Influence of storm events on surf zone zooplankton in a Southwestern Atlantic sandy beach: A preliminary methodology using high-frequency physical data

Abstract

Here we present a preliminary methodology and unprecedented data for sandy beach surf zones, focused on understanding the effects of the passage of storm events in surf- zooplankton communities. The main objectives of the present study were to analyze the variation of surf zone physical parameters during several storm events, which have occurred on Pehuen Co beach (PC), using high-frequency physical data and to explore the influence of these events on surf zooplankton taking into account some ecological community indicators such as taxa richness, abundance and diversity. We observed that the zooplankton community structure was significantly altered after the storms, mainly in terms of abundance, but also in the number of taxa and general diversity. In addition, important differences between storm duration were registered. The short-duration storms (< 6 h) were associated with an increase of zooplankton abundances after the events, whereas the long-duration ones (> 6 h) showed a sharp decrease in the number of organisms. Based on the present results, the coastal biological system could be completely altered during storm events, considering that the observed changes in the zooplankton community probably affect other species that interact with them, altering the trophic relationships in surf waters. Additionally, the high-frequency data provided us valuable information not only to visualize the hydrodynamic consequences of the storms, but also to explain the changes in the zooplankton community. The present contribution provides an initial step toward comprehensive research about the physical-biological interactions in surf zone waters during storms, even more in the actual context of climate change where extreme events are expected to increase in frequency and intensity.