1996 Spawning Results - It's Worth The Work

It took a very long time for the autumn rain to make good the long summer drought, though fish were seen ascending main river falls during the last days of the fishing season. These were fish of 8-12 Ibs that had been in the river for some time. It seemed that they progressed quickly up the main river. It was not until mid-November that they were seen at the falls on some of the smaller tributaries, most of which they easily ascended. Water temperatures remained relatively high for the time of year.

This was followed by a dry spell, which became increasingly cold, culminating in the first snow of the year. From this point on, water temperatures were low, typically around 42F. The last appreciable rain was in early December and this took the river to its highest level of the year (including last winter and spring) though by no means as high as it usually rises in winter.

DECEMBER GRILSE

Early December saw a run of grilse that the rods had not seen during the fishing season. Although in good numbers they were surprisingly small for so late a run. Many were below 31bs and some ten or more were photographed in a small tributary -three tiny grilse cock fish were fighting over the ladies and two small patches of gravel!
As reported earlier, we had put in place four fish passes and removed more than 400 separate clearings to allow greater numbers of fish to survive.

The Clettwr was the first of our efforts to be successful. The falls at Erwood were made easier to ascend by placing a line of gabion baskets below with a small gap to let fish through. The level immediately below the falls was raised some 26 inches this way and during the earlier part of the run a considerable number of fish were seen to ascend. One observer saw more than thirty go over. However, the long dry and cold spell in later November saw no spawning and we presume that most returned. When the water rose again in December, we found some five redds above the Erwood falls but none above the top falls.

It seemed that the cold water turned what was otherwise a passable barrier into an obstacle. We were amazed at the change that even one or two degrees could make. Our thinking on what is and could be a passable barrier needed drastic revision!

MORE SUCCESS

Elsewhere, on the Clywedog, where we had removed an entire weir, we now understand why this apparently innocuous structure was such a barrier and although the general trend was for fish not to penetrate too far up the system this winter, we were pleased to record that more fish had spawned above the former site of the weir than below. In addition, the main tributary, the Bachell, which Richard had cleared in the summer, had four fish spawn in it. None had been recorded there for five years or more. The Hafrena was cleared in 1995 up to the weir but it was only in June 1996 that the owner's permission was obtained to modify this obstruction. 

The section above was substantially blocked and both the clearing and the weir modifications were completed by August. 1995 produced 7 redds but in 1996 some 14 were counted below the weir and a further 3 above. The EA monitored activity both above and below in the summer. Salmon fry and parr were found below the weir but not above. We shall look forward to reporting the actual densities of both years in the next newsletter.
A road culvert was blocking the tiny Estyn Brook to ascending fish. The Countryside Council brought this to the attention of the Foundation and heresay accounts existed of spawning fish in bygone years. EA electro surveys showed no fish whatever above the culvert but a low density below. The fish pass was completed in early August. It was not until early December that we found two redds upstream. However we noted that during winter flows, there were few places that afforded the right sort of spawning gravels.

PLENTY OF FISH

The fish pass on the Duhonw allowed plenty of fish to ascend during the first flood but no redds were actually found above. There are a number of possibilities for this, ranging from us not finding the redd sites if there were any, access gained by cock fish only, the falls immediately above not being surmountable, to poor gravels. We plan certain modifications for the coming year.

As far as the way in which log jam clearance influenced events, either by spreading out or increasing redds counts; the following examples give some idea of the benefit:

Stream   1995 1996
Hirnant 3 30+
Nantmel Dulas 0 37

Those streams which cleared in 1994 or 1995 generally recorded better results this winter: (1996) eg Bachawy whose redd count since 1993 is as follows:

0(93) 7(94) 9(95) 14(96)

(Cleared end of 94)

These are just a few examples of the benefits of the summer's clearance work.

Gravel raking was another of the Foundation's activities. Bailiff Ray Dobbins reports that both the sites raked on the Elan had exactly 39 redds on each of them. Both of these areas could be comfortably accommodated within a tennis court! The total for the Elan was 164 compared with 54 in 1995. The Elan is a regulated stream which means it seldom has a large spate. Gravel tends to become compacted in these circumstances.

We should like to record our grateful thanks to the Countryside Council for Wales for grant aiding the fish passes.