Quantification of cardiac performance in mollusks subjected to realistic simulations of intertidal thermal conditions

LUIS PEREIRA; ROCIO NIETO VIELA; MAR HUMET; RUI SEABRA; BRUNO LOUREIRO ; FRANCISCO ARENAS; FERNANDO LIMA

North Devon

Simposio; Fourth International Symposium Advances in Marine Mussel Research; 2022

Intertidal systems are among the most thermally complex environments onEarth. They are inhabited by marine organisms that must withstandterrestrial conditions during low tide, and whose responses are thereforeregarded as early indicators of climate change. Despite recent progress inour understanding of their physiological response to thermal stress, majorlimitations persist, severely restricting our ability to forecast the trueecological consequences of climate change. Current methodologies areneither good at simulating realistic conditions nor at measuring sub-lethalthermal stress. In this talk we will describe a methodological pipeline whosemain focus is to bring realism to laboratorial thermal stress trials. It startswith the collection of long series of temperature data at the scale of thestudied organisms using autonomous loggers in the field. Then, it uses aself-contained, experimental system that simulates the intertidalenvironment to replicate those realistic thermal profiles in the lab. It’s like aPCR machine for the intertidal, featuring automatic control of tides, light,water temperature and infra-red heating. It can be remotely monitored andexperimental conditions changed in real time though a dedicated webpage.Finally, heat stress can be measured in a non-invasive way by means of aninfra-red heart frequency logger which can record the cardiac frequency ofup to ten animals simultaneously. It has been extensively validated inmollusks such as limpets, mussels, periwinkles, or oysters. Since the devicerelies on non-invasive technology, it is harmless and can be used on liveanimals, providing on-the-fly data on their physiological performance. Thispipeline can be used to study current conditions or to experiment with“what-if” scenarios involving virtual translocation of species or predictedfuture environmental conditions.