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Description of Work In 2011, the US EPA, USGS, and Canada’s DFO/EC continued the evolution of the strategy to conduct an “integrated’ (water quality to fish) spatially-consistent assessment for the entire lake in order to provide biomass estimates for each trophic level. A total of 54 sites were sampled during summer 2011. Water chemistry, nutrients, phytoplankton, zooplankton, benthic invertebrates, Mysis, and pelagic and benthic fish were collected at each site.
Lake Ontario Component - Exploring changes in nutrient transfer within Great Lakes food webs: implications for fish production
Description of Work USGS scientists will support EPA's year of intensive sampling around the Great Lakes to complement and expand upon EPA and other partner entities work. In 2013, on Lake Ontario USGS will sample the food web from a nearshore (20 m) to offshore (100 m) gradient where seasonal sampling of primary producers, benthic invertebrates, zooplankton, prey fish, sport fish, and their diets will occur. We will work closely with state management agencies and stakeholder groups to ensure that ecosystem models that emerge from this work explore relevant future management scenarios. Scientists will analyze the diets of the six species of trout and salmon currently occurring in Lake Ontario. This predator diet...
Exploring changes in nutrient transfer within Great Lakes food webs: implications for fish production in Lake Michigan in support of CSMI 2010
Description of Work USGS will conduct seasonal sampling of benthic invertebrates, zooplankton, prey fish, sport fish, and their diets to complement the seasonal lower trophic level sampling by EPA. This data will provide a more holistic understanding of how invasive-driven, food-web changes could be altering energy available to sport fishes in the Great Lakes and used to build a decision support tool that can explore how different scenarios (dreissenid control, nutrient reductions, changes in fish stocking) influence the biomass of economically important fisheries.
Exploring nearshore-offshore linkages in energy transfer within Great Lakes food webs: implications for fish production in Lake Michigan in support of CSMI 2015
Description of Work Since the early 2000s, the LaMP has proposed adding nutrients (specifically phosphorus) to its “pollutant of concern” list, given that excessive nutrients were believed to cause impairments in the nearshore waters. Since that time, scientists have highlighted the “shunting” of nutrients to the nearshore, owing to the ability of invasive dreissenid mussels to capture some portion of allochthanous phosphorus that enters the lake through tributaries. These changes are believed to underlie a series of changes in the nearshore, including increased biomass of cladophora and hypothesized increases in benthic and pelagic biomass, including zooplankton and fish. As an extension, this model proposes the...