Karst sinkholes discharging groundwater onto the Lake Huron floor through Paleozoic bedrock have created unique habitats characterized by steep environmental gradients and conspicuous benthic microbial mats and organic-rich sediments. These ecosystems feature high microbial biomass and intense activity - biogeochemical "Hot Spots" (Biddanda et al. Ecosystems 9:828-842, 2 6). We have identified three sinkhole communities along a depth gradient in Thunder Bay National Marine Sanctuary. The principal goals of this 2-year (9/ 6-8/ 8) study are to: (1) Describe the abundance, diversity and activities of the microbial community in the submerged sinkhole ecosystems located along the depth gradient, and (2) Determine how the changing environmental gradients in submerged sinkhole ecosystems impact microbial composition and processes. Microbial communities are being characterized using molecular techniques that target different molecules. First, membrane lipid profiling is combined with measurements of stable carbon isotope (13C) incorporation into individual fatty acids to provide an integrated view of community composition and activity. Second, genetic diversity profiles (ARISA) and DNA sequence data provide a high-resolution view of community composition. Third, fluorescence microscopy and radioisotopic tracers are used to directly assess microbial abundance and growth rates. We are using these tools to test the hypothesis that photosynthesis-dominated microbial communities in shallow sunlit sinkholes give way to chemosynthesis-dominated sinkhole communities in deep aphotic water. In these model sinkhole habitats, we will test the hypotheses about the role of microbial diversity in determining community function including carbon flow and nutrient cycling. These analyses provide the first detailed picture of microbial life in sinkhole ecosystems of the Laurentian Great Lakes.
- Preliminary Evaluation of a New Technique for Linking Picoplankton Community Structure with Function in Aquatic Environments
- The economic impact of climate change on Canadian commercialnavigation on the Great Lakes
- Further Investigation of the Sources of Fecal Indicator Bacteria in Wakulla County, Florida
- Interpreting the biological significance of bioaccumulation data: A field test of the critical body residue hypothesis
- Development of a DNA Marker Gene System to Determine Sources of Fecal E. coli in Watersheds
- A genomic and proteomic approach to characterizing natural variation in E. coli: Toward construction of a microbial source tracking database to identify sources of fecal water contamination in the State of Montana
- Digestive physiology as it relates to food preference as a mechanism explaining differential bioaccumulation of lipophilic pollutants among benthic invertebrates
- Larval Fish Flux between Metzger Marsh and Lake Erie
- Nitrate Source Tracking: Combining Isotopic, Microbial, and Chemical Tracers in a Mixed Land-Use Watershed
- Montana Creek Water Quality Monitoring
General
Monitoring
Annex
General
- Scope of Study
Scope of StudyField InvestigationLaboratory InvestigationLiterature / Existing DataTheoretical
- Scale of Phenomena
Scale of PhenomenaBiochemicalCellularCommunityEcosystemOrganismPhysical/Chemical
- Impact of Pollutants
Impact of PollutantsNutrients, Including Phosphorus
- Processes
ProcessesNatural Ecological ProcessesNatural Physical/Geological Processes
- Land Use and Habitat
Land Use and HabitatShorelineWetlands
- Resource Management
Resource ManagementFisheriesWildlife
- Socio-Economic
- State / Province
State ProvinceMichigan
- Lake Basin / Connecting Channels
Lake Basin Connecting ChannelsLake Huron
Monitoring
- Purpose of Project
- Frequency
FrequencyMonthly
- Number of Sampling Entities
- Data Availability
Data AvailabilityDigitalGeo-referenced
- Region Being Monitored
Region Being MonitoredNear and OpenShore WatersNearshore Terrestrial
- Resource Being Monitored
Resource Being MonitoredGroundwaterHydrologic / Hydrometric / ClimaticPlankton / Microorganisms
- Program Drivers
- Beneficial Use Impairment Assessments
Aquatic Nuisance Species
Annex
- Annex Numbers
Annex NumbersPollution from Non-Point SourcesResearch & Development
- Annex 17
Annex 17Impact of water quality and AIS on fish and wildlife populations and habitatsPhysical and transformational processes affecting delivery of pollutants