INVESTIGADORES
CRESPO Enrique Alberto
artículos
Título:
Reduction of skull size in South American sea lions reveals density dependent growth during population recovery.
Autor/es:
DRAGO, M, L. CARDONA, E.A. CRESPO, M.F. GRANDI & A. AGUILAR
Revista:
MARINE ECOLOGY PROGRESS SERIES
Editorial:
INTER-RESEARCH
Referencias:
Año: 2010 vol. 420 p. 253 - 261
ISSN:
0171-8630
Resumen:
ABSTRACT: Craniometrical data of male and female skulls collected from 1974 to 2007 were used to
test the hypothesis that the somatic growth of South American sea lions Otaria flavescens in northern
Patagonia has been affected by a reduction in the per capita food availability, due to a combination
of the population recovery after cessation of sealing and the development of industrial fishing targeting
Argentine hake Merluccius hubbsi. Most of the 19 craniometric variables considered decreased
through time in both sexes, and the same trend was found for a variable extracted by means of principal
component analysis that was related to skull volume. Most of the reductions in skull size and
volume have happened since 1990, when the sea lion population peaked and the hake population
collapsed. This evidence, combined with a review of supplementary data derived from stable isotope
analysis, supports the hypotheses that the somatic growth of South American sea lions is densitydependent
and that industrial fishing has reduced the carrying capacity of the ecosystem for South
American sea lions.