Unravelling the Influence of ENSO and SAM Patterns on Skate Growth: The Case of the Shorttail Yellownose Skate in Patagonia, Argentina

HEREDIA, FEDERICO M.; TSCHOPP, AYELEN; CRESPO, ENRIQUE A.; GARCÍA, NESTOR; GRANDI, M. FLORENCIA

FISHERIES OCEANOGRAPHY

WILEY-BLACKWELL PUBLISHING, INC

Año: 2024 vol. 34 p. 1 - 12

1054-6006

In recent decades, the growth, physiology and distribution of many elasmobranch species have been altered as a result of environmentalchanges that affect prey abundance, availability and composition. Consequently, variations in nutrient input duringclimate events could manifest in the growth of their hard tissues. This study focuses on assessing the impact of the El Niño-SouthernOscillation (ENSO) and the Southern Annular Mode (SAM) on the growth of Shorttail Yellownose skate (Zearajabrevicaudata) in Patagonia, Argentina. To achieve this, vertebrae from 115 Z. brevicaudata specimens were analysed, and growthrings were dated and measured. By using cubic splines with varying flexibility, we constructed three standard chronologies.Generalized additive models (GAMs), the chronology with the best the R-bar(r) and expressed population signal (EPS) wereemployed and values obtained from them linked to annual time series data of the Multivariate ENSO Index (MEI) and SAM,considering lags in the biological response. Surprisingly, no significant association was found with the MEI time series. However,a noteworthy positive association emerged between the chronology and the SAM time series lagged by 1 year, suggesting thatSAM-relatedclimatic conditions could delay their transfer into the Patagonian marine ecosystem, subsequently impacting thegrowth of this ectothermic predator.