Folder LCWC EWM Research

pdf WC1_ESI DAT SUMM FROM 2016 060317

Rapid decline in Eurasian watermilfoil and planktonic algae in Les Cheneaux waters over a four-year period

Authors: R. Smith

Author Affiliation: LCWC

Journal: Unpublished Report; March 2017

Abstract: Three lines of evidence suggest that characteristics of Les Cheneaux waters have changed during the past four years as reflected by a sharp decline in stemmed aquatic plants, especially Eurasian watermilfoil (EWM), and in free-floating algae (phytoplankton) densities. Eurasian watermilfoil density decreased by 80% from 2013 through 2016 in the two most infested bays, Sheppard and Cedarville, for this period. This is not to say that LCI water quality has declined. In fact, the recreational water quality of LCI waters is excellent. The shift in EWM and plankton densities appears real and, with the decline of EWM as well as the plankton community, long term shifts in the lower aquatic food web could occur. Changes in the lower food web can affect the invertebrate populations such as dragonflies, mayflies and damselflies which, in turn, can affect the fishery.

Two other lines of evidence for shifting water characteristics are the decrease in algae concentration and the simultaneous rise in Soluble Reactive Phosphorus (SRP), a primary algal nutrient during the 2013-2016 period. SRP concentration increased throughout LCI waters as the planktonic algae community density decreased. With SRP being a primary planktonic algae nutrient, it follows that SRP concentrations would increase if the algal population had less demand for using it as a nutrient.

pdf WC2_Combating Invasive Species in the Les Cheneaux Watershed Great Lakes Coastal Resilience Planning Guide

Combating Invasive Species in the Les Cheneaux Watershed

Author: Bridget Faust

Author Affiliation: Association of State Floodplain Managers

Journal: Great Lakes Coastal Resilience Planning Guide; February 14, 2014

Abstract: Demonstrate how low water levels and invasive species have adversely impacted the Les Cheneaux Watershed, describe the different strategies used by the community to combat them, and provide communities with the decision support tools necessary to decide when and how to manage invasive species.

pdf WC3_LCWC Clark Twp Report FINAL

Milfoil Control Services Report


Author: Mark Clymer

Author Affiliation: LCWC

Journal: Unpublished Report for the Mackinac County Board of Commissioners and the Clark Township Board

Abstract: This Milfoil Control Project and it’s impact are part of a functional and ecosystem level effort in the Les Cheneaux Islands (LCI) watershed to balance native and invasive species by facilitating the natural diversity still present.

Results of this project indicate that some Aquatic weeds appear able to compete with Milfoil, and that Milfoil does not appear to be as severe an ecological threat in LCI currently as was witnessed in 2011‐2013. This statement does not mean there is no problem, only that under favorable conditions the Pondweed family, Naiad, Chara, and Eel Grass for instance, are able to successfully cohabitate with Milfoil, as demonstrated in the 2014 Aquatic Vegetation Assessment Site (AVAS) survey and a Point Intercept (PI) survey findings. Favorable factors include cooler water temperatures, less available sunlight, and the presence of Milfoil pathogens & predators.


Eurasian Watermilfoil Strategic Biological Control Program 2011-2013: Final Technical Report 

Author: Mark Clymer

Author Affiliation: LCWC

Journal: EPA/GLRI Invasive Species Grant: No. GL-00E00809; March 31, 2014

Abstract:  This project supports the Great Lakes Restoration Initiative and the Great Lakes Water Quality Agreement, pursuant to Public Law 112-10. The grant will support the Les Cheneaux Watershed Council’s work to stock 65,000 milfoil weevils in approximately 16 locations in three bays in the Les Cheneaux Islands region of northern Lake Huron, Michigan to control the invasive Eurasian watermilfoil and restore important perch spawning grounds. The project includes monitoring to assess the long-term effectiveness of this biological control strategy for watermilfoil.