January 28, 2016
Kevin Cronk, Tip of the Mitt Watershed Council
Gradually and subtly, non-native Phragmites crept into Michigan’s Northern Lower Peninsula, under the radar of many local natural resource managers and residents. Staff at the Tip of the Mitt Watershed Council (Watershed Council) first learned of the threat from environmental activist Pamela Grassmick some 10 years ago, who was working with the Michigan Department of Natural Resources (DNR) to control the Beaver Island non-native Phragmites invasion. Shortly thereafter, following an invasive Phragmites awareness meeting in Traverse City organized by Brian Piccolo of the DNR, the Watershed Council started down the path of non-native Phragmites control.
Early surveys by the DNR, our staff, and researchers at the University of Michigan Biological Station showed that non-native Phragmites distribution in the northern Lower Peninsula was largely limited to the Great Lakes shoreline. We worked with lake associations and road commissions to address the handful of infestations found inland, while responsibility for the Great Lakes shoreline was divvied up among water resource organizations and local governments. The Watershed Council was responsible for surveys and treatment in Emmet County and we took it upon ourselves to “de-phrag” all 75 miles of the county’s Lake Michigan shoreline.
Since 2010, staff and interns from our Watershed Protection Team have hiked the entire Emmet County shoreline, roughly from Petoskey to Mackinaw City, every two (even) years to document non-native Phragmites. Our Policy and Advocacy Team worked with local governments to pass a non-native Phragmites ordinance for Emmet County, which appoints a county non-native Phragmites Administrator and requires annual reports on the status of the shoreline. The ordinance also allows the county to obtain court orders to enter and inspect properties for non-native Phragmites, if the property owner has refused permission. Using our survey results, we partner with the county to send letters to landowners to inform them of invasive Phragmites and facilitate treatment. Additionally, the Watershed Council assists Emmet County with county-wide treatment permit applications. In off (odd) years, the teams work together to revisit infestation sites to evaluate treatment effectiveness and advise landowners regarding follow-up treatment.
Our first surveys, in 2010, found nearly 300 non-native and 2,500 native Phragmites stands along the Emmet County shoreline. In 2010 and 2011, the Watershed Council worked with 111 property owners to control the 286 non-native Phragmites infestations. By 2012, the number of infestations had been reduced to 87 and in 2014, just 55 remained. However, many of the remaining infestations were proving difficult to control and persisting from year to year, either because of plant regeneration or failure of landowners to pursue treatment.
When revisiting sites in 2015, we were shocked to find only five of the 55 non-native Phragmites infestations documented in 2014!
What had changed in that time period? We believe that changing Great Lakes water levels impacted our non-native Phragmites infestations. Most of the infestation sites are now completely submerged under a foot or two of water and we believe that our efforts to de-phrag the Great Lakes Shoreline in Emmet County have gained an unforeseen ally. The sudden and swift increase in Lake Michigan-Huron water levels, which returned to and surpassed long-term averages in just two years, could have been the master stroke that ultimately repelled our invasion! Of course, when Great Lakes water levels inevitably drop again and waters recede, non-native Phragmites infestations levels will undoubtedly change. However, we are now armed to resist the invasion, with the power to identify this problematic invasive plant, and carry out effective control measures.
All photos courtesy of Kevin Cronk, Tip of the Mitt Watershed Council.