Juvenile Salmonid Surveys
Over the last few years the Ness and Beauly Fisheries Trust has completed a comprehensive programme of electro-fishing across both catchments. The results have provided a measure of the extent to which spawning and nursery habitats are being utilised, an assessment of the demographic structure of the populations, identified adverse environmental impacts and highlighted recruitment failures.
Members of the Trust team undertaking an electro-fishing survey
At all sites the number of salmon and trout and their fork lengths (to the nearest millimetre) are recorded. Scale samples are taken from a representative batch of fish in order to determine their ages and the size range of each year class. Tissue samples are also be taken from a representative batch of fish to provide information relating to genetic structuring.
Counting and recording the fork length of salmon fry captured during a survey
A detailed habitat survey is completed at each electric fishing site, with information on flow characteristics, depths, substrate type and quality, in-stream, bank and canopy cover and site dimensions being recorded. Photographs and water temperature measurements are also taken.
Trust staff carrying out an habitat survey of an electro-fishing site
In addition to the core Index Monitoring sites, additional project specific ‘Investigative Surveys’ are be completed as required. Contract work is also considered on a case by case basis and when time allows.
Other Fish Species
The Trust routinely records all fish captured during its routine juvenile salmon surveys. In addition to this we also undertake species specific surveys as and when required. As a result we have established an extensive database relating to all notable species present in the Ness and Beauly catchments; including eels, lamprey and freshwater pearl mussels.
An eel captured during a routine juvenile salmon survey
A juvenile brook/river lamprey ammocoete captured during a pre-project appraisal on the River Tarff
Trust staff checking for the presence of freshwater pearl mussels
In recent years the capacity to undertake seine net surveys in both lochs and coastal areas have increased the range of species that can be captured the life stage at which they can be captured and the type of habitat they can be captured within. It is envisaged that this capacity will be developed in future years.
Undertaking a seine survey in the Beauly Firth