Climate anomalies influence tooth growth patterns of South American sea lion

HEREDIA, F.; SOSA DROUVILLE, AILÍN; SRUR A. M.; CRESPO, ENRIQUE A.; GRANDI, M. FLORENCIA

MARINE MAMMAL SCIENCE

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2021

0824-0469

El Niño-Southern Oscillation (ENSO) and Southern AnnularMode (SAM) indirectly affect tooth growth of marine mammals, through changes in prey abundance, availability, andcomposition. This is reflected as variation in the dentinedeposition, which determines the formation of annuallayers, called growth layer groups (GLGs). The aim of thiswork was to study potential effects of ENSO and SAM onSouth American sea lion (Otaria byronia) of Patagonia, byexamining interannual variability of GLG width. Adaptingdendrochronological techniques, we analyzed 97 individuals(60 females and 37 males) and built six chronologies (threefor each sex) by using cubic splines with different rigidity.Chronologies were correlated with MEI (Multivariate ENSOIndex) and SAM index time series, considering lags in the biological response. The chronologies of females spanned39 years and only two of these chronologies showed negativecorrelation with 1 year lagged SAM events. The chronologiesof males spanned 23 years, but none showed significant correlation with these indexes. Our results did not indicate anyENSO effects on this species, while positive SAM events couldreduce the abundance or availability of South American sealion´s prey, affecting the nutritional status of females and generating thinner GLGs during the next year.