6. Thermal generating stations
6.1 The Committee has been continuing to press Scottish Power to take steps to reduce the massive annual entrainment of fish on the cooling water screens of the Longannet Power Station. Following a confidential report by researchers at Stirling University the Committee met with Scottish Power in February 2003 and, as mentioned in last year's report, was advised that an acoustic deterrent system was being investigated. This system has been used successfully elsewhere, namely the Doel power plant on the Scheldt estuary (Belgium) where it is understood that entrainment has been reduced by almost 60% [1].
6.2 The situation on the Forth estuary is considered by the Committee to be serious, not only for the local salmon and sea trout populations, (it is arguable that in some years a significant proportion of the annual smolt production of local rivers may be at risk), but for the environment as a whole, as 34 different species have been identified from the screens, some of commercial marine fishery importance.
6.3 The Committee is therefore disappointed to hear that a decision on the proposal to install an acoustic deterrent has been further delayed because of concerns about performance guarantees, cost/benefit considerations, and health and safety, for a system that would provide a 50% reduction in the number of fish entrained. With the numbers involved, even a 50% reduction represents a very significant number of fish, although different species may react differently to the deterrent.
6.4 The Committee understands that Scottish Power may be considering operational changes at Longannet to comply with emissions targets and is keen that these should take full account of the pressing need to reduce the entrapment of fish - especially migratory salmonids - at the intake.
[1] Maes, Turnpenny, et al., 2004, Journal of Fish Biology, 64, p.938-946