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Habitat use, seasonality and demography of the broadnose sevengill shark Notorynchus cepedianus in central Patagonia: Another piece of the puzzle
Author(s) -
Irigoyen Alejo J.,
Bovcon Nelson,
Trobbiani Gastón,
De Wysiecki Agustín M.,
Argemi Federico,
Jaureguizar Andrés J.
Publication year - 2019
Publication title -
austral ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.688
H-Index - 87
eISSN - 1442-9993
pISSN - 1442-9985
DOI - 10.1111/aec.12820
Subject(s) - seasonality , bay , abundance (ecology) , habitat , ecology , predation , geography , population , fishery , biology , demography , archaeology , sociology
Abstract The habitat use, seasonality and demography of the broadnose sevengill shark Notorynchus cepedianus were investigated in central Patagonia, where a data gap exists for the species. Catch and effort and video‐derived indices indicated high relative abundance of sharks during warm months. Video stations revealed differences in the spatial use by sharks, being more frequently observed in the inner section of the bay. Complementary tagging efforts evidenced both a seasonal residence pattern and site fidelity between consecutive warm seasons. Juveniles outnumbered adults, which suggests that they may use the study area as a secondary nursing ground. Evidence from spontaneous regurgitation further suggests that prey abundance may be driving the seasonal occurrence of sharks in the region. This study allows for a more comprehensive understanding of the population structure and dynamics of sevengill sharks in the Southwest Atlantic. Abstract in Spanish is available with online material.