In October 2010, the Government announced:
that it does not see a strategic case to bring forward a tidal energy scheme in the Severn estuary at this time (Severn Tidal Power, Feasibility Conclusions).
In this month’s British Birds, a short article reports BTOs findings on the potential impact that each of the proposed five alternative developments would have on the estuary’s avifauna.
All five schemes would reduce the available inter-tidal habitat available to waders and Shelduck. The remaining habitat would be underwater for a greater length of time, resulting in less time available for birds to feed. The largest barrage scheme would result in the loss of up to three quarters of inter-tidal sandflats and a quarter of saltmarsh being lost. All five schemes would result in significant declines in waterbird populations.
Water flow would be reduced as a result of each scheme, resulting in a less murky estuary, enabling plankton to flourish along with other species up the food chain, including the invertebrate prey of birds. This positive effect however, would be small in comparison with the predicted large-scale loss of habitat. Furthermore, increased long-term erosion of habitat is also predicted, again resulting in waterbird decline.
Wright, L.; Burton, N. & Clark, N. (2011) The potential impacts of tidal-power development on the Severn Estuary, British Birds 104, pp. 161.