Drivers of regional-scale variability in the abundance of an invasive bryozoan in the kelp beds of the northwest Atlantic Ocean

Abstract

Species distribution models (SDMs) are important tools for predicting changes in the distribution and impact of invasive species due to climate change. In this thesis, I developed and applied SDMs predicting the abundance of Membranipora membranacea, a bryozoan invasive to kelp beds in the northwest Atlantic Ocean (NWA). With a large, compiled dataset, I employed a multimodel inference approach to select relevant predictor variables for SDMs for M. membranacea, and developed a conceptual framework from my results to guide variable selection for SDMs of other organisms (Chapter 2). I then constructed SDMs predicting the abundance of M. membranacea in the NWA (Chapter 3). The future abundance distribution of the bryozoan depended on the magnitude of climate change and possible invasions of M. membranacea from new source populations. My results are applicable to the management of M. membranacea and kelp beds in the NWA, and to invasive species and SDMs generally.