Examinando por Autor "Van Waerebeek, Koen"

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    Ítem
    New northernmost distribution records of the Eastern South Pacific southern right whale (Eubalaena australis), including the first cases from Ecuador and northern Peru
    (Public Library of Science, 2024) Castro Ayala, Cristina; García-Cegarra, Ana M.; Uceda-Vega, Piero; Aguilar, Luis; Kelez, Shaleyla; Buchan, Susannah J.; Félix, Fernando; Stack, Stephanie H.; Van Waerebeek, Koen
    The Eastern South Pacific Right Whale (SRW) (Eubalaena australis) population has gained interest due to its Critically Endangered conservation status. So far, this population has been confirmed only along the coasts of Chile (18˚20’S to 56˚30’S) and from southern to central Peru (17˚38’S to 12˚11’S). Recent records have extended the species’ known range, highlighting its geographic distribution, now reaching 1500 km north. Here, we report six recent records, consisting of five sightings and one stranding, that expand the documented range to northern Ecuador (0.6˚N). The northern extension of the population may be associated with the unusual three-year-long cold phase (La Niña) of the El Niño Southern Oscillation (ENSO) in the eastern South Pacific, population expansion, movement and redistribution of the species, increased monitoring effort, or a combination of these factors. These observations raise hope for the Critically Endangered SRW population, as the occurrence of mother-calf pairs may indicate a potential for population recovery. Nevertheless, these findings intensify concerns for what is still the least abundant SRW population, underscoring the urgency for more targeted research and conservation measures.
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    Ítem
    Site fidelity and external health of two distinct fin whale populations from the Northeast and Southeast Pacific Ocean
    (Elsevier GmbH, 2025) Guevara, Consuelo; Arriagada, Aracelli; Fishbach, Michael; Van Bressem, Marie-Francoise; Van Waerebeek, Koen; Garcia-Cegarra, Ana M
    Human activities such as marine traffic, fishing, and pollution are the main threats to large cetaceans, especially to resident whale populations inhabiting heavily exploited enclosed seas or gulfs. Skin is indicative of whale health status because it can display wounds and scars from interactions with fishing gear, boat strikes and natural predators as well as infectious diseases. We evaluated the residence time of two fin whale, Balaenoptera physalus (Linnaeus, 1758) populations: one resident in the Gulf of California (GC), Mexico, and another potentially migratory found at Mejillones Peninsula (MP), Chile. We also compared skin conditions by analyzing photographs for the period 2016–2022. The results show that the GC population is closed while the MP population has a low residence time (5–6 months). The GC population has a significantly higher prevalence of the mesoparasite Pennella sp., commensal Xenobalanus globicipitis and scars from collision with vessels than its MP counterpart. The MP population has a significantly higher prevalence of skin conditions of natural origin such as cookie-cutter shark (Isistius sp.) bites, predation by killer whales, Orcinus orca (Linnaeus, 1758), and orange-brown and green–brown diatom patches than the GC population. These results show that a fin whale population residing year-round in an area with high industrial, fishing, and marine traffic presents more skin conditions related to anthropogenic origin than an oceanic migratory population, which mainly presents scars of natural origins (predation). It is recommended to review the conservation status of the GC resident fin whale population and propose management strategies to guarantee their long-term conservation and welfare.