Sudden seasonal occurrence of humpback whales Megaptera novaeangliae in the Firth of Forth, Scotland and first confirmed movement between high-latitude feeding grounds and United Kingdom waters

摘要

Here we report on the sudden seasonal occurrence of humpback whales Megaptera novaeangliae within the Firth of Forth, Scotland, UK over the winter months of 2017 and 2018. Sightings and photographs collected by citizen scientists of the Forth Marine Mammal Project were inspected and a fluke photograph compared to existing catalogues from all known feeding and breeding grounds across the North Atlantic. No matches to breeding grounds were found but a fluke match to a non-catalogued individual in Svalbard (Norway) constitutes the first confirmed movement of a UK-recorded humpback whale from high-latitude feeding grounds. A different individual was photographed in the Firth of Forth in both 2017 and 2018, providing evidence of a whale returning to the Firth of Forth in consecutive years. Despite year-round observation, the discrete seasonality of sightings suggests that the Firth of Forth may represent a migratory stopover or alternative destination for humpback whales on their southbound migration. Overall, these findings constitute a formalised baseline of information regarding the occurrence of humpback whales in the Firth of Forth and contribute to our understanding of the migration habits of humpback whales in the eastern North Atlantic.