"Anthropogenic influences on the temperature regime in a chalk river - potential for impact on suitability as salmon habitat".
Dr Graham Lightfoot.
Background.
Recent investigations have indicated that the temperature regime of the River Avon and other southern chalkstreams may be marginal for supporting Atlantic salmon, and that a number of human activities may be exacerbating the situation.
Study aims
The aim of the study would be to review the literature and existing environmental data to describe the situation, analyse the impact of human activities as far as possible, undertake limited fieldwork to gather additional data (option to be considered), consider the likely prognosis based upon projections of human activities and climate change, make recommendations for further investigation, and make tentative proposals for management of the situation if this is concluded to be necessary.
Human activities to be considered
The human activities that will be considered will include, but will not necessarily be limited to:-
- land use changes and agriculture
- water meadow operation
- abstraction of groundwater and surface water
- STW effluents and other discharges
- fish farming
- weed cutting and other river management activities
- climate change
Sources of information
Sources of information will include:-
- Published and "grey" literature on the effects of river temperature on the ecology and behaviour of salmon, with particular reference to chalkstreams.
- Published and "grey" literature on chalkstream hydrology and temperature regimes, and impact of human activities on stream temperatures (significant interest on this in N. America).
- Data held by the Agency, Water Companies and others on water temperature in the River Avon and groundwater temperatures.
- Long-term weather records (eg Central England temperature record) and predictions of future climate change.