Ann Lake Paleolimnology Study

Ann Lake has been the subject of lake management interest for several years. Ann Lake is a high resource value lake in North Central Minnesota. This is a unique lake (flow through, wild rice, native benthic species of concern to DNR non-game program, public land surrounding the lake). Stakeholders have expressed frustration due to missing information surrounding the history of primary production in the lake.
 
A Total Maximum Daily Load (TMDL) report was completed. The TMDL analysis indicates high levels of sedimentary phosphorus that may be available as internal load and which may need significant reduction to meet lake standards. Stakeholders have completed several watershed-wide Best Management Practice’s (BMP’s) and are now considering targeting internal load sources. The watershed is a predominantly forested watershed, with a large percentage protected by state land and wildlife refuge management. 

Paleolimnilogical analyses can provide several crucial lines of evidence that provide answers to missing information prior to expensive in-lake BMP treatments to manage internal load