Freshwater Mussels, Ecosystem Services, and Clean Water Regulation in Minnesota: Formulating an Effective Conservation Strategy

Abstract

Freshwater mussels are threatened with extirpation in North America. They are a sentinel species for ecosystem function and contribute towards many ecosystem services. As mussels require clean water to survive, and since conserving ecosystem services is implicit in the federal Clean Water Act, incorporating mussel conservation into state water policies could serve multiple conservation goals. In this paper we conduct a comprehensive critical review of three topics related to freshwater mussels: their contribution to ecosystem services, their links with water quality, and threats to their survival from water pollutants and extent of protection available from regulation. In so doing, we identify gaps between the water quality requirements of mussels and the protection provided by current water regulation to help inform clean water and conservation goals in Minnesota. We find freshwater mussels to be generally sensitive to a wide variety of pollutants, and particularly to nutrients such as total nitrogen and total phosphorus and to major ions such as chloride. In addition, we find that current state water quality standards may not be sufficiently protective of mussels. We formulate a framework for determining an effective conservation strategy for mussels in Minnesota based on ecological and economic criteria to ensure adequate conservation at a reasonable cost.