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In this Section
Physical and Chemical Limnology
Fundamentals of water column characterization will be illustrated through the use of physical and chemical analysis of water through out the water column using automated sampling (CTD probes) and discrete sampling techniques (Rosette sampler). Physical limnological concepts (e.g. diffusion, water movements [currents, waves], heat budgets, light transmittance, sedimentation) and chemical limnological concepts (e.g. chemical speciation, ionic composition, dissolved organic matter, particulate matter) will be discussed in relation to their impact on organisms. Hands-on modules will be:
  • CTD profile interpretation;
  • light extinction coefficient measurements;
  • discrete water sampling (using Van Dorn bottles on the Rosette, and trace metal-clean pumping system);
  • measure various parameters in discrete water samples in the chemistry lab (e.g. conductivity, pH, alkalinity, chlorophyll-a, and nutrients); and
  • sample sediments using a box corer for characterizing sediment surface properties and for collecting benthic invertebrates as part of LOLA (a USEPA Lake Ontario sampling project).
Biomolecular Ecology
Phytoplankton respond to changes in environmental parameters through the induction of specific proteins and enzymes systems. As such, the cells themselves often serve as informative sentinels of the environment. Nutrient deficit, in particular, is reflected in the induction of specific proteins that position the cell to better compete for scant nutrient resources. This module will introduce students to some of the approaches used to assess phytoplankton nutrient status. Included will be:
  • fluorometric analysis of ectoenzyme activity (e.g. alkaline phosphatase), including consideration of enzyme kinetics; and
  • the use of luminescent whole cell bioreporters to assess bioavailable N, P and Fe in aquatic systems.
Plankton and Benthic Ecology
The major goal of this module will be to help the students to gain a better appreciation of the microbial component of Lake Ontario. Although limited by our time constraints, we will have the students undertake a series of basic measures along the transect that will allow them to develop an appreciation for microbial interactions as well as the influence that microbes may have on human activity. As such, several specific goals will be realized during this cruise:
  • the enumeration by fluorescent microscopy of the total viral and bacterial load at each station;
  • the isolation of specific microbes of interest to human health issues;
  • the isolation of microbes important in the dynamic of the lake's carbon budget;
  • the isolation of viruses specific to lake microbes; and
  • the use of dilution assays for measuring microbial growth and grazing rates. During the cruise, students will learn basic aseptic techniques that can be applied in field studies.
Ornithology and Environmental Change
This module will focus on the behavior and ecology of Great Lakes 'waterbirds' (birds that feed on aquatic organisms, or nest on islands or wetlands bordering the Great Lakes), and how waterbirds impact and are impacted by anthropogenic environmental change. Waterbirds are important indicators of environmental health in the Great Lakes ecosystem. We will focus on five related topics:
  • bioamplification of toxic compounds in waterbirds that feed on fish and mollusks;
  • increase in avian botulism associated with invasive, exotic species (zebra mussels and round goby);
  • consequences of new food sources provided by humans (e.g. refuse dumps) on waterbird populations;
  • causes, consequences, and management options of a population explosion of a native waterbird species (double-crested cormorant); and
  • effects of changes in shoreline land use and water level fluctuations on breeding waterbirds. During the cruise, participants will learn how to make valid population abundance estimates of waterbird species through observational census techniques. Participants will collect data on bird abundances, and compare the results to spatial location within the basin (relative to shorelines), bathymetry, and local aquatic productivity to infer how species are distributed within Lake Ontario. They will learn how these data can be use to monitor the health of the lake, and the uncertainties and problems associated with use of birds (and other animals) as indicators of ecosystem health.