Population Surveys on the River Avon and Tributaries – May 2012
Once again FDSFB provided the services of their biologist, Dr Joanne Girvan, for four days in 2012, three days in May and a day in September. The intent was to determine the presence or otherwise of salmon parr in various in various sections of the Avon and its tributaries and to monitor the success of “Trout in the Classroom” programmes at two local Primary Schools.
On the first day, four sites were chosen and fished. One upstream of the Bathgate WWTW on the Coulston Burn and three on the Logie Water. These sites included one downstream of the bridge on the B8028, that was fished in 2011, a site several hundred metres downstream of the Armadale WWTW and a site just below the bridge on Mill Road, Armadale near the Garden Centre. In general the water was running slightly cloudy in all four sites. Results from the Coulston were as disappointing as 2011. The water smelled slightly of animal sewage and only a handful of Stoneloach and minnows were found in a 25m stretch of the Burn. This confirms that the Burn remains unattractive to trout despite the upgrade work to the WWTW. The site at the B8028 (see 2011 above), and that below the Armadale WWTW again yielded no trout but numbers of stone loach, stickleback and minnows. Fortunately the last site found two year classes of trout, proving breeding as well as large numbers of minnows, sticklebacks and some stone loach. The cloudy water may have affected the fishing and further surveys will be carried out next season.
Day two concentrated on the upper Avon and the Culloch Burn at Slamannan. The stretch at Balmitchell Bridge which had effectively suffered a total kill in July 2011 due to pollution yielded 6 trout, and significant numbers of minnows. There were no trout from the 2011 year class. A site at the Slamannan WWTW yielded a mere 3 trout. (See also below). Fortunately sampling the Culloch Burn above the bowling green area provided 17 trout, mainly from 2010 and 2012 year class. Again there were no trout from 2011.
Day three saw the team back at the base line site at Aldi in Linlithgow. This time electrofishing found a total of 23 trout of three different year classes, but again none from 2011. A 100mm roach was also found obviously from the canal.
We also carried out an educational project by electrofishing the Manuel Burn at Whitecross Primary School. This had been the release site for the trout hatched by the School children under the Trout in the Classroom Programme. Under the watchful eyes of around 30 children, we collected a total of 53 trout up to 6” in length. Although the majority were 2012 year class, there were fish from 2011, 2010 and 2009 in the sample. Even without the 2012 fish, the burn is obviously very healthy.
In September we were able to revisit sites on the upper Avon for further electrofishing. The results were surprising given the experience in May. The site at Slamannan WWTW, two sites on the Culloch Burn near the fire station and a site upstream of the Culloch were sampled. We collected a total of 36 trout of several year classes, and 36 trout parr, all from 2012 year class. These had managed to evade us in May, and we were delighted with what equated to one parr per metre of river.
Our Burns have a very healthy population of juvenile trout, although it is unlikely if trout in the Mains, the Manuel, the Logie or the Culloch Burns would actually drop down into the main Avon. More importantly, we proved that salmon are spawning further upstream that we previously knew, and that our salmon population has managed to survive the 2011 fish kill.