April Update from the Central South Island Region
Graeme Hughes, Fish and Game Officer.

The 2008 fishing season in rivers of the region is almost at an end. There has been a considerable and sudden change in the climate, with a series of Southerlies , snow and the first of the winter frosts.

Trout fishers begin to dwindle however it appears their season has been a good one and, in spite of didymo the Waitaki River produced good fishing at the lower levels. High flows towards the end of the season made conditions difficult. Conversely low flows in most other waters had a similar effect especially in the Hakataramea, Maerewhenua and Ahuriri Rivers. While anglers reported sighting encouraging numbers of trout . convincing the fish  to take interest in  flies, nymphs or lures was mostly unsuccessful. The drought conditions remain  and significant rainfall is required to rectify the present situation. 

The salmon season on the Waitaki River was I believe  not as good as last years, again the good catches occurring in the last few weeks of the shortened season.  While it is not known at this time what the salmon anglers caught on the Waitaki , the Rangitata produced about 2000 salmon and the Opihi River mouth about 700.

The salmon harvest will be remembered for the large fish and best conditioned fish seen for some time. As the season progressed smaller fish were taken, presumably  a run of 2 year olds

Mark Webb, Fish and Game officer, reports on other salmon related matters.

Bio Acoustic Fish Fence.
The Bio Acoustic Fish Fence  is programmed to be fully operational following the May Rangitata Diversion Race shutdown.  Testing of the screen and sampling methods will be undertaken in preparation for the first full season of juvenile salmon migration starting in August. 

McKinnons Stream Hatchery
The Montrose hatchery run by NCFG suffered fry losses during low flows early in the year.  The McKinnons hatchery offered to return 30,000 fry to restock Montrose and these were transferred in early March.  Didymo testing to enable fish transfer consent to be obtained from Ministry of Fisheries was completed. 

Approximately 90,000 juvenile salmon remain at the McKinnons hatchery.  Fin clipping of these will be undertaken over the weekend of 26/27 April by volunteers. 

Ranging
A consequence of increased salmon presence is increased reporting of alleged illegal angling activity – exceeding the bag limit, sale of salmon, and spearing of salmon.  Staff and rangers have undertaken targeted ranging on the Opihi at the mouth and between Hanging Rock and Pleasant Point and on the Rangitata at the mouth, SH 1 to mouth and Turn Again Point to the gorge.  This is in addition to normal operations by honorary rangers.  Targeted ranging continued until the end of the salmon fishing season – there is no season for illegal activity.

Prosecutions
Four offences were detected by rangers.  Two, fishing without a licence and taking a foul hooked fish, have been dealt with by reparation.  Reparation has been offered in another unlicensed fishing case and court prosecution has been completed for two people for using a gill net in the Tekapo Canal.  The offenders were fined $500, court costs, $130, and contribution to Fish and Game solicitors fees $100 each.

Sockeye  Salmon spawning migrations  outnumber those of 2007
Graeme Hughes.
The exciting resurgence of Sockeye Salmon in the upper Waitaki catchment  has recently been confirmed  in Larch Stream,  Stockyard Stream and its associated springs which run into the Dobson River the major tributary of Lake Ohau.

Sockeye Salmon Count. 2008.
An aerial count of Sockeye salmon spawning waters on the 13th March, financed by Meridian Energy, showed salmon spawning in the Lower Ohau, Tekapo, and Twizel Rivers. In the enhanced Ohau tributary, now cleared a further kilometre upstream by Environment Canterbury, numbers are significantly increased.

Didymo growth in the Ohau River has not deterred the “sockeyes” and they have cleared hundreds of square metres of river bed during redd excavation.

As a cost saving, Twizel and Tekapo counts were significantly shortened.
The manager of Glen Lyon Station, a property located on the lower Dobson River near its confluence with Lake Ohau, reports  that in one of the Dobson River’s spring fed  tributaries near Stoney Stream, large numbers of small fish have appeared and they are thought to be Sockeye Salmon.

Larch Stream, a historical “sockeye” spawning stream on the opposite side of the Dobson River was checked for Sockeye salmon on March 19th, 5730 salmon were counted.

Larch Stream lies in the shadows of the main divide and is the  historical spawning grounds for Sockeye salmon

On April 3rd Stock Yard stream and associated springs were surveyed, assisted by Fish and Game Officer Stevens 1103 Sockeye salmon were counted. These waters were last used by Sockeye salmon in the 1970’s.
 
Aerial Sockeye salmon Counts, 13.3.08.
Location 2007 2008
Lower Ohau 7400 6840
Enhanced Ohau tributary 300+ 790+
Tekapo River  (Lake to Forks River) 1600 150 (Lake to Steel Bridge 4.5km)
Twizel River (Ohau River to SH 1) 570 350 (Ohau River to ford, 3 km) 

Ground count of Sockeye salmon.
Location  2007 2008
Larch Stream   0  5730  (G.Hughes)
Temple Stream (lower)   0 15   (G.Hughes)
Stockyard Stream   0 1103  (Hughes/ Stevens)

30 spent salmon in Larch Stream were captured and otoliths removed. These have been requested by NIWA fisheries staff to age the fish and to identify waters of origin of the different migrations.

Sockeye salmon on their spawning grounds in Larch Stream. Sockeye have not been seen here for at least 20 years

The Lake Ohau migrants are smaller than the Lake Benmore salmon. The same size difference applied during the salmon runs in the 1970’s. Sockeye salmon are plankton feeders and  Lake Ohau provides less plankton  compared with the more fertile Lake Benmore. As a  result  Benmore fish were always larger. The Lake Ohau Sockeye salmon are generally  dull in colour where a great many of the Benmore salmon, especially larger specimens, are orange to red in body colour with a green to olive head.

Fish Salvage 
Approximately 2000 salmonid juveniles, Brown and Rainbow trout and Chinook salmon smolts  have been netted or electro fished from drying areas of the Hakataramea River. The increased flow brought about by rain in February was short lived, drought conditions have returned  and  the river continues to recede. It is presently flowing at  800 litres per second. With the low flow there is little chance of any Waitaki salmon moving into the Hakataramea River unless there is significant rainfall over the next two or three weeks.

A Chinook salmon taken from the Hakataramea River barrier trap. With drought conditions and The Hakataramea River dry in the lower reaches there will be no salmon migration into the Hakataramea River, the largest tributary of the Waitaki River
 
National Children’s Day
Mark Webb

Assisted by Council member Frank Hamilton and angler Barry Stone, I ran casting tuition on behalf of Fish and Game at the annual children’s day family event at Timaru.  At times we needed another four helpers with kids and families lined up and each taking up to 15 minutes if they were new to the sports – and there were plenty.  For the day we probably gave personal attention to 80 children and this number could have doubled if the southerly had not caused an early closure.

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