Grant: Discovery Grants Program - Individual

Most aquatic ecosystems are no longer controlled by Earth systems processes but by global change and multiple anthropogenic stressors acting simultaneously. These environmental changes will leave lasting impacts on ocean life in the decades to come. Climate change and increasing local anthropogenic stressors have already led to the degradation or disappearance of many coastal habitats, causing the extinction of multiple associated species and reducing a third of the fisheries considered viable. At the land-sea interface, coastal sedimentary ecosystems provide multiple functions, including nutrient and organic matter cycling, habitat provisioning and trophic support. These very dynamic systems experience cumulative global and anthropogenic stressors. Although multiple-stressor research is rapidly expanding, we still lack a general understanding of how these coastal sedimentary ecosystems respond, both structurally and functionally, to interacting stressors or gradients of stressors. Moreover, very little work that accounts for complex interactions at the species, community and ecosystem levels has been conducted when assessing the impacts of multiple stressors. Acquiring this understanding is, however, crucial to improve and supporting coastal habitat protection. Over the next 5 years, my goal is to understand how multiple stressors influence shallow sedimentary ecosystem structure and functioning. Three interrelated specific objectives are designed to (1) achieve a mechanistic understanding of the drivers of biogeochemical processes in shallow sedimentary ecosystems exposed to multiple stressors; (2) determine the effects of multiple stressors on primary producers and the structure, condition and sharing of trophic resources within the benthic communities; (3) identify potential thresholds for shifts along stressor gradients in benthic species, community and ecosystem processes. Overall, the proposed research will both contribute to advance our critical understanding of fundamental biogeochemical and ecological processes that are of broad interest to the scientific community and provide specific applications to management decision for natural resources at the coastal scale: i.e. assessing the combined impact of global change and anthropogenic stressors on ecosystem engineering. Results will support the priorities of the Canada's Oceans Protection Plan, aiming at keeping a healthy multilevel ecosystem, especially in coastal zones.