steele-Mortimer found the number of seabirds caught in the southern squid trawl fishery, verified by Ministry for Primary Industries independent observers, had decreased markedly in the ten years to 2020.
The group estimates the number of reported seabirds captureed in the squid fishery has fallen 60 percent from 1213 seabirds in 2005-06, to 481 in 2019-20.
The research focused on the southern squid fishery due to its high observer coverage, with more than 80 percent of trawls observed by government observers over the past 10 years.
The fishery also overlap with the breeding season and range of many seabird species, including sooty shearwaters, white-chinned petrels, white-capped and Southern Buller's mollymawks.
The foraging birds, which are aggressive feeders around fishing vessels, end up interacting with fishing gear.
Steele-Mortimer presented the research paper at conference in Edinburugh, where a group of experts recently met to discuss the latest developments in reducing accidental seabird captures in fishing gear.
The Agreement on the Conservation of Albatrosses and Petrels (ACAP) Seabird Bycatch Working Group includes members from governments, NGOs, academic institutions and the seafood industry.
A Net Capture Programme was established in 2019 by the Southern Seabirds Trust (made up of industry, the World Wildlife Fund, and the Seafood New Zealand Deepwater Council) to investigate, innovate and trial operational approaches to minimise net captures of seabirds at sea.
Steele-Mortimer said there was no silver bullet in ensuring the birds' safety, and it required incremental reductions.
"Skippers, shore staff, fisheries and conservation managers and MPI observers have all played an important part in reducing the interactions of seabirds with fishing gear."
Tori lines made from colourful streamers to deter birds from striking the wire warps attached to the net have long been in place, as has delayed offal disposal.
New ways to reduce interactions with seabirds were being investigated, Steele-Mortimer said. High-pressure water sprayers, noise and strobe lights were trialled but found to be impractical or ineffective.
Deepwater Council general manager Aaron Irving said reducing risk to seabirds had always been a priority for the seafood industry.
"Our people do not want to interact with birds or other species for that matter when they are fishing, and that is why they do all they can to reduce vessel interactions."
Irving said the group was committed to seeing that risk of net captures continue to drop further.