Species Range Dynamics and Monitoring Biodiversity in a Changing Ocean
- McElroy, Mary
- Advisor(s): Gaines, Steven D
Abstract
Globally, marine species are shifting poleward toward cooler latitudes as the ocean warms due to climate change, but shifts do not always track temperature in the ways we expect, and other environmental and biological drivers likely play a role. Robust ecological inferences about these drivers are limited by a mismatch between the spatiotemporal scale of biodiversity observations and mechanisms underlying species range dynamics, particularly in vast coastal systems connected by ocean currents. Novel monitoring methods based on sequencing environmental DNA (eDNA) can dramatically expand the scale of biodiversity observation, which could improve both detection and prediction of marine range shifts. However, emerging methods require critical consideration of their strengths and limitations relative to conventional capture or visual surveys. In this dissertation, I 1) analyze long-term spatial dynamics of range edges for 100 invertebrate and algae species using rocky intertidal visual survey data, 2) integrate novel eDNA methods to characterize coastal biodiversity alongside these visual surveys, and 3) conduct a global synthesis of published field studies comparing eDNA and conventional surveys to generate broad, cross-system insights about the relative performance of new methods and how they can fill important gaps in aquatic biodiversity monitoring.