Comments:pdf
Ref.: Oceans, 5, 770-784, 2024
(doi).
Abstract:
Recent years have seen a notable rise in dolphin-watching boat activities along the Algarve
coast in Portugal, potentially affecting the common dolphin (Delphinus delphis) and bottlenose dolphin
(Tursiops truncatus) local populations. This study examines the impact of increasing underwater noise
levels from these boats on dolphin vocalizations. Field recordings were conducted from June to
September 2022, analysing dolphin whistles in various boat presence scenarios. The results indicate
significant changes in whistle-frequency characteristics with boat presence, including increased start,
low, and high frequencies, alongside a decrease in the number of inflection points in modulated
whistles. The changes might negatively impact dolphin populations viability, underscoring the
need for further research. Additionally, improved mitigation strategies may be necessary to reduce
the potential negative effects of dolphin watching on cetacean communication and behaviour in the
Algarve region.