EES Departmental Seminar: Elucidating food-web dynamics at the Makkovik Hanging Gardens off northern Labrador using compound-specific δ¹⁵N of deep-water corals and associated fauna
Dr. Wilder Greenman
Post-Doctoral Scholar
Earth and Environmental Sciences, Dalhousie University
Title: Elucidating food-web dynamics at the Makkovik Hanging Gardens off northern Labrador using compound-specific δ¹⁵N of deep-water corals and associated fauna
Link to recorded lecture (YouTube)
Abstract: Deep-water coral and sponge grounds are biodiversity hotspots that support culturally and economically important species but are highly vulnerable to bottom-contact fishing and climate stressors. Despite their ecological value and recognition as vulnerable marine ecosystems (VMEs), large areas of northern Canadian waters remain poorly explored, hindering efforts to identify and conserve these habitats as part of Canada’s UN commitment to protect 30% of oceans by 2030. To address this knowledge gap, the Nunatsiavut Government, in collaboration with DFO and university partners, is combining Inuit knowledge with targeted scientific studies - an approach that led to the recent discovery of the Makkovik hanging gardens, a vertical wall community of deep-water corals and sponges 30 kilometers off northern Labrador.
This seminar will provide an overview of the Makkovik hanging gardens, and demonstrate how geochemical tools, particularly compound-specific isotope analysis of amino acids (δ¹⁵N-AA), can disentangle complex food-web dynamics and reconstruct paleoenvironmental records where long-term historical data is sparse. These isotopic archives allow us to assess decadal-scale changes to coral feeding patterns, monitor present ecosystem function, and forecast their response to future climate change. A review of recent work from the Scotian Shelf will illustrate the insights these geochemical tools reveal about deep-sea food webs. Preliminary results from the Makkovik Hanging Gardens reveal distinct isotopic niches among primary consumers, which may help buffer these habitats during periods of diminished quality and quantity of surface-derived particulate organic matter.
Time
Location
Milligan Room, B-8007 8th Floor Biology/EES wing of the LSC