My husband, Dale, and I live on Lake Arrowhead’s lakefront in York County. Our lake is infested with Variable water-milfoil, and our Conservation Council uses a diver assisted suction harvester to keep it from choking up our boating areas. At the beginning of July, we participated in the free online Aquatic Species Plant identification course run by the Lake Stewards of Maine. It was a perfect thing to do during our COVID-19 shelter-in-place measures. Up until then, we classified aquatic plants into Variable water-milfoil, and NOT Variable water-milfoil. Part of the LSM coursework was to collect and identify a few plants, using the online key and distinguishing characteristics that Roberta had taught us, and share our findings on Zoom. We passed our tests, and became certified Plant Patrollers.
After the course, I continued looking carefully at the plants and fragments being washed up in my cove because I’d discovered a new-found interest. I was fascinated, and keen to practice my new skills. It was like a new puzzle or sleuthing project, and the detective in me kept trying to figure out what I was seeing. On Aug 21, I became aware of a plant fragment that looked unfamiliar, and very different from the usual varieties that washed up on my shore. I became suspicious. It was crispy to the touch, and had very distinctive teeth along each curved leaf. It’s quite possible it had showed up previously, but I had not yet reached the level of discernment I needed to acknowledge its distinctness.
I felt alarms going off in my head when I saw it, and went to the online identification key. It looked like one of the 11 invasives listed, and I felt a horrible sense of dread. Dale looked at it, and came to the same conclusion. I immediately texted some pics through to Roberta, explaining that I suspected I’d found the invasive European Naiad (Najas minor). Her response was swift, and concurred with my initial identification, but in order to be 100% sure, she needed to examine a sample, which I mailed to her. After confirmation from fellow taxonomists, she gently let me know that I was, unfortunately, correct. I was devastated - I had correctly identified the plant, which made me feel good about my identification skills, but upset that I had confirmed another invasive for our lake. It was a terrible blow. Now I needed to find where the fragments were coming from. I scoured the cove in front of our property and found 8 skinny plants growing right under my nose! I felt awful, as if I were harbouring a fugitive. But these few plants couldn’t account for the fragments washing in from the open boating area. Dale and I started kayak-surveying along the shoreline, on both sides of the dam, and came up with nothing.
The DEP responded rapidly after the confirmation ID. I got a call on Monday morning from Laurie Callahan of the York County Invasive Aquatic Species Project (YCIASP), saying she was at the boat launch with a team of volunteers and would be in my cove in 20 minutes! The response that the DEP had set in motion was amazing! I’m so impressed at how quickly they took action. The Lake Arrowhead Conservation Council’s DASH team participated too, and located a flourishing mat of the invasive in an area estimated to be about 50 feet across, just outside our cove. I felt sick to my stomach, as up until now, we’d only seen individuals scattered here and there in our cove. More importantly though, the site of the large infestation was where our Public Works crew would be installing a water pipeline in the upcoming weeks. It was imperative that we remove that infestation before the scheduled disturbance began. Four days later, Milfoil New England came in to remove the large mat of plants, and any others we’d marked during the subsequent organized surveys by YCIASP’s enthusiastic volunteers. The Lake Arrowhead Conservation Council and DASH team used this as a learning experience to find out how to adapt our suction harvesters so that they could tackle this plant next year.
Dale and I continued surveying whenever we could, especially when the light was good, using the skills we had learned from Laurie’s trained volunteers. We located another large infestation in better lighting conditions in an area previously surveyed. That is the beauty of having a team on site and available when conditions are perfect. Dale donned his wetsuit and began snorkeling in earnest to help get a broader view of plants, without the nuisance of surface winds and ripples. This enabled the discovery of numerous additional plants. With the permission of John McPhedran of the DEP, he was able to dive and harvest individual plants with a deep landing net, which he handed to me in my kayak to empty into plastic bags. I floated above the site and scooped up any surface fragments with my hand net. Though very few escaped his net, I nevertheless made sure to “scoop first, ask questions later.” That way, I didn’t miss anything. We have since removed over 50 individual plants in this manner. (See video.) With very little time left in the season for removal, we recently constructed an enormous hoop with mosquito-netting mesh to remove a large stand that won’t be able to be tackled by a suction team this year.
Were it not for COVID-19 restrictions, I’d likely not have spent time on an online plant ID course. Everything just seemed to fall into place to discover that suspicious plant when I did. If I’d seen it without benefit of the course, I’d have overlooked it completely, which is a very scary thought, because before July of this year, I had NO idea what this plant looked like. Additionally, Dale and I are thrilled to have made new friends and found a community of like-minded people who care about Maine’s lakes as we do.