Percorrer por autor "Gennari, Ginevra"
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- First catalogs of humpback and fin whales in the Algarve regionPublication . Gennari, Ginevra; Castilho, RitaBaleen whales such as humpback (Megaptera novaeangliae) and fin whales (Balaenoptera physalus) are among the most highly migratory marine species. After experiencing severe population declines during the whaling era, both species are now showing signs of recovery. However, their complex movement patterns, wide-ranging distribution, and the absence of clearly defined population boundaries—particularly in the North Atlantic—pose challenges for monitoring and effective conservation efforts. While certain areas are recognized as key migratory corridors, the role of the southern Iberian coast, including the Algarve region in south of Portugal, remains largely unexplored. This thesis presents the first two photo-identification (photo-ID) catalogs of humpback and fin whales in the Algarve, establishing baseline data for this understudied region. The humpback whale chapter documents occurrences collected from 2009 to 2024 in collaboration with whale-watching companies and the Algarve Stranded Network (RAAlg). Fluke photo-ID allowed for the identification of 13 unique individuals. Comparison with the North Atlantic Humpback Whale Catalog identified matches with individuals previously sighted in distant locations, including Cabo Verde, the Ligurian Sea, and Scotland. Entanglement, particularly among juveniles, emerged as a recurrent anthropogenic threat. The fin whale chapter analyzes opportunistic data collected from 2020 to 2024, namely photo-ID and GPS boat tracks, resulting in a catalog of 86 unique individuals. Spatial capture-recapture modeling estimated a local population of 1,476 individuals suggesting that a large part of the population hasn’t been identified yet. Sightings peaked in spring and were often associated with feeding behavior, suggesting that the Algarve may serve as a seasonal foraging ground. However, low re-sighting rates across years suggest a transient rather than a resident use of the area. These findings highlight the ecological relevance of the Algarve for migratory baleen whales and underline the value of photo-ID and collaborative data collection with whale-watching companies. The two catalogs provide essential references for future research and inform conservation strategies in Portuguese waters.
- Opportunistic data for assessing abundance and site fidelity of fin whales (Balaenoptera physalus) in the Faro area, PortugalPublication . Gennari, Ginevra; Rodrigues, Alfredo; Carvalho, Pedro; Gil, Susana; Magno, Ramiro; Castilho, Rita; Peres dos Santos, Rui PedroThe distribution and migration of fin whales (Balaenoptera physalus) remain poorly understood in parts of the North Atlantic. One of these regions is the Algarve in southern Portugal, which is shaped by seasonal upwelling and the exchange of Atlantic and Mediterranean waters. This area represents a potentially critical yet poorly understood habitat for this species. This study presents the first comprehensive assessment of fin whale abundance and site fidelity in the Faro area, located approximately between 36–37° N and 8–7° W. Data was collected from 2020 to 2024 through photoidentification and GPS vessel tracks, in collaboration with a local whale-watching company. A regional catalog of 86 individuals was established, and an open spatially explicit capture-recapture model estimated a population of 1.476 individuals. Sightings peaked in spring, likely linked to phytoplankton blooms and foraging opportunities. While re-sighting rates were low, some individuals returned across years, indicating possible seasonal site fidelity. Our results demonstrate the value of data collected from platforms of opportunity in an under-surveyed region, providing a foundation for ongoing monitoring efforts. Results also highlight the Faro area’s ecological relevance as a seasonal feeding ground for fin whales and offer insights to support future conservation in the eastern North Atlantic.