Seafood to Avoid Rig shark/ Lemonfish Scientific name: Mustelus lenticulatus Other names: Lemonfish, spotted dogfish, spotted estuary smooth-hound, gummy shark Ranking: E (Red - Worst Choice)

Icon Explanations

The main concerns with this fishery are: the bycatch of globally threatened Hector's and Maui's dolphins, the bycatch of non-target fish, seabed damage, unknown sustainability of some catch levels and limits, the unknown long-term viability of the current commercial catch limits, the bycatch of seabirds, the limited research, the lack of quantitative stock assessments, and the lack of management plans.

The fishery assessment plenary report states: No estimates of current or reference biomass are available. For SPO 1 and SPO8 : "it is unknown whether the current TACCs [total allowable commercial catches is sustainable or whether the recent catch levels and the current TACC are at a level that will allow the stock to move towards a size that will support the maximum sustainable yield. SPO2 : "it is not known whether recent catches and the current TACC are are at levels that will allow the stocks to move towards a size that will support the maximum sustainable yield. For SPO3 "recent catch levels and current TACCs are thought to be sustainable, but it is unknown if they are at levels that will allow the stock to move towards a size that would support the maximum sustainable yield." For SPO7 : "based on a stock assessment, and trends in abundance indices..SPO7 was below Bmsy and that neither current catches nor the TACC were sustainable." (MFish, 2007, p750)

Market: New Zealand and Australia with exports of about $2.5 m.

Status and sustainable yield
Status: Unknown.
Annual catch limit: Set at 2,048 tonnes in 2004-05.
Recorded catch: Reported landings of 1295 tonnes in 2005-06 are the lowest in nearly 20 years and are well under half the annual landings reported in the early 1980s and which peaked at 3,826 tonnes in 1983.
Population size: No estimates of current and reference biomass are available.
Stock trends: Uncertain, but a decline in CPUE (catch per unit of effort) in SPO 1 West, SPO3, and SPO 8. SPO 7 (Tasman Bay/Golden Bay) catch rates have declined by over 70% in the last 15 years and biomass has decline in the West Coast South Island trawl survey.

Fishing method
Method: Trawling and bottom set nets, as well as bycatch in other trawl fisheries.
Habitat damage: Trawling damages deepwater habitats and associated diversity.
Bycatch: Globally threatened Maui's and Hector's dolphins in set net fisheries, which also catch other marine mammals, seabirds and non-target fish. Juvenile rig shark are also caught in harbours.
Ecological effects: Impact of set netting and trawling on species diversity and ecological systems.

Management
Stock assessment: No quantitative stock assessment.
Management plan: No.
Quota Management Species: Yes, since 1986.

Biology
Distribution: Common in coastal waters, especially shallow bays around New Zealand with adults out to 200m.
Maximum age (years): 20 (uncertain)
Age at sexual maturity: 4-7
Growth rate: Moderately fast.
Reproductive output: Medium to very high.
Age exploited: 2

References: Report from the Fishery Assessment Plenary, May 2007: stock assessments and yield estimates. Part 3: Pilchard to Yellow-eyed Mullet. Science Group, Ministry of Fisheries; Guidebook to New Zealand Commercial Fish Species, Revised Edition 1990, NZ Fishing Industry Board.

This page was updated on 10 November, 2007