Rig spotted dogfish
Introduction
Rig was introduced into the Quota Management System (QMS) on 1 October 1986. The commercial fishing year for rig is 1 October to 30 September the following year. The QMS stock code for rig is SPO.
Fisheries New Zealand (FNZ) advise that prior to the introduction of the QMS in 1986, 80% of the commercial catch was taken by bottom set net and most of the remainder by trawl.
Total reported landings of rig increased rapidly during the 1970s and averaged about 3200 tonnes per year during the late 1970s and early 1980s. Since then a larger proportion of rig catch has been taken by trawlers as bycatch.
Total Allowable Commercial Catches (TACCs) for all rig stocks except SPO 10 were increased by 20% for the 1991-92 fishing year under the Adaptive Management Programme (AMP). All AMPs ended on 30 September 2009.
Rig was introduced into Schedule 6 on 1 May 2012 which means that rig that are caught, are alive and likely to survive can be released back to the sea by commercial fishers. Schedule 6 releases must be recorded and reported to FNZ.
Rig is the most commonly caught shark species by recreational fishers in New Zealand. Rig are an important catch for land-based fishers. The 2017-18 National Panel Survey found 76% of recreational catch was taken by land-based fishers.
Biology
Rig are around 25cm to 30cm when born. Off the South Island rig mature at 5-6 years for males and 7-8 years for females. Rig in the Hauraki Gulf mature earlier, 4 years for males and 5 years for females, and at smaller sizes.
Rig give birth to young during spring and summer. Most females breed annually. Young rig are generally born in shallow coastal waters, especially in harbours and estuaries. They grow rapidly during their first summer and then disappear as water temperatures drop in autumn. It is assumed they moved into deeper waters.
Stock status
There is poor information on the stock status of rig. FNZ note that the lack of historical information relating to stock abundance during the 1970s and 1980s when the stock was believed to have been heavily fished means that stock status relative to early levels of abundance is difficult to determine.
Catches
Rig are largely targeted by set net but are also caught as bycatch in target fisheries for school shark, flatfish, red cod, spiny dogfish and elephant fish, in set net, bottom trawl and bottom longline fisheries.
Table 1: Total Allowable Catches (TACs), Total Allowable Commercial Catches (TACCs) and allowances for rig, in tonnes (t).
| Fishstock | Recreational allowance | Māori customary allowance | Other mortality | TACC | TAC |
| SPO 1 | 25 | 20 | 15 | 692 | 752 |
| SPO 2 | 10 | 5 | 12 | 119 | 146 |
| SPO 3 | 20 | 20 | 66 | 660 | 766 |
| SPO 7 | 33 | 15 | 27 | 298 | 373 |
| SPO 8 | 60 | 31 | 0 | 310 | 401 |
| SPO 10 | — | — | — | 10 | 10 |
Management controls
In SPO 3 a 4 nautical mile set net closure has applied since October 2008 to reduce the bycatch of Hector’s dolphins.
On 1 October 2020 new commercial and recreational set net fishing closures out to 4 nautical miles offshore took effect within Golden Bay and Tasman Bay, from Farewell Spit to Cape Soucis (Raetihi).
Daily bag limits are the main method to manage recreational harvest of rig. Spatial and method restrictions also apply in selected areas.