WS10: Ecological Consequences of Tidal and Wave Energy Conversion

It is inevitable that the deployment and operation of marine energy extraction devices will disturb the surrounding environment. With the progressive tightening of statutory marine environmental controls, it is essential to be in a position to address the issues that are likely to arise as new controls are introduced, especially as the onus will be on the industry to demonstrate minimal environmental disturbance. Experience has already shown that the challenges in obtaining statutory environmental permission for the deployment of such a device can have significant economic costs.

Difficulties in predicting ecological responses to the extraction of marine energy arise for several reasons. Firstly for the majority of organisms, the responses associated with a change in their exposure to variations in energy regime (often accompanied by changes in sediment load and abrasive and mechanical perturbation) are not well understood. Secondly these responses, to what ecologists aggregate in the term “exposure” will, inter alia, vary with the stage of the life cycle of the organism, and its sensitivity to extreme perturbation events as well as to the degree of ambient exposure. Even less well understood are the impacts that species changes may have on local community structure and functioning, as other biotic factors such as competition, come into play. Even where the physical changes induced by the energy extraction device is relatively small, the ecological consequences may take time to manifest, but may still be observable in the longer term.

Conceptually, the standard approach to addressing these problems is to carry out ‘before’ and ‘after’ studies: however, these are costly, take time to conduct, and few if any, have been carried out for energy extraction devices. It is essential that research studies are initiated and monitoring data collected. Concerns focus on what ecological metrics to measure, how, and how often.

The understanding gained in this workstream will provide real opportunities to address the key ecological issues associated with the deployment of these new technologies and to forge greater interaction between ecological process, and physical process.