Are the Lichens Likin’ Salt?: Salinity Tolerance and Resilience of Littoral Lichen Species

A limited number of lichen species live on seaside rocks, and little has been studied for these species on the California coast. The salt tolerance of these organisms is interesting – it is unclear whether they have adapted to survive with salt exposure, or if some species depend upon it. Three species of littoral lichens, including Caloplaca coralloides, were collected along the rocky intertidal zone of Monterey Bay and subjected to treatments of varying salinity levels. Photosynthetic activity was assessed based on the Electron Transport Rate (ETR) measured by a miniature Pulse-Amplified Modulated . No significant effect of treatment type was found for any of the species, but there was an effect of the number of days since start of treatment, and no interaction was found between these variables. Based on the results of this preliminary experiment, I propose a follow-up experiment involving the investigation of another possible factor influencing littoral lichen distribution: inundation time. My preliminary work serves to inform how lichens fare in laboratory settings, and how and my persisting inquiries will serve to improve our understanding of their physiology, as well as their role in ecosystem functioning.