Abstract
- Limited information on minke whale spatial and temporal distribution in the Moray Firth contributed to uncertainties during Moray West impact assessment. Thus, digital aerial surveys (DAS) conducted to survey seabirds and passive acoustic recordings were analysed to collect additional data on minke whale occurrence.
- Minke whales were sited on over 50% of the 16 DAS conducted in 2021 and 2022. Whales were located across the development but, with only 11 sightings in each year, these data were insufficient for more detailed analysis of variation in occurrence across the DAS area.
- Broad-band recordings were also obtained from a site within Moray West during the summers of 2021 and 2022. Processing of acoustic monitoring is often constrained by the time it takes to manually process acoustic recordings. Thus, we developed a collaboration to develop and train an automatic detector for minke whale calls. Archive data collected through the MMMP contributed >800 minke whale calls and >1M noise samples towards the training dataset for the automatic detector.
- Manual annotations of minke whale calls during 2021 and 2022 were used to explore differences in occurrence between the DAS and passive acoustic monitoring (PAM) surveys. This highlighted how the two methodologies can complement each other, providing information on spatio-temporal variability of minke whale occurrence across the study site.
- Colleagues at NOAA are currently optimising the minke whale detector using data from the Moray Firth, Scottish West Coast and US East Coast. This will be tested using the 2022 manual detections from Moray West. Once finalised, this automatic detector promises to provide a valuable tool for assessing patterns of occurrence across ScotWind developments and in other North Atlantic waters.