Posts Tagged ‘salmon’
Water releases from the Avon dam have been negotiated by the Devon Avon Group during dry spells of weather in order to facilitate, for example, the migration of salmon smolt. Full details are available in Notes from the DAG meetings, elsewhere on this website.
Currently (10th May) the river water level at the Loddiswell gauging station is 0.28m – at the low end of the normal range of 0.25m-1.80m. Therefore, the Environment Agency has triggered, with the close collaboration of SWW, the release of an extra 65ML per day of water from the dam between 3.00pm on Friday 6th May and Monday 9th May. Most of the benefit will be in the upper reaches of the river, which for many years have run very low during dry weather.
In mid-April, the first ever water release was made from the Avon Dam in the hope that the extra water would facilitate the natural movement of salmon smoult which takes place at this time of year. The release, the first in the 60-odd years since the dam was built, was made after a prolonged dry spell of weather when the river was at the lower end of its normal depth range. This trial release was made after prolonged negotiations between the Environment Agency, South West Water and the Avon Fishing Association, facilitated through meetings of the Devon Avon Group just as the South Hams Rivers Improvement Project comes to an end. However, it is hoped that the ‘trial’ will be the forerunner of further releases to be made for ecological purposes.
Details of the agreement are available here – http://auneconservation.org.uk/wp-content/uploads/2015/04/Fisheries-Bank_-Reservoir-water-release_2015.docx
This report by Scott West, the SHRImP project manager from The Westcountry Rivers Trust (WRT) describes a semi-quantitative fry index electrofishing survey throughout the Rivers Avon, Yealm & Erme in July and August 2014. This was the second year of fish monitoring of this type and goes someway to establishing a longer term data set for the South Hams Rivers.
The surveys were targeted to complement the Environment Agency (EA) electric fishing monitoring undertaken in 2014, although both data sets use different methodologies with the primary difference being the use of fully quantitative depletion methods used by the EA and a semi-quantitative fry index method used by WRT (to be detailed in Field sampling and data analysis methods section). A total of two sites on the Avon, two sites on the Erme and 16 sites on the Yealm were surveyed by the Environment Agency in the 2014 season (see appendix D).
The full text of the report may be found in the RESEARCH REPORTS section of the RESEARCH page.