NatureScot Research Report 1279 - Analysis of Basking Shark Watch Database 1987 to 2020.
Abstract
This report provides an update on the Basking Shark Watch (BSW) public sightings scheme, which has recorded 17,697 surface sightings of basking sharks in UK coastal waters since 1987. Managed by the Marine Conservation Society and the Shark Trust, the scheme aims to indicate the seasonality and distribution of basking shark sightings. The project focused on updating the dataset analysis to improve data accessibility and utility. The report details the database structure, spatial validation of sighting coordinates, and identification of potential duplicates. It also discusses spatial and temporal patterns, particularly in the Sea of the Hebrides Marine Protected Area and broader regions. Key findings include a peak in sightings from 2004 to 2013, a decrease since 2014, and distinct regions with high sighting frequencies. The report emphasizes the importance of consistent promotion and ease of reporting for the ongoing management of BSW data.