Waitaki River provided mixed results for the new season.
Graeme Hughes.

The opening weeks of the new season will have frustrated many anglers due to climate. In many areas of the region, especially inland, the ubiquitous “nor-wester” has foiled the attempts of many, especially the fly casters. Many boating outings on the  lakes have been postponed. The southerly blast which invariably follows lowers temperature and has regularly replaced some of a rapidly disappearing snow cap on the highest peaks. This snow is only  temporary however, up until the next “nor-wester”, and to date, despite regular high altitude snow events with the continual winds, the tops show only remnants of the winter falls.

Although it was an over cast, wind blown working day, a surprising number of anglers  were out early on the lower Waitaki River which just proved that enthusiastic anglers can wangle a day off work when it is absolutely necessary. Angler success was varied from none to bag limits (4). Several jet boats were launched at the Kurow bridges and with their ability for unrestricted access the anglers with boats appeared to be the most successful. While a jet boat is a huge advantage on the Waitaki River its use  is not without problems, primarily in the form of a rejuvenated crop of didymo. The algae, which from my observations and the observations of other river users appeared decidedly unhealthy during the late summer has recovered. In those places which had previously been devoid of didymo the algae is growing profusely. One boat with 3 anglers aboard sucked in a grill  full of didymo near the Kurow bridges and with the motor at running at high revolutions made a slow downstream route, barely making steerage, to beach on an island  where a weed rake was successfully employed to remove the blockage. Some boat owners report that at times a weed rake is unable to free the algae and it requires removal by hand which means, unless you have very long arms, stripping off and getting wet.  Working on the Waitaki over the last few days it is quite evident that didymo is in good health with copious quantities of it being transported downstream. With the many instream standing willows peculiar to the Waitaki River, local boaters are aware of the need for starting motors over deep water to prevent intake blocks which could lead to a lost boat or worse. Warning signage for visiting boaters somehow lacks emphasis of  the extreme danger didymo presents to those operating jet boats in the Waitaki River. 

Saturday of the first weekend of the season, when I expected increased angler numbers, the weather was again affected by nor-westers and very few anglers were seen in the upper lower Waitaki River area. There was no flotilla of jet boats trailers at the ramp and for an opening weekend it was a very subdued event.

The anglers catch, for the first few days has been mostly brown trout, most of which appeared to be in good, early season condition. The continued good health of the fishery defies a common sense explanation. With, lets say 75% of the food producing river bed colonised by didymo, the invertebrate diversity has been affected and many of the clean gravel and cobble habitats no longer produce the species trout rely, on it is reasonable to assume that trout condition factor should be on a steady decline. So far, this is not obvious and if it was undoubtedly I would be hearing about it. Large populations of potamopyrgus, the common small snail, are the most obvious aquatic inhabitant. In all but the swiftest of currents, they are prolific and widely distributed over a carpet  of didymo, 
I would have expected trout to be feeding on these almost exclusively however they aren’t which suggests that there are still parts of the river where conditions do not favour didymo and where trout can find suitable sustenance.

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