Managing the Impact of Multiple Stressors in Saginaw Bay

Identified at the Multiple Stressors in Saginaw Bay: Navigating the Issues workshop. Hosted by NOAA-GLERL, April 02, 2008.

Top Management Objectives

Management of dominant percid (walleye and yellow perch) populations and their associated fisheries
Manage for diverse ecosystem, fish community and fisheries
Restoration of native species and control of non-natives
Manage for long-term sustainability

Primary Knowledge Gaps

Understanding yellow perch recruitment dynamics and bottlenecks to production
Understanding walleye recruitment dynamics and bottlenecks to production
Elucidation of fish community dynamics (incl. role of forage fish and invasive species in Saginaw Bay)
Is reestablishment of lake herring in Saginaw Bay feasible?
What are the important ecological connections between Lake Huron and Saginaw Bay?

Top Management Objectives

Predicting and managing muck deposition on beaches.
Prediction and managing E. coli/pathogens outbreaks.
Determine what type of management efforts or policy changes would be effective in reducing the impacts of contaminants in Saginaw Bay (i.e. dredging of hot spots)
Managing sediment loading.
Managing and understanding the impacts of agriculture in Saginaw Bay (i.e. nutrient loads, sedimentation, E. coli)

Primary Knowledge Gaps

What are the primary drivers of muck deposition on beaches? What is its composition of muck (e.g. E. coli)?
What and where are the primary sources of E. coli?
What are the impacts of contaminants to water quality in the bay?
How much is sediment loading contribution to nutrient loading in the bay?
What aspects of agriculture impact water quality and what can be effectively implemented to mitigate impacts?

Watershed Recommendations and Observations

Management options should not be defined just as target loads, but mainly as policies to achieve those targets. Defining management options requires active participation of stakeholders.
Land use scenarios should include “presettlement” (USGS) scenarios and best-management (land) options as best-case scenarios.
In-stream retention basins have been explored (Sebewaing River) as a means to reduce sediment and pollutant loads. They should be included in the model as a management option, alone or in combination with others.
Modeling should focus on areas where TMDL studies are on-going or planned. Attention should be devoted to the preservation and expansion of wetland areas.
The concentration of livestock in CAFOs could decrease the traditional reutilization of manure and increase the nutrients load exported to the bay.
No significant increase in pollutant loads from municipal sources is expected in the near future; further, the decline of industrial activities in the watershed should reduce pollution loads from manufacturing.

Primary Knowledge Gaps: Modeling Priorities

Insufficient knowledge of backwater effects in the lower Saginaw River related to loading dynamics.
Wind induced erosion could be a substantial source of pollutants, especially during winter.
The contribution of wildlife to nonpoint pollution is unknown.
Role of rural sanitation systems should be addressed.
Water quality and quantity monitoring outside the Saginaw River watershed is poor.