Posted on 01.03.2011 - 13:00 EST in SURVEY NEWS by Rons_ROV_Links
Bowtech Surveyor-HD video camera (a) and LED-1600 lamps (b) have been deployed in surveying potential offshore renewable energy sites to characterise the habitat and monitor how the benthos (organisms living in, on or near the seabed) are affected by these developments. Bowtech Products supplied the HD camera and LED lights for the project and also designed and supplied the topside control system and umbilicals specifically to meet the project requirements.
The Marine Institute at Plymouth University, jointly with Peninsula Research Institute for Marine Renewable Energy (PRIMaRE), have developed and published a new survey method using a HD camera mounted on a towed ‘flying array' allowing them to quantify the seabed and the associated flora and fauna in adverse wave and tidal conditions over heterogeneous habitats (from sandy, pebbly flats to challenging boulder fields and rocky ledges).
Previous methods using bottom towed sledges, SCUBA divers or remote-operated vehicles were inappropriate due to cost and practicality. It was necessary to develop a method that was cost-effective, relatively non destructive and suitable to work over a range of habitats, as future sites proposed for marine renewable energy that are located over a range of habitat types, may displace fishing activity acting as pseudo Marine Protected Areas. It was therefore important to develop an affordable relatively non destructive method to monitor how the benthos are affected by these developments
The methodology is based on a high-definition video camera, plus LED lights and laser scale markers (c), mounted on a "flying array" that maintains itself above the seabed grounded by a length of chain, thus causing minimal damage. Samples are taken by slow-speed tows of the gear behind a boat. The HD video and randomly selected frame grabs are analysed to quantify species distribution. The equipment was tested over two years in Lyme Bay, UK (25 m depth), then subsequently successfully deployed in demanding conditions at the deep (>50 m) high-energy Wave Hub site off Cornwall, UK, and a potential tidal stream energy site in Guernsey, Channel Islands (1.5 ms-1 current), the first time remote samples from such a habitat have been achieved.
Dr Emma Sheehan, lead author on the publication has previously discussed the vulnerability of these coastal ecosystems with John Craven on BBC's Countryfile (September 2009). http://www.marinereserves.org.uk/2009/09/countryfile/.
Dr Sheehan says "Our new survey method using a HD camera mounted on a towed ‘flying array' allows us to quantify the seabed and the associated flora and fauna in adverse wave and tidal conditions over heterogeneous habitats (sandy, pebbly flats to challenging boulder fields and rocky ledges). In addition, it is also cost-effective and can easily be used to survey large offshore areas. Equipment and support provided by Bowtech played a vital role in developing this work".
The full paper can be found at http://dx.plos.org/10.1371/journal.pone.0014461