This paper consider whether good environmental performance by corporations affecting Great lakes ecosystem function can serve as a basis for investment advice. Resource conservation by business can be seen as an opportunity to create value in the Great Lakes region over and above the direct total return from investment, of businesses that manage resources well. Such investment advice requires working of the environmental fundamentals of companies so that investors can rely on recommendations about their products or production processes being supportive of the region's resources. Our recent work on scoring the environmental performance of publicly traded companies is seen here as part of a progression toward improved technical analysis. We consider environmental fundamentals in terms of ten major Great Lakes ecosystem functions and 36 associated services. Our criteria evaluate business decisions and supports incentives as well as investment advice. Documentation of regional ecosystem benefits provides useful information for all capital market analysts. Ratings range from AAA for the most significant and geographically extensive conservation measures to BB for simple maintenance of the status quo, to C, for performance that is qualitatively negative.