Quantifying Nutrient Retention by Lake Erie Coastal Wetlands

  • Wetland restoration can be a critical management tool to reduce nutrient loading to Lake Erie.

    Wetland restoration can be a critical management tool to reduce nutrient loading to Lake Erie.

  • As phosphorus flows through a wetland, some is buried and stored long term in the wetland's sediment and peat.

    As phosphorus flows through a wetland, some is buried and stored long term in the wetland's sediment and peat.

  • This project drew on the long-term water quality monitoring record at Old Woman Creek Reserve to quantify a riverine wetland's capacity to retain phosphorus.

    This project drew on the long-term water quality monitoring record at Old Woman Creek Reserve to quantify a riverine wetland's capacity to retain phosphorus.

  • This approach can be applied to riverine wetlands and some constructed wetlands that have distinct water inflow and outflow locations.

    This approach can be applied to riverine wetlands and some constructed wetlands that have distinct water inflow and outflow locations.

  • A Collaborative Learning Group shared information with conservation organizations, federal, state and county agencies, universities and community groups.

    A Collaborative Learning Group shared information with conservation organizations, federal, state and county agencies, universities and community groups.

Excessive amounts of phosphorus entering Lake Erie has been leading to harmful algal blooms in the lake and low oxygen conditions in lake bottom waters. Coastal managers identified wetland restoration as a critical management tool to reduce nutrient loading to Lake Erie and Sandusky Bay, Ohio. However, the capacity of different coastal wetlands to retain nutrients and improve water quality is not well understood.

This project addressed key information gaps identified by land managers, regulators, and conservation groups involved in coastal wetland restoration and management efforts around Lake Erie. The project developed a unique analytical approach -  a Bayesian hierarchical model - to quantify the long-term capacity for riverine Lake Erie coastal wetlands to retain phosphorus. The team developed a series of technical tools, including a monitoring protocol and freely available statistical code, to enable others to repeat their analysis and calculate the retention capacity of their own wetlands. 

An infographic and story map were developed to explain the services wetlands provide for humans, how wetlands can be managed for different services, and the ability for wetlands to intercept nutrients before they reach Lake Erie. A core group of project end users met regularly throughout this project to provide guidance and feedback, and this group is helping ensure that project findings are incorporated into a new water quality initiative, H2Ohio, which is funding the restoration and enhancement of over 35 wetlands across Ohio.