Wetlands are a prominent feature of Minnesota's surface waters, but it is not well understood how pollutants and physical alterations impact wetland quality. The MPCA has been actively developing methods and building capacity to improve our ability to monitor and assess wetlands.
The goals of this effort are ultimately to protect and restore the integrity of Minnesota's wetlands by providing scientifically valid information to make informed management decisions and monitor the status and trends of wetland quality.
Wetland quality status and trends monitoring
Status and trends monitoring of wetland quality is a central wetland monitoring activity at the MPCA. Overall wetland quality can be tracked by randomly sampling a small number of sites—like a political or marketing poll where results of a population can be obtained by surveying a limited number of individuals. Two statewide probabilistic wetland quality surveys are underway to provide estimates of the baseline status of wetland quality in Minnesota. These surveys will be repeated periodically to estimate wetland quality trends and ultimately, help determine whether Minnesota is meeting the no net loss wetland policy.
The MPCA conducts monitoring, assessment, listing and implements water quality improvement activities for lakes and streams on a rotating major watershed basis. This is called the watershed approach.
Wetlands are an integral part of Minnesota's water resources, and wetland monitoring information will be an essential component as efforts to protect and restore lakes and streams are implemented. The MPCA is in the early stages of incorporating wetland monitoring activities into the watershed approach to support water quality decisions. These activities may include:
- Status and trends monitoring of wetland quantity and quality by major watershed.
- Natural background determinations for more accurate stream and lake assessments.
- Linking wetland condition and ecosystem services to lake and stream impairments.
- Identifying opportunities for wetland protection and restoration for water quality improvements.
Wetland information will begin to be included in major watershed monitoring reports in 2013.
Biological assessment methods and sampling protocols
A primary focus of wetland monitoring and assessment at the MPCA has been biological monitoring. Aquatic organisms are fully exposed to human-caused stressors such as hydrological changes that disrupt natural water dynamics; excess sediment and nutrient loading; chemical pollution; and encroachment by invasive species. Biological communities typically respond in predictable patterns to stressors—integrating their effects over time—and can represent the condition of the aquatic environment.
Since the mid-1990s, the MPCA has worked to characterize wetland invertebrate and plant community responses across gradients of human stressors. This work has resulted in the development of invertebrate and plant Indices of Biological Integrity (IBIs) for depressional wetlands (i.e., wetlands within a depression in the landscape that typically have standing open water fringed by an emergent marsh plant community) for each of the major ecoregions in Minnesota. More recently, work has been completed to increase our capacity to monitor all wetland types in the state by focusing on plants and using the Floristic Quality Assessment.
- Floristic Quality Assessment
- Development and validation of indices of biological integrity (IBI) for depressional wetlands in the Temperate Prairies ecoregion
- Indexes of Biological Integrity for large depressional wetlands in Minnesota
- Reconnaissance procedures for depressional wetland monitoring sites
- Macroinvertebrate community sampling protocol for depressional wetland monitoring
- Water chemistry assessment protocol for wetland monitoring sites
- Aquatic plant community sampling protocol for depressional wetland monitoring sites
Impaired waters assessment
The MPCA has assessed a limited number of depressional wetlands for Aquatic Life Support using the plant and invertebrate IBIs. This has resulted in listing 14 wetlands on the 303(d) list of Impaired Waters through 2011. Efforts are underway to incorporate impaired wetlands in to the Total Maximum Daily Load (TMDL) process. For more details on these impaired wetlands and the rationale for listing wetlands on the Impaired Waters List, see the 2008 Wetland Assessment Documentation and Defining Wetland Condition Assessment Processes.
Long-term wetland monitoring
The MPCA has been regularly sampling a small set of depressional wetlands located within relatively stable land use settings to study whether large scale factors (e.g., climate, atmospheric deposition) are affecting the condition of Minnesota's wetlands. More information and site reports are available on the long-term wetland monitoring page.
Citizen wetland monitoring
The Wetland Health Evaluation Program (WHEP) is a citizen volunteer wetland monitoring program that is focused on educating the public on wetland ecology and quality issues; as well as, providing local governments with wetland planning information. WHEP is currently active in Dakota and Hennepin counties, with a number of cities sponsoring local monitoring teams. The MPCA was instrumental in developing the WHEP sampling invertebrate and plant guides, which were adapted from the depressional wetland IBIs.
For more information
For more information about wetland monitoring and assessment at the MPCA, contact Michael Bourdaghs at 651-757-2239.