Scientific name: |
Seriolella caerulea |
Other names: |
Deepsea wharehou |
White warehou is a worst choice seafood. A better alternative is trevally or terakihi.
White warehou is the deepest ranging of the three warehou species in New Zealand and is common in south eastern waters and on the Campbell Plateau in the sub-Antarctics. It is mostly taken as a bycatch in bottom trawl fisheries for hoki and silver warehou.
White warehou is caught by bottom trawling. Concerns associated with this fishery include the absence of some basic biological information about white warehou, the absence of a quantitative stock assessment, the unknown stock size, uncertainty over stock boundaries and the unknown sustainability of recent catch levels. There are also concerns about past misreporting of white warehou as silver warehou catches, plus there is no specific operational plan. White warehou is mainly caught as bycatch in bottom trawl fisheries like hoki which cause considerable damage to seafloor communities. These fisheries are also associated with the bycatch of seabirds, fur seals and a range of non-target fish.
Not certified under any scheme.
White warehou exports were included in other warehou exports of $3.8 million in 2015 which is mainly exported to China and Japan.
Asssessment output
No regional or fishing method difference.
| Score: | D |
| Population size: | Unknown |
| Annual catch limit: | Limit set at 3,735 tonnes since 2006-07. |
| Recorded catch: | Reported landings of 845 tonnes in 2014-15, the lowest reported catch in over 20 years. |
| Stock trends: | Unknown but, while catch limits were increased in 2006, catches have declined. |
| MSY Status: | Unknown – there are no biomass estimates. |
| The Ministry of Primary Industries assessment plenary report includes: | “It is not known whether recent catches are sustainable or if they are at levels that will allow the stock to move towards a size that will support the maximum sustainable yield.” (MPI 2016, p 1548). |
| Score: | C |
| Distribution: | Most common off south east New Zealand and on the Campbell Plateau. |
| Maximum age (years): | 23? |
| Age at sexual maturity: | 3-4 |
| Growth rate: | Moderate |
| Reproductive output: | Moderate |
| Age exploited: | 3-4 |
| Ability to recover: | Moderate |
| Score: | E |
| Fishing method(s): | White warehou is caught as bycatch in bottom trawl fisheries, primarily hoki and silver warehou fisheries and, to a lesser extent, the hake, ling and scampi fisheries. Only 8% of the catch is from targeted fishing. |
| Habitat damage: | Bottom trawling destroys sea floor species assemblages and fragile seamount habitats. It decimates black coral, lace corals, colourful sponge fields, long-lived bryozoans and many other invertebrate species. Bottom trawl impacts include habitat modification, loss of biodiversity, loss of benthic productivity, modification of important breeding and juvenile fish habitat. The trawl footprint area and contact areas vary, but the Snares Shelf area, the Auckland Islands shelf, West Coast South Island, and northwest and southwest Chatham Rise were identified as amongst the highest frequency trawled areas in the New Zealand zone. |
| Habitat of particular significance: | hasn’t been defined in New Zealand. |
| Bycatch: | As white warehou is caught in other target fisheries, it is associated with a wide range of non-target catch and non-target fish. (See hoki, arrow squid, barracouta and jack mackerel for more information.) |
| Ecological effects: | The combined effects of destroying seafloor habitats and seamount ecosystems, non-target fish bycatch and protected corals can have considerable ecological implications. |
| Score: | E |
| Bycatch: |
As silver warehou is caught in other target fisheries, it is associated with a wide range of non-target catch, including marine mammals and seabirds. See hoki, arrow squid, barracouta and jack mackerel for more information. Hoki trawl: An estimated 192 fur seals are captured in the hoki fishery (5-year average). Based on the recent catch spread of hoki, the main captures occur in the Cook Strait (54%), off West Coast of the South Island (24%), off east coast of the South Island and Chatham Rise (15%). The hoki fishery catches about half of the estimated fur seals caught by trawling. The sub-Antarctic and Snares Shelf hoki fishery has a low capture rate for nationally critical New Zealand sea lions of about one a year. The trawl fishery also captures about 1420 seabirds a year (5-year average): main species are Salvin’s albatross, southern Buller’s albatross, white-capped albatross, sooty shearwater, white-chinned petrel, and cape petrels. Protected coral species are also reported caught in hoki tows in most quota areas. The corals caught include gorgonian, hydrocorals, black corals (Antipatharia) and stony corals (Scleractinia) – which includes reef-like, tree-like, and solitary small corals.Other bycatch species include vulnerable deepwater sharks (e.g. shovelnose dogfish, seal shark and Baxter’s dogfish). These low productivity species also include threatened basking sharks (observed at one per year, but could be higher), deepsea skates and some other elasmobranchs. |
| Score: | A |
| Management component: | Single species. However, there is a problem in that quota areas do not match possible spawning areas. |
| Score: | E |
| Quota Management Species: | Yes since 1998. |
| Catch limits: | Yes |
| Management plan: | Deepwater management plan for 2010-15 is out of date, and has yet to be reviewed and replaced. White warehou is an associated species to the hoki target species in the current plan. There is no operational plan and the old Deepwater plan lacks key environmental standards. The National Plans of Action on Seabirds and Sharks are more relevant to bycatch issues but they are slow to be implemented. |
| Stock assessment: | No quantitative stock assessment. |
| Research: | There is little directed research on white warehou in the last 5 years. |
| Observer coverage: | Observer coverage in the middle depth is about 8% and in the hoki fishery it is 27.3%. The middle depth coverage is unlikely to be spatially or temporally representative of the fishing effort. |
Fisheries map
Taken from the Ministry for Primary Industries’ Plenary report for fisheries management.
References
Paste here.