Scientific Literature: Searchable Database

There has been a globally growing interest in cetacean-based tourism resulting in increasing cumulative impacts on many wildlife species. In the Azores archipelago, the local whale watching industry has drastically evolved over the last two decades, especially targeting a population of sperm whales that use the habitat as important feeding ground and can be found year-round. Some individuals return annually to the area and stay over several weeks to breed, which makes them especially vulnerable to human-induced disturbance. Hence, this study aimed to contribute to the establishment of a conservation framework to ensure the future sustainability of this industry by including the comprehensive evaluation of cumulative exposure of sperm whales to whale watching boats in the area into the management of human activities. For the first time spatially-explicit capture-recapture (SECR) models have been developed to quantify the cumulative interaction time between photo-identified individual sperm whales and whale watching boats in the area. The study provided baseline estimates of sperm whale encounter probabilities which were integrated together with the whale watching intensity in the area to estimate spatial variations of exposure on individual-level. Model estimates revealed that whale watching activities were mainly concentrated in two distinct areas north of Faial and south of Pico island, consequently exposure levels were found to be significantly higher in respective ‘core’ areas of disturbance. Furthermore, results indicated seasonal variations in daily individual exposure levels with a peak in June, where the most repeated interactions between the same individual and whale watching boats took place. The present findings stress the importance of taking the individual exposure into consideration when it comes to the management of potentially harmful human activities and support a precautionary approach.