Species interactions in a changing ocean: A study of inducible traits to understand community responses

Abstract

Marine communities are experiencing rapid environmental changes including warming temperatures and ocean acidification (OA). For organisms within these communities, responses to ocean change are shaped by population- and community-level interactions which may modify their responses. This dissertation integrates experimental, field, and modeling approaches to understand how marine communities are responding to ocean change by studying species interactions and understanding propagating effects. Organisms with inducible morphologies, physical characteristics that can change based on exposure to specific predators (inducible defenses) or food sources (inducible offenses), can be a tool to track and quantify interactions in a changing ocean. In this dissertation, I present research on two marine invertebrates that exhibit inducible morphologies to demonstrate how studies of inducible traits provide a tool to understand community responses to ocean change. In Chapters 2 and 3, I explored the individual- and population-level effects of OA on inducible defenses in the calcifying bryozoan, Membranipora membranacea. Predator exposure continued to induce defenses and modify M. membranacea colony growth in OA conditions. Population-level space competition also modulated costs of inducible defenses in OA conditions. In Chapters 4 and 5, I investigated the effects of an inducible offense on responses to warming temperatures in the marine snail, Lacuna vincta. Field surveys of inducible morphology documented frequent adult dispersal between eelgrass and macroalgal habitats, and experiments revealed that consequences of dispersal influenced L. vincta response to warming temperatures. Overall, M. membranacea and L. vincta were largely robust to the stressors they were exposed to and species interactions, documented using inducible traits, greatly influenced responses to ocean change in both organisms. In Chapter 6, I developed and evaluated a K-12 sensor-building module inspired by methods used in my own scientific research to create authentic STEM experiences for high school students. Using hands-on sensor building and local environmental change helped contextualize basic chemistry concepts and increased student learning. This dissertation provides insight into how integrated studies of inducible traits can help shed light on community responses to environmental change and provides ways to integrate ocean change research and educational initiatives through placed-based sensor building programs.