How “Dry” to “Die”? – An Interesting look at Eurasian Watermilfoil Dessication and Viability

As if straight out of a Hollywood horror flick, a monster is chopped up into many pieces, only to come back at the end of the movie to warrant sequel after sequel of terror.  As many of you may know, invasive aquatic plants can embody this heinous trait in real life, making their way from water body to water body as pieces of their former selves.  This is especially true of Eurasian watermilfoil (EWM), a troublesome invader found growing submersed throughout many regions of the United States.   Fragments of the plant can easily catch on boat trailers, jet-skis, fishing equipment, and other equipment making them easily transported within AND beyond various water bodies.


Photo credit:

While many are aware of these sinister hitchhikers, the question of just how long these plants can survive outside of water is one that has remained relatively unknown… until recently.  A group of researchers from the Adirondack Watershed Institute at Paul Smith’s College have shed light on that very question.  Celia Ann Evans and her team at PSC recently published findings related to the desiccation (extreme drying) and viability (ability to live) of EWM to see just how long the plants could survive out of water, and thus be transported from water body to water body.


Photo Credit:  Adirondack Almanack

Evan’s team ran a series of laboratory and field experiments to determine the rate at which EWM desiccates, the likelihood of new growth based on time out of water, and the time it takes for new plants to grow and establish.  The studies findings were quite shocking to say the least.  As many could believe, the plants were approximately 96% desiccated after only a few hours out of water and 100% desiccated after 13 hours out of water.  What came as a surprise to many however, was that some plants of 100% desiccation were STILL able to produce new plants!!!!  Talk about coming back from the dead.  Although the number of plants that came back were few, and they took more time than others to establish, they were still able to survive and thrive!

The research completed by the group at PSC certainly shares a somewhat scary story to those in aquatic plant management, especially those in the business of prevention.  Even one plant in 50 surviving can lead to new infestations in new water bodies.  These infestations can cause severe environmental impacts as well as deleterious economic conditions.  While you won’t likely see Eurasian watermilfoil in the next episode of your favorite zombie thriller, it seems to have the ability to come back… again… and again…. and again!

For the entire article entitled “Fragment viability and rootlet formation in Eurasian watermilfoil after desiccation”, please go to the article online made available in the Journal of Aquatic Plant Management.  For more information on Eurasian watermilfoil and other troublesome invaders, go to the Aquatic Plant Management Society Website.  For more information on EWM, visit the APMS EWM webpage.  Stay tuned for more information on all that is Aquatic Plant Management on our Blog!

The APMS Blog is prepared by Dr. Brett Hartis, NC State University
This entry was posted in APMS Blog, eurasian watermilfoil, invasive species, milfoil, Myriophyllum spicatum.