As part of the Commonwealth Marine Economies Programme (CMEP) Cefas collected
87 drop camera video tows of the seabed on the southern and western sides of
the island of Grenada and around the Carriacou and the Grenadines Islands.
These videos of the seabed were to characterise the benthic fauna within the
area and support the creation of benthic habitat maps from UKHO lidar data.
The videos and still images were acquired during the 2017 survey using a
lightweight drop camera frame with two GoPros simultaneously collecting stills
and video data. Two lasers were fitted for scaling images and additional
lighting provided real colour images of the seabed. The drop camera frame was
lowered to the seabed by hand from a vessel, with the video monitored to
maintain a consistent height above the seabed. Tows were 15 minutes long with
the vessel drifting in neutral so the distance covered in each tow varied.
Sample depths ranged from 3-40 m and covered a range of habitats including
bare sediment, seagrass, and coral and sponge dominated reefs. Still images
were acquired every minute at a point when the seabed was clearly in focus.
