Integrating in situ and satellite-based observations to unravel a mass mortality event of mussel beds in Patagonia, Argentina

GREGORIO BIGATTI; JUAN PABLO LIVORE; MARIA M MENDEZ; ENRIQUE MONTES

San Fransisco

Congreso; AGU Fall Meeting 2020; 2020

A continuous global decline in biodiversity highlights the urgency of increasing our knowledge on the spatial and temporal variation of the abundance of key species. The development of the Marine Biodiversity Observation Network Pole to Pole of the Americas program is contributing to this goal by coordinating biodiversity surveys in the coastal zone throughout the continent. The program combines biodiversity data with in situ and remotely sensed environmental properties to gain a broader understanding of the sensitivity of coastal biological communities to multi-scale variability in atmospheric and oceanographic conditions. This study illustrates how in situ and remotely sensed environmental observations are related to documented changes in percent cover of mussels (Brachidontes rodriguezii and Perumytilus purpuratus), the primary space holders on rocky shores of the continental Argentinean Patagonia (~41-52 ºS). Major changes of mussel bed cover were observed at five monitoring sites in Golfo Nuevo in the northern region of Patagonia between 42.35-42.50 ºS, showing drastic losses from ~ 45 to 90 % cover from November 2018 through May 2019. The observed cover loss of mussels appeared to result from coinciding high atmospheric temperature (> 35 °C), strong offshore winds (> 30 knots) and low tides that exposed these organisms to prolonged thermal and desiccation stress over several continuous days. Sea surface temperature anomalies exceeding 1 °C were observed in Golfo Nuevo in December 2018 and February 2019, indicating the presence of heat wave conditions during the 2019 austral summer. The combined use of in situ biodiversity monitoring and satellite remote sensing data can provide information to anticipate future changes in Species Populations and Community Composition, two Essential Biodiversity Variables in coastal habitats. Early warning signs based on satellite observations can inform managers and decision makers of when extreme conditions are present in these ecosystems to effectively implement strategies for the conservation of living resources and the services they provide.