Visual sightings data set 2003-2016
HWDT assess the relative abundance, densities and distribution of marine mammal species and basking shark on the west of Scotland using an 18 m motor-sailor vessel Silurian that conducts systematic line transect surveys. Effort and sightings data is collected between April and October during daylight hours.
When cetaceans, seals, sunfish, turtle species or basking sharks are sighted, species, group size and composition and other data (estimated distance to animal, bearing and heading) are recorded. Additionally, GPS positional data, effort status, boat speed and sea conditions are also recorded.