After discovering Najas minor growing near the Ledgemere dam of Lake Arrowhead in late 2020, I was raring to start surveying for this ‘enemy’ by the time June rolled around the following year. I was super-motivated and confident that finding them early would stop them becoming problematic and well established. Our DASH (Diver Assisted Suction Harvester) team was ready to act and remove growing stands as soon as I found them.
It was difficult to distinguish easily between young N. minor and N. gracillima plants this early in the season. Both species were bright green, and the strap leaves serrated. I began to doubt whether I’d ever get them sorted out, and kept second-guessing my identification. But we got them figured out eventually, with help from books and real-life experts.
The search continued to be frustrating - I was bursting with eagerness and enthusiasm, but these weren’t enough to produce results. No matter how much free time and energy I had available to survey, no matter how much time I put in, I couldn’t get the results I craved. I’d go to bed every night excited, anticipating that the next day might be my big find, that I’d finally be able to expose the hiding place of those wretched invasive naiads. My hope for discovery kept me motivated.
I knew they were out there, but where? The floating N. minor fragments were a big tease - they let me know they were rooted somewhere, but the location of their nursery remained a secret. I surveyed both new, and already-checked, areas over and over again. I tried honing in on areas where we’d found them growing last year, and tingled each time I went out, poised and ready to swoop in and be rewarded with a find (horrible as that might be). A check of wrack on our beaches and boat launches gave me a broader picture of the plant’s distribution in our lake (a highly fractal shoreline), but the location of growing patches still eluded me.
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| My surveying method in shallow, silty areas |
By mid July, I had found a few individual straggly plants growing in my own cove, which I usually comb through, and weed, on foot or boogie board. When I found a 14" long N. minor fragment near the dam, I panicked. A diver tow through the area yielded very little - the viewing conditions and coloration of the water restricted visibility. And possibly, the plants hadn’t matured sufficiently to show off their unique, unmistakable ‘signature,’ seen below.
I continued surveying, going to bed each night with eyestrain from continued scouring of the water column. I began to think I might be going insane - I was going back to the same places over and over again, expecting a different result. I have learned that the insane part is getting the timing wrong. In the case of plant growth, timing is key, and slowly but surely, by mid August, I began to find small groups of growing plants. September was like hitting the jackpot! Every time I went out to places I’d monitored a few times already, I found a few more. The plants don't show up early enough, and I had to learn to be patient. I was shocked at how excited I was about finding this invasive growing! With more and more experience in removing the marked plants, our DASH crew began finding plants in the deeper areas without my help. They successfully removed all the plants we could find, but what makes N. minor a difficult plant to manage, is that the window of opportunity for finding and removing it is incredibly short and intense.
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| Najas minor, European or brittle naiad |
I’ve really enjoyed going out onto my lake with a purpose. I feel as if I’m doing something meaningful and worthwhile with my time, and I always find and discover fascinating new things I wasn’t expecting. I happened to come across a small patch of Lythrum salicaria (purple loosestrife) during my scouring of the lake, and was able to remove it in its entirety (win). I saw and enjoyed remote and less-traveled parts of our lake, and figured out how to transport a kayak inside a small compact car, and close the trunk! Next year however, I shall save my naiad-nerd intensity for the appropriate part of the season.