Browsing by Author "Irigoyen, Alejo J."

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    Baited remote underwater video stations as a potential tool for assessing coastal rocky fishes in Chile
    (2024) Irigoyen, Alejo J.; Flores, Andres; Gacitua, Santiago; Merlo, Pablo; Wiff, Rodrigo; Canales, T. Mariella
    Coastal rocky fish species support important fishing activities, but basic information is lacking for many before catches decline. Monitoring and management of coastal rocky fish species is urgently needed in Chile, but knowledge of these species is fragmentary at best. Performance of Baited Remote Underwater Video Stations (BRUVS) for assessing rocky fish assemblages was evaluated in south-central Chile. Seven medium- to large-sized exploited species dominated fish assemblages in the survey area, including five small cryptic rocky reef fishes, one agnathan and a catshark species. These seven species represented 78% of the species targeted by commercial fishing in the survey area. Furthermore, this tool provided new information on behaviour of rocky fish species. The simple, inexpensive and light nature of single-camera BRUVS may be crucial for maintaining monitoring programs along remote areas of Chile.
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    The essential habitat role of a unique coastal inlet for a widely distributed apex predator
    (2023) De Wysiecki, Agustin M.; Barnett, Adam; Cortes, Federico; Wiff, Rodrigo; Merlo, Pablo J.; Jaureguizar, Andres J.; Awruch, Cynthia A.; Trobbiani, Gaston A.; Irigoyen, Alejo J.
    Essential habitats support specific functions for species, such as reproduction, feeding or refuge. For highly mobile aquatic species, identifying essential habitats within the wider distribution range is central to understanding species ecology, and underpinning effective management plans. This study examined the movement and space use patterns of sevengill sharks (Notorynchus cepedianus) in Caleta Valdes (CV), a unique coastal habitat in northern Patagonia, Argentina. Seasonal residency patterns of sharks were evident, with higher detectability in late spring and early summer and lower during autumn and winter. The overlap between the residency patterns of sharks and their prey, elephant seals, suggests that CV functions as a seasonal feeding aggregation site for N. cepedianus. The study also found sexual differences in movement behaviour, with males performing abrupt departures from CV and showing increased roaming with the presence of more sharks, and maximum detection probability at high tide. These movements could be related to different feeding strategies between sexes or mate-searching behaviour, suggesting that CV may also be essential for reproduction. Overall, this study highlights the importance of coastal sites as essential habitats for N. cepedianus and deepens our understanding of the ecological role of this apex predator in marine ecosystems.