On a 93 degree day, nobody wants to do trail work or any type of hard labor outside. It seems on the 29th and 30th of June I lucked out and landed an opportunity that provided a cool environment and a lot of sunshine. Eurasian Milfoil. Yes, an aquatic invasive plant species was the reason I spent two entire days canoeing and trenching through Coldwater Lake, getting badly sunburned and shivering until my lips turned blue. Not to mention, our crew for the project was so cool, I can say this is an experience that I will not forget.
Monday the 29th started with a 2 hour drive to the lake. I was pretty excited for this project, not just because it was 93 degrees and I was dying to get out on the lake; but it was a different type of opportunity that I haven’t experienced yet. It was a chance to learn about species inside of a lake that was formed from the result of a volcanic blast. Although we focused heavily on Eurasian Milfoil, I was with a fish biologist and a group with plenty of experience identifying aquatic plants.
The first day was a recon day where I met with a couple of plant experts from Skamania County who provided me with a lesson in Milfoil and the various other plants growing at 20ft depths in the lake. We paddled along the West, South and North shore of Coldwater Lake plotting points of plant species by dragging a rake connected to a rope and looking through a tube with a clear lens on the end. Low tech devices, but highly effective. We were able to compare our results from a survey in 1998 and realize that the Milfoil levels have mysteriously gone down. Although I did not get my hands on these notes, we were briefed that it was a dramatic decrease in Milfoil in comparison to our findings. We were only able to find Eurasian Milfoil in and around the stream on the west end of the lake.
The following day we set up two 30ft nets at a marked point in the stream to create one giant net. This is where we broke into our job duties that included 3 forest service master divers, 3 people with hand nets collecting fragments of milfoil in the water and another three assisting the divers by collecting the milfoil that the divers pulled and placing them into mesh bags. By now, I imagine you are wondering why I haven’t completely described the problem with Eurasian Milfoil yet. Eurasian Milfoil is an aquatic invasive species native to Europe, Asia and North Africa. It reproduces from small leaf fragments floating in the water and fragments very easily. It also destroys other plant life by pulling oxygen from the water and blocking sunlight. There are plenty of other details of this species, I just want you as my reader to understand that it’s invasive and a problem. It can also be spread by boats, boat trailers and water fowl.
My first duty was to follow one of our divers with a mesh net. He snorkeled through waist high water in the stream, pulling the milfoil by the roots where I followed up by placing the chunks of milfoil into a mesh bag. This went on for about an hour until the water reached up to my neck, where our diver traded out his snorkel for a couple of diving tanks. There wasn’t a whole lot of me moving around in this neck deep water and this lasted for about another hour. My movements were about 6 inch steps every 45 seconds. I eventually started shivering and I was told my lips turned blue. As you can imagine I was also told to get out of the water. I was a little bummed over that, but was relieved to go post up in the sunshine for a while. From there, my duty was to help out by netting fragments of milfoil in the water and also empty out mesh bags for our people that were assisting the divers.
Being out in the sun definitely had its perks; it helped me have a speedy recovery from getting cold in the water and it also felt so good considering I haven’t sat out in the sun like that since last summer. Then, I was told to get out of the water again. Apparently (which now I can really feel), my back was annihilated by the sun. I had already put on a huge amount of SPF 40 sunblock before coming out, but clearly my skin is not accustomed to that much sunlight. I was then told to hold out my arms and got sprayed with massive amounts of SPF 70. It actually smelled pretty good, but I’m not sure how long it lasted considering I went directly back into the water.
We finished up at about 4:30pm. By the looks of things, our manual pulling efforts have cleared Coldwater Lake of its Eurasian Milfoil problem. We then gathered up all supplies, took some soil samples to examine the volume of the soil that the milfoil was growing in and debriefed. We talked about methods that we found useful for pulling the weeds and also discussed how effective we thought our efforts were. Unfortunately in most cases a manual pull is not very effective for eradicating milfoil, but our observations of the milfoil not acting as invasively as it normally does is keeping our hopes up. It sounds like we may go back in August and see if the problem continues. I guess we can only keep our fingers crossed.