Larval dispersal, population connectivity and species distributions in a changing ocean

The world's oceans face multiple anthropogenic threats, including climate change, habitat loss and invasive species, with significant impacts in most regions. Species can respond to warming temperatures by shifts in distribution or changes in the timing of physiological events. Additionally, exploitation of living and non-living resources is accelerating, and occurring at increasing depths, where species' distributions and the factors that regulate them remain poorly-known, and recovery from disturbance can take many decades. The cumulative effects of multiple stressors represent a major concern for the global ocean, and an urgent research priority. To manage multiple uses, marine spatial planning is used as a tool to inform restrictions to location, timing or types of use for an ocean region, habitat or species, and to delineate marine reserves. Studies on global change and conservation focus on the resilience of populations to perturbations and on changes in species distributions. Population connectivity refers to the exchange of individuals among populations, achieved through dispersal or migration, and can play a critical role in determining species distributions and population persistence. With the proposed program, we will evaluate the role of larval dispersal and population connectivity in species distributions in a changing ocean, with a combination of approaches including field sampling, experiments in the laboratory and predictive modelling. We will use two model systems that involve human intervention but which vary greatly in remoteness and available data: a marine invasive, Membranipora membranacea, which under future climate scenarios can lead to major shifts in kelp ecosystems in the NW Atlantic; and deep-water corals, unique deep-sea ecosystems, currently under threat by physical disturbance due to resource extraction. The marine invasive exhibits high dispersal potential and connectivity will be significant in modulating shifts in distribution. For deep-water corals, population connectivity is likely critical in sustaining viable populations, particularly in the face of anthropogenic disturbance. This program wil provide scientific information that can influence management decisions, in arenas where such information is lacking.