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Ohio Sea Grant College Program
and Stone Laboratory

Ohio Sea Grant and Stone Laboratory

A Model for Internal Chemical Loading in Lake Erie

Project Number: R/EM-021-PD, Completion Report

Start Date: 8/1/2000

Completion Date: 7/31/2001

Revision Date: 4/27/2012

Principal Investigator(s)1.Gerald Matisoff, Geological Sciences Case Western Reserve University*
Associate Investigator(s)2.William Fornes, Case Western Reserve University*
This shows the current affiliation and may not match affiliation at time of participation. *

Funding Record

Source: Ohio Sea Grant College Program
Source FundState MatchPass Through
First Year$ 7,500.00$ 7,500.00$ 0.00
Total$ 7,500.00$ 7,500.00$ 0.00

Objectives

Develop Model for internal loadings of nutrients and metals to Lake Erie
Adapt an existing model of sediment-water exchange developed for marine systems to the freshwater environment of the Great Lakes
Calibrate the model for several environments in Lake Erie.

Abstract

Internal recycling of nutrients and contaminants from sediments is a well-recognized and important input to the water column. However, models of biogeochemical cycling are not well developed. To directly address this deficiency, we apply the CANDI model to improve predictions of internal chemical loading to the Great Lakes. The model considers kinetically controlled reactions including degradation of organic carbon by oxygen, Fe and Mn oxides, nitrate, sulfate and methanogenesis, carbonate dissolution, and pyrite formation and equilibrium reactions that govern pH. Results to be presented include the proportional effects of suboxic and anoxic reactions on organic carbon diagenesis, the effects of bioturbation on the release on nutrients to the water column, and the changes in nutrient fluxes from the sediments in response to changes in nutrient deposition fluxes.

Rationale

  • Recent ecosystem changes and P load reductions have led to significant changes in nutrient cycling and to the oligotrophication of the off-shore regions of Lake Erie.
  • Nutrient loads have not been evaluated in the context of the current ecosystem
  • Internal recycling of nutrients and contaminants from sediments is a well-recognized and important input to the water column.
  • Current models of the chemical exchange between sediments and water are inadequate.
  • Methodology

    • Adapt the CANDI model of sediment-water exchange developed for marine systems to the freshwater environment of the Great Lakes
    • Calibrate the model for several environments in Lake Erie.
    • Improve predictions of the internal chemical loading to Lake Erie.

    Benefits & Accomplishments

    Benefits:
    The proposed work will be useful in recalculation of P loads and will be a significant improvement in ecosystem models.

    Accomplishments:
    The CANDI model was obtained, modified for freshwater sediments, and debugged. Crude calibration was completed. Proposal submitted and funded by EPA to collect cores from Lake Erie and analyzed for pore water chemistry. Data to be used for future model calibration. Model of oxygen developed and calibrated. Data to be presented at IAGLR 2003.

    Publications & Media

    Peer-reviewed reprints
    Peer-reviewed reprintsG. Matisoff and T. Neeson 2005, Oxygen Concentration and Demand in Lake Erie Sediments
    Journal of Great Lakes Research. Made available by Ohio Sea Grant as OHSU-RS-465
    Conference, symposia, or workshop proceedings, and summaries
    Conference, symposia, or workshop proceedings, and summariesFornes, W.L. and G. Matisoff. 2001, A model for sediment biogeochemical cycling and internal chemical loading in the Great Lakes
    44th Conf. on Great Lakes Res., Green Bay, WI.
    Conference, symposia, or workshop proceedings, and summariesMatisoff, G. and Neeson, T. 2003, Quantifying Sediment-Oxygen Demand in Lake Erie
    46th Conf. on Great Lakes Res., Intern. Assoc. Great Lakes Res., Chicago, IL.
    Conference, symposia, or workshop proceedings, and summariesMatisoff, G. 2004, Reaction transport modeling of sediment oxygen demand in Lake Erie sediments
    47th Conf. on Great Lakes Res., Intern. Assoc. Great Lakes Res.
    Conference, symposia, or workshop proceedings, and summariesMatisoff, G., D.R. Aguilera and M. Thullner 2004, Reactive Transport Modeling of Sediment Oxygen Demand in Lake Erie Sediments
    Geochimica et Cosmochimica Acta, 2004 V.M. Goldschmidt Conference, Copenhagen, Denmark

    Supported Students

    StudentDr. Bill Fornes (Graduate)
    Case Wesern Reserve University
    Title: CANDI model code debugging
    StudentTom Neeson (Undergraduate, B.S.)
    Case Wesern Reserve University
    Title: Oxygen Model