Strong winds as driver of surf zooplankton abundance and composition in a temperate sandy beach

Abstract

This study explores the effect of different wind events (direction and duration) on the surf zone zooplankton community in a temperate sandy beach. Samplings were realized on the surf zone of Pehuen Co sandy beach during 17 wind events from May 17th, 2017, to July 19th, 2019. Biological samples were taken before and after the events. The identification of the events was realized using recorded high-frequency wind speed data. General Linear Model (LM) and Generalized linear models (GLM) were employed to compare physical and biological variables. We observed that the wind direction unequally altered the ecosystem along with its duration, modi- fying the composition and abundance of zooplankton communities. Short-duration wind events were associated with an increment in the zooplankton abundances, being Acartia tonsa and Paracalanus parvus dominant. Within the short-duration cases, winds from the W sector were identified with the inner continental shelf species’ presence, such as Ctenocalanus vanus and Euterpina acutifrons, and to a lesser extent, Calanoides carinatus, and Labidocera fluviatilis, together with surf zone copepods. Long-duration cases were associated with a significant decrease in the zooplankton abundance. Within this group, SE-SW wind events were identified with adventitious fraction taxa. Considering that the occurrence of extreme events is growing because of climate change, affecting the frequency and intensity of storm surges, the knowledge of the responses of biological communities to these events is necessary. This work provides quantitative evidence on a short-time scale of the implications of the physical-biological interaction during different strong wind cases in surf zone waters of sandy beaches.