Angling: Rivers looking good for weekend

Despite rising a little last weekend, rivers continue to fall and are approaching summer levels and are looking good for this weekend.

For the first time this season the whole of the Taieri is looking good. The only factor working against the upper river is the weather, which has been forecast to be damp and windy.

This part of the river offers little shelter for anglers; however, the rest of the river is much better in this respect. The best fishing will probably be in the evening, especially if it is warm and the wind drops. There could be hatches of both sedge and mayfly and both will bring trout to the surface.

If the Taieri is not your cup of tea then the Mataura is a good alternative as it has dropped more than other waters and it will only get better as it drops further.

The best fishing will be with a nymph in the ripples or to fish cruising the shallow flat water. There was a conference on fresh water in Dunedin this week.

Among the topics discussed was the state of our rivers and it will come as no surprise to anglers that our rivers are not doing well.

Our rivers mostly still hold fish and the insects that they feed on, but they are deteriorating and, in some cases, at an increasing rate.

Rivers are lower for longer periods in the summer, especially small streams. This is because of the disappearance of wetlands and the result is less water to dilute pollutants, which have also increased because of intensive land use. Consequently, there is an increase in algae on the river bed, which is detrimental to insect life. Low streams also heat up more than when there is a greater flow and this is reduces oxygen levels, again affecting fish and insects.

It is easy to see how rivers are affected by comparing the upper reaches to the lower reaches. I did this a few years ago on the Silver Stream, a tributary of the lower Taieri.

In the upper reaches where it flows out of the Silver Peaks, it has a healthy population of invertebrates, including sedges, mayflies and stone flies, the latter being a strong indicator of good water quality. By the time the water reaches Puddle Alley, the stone flies have disappeared and there are fewer mayflies and sedges.

At the Gladfield Rd ford the only living creatures I could find were a few snails and some small worms.

Much the same thing happens on most of our rivers to a greater or lesser degree. There are plenty of small trout in the Silver Stream at Whare Flat but none at Gladfield Rd because of a lack of food and the high water temperatures in the summer because of the low flow.

What this tells us is that whatever is happening in the whole catchment is most obvious in the lower reaches. If we look after the small streams, the main river will be fine.