Meeting Abstract
Predicting responses to climate change requires an understanding of how microhabitats and associated abiotic conditions differ across species’ lifetimes. We addressed the question: how do microhabitats and thermal conditions differ across life stages of two marine invertebrates, the mussel Mytilus californianus and the barnacle Chthamalus fissus, inhabiting the rocky intertidal at Crystal Cove State Park, CA? To determine the distribution of ages of the study species across microhabitats, we quantified individuals of different ages (using size as a proxy) every 0.2 m in tide height along N=5 transects. To assess age-specific variation in thermal conditions, we used in vivo thermistor measurements from 3 (high, mid, and low) tide heights within the species’ distributions to compare time series of body temperatures for juveniles and adults. Tide height distributions and temperatures differed by age for M. californianus but differences among age classes were not as pronounced for C. fissus, for which multiple ages shared more similar microhabitats. Thus, we found that ontogenetic variation in microhabitats and environmental conditions was species specific, a finding that has implications for attempts to predict future responses to climate change.
