The slow death of a 200-year-old fish
It was the white-gold rush of the 1970s, that became a cautionary tale of overfishing . When stocks of orange roughy began to crash, drastic catch reductions were imposed and fisheries closed to allow populations to recover. The rescue mission was trumpeted around the world with 70% of roughy in New Zealand waters certified sustainable . But now it seems the recovery of the valuable deepsea fish wasnt as successful as first thought. And there are new, grave fears for the health of the species with the Government once again considering limits to the commercial catch. The Ministry for Primary Industries is reviewing allowances for the ORH 3B fishery, which stretches from the South Islands east coast to Southland, and includes the Chatham Islands and subantarctic waters. Crucially, it includes the nursery grounds of the Chatham Rise an underwater plateau extending 1,400 kilometres east of Banks Peninsula which reached near collapse in the 1990s. A review of sustainability measures revealed a flat or declining trend and the Ministry has also re-evaluated a previous assessment from 2020 because the data is inconsistent with this years findings. The sweet, buttery easy-to-cook fish is caught by bottom trawling, and a Ministry report reveals crews are working harder to catch them, towing for far longer periods and yet still catching fewer fish. Officials are now seeking feedback on proposals to reduce the commercial catch because they believe it has been set too high since 2014/15. Marine conservationists agree and said the claims of recovery were premature. Environmental groups are now pushing for even tougher action including a ban on trawling on seamounts, where orange roughy gather in large numbers to spawn, and where they are targeted by trawlers. Once known as slimeheads, the fish's popularity as a food item exploded when they were rebranded as orange roughy. Because they gather in large groups, commercial fishing crews could easily haul in tonnes using trawl nets. The species was heavily exploited for two decades until it became clear that the fish werent as productive as first thought they grow incredibly slowly and dont breed every year. Their lifespan is extraordinary with some living beyond 200 years old. But when harvested in huge numbers, the species is slower to recover than fish with a shorter lifespan which reproduce earlier. Barry Weeber, of the Deep Sea Conservation Coalition , says the new data suggests stocks were not as healthy as suggested by the earlier stock assessment, and data remains patchy. Ive been following orange roughy since the late 80s, and the same mistakes are made over and over again, Weeber said. That's what history of orange roughy fishing is. We reduce populations to very low levels, and we still don't know what's sustainable. Earlier this year, a government forum gave advice to Ministers on managing the impact of trawling, including a possible ban on seamounts, but a decision is yet to be made. Greenpeace NZ oceans campaigner Ellie Hooper says the data shows urgent action is needed. Orange roughy aggregate on seamounts while spawning...But in targeting them, they wipe out the biodiverse habitat, and they disturb the fish while they are trying to rebuild their numbers. And then theyre surprised when the fish are no longer there. The MPI report reveals that there is just one seamount where orange roughy are increasing and that is closed to trawling. What does that tell us? Protecting these areas allows the fish to rebuild and to spawn undisturbed. Surely this is the long term interest of the commercial fishing industry too?, Hooper said. But the industry says no seamounts are being fished for orange roughy on the Chatham Rise. Aaron Irving, general manager of the Seafood New Zealand Deepwater Council, also said smaller catches are being targeted in each tow because of crewing challenges during the Covid pandemic, rising fuel prices and demand for improved quality from the Chinese market. Most of the fishing occurs on the same grounds that have been bottom trawled for decades, on areas of flat ground and over parts of small features such as underwater hills and knolls, he said. Given the changes in fishing operations, an increasing proportion of the catch is now being taken from areas of flat ground and fewer tows are occurring on hill and knolls. Irving said it was disappointing that NIWA was unable to undertake a stock assessment for the fishery this year. But he said acoustic biomass surveys showed the stock size has remained the same over the past 12 years. This is how we know that orange roughy stocks are being sustainably fished. The industry is supportive of a precautionary reduction in catch until a new stock assessment can be completed, he added. We have advised MPI that the sensible option is to set a catch limit at the average of the last 12 years, during which time the stock size has remained stable.