Govt relies on decade-old orange roughy data to set catch limits

Information more than 10 years old has been used as the basis for the latest orange roughy catch limit review because more recent surveys failed to find fish.
A decision on orange roughy catch limits on the Southwest Challenger Bank, located in the Tasman Sea, will be announced by Fisheries Minister Shane Jones in the coming weeks.
Fisheries NZ has provided the minister with four options for the future of the fishery, all based on the most optimistic model, which uses biomass data from 2013.
This model, which places the stock at 35 percent of historic levels, excludes acoustic surveys from 2018 and 2023 which failed to find fish in the relevant zone – though it did find fish in the international waters part of the fishery.
The Southwest Challenger Bank comprised nearly 20 percent of New Zealand’s orange roughy catch in the 2022 to 2023 fishing year.
Orange roughy is targeted when bottom trawling or for scientific purposes when they are spawning around seamounts, a phenomenon determined by moon phases and other variables.
While popular table fare, it has been a problematic species.
Late last year Seafood NZ self-suspended Marine Stewardship Council certification for orange roughy caught off the east and south Chatham Rise over concern about stock measurements.
Aggressively targeted throughout the 1990s, three fisheries had to close for a decade in response.
Since then, catch limits have been slashed significantly, but the fish are proving to grow more slowly than previously thought, and the species isn’t doing as well as hoped.
The consultation document on the options said there was “relatively high uncertainty” in the chosen model because of the age of the data in the base model.
“While an acoustic survey was undertaken in 2023, the biomass estimates from this survey were not included in the base assessment model, because spawning aggregations could not be found, and it is uncertain whether the survey timing coincided with peak spawning,” the report read.
The fishery straddles New Zealand and international waters, so management is shared with an international body, the South Pacific Regional Fisheries Management Organisation.
That 2023 study found a spawning aggregation on one seamount outside of New Zealand waters.
“The inclusion of this survey (and earlier surveys that had similar issues) in other models presented to [Deep Water Working Group] predict a more pessimistic stock status, including below the soft limit.”
The soft limit for a fishery in New Zealand is 20 percent of the natural population.
While the chosen model places the fishery at 35 percent, a model that factored in the most recent surveys placed the population at 16 percent. Current catch limits could see that reduce to 10 percent over the next five years. 
Fisheries New Zealand acting fisheries management director Jacob Hore said there were question marks over the 2018 and 2023 follow-up surveys as they didn’t appear to coincide with fish aggregation and spawning times.
“The science working group comprised of government, environmental non-government organisations, and industry agreed to set those surveys aside. The 2013 survey provided good information and insights into the state of the fishery at that time,” Hore said.
“This provided the best available picture of the stock. To reflect the uncertainty in these data a wide range of options were put forward for consultation.”
The four options put to Fisheries Minister Shane Jones range from keeping the status quo, a 20 percent cut, a 40 percent cut and a 57 percent cut.
Environmental group Deep Sea Conservation Coalition said even with the biggest cut there was no recovery predicted within the next five years under the most optimistic model run excluding recent survey information and that any of the other options assessed would see the stock decline further.
Part of the fishery is outside of New Zealand’s economic zone, and the most optimistic model places the stock under the South Pacific Regional Fisheries Management Organisation’s target limit of 40 percent.
New Zealand’s high seas permit to fish this area expires at the end of this year, and it will need to seek a new one from the management organisation.
Deep Sea Conservation Coalition campaigner Karli Thomas said the fact that spawning aggregations were not found in New Zealand waters in 2023 was a concern in itself as loss of spawning aggregations has also been observed in stock assessments elsewhere, with spawning seeming to move away from heavily trawled seamounts to those that aren’t targeted.
The area where fish were found in the 2023 survey hadn’t been trawled for two years – Thomas said it was important the identified spawning aggregation wasn’t aggressively targeted.
She acknowledged there were many factors and unknowns about when and where orange roughy spawning aggregations take place, “But that’s where you start to have to manage a fishery with precaution because of the uncertainties.
“Yes there can be spawning aggregations might start to form and then disperse again, so it could have been not in the right place at the right time, but they were surveying at the traditional time where they have been able to find spawning aggregations in places where they found them before.”
The fisheries minister’s decision needs to be made by the start of October, when the 2024/2025 fishing year begins.
Jones said he couldn’t delay the decision to wait for more evidence.
“Under the Fisheries Act I am obliged to use the best available information, but at the same time I must not avoid nor delay making decisions due to a lack of information.
“I will be announcing my decisions and the reasons behind them before 1 October.”
As well as facing further scrutiny from the South Pacific fisheries forum, the decision will also be assessed by the Marine Stewardship Council, which will audit the fishery’s sustainable certification later this year.
Thomas said the Deep Sea Conservation Coalition had written to the council and its assessor, MRAG Americas, urging them to suspend the sustainability certification  because of declining stocks and environmental impact of bottom trawling of vulnerable marine features such as seamounts.