The Rise and Fall of Orange Roughy: Inside the Boom and Bust of Deep-Sea Fisheries

The east coast of New Zealand is home to the world’s largest orange roughy population. This vulnerable and long-lived species – which can live to over 200 years – has been the target of intensive fishing activity by New Zealand bottom trawling vessels for decades. Now, new data shows that this population is on the verge of collapse. 

Karli Thomas, New Zealand and South Pacific Seamounts Campaign Lead, described the situation as “the perfect storm of poor fisheries management – decades of overfishing, targeting a long-lived species on their seamount breeding grounds, and using destructive bottom trawls, which destroy ancient corals on those seamounts.”

A New Zealand Government report from 2023 found that bottom trawling accounted for more than 99% of reported coral bycatch over a 13-year period, which amounted to more than 200 tonnes of coral, and this is only reported coral bycatch. Fishery observers cover only around 30% of bottom trawlers, and the coral that comes up in the net is only a tiny fraction of what is destroyed on the seabed. 

New Zealand catches around 80% of the total world catch of orange roughy, and this fishery accounted for half of the country’s catch in the last fishing year (2023-24). A new stock assessment in 2025 has confirmed that the fishery’s stock is close to collapse (8-18% biomass) with one of four models showing it may have already collapsed.

 Modeling also shows that even if the fishery is closed now, it would take at least 33-74 years to recover to a safe level, possibly over 100 years. The New Zealand Government must now consider how to manage the collapsing population in this fishery, from maintaining the status quo to closing the fishery completely, or cutting the catch limits significantly. 

Fisheries New Zealand is consulting on proposed changes to catch limits, and potentially an area closure. You can ​support the campaign and write a submission, due on 28 July. 

One orange roughy population near this fishery is faring better, which scientists suggest may be because the main spawning area – Morgue Seamount – has been protected from bottom trawling for more than two decades. Spawning aggregations are no longer found on the heavily trawled Graveyard Seamount nearby. When seamounts are protected, the effects reach far beyond them and into the open ocean, supporting fish populations. 

New Zealand is also the only country that still bottom trawls in the high seas of the South Pacific, and has resisted efforts by other members of the South Pacific Regional Fisheries Management Organisation (SPRFMO) to increase the protection of vulnerable ecosystems like seamounts.

Sign the petition to the New Zealand Government: Stop the destruction of ancient coral forests

From a local to global perspective 

Many high seas fisheries, especially those targeting seamounts, have been shown to be “boom and bust” fisheries, only lasting between a decade to a couple of decades before they are no longer economically viable. This pattern has been seen in deep-sea fisheries across the global ocean, yet regional fisheries management organisations and States continue to disregard the science and push species to the brink of collapse. 

This boom and bust pattern was seen in the Irish orange roughy fishery within the jurisdiction of the North East Atlantic Fisheries Commission (NEAFC). Fishing for orange roughy began in earnest in the mid 1990s, and by the time a New Zealand vessel came to the fishery in the early 2000s the stock was already in decline. NEAFC only began regulating the catch of deep-sea species in 2002, when the population of orange roughy was already depleted. The fishery has since been closed and reopened multiple times, with the latest guidance lasting until 2028. The recommendation from NEAFC directly mentions intensive fishing activity and a low level of spawning orange roughy in the region.

States must take notice of the cautionary tales provided by boom and bust deep-sea fisheries and follow the precedent-setting actions of NEAFC; taking precautionary measures to protect species such as orange roughy, and the habitats they rely upon – seamounts. 

The UNGA Bottom Fisheries Review next year (2026) marks a pivotal moment for the international community to finally deliver on two decades of commitments and protect deep-sea seamounts from destructive practices, such as bottom trawling. In fully protecting these biodiversity hotspots, our #OceanLifelines, a significant foundational layer of high seas protection can be delivered.