Wave and tidal devices show minor effects on marine wildlife

A study into the impacts of tidal and wave devices on marine wildlife found little evidence of long-term effects on use of the seas by birds and marine mammals as a result of the operation and installation of such devices at the test sites.

The report, commissioned by Scottish Natural Heritage (SNH), Marine Scotland, and the European Marine Energy Centre (EMEC), looked into how species distribution and numbers had varied across the test site, relative to different levels of site activity.

The detailed records on marine mammal and birds present at sea, in and around the test berths, were collected through the Wildlife Observation Program which was running alongside device testing at EMEC.

The land-based observer data collected has been extensive with over 11 years of data from the tidal energy site, Falls of Warness, and six years at the wave energy test site, Billia Croo.

The study found that no significant changes in wildlife distribution were detected around the test berths at the wave energy test site at Billia Croo.

Observations at the Fall of Warness tidal test site showed slightly reduced numbers in some species in the vicinity of the test berths after construction work started.

However, in all cases this returned to previous levels during subsequent deployment and operation of the turbines, according to Marine Scotland.

It is therefore possible that increased vessel activity associated with installation is likely to be causing this change in distribution.

For most other species, no such pattern of change around the Falls of Warness test berths could be detected.

The observations used in this study were made from land overlooking the test sites, so possible wildlife interactions with turbines below the sea surface, were not determined, Marine Scotland noted.

George Lees, Marine Energy Manager at SNH, said: “These initial results are reassuring and show that the deployment and testing of multiple wave and tidal energy converters in the seas off Orkney over more than a decade has not had a significant impact on the diverse and abundant wildlife living there.”

Caitlin Long, Consents and Project Officer for EMEC, who conducted the research, added: “This project was set up to assist the industry in developing an understanding of the potential wildlife displacement associated with the deployment of marine energy devices.

“The culmination of the extensive wildlife observation program and this statistical analysis project, should aid regulators, advisory bodies and developers in assessing the potential environmental effects of deploying such devices in our precious marine environment.”