Sally Leys
Department of Biological Sciences, University of Alberta
Sponge Function and Resiliency
This project aims to quantify the ecosystem function of sponges through habitat formation and filtration of water and the nature of links with environmental conditions that maintain the resilience of sponge reefs and to determine the thresholds under which productivity of the community as a whole is maintained.
Established, healthy, ecosystems rely on a diversity of species for their effective function. However, in many ecosystems, the existence of the entire community is tied to the presence of a small number of foundation species which require particular environmental characteristics to survive. Quantifying the components of the environment, linkages that exist between them and how external forces directly affect these linkages allows an understanding of the ecosystem services and function and can lead to concrete management strategies. The benthic habitats of Hecate Strait, Queen Charlotte Sound and neighboring fjords harbor thousand-year-old glass sponge reefs covering hundreds of kilometers of seafloor. They are also areas that are heavily exploited for fisheries and transportation, and which have the potential for future oil/methane extraction. The reefs support diverse communities of fishes and other invertebrates and are hotspots of nutrient cycling. As a result, they were identified as an Area of Interest to become established as one of Canada’s largest Marine Protected Areas. We aim to develop models to facilitate monitoring of ecosystem function, and which will identify key data required that can be obtained readily over time and applied to sponge communities in Arctic and Atlantic oceans to guide broader ecosystem management.
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Identification of significant ecosystem components and ecologically and biologically significant areas related to glass sponge reefs to distinguish the areas that most require protection is in progress.
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Expert Opinion Matrix of the associations and physiological functions of species in the sponge reefs to classify species and habitats of importance for maintaining biological diversity is delivered to DFO Marine Protected Areas Team.
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Development of methodologies for monitoring reef cover and function by AUV or other remote mechanisms is in progress.
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Two research cruises to Hecate Strait (2015 and 2017) are complete.
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Lauren Law graduated from the MSc program. In her thesis, she focused on methods of mapping the reefs and monitoring them in the future and describing the cryptic diversity of the reefs by identifying a range of other sponge species and in particular describing a new species of sponge that encrusts on the reef-forming sponges.
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The planning of a series of experiments (before/after, control/impact) to evaluate the effect of resuspended sediments on sponge tissues over time is in progress.
