Species Distributions in a Changing Ocean: from Individuals to Communities

Abstract

Changing ocean conditions and biotic dependencies will influence commercially important species distributions in this interconnected and rapidly changing world. In this dissertation, I employ random forests, GAMs, and a generalized joint attribute modeling technique to study the impacts of climate, substrate, and fishing pressure on nearshore and pelagic species distributions and abundances in the North Atlantic. Through these approaches, I provide insights on which species have shifted environmental associations over time to more accurately model potential distribution shifts going forward. By comparing pelagic and nearshore species, I enlighten future modeling and management to the fact that not all species will behave the same in the face of a changing climate. By including fishing pressure in my models, I provide a better understanding of the relative effects of fishing pressure compared to climate on species distributions and abundances resulting in a more realistic and comprehensive understanding of the causes of shifting distributions. I utilize a joint modeling approach to help better inform the interspecific interactions that shape a species’ distribution. Finally, by modeling fishing gear as a species, I attempt to get us one step closer to an ecosystem approach to fisheries management.