Status Assessment 2025 - Orange Roughy

Confidence

High

Background Information

• Year added to OSPAR list: 2003. A case report was published in 2008 (OSPAR, 2008).
• Original evaluation against the Texel-Faial criteria referred to rapid decline in abundance, sensitivity deriving from slow growth, with the main threat from fishing.
• Decline: the species was evaluated as significantly declined at the time of listing, especially to the West of the British Isles.
• Sensitivity: the species was evaluated as sensitive at the time of listing because of its low resilience to targeted fishing and slow recovery.
• Anthropogenic pressures and biological factors: The species was threatened by development of fisheries in the late 1980s. These targeted dense aggregations, mostly to the West of the British Isles.
• Last status assessment: 2008. A background document was published in 2010 (OSPAR, 2010).

Geographical Range and Distribution

Orange roughy occur along the continental slope in the Atlantic, Indian, and South Pacific oceans mostly at depths from 800 to 1300 m.

In the Wider Atlantic (OSPAR Region V) the species also occurs along the mid-Atlantic Ridge from Iceland to the Azores, and in Faroese waters. No change of range and distribution over time is reported.

Population/abundance

There are no absolute estimates of orange roughy biomass in the OSPAR regions. ICES assessments were based upon trends, primarily in fisheries landings (ICES, 2023). Dense aggregations of orange roughy found to the west of the British Isles in the late 1980s were depleted by fisheries from the early 1990s to the late 2000s. This depletion was probably strongest in ICES Subarea 6, followed by Subarea 7 (both intersect OSPAR Region V). Fisheries catches in the Bay of Biscay were limited and were insignificant further south (west of the Iberian coast). Trends in landings were considered representative of trends in abundance given the absence of fisheries regulation before 2004. The proportion of total biomass on exploited fishing grounds is unknown but was assumed to be high. There are no research surveys suitable for deriving trends in orange roughy abundance.

Condition

The very low biological productivity of orange roughy populations was understood in the 1990s and radiometric analysis confirmed a longevity of over 100 years (Andrews et al., 2009). Fisheries landings from OSPAR regions mostly comprised large adults with a mode between 50 and 60 cm total length, close to the asymptotic length and a result of the accumulation of numerous cohorts of adult fish before fishing. No temporal trend in length distributions were observed. This indicates that fisheries exploited the accumulated biomass in aggregations and moved on when biomass dropped to low levels.

Threats and Impacts

The main threat to orange roughy is from fisheries, with the main "OSPAR pressure" being removal of target species.
Orange roughy can only sustain a very low rate of fishing mortality. Estimating sustainable catch (which may correspond to approximately 1% of pre-exploitation biomass) would require estimates of stock biomass, which were never available in the OSPAR regions.

The impact of other anthropogenic pressures at population level is unknown, although pressures such as organic contaminant burden may be high.
 

Measures that address key pressures from human activities or conserve the species/habitat

Since 2010, all EU TACs for orange roughy in the North-Eeast Atlantic have been set to zero, and since 2017 the species has been included in the list of prohibited species in the EU regulation for fishing opportunities. Further, since 2016, fishing with bottom trawls at a depth below 800 m is prohibited in EU and UK waters and also applies to EU and UK vessels in international waters of the North-East Atlantic. This prohibition protects a large proportion of orange roughy habitat from trawling (Ehrich, 1983). In waters shallower than 800 m there are a range of other closures and gear restrictions which would also reduce any fishing impacts on orange roughy, including closures to protect vulnerable marine ecosystems.

Conclusion (including management considerations)

Owing to management measures applying to deep-water fisheries, including a zero Total Allowable Catch (TAC) for orange roughy and depth and spatial restrictions on fishing gears, most orange roughy habitat is protected from fishing, the main threat to the species. Consequently, biomass is expected to be recovering slowly. There is no current monitoring of the recovery, which can only be very slow owing to the low biological productivity of the species.
Because of the slow recovery, the status of the species continues to be classified as “poor”, and orange roughy is only assessed by ICES every four years. Owing to the near absence of new data on orange roughy since 2020, the 2024 assessment for years 2025-2028 did not change from the 2020 assessment. Unless there are substantial changes in fishing pressure an OSPAR re-assessment is only necessary in the long-term, e.g. 10 years.

Knowledge Gaps

In the OSPAR maritime area, the metapopulation structure, population abundance and distribution of orange roughy are not well understood.

Biomass and fishing mortality rates are not known, and data are not currently available to estimate them. One alternative method to estimate biomass may be close-kin mark recapture, which, in the absence of commercial fishing, would require dedicated sampling to catch several thousands of individuals (Bravington et al., 2016).

The spatial distribution is poorly known. A potential method to assess the spatial distribution with a higher sampling capacity than submersibles is environmental DNA (eDNA).

Deepwater fauna may be exposed to a higher organochlorine burden than continental shelf fauna (Feist et al., 2015), so exposure and its effect on populations may require further investigation.

Sheet reference:

BDC2025/Orange_roughy