Mr Nathan Spindel1, Maya Munstermann1, Sam Karelitz1, Aaron Galloway2, Julie Schram3, Lynn Lee4, Ondine Pontier5, Brenna Collicutt5, Kate Rolheiser5, Iria Gimenez5, Evan Cronmiller5, Megan Foss5, Natalie Mahara5, Wiley Evans5, Daniel Swezey6, Laura Rogers-Bennett6, Daniel Okamoto1
1Florida State University, Tallahassee, United States, 2Oregon Institute of Marine Biology, Charleston, United States, 3University of Alaska Southeast, Juneau, United States, 4Gwaii Haanas National Park Reserve, National Marine Conservation Area Reserve, and Haida Heritage Site, Skidegate, Canada, 5Hakai Institute, Heriot Bay, Canada, 6Bodega Marine Laboratory, Bodega Bay, United States
Multiple climatic drivers including ocean warming (OW) and acidification (OA) directly impact marine consumer physiology, often nonlinearly, such that emergent ecological dynamics defy globally generalized predictions based solely on body mass and temperature. Such predictions are especially important for key consumer taxa like the purple sea urchin, Strongylocentrotus purpuratus, a voracious grazer responsible for regime shifts in macroalgal forest ecosystem productivity throughout many temperate reefs. Moreover, whether and how the temporal regime of the thermal environment, be it static or dynamic, affects bioenergetics of marine consumers is understudied. Regional extreme and rapid warming events such as marine heatwaves (MHW) have punctuated gradual climate driven OW in recent decades with devastating consequences for commercial fisheries and biomass production. We present results of a large-scale manipulative experiment in which we quantified body size specific thermal performance of benthic stage S. purpuratus across a gradient of static temperature treatments ranging from 10-20 ℃ at both ambient and elevated pCO2 as well as two MHW treatments representing El Niño-Southern Oscillations observed in Southern California. We demonstrate that exposure to MHWs reduced both gonadal and skeletal growth more than exposure to static temperatures with equivalent means. Moreover, OW combined with elevated pCO2 increased rates of consumption with lower gonadal food conversion efficiency more than OW alone. Our empirical thermal performance curves and modifications thereof due to both MHWs and OA in this key consumer are crucial to the pursuit of improved mechanistic understanding of emergent ecological dynamics in temperate reefs under global change.
Presentation Slides – Nathan Spindel
Biography:
Nathan Spindel is currently a PhD candidate in the Department of Biological Science at Florida State University as well as Predoctoral Fellow with the Smithsonian Institute. His research includes both temperate and tropical reef ecosystems, and he is keenly interested in how we can better scale up insights from holobiont physiology to ecosystems under global change. Specifically, he studies how multiple environmental drivers interact to shape invertebrate herbivore performance traits, energy budgets, emergent ecological interactions, and subsequent dynamics of populations and communities. Nathan’s favorite place to conduct research is on SCUBA over subtidal kelp forests and coral reefs.
