Science & Environment

HD video to assess wave energy device impacts

High definition (HD) video can offer scientists a unique insight into how wave energy devices will affect the ecology of coastal areas, say researchers.

A team from South-West England have designed a system that includes mounting HD video cameras on a floating array, allowing it to operate in most conditions.

It will be used at the site of the Wave Hub, located off the coast of Cornwall.

The findings were presented at the British Ecological Society's annual meeting, which is being held at the University of Leeds.

Wave energy devices harness the energy in ocean surface waves for a variety of purposes, such as generating electricity.

The HD camera system has been developed by Emma Sheehan and colleagues from the UK's Peninsular Research Institute for Marine Renewable Energy (PRIMaRE).

Speaking at the annual meeting, Dr Sheehan - from the University of Plymouth - said the team had developed the device for use in the marine environment surrounding the Wave Hub, a £42m offshore "socket on the seabed" that will allow wave energy converters to be tested.

The Hub is described as being the biggest wave energy test site in the world, allowing four systems to be tested simultaneously.

Image caption The wave hub will become a permanent fixture off the Cornish coast

Dr Sheehan said that the team had considered ways to monitor the potential impacts of the operational devices.

"(One) obvious option would be to use remote operated vehicles (ROVs), but it is an extreme environment.

"We simply do not have the budget to survey the whole of the area," which covers eight square kilometres.

"Our way of solving the problem is to use HD video," alluding to the device that Dr Sheehan and her team had developed.

The system consists of a HD camera, with three high-powered LED lights, fitted to a cage that can be pulled along by a survey vessel just about the sea bed.

It also allows the researchers on board the research vessel to view live pictures, while recording the footage to allow the team to carry out more detailed research at a later date.

'Challenging site'

The system also beams two lasers on the sea bed that will allow the team to calibrate distances on the video footage.

Dr Sheehan said that there were a number of challenges associated with monitoring an offshore site.

"A lot of these sites are not pristine habitats, they have been fished, trawled, dredged. In essence, you are trying to look for the impacts on an impacted site."

She added that marine renewable energy installations (MREI) are located in difficult areas.

"Studying animals and their habitat at the Wave Hub site is difficult because the seabed is comprised of rocky ledges, boulders and gravel. It is also a 60-metre deep site and is extremely exposed."

She added that it was one of the most challenging sites she has had to work on in her career.

However, the team say the HD video system, which has been tested in Lyme Bay, Dorset, has been designed to perform in waves and tidal currents, and over a variety of different habitats and depths - with little disturbance to the marine flora and fauna.

The next stage for the researchers will be to monitor the ecological impact of the wave energy devices on sea birds, as well as whale and dolphins.

The Wave Hub is expected to become operational in 2011.

More on this story

Related Internet links

The BBC is not responsible for the content of external Internet sites