This Summer We're Thinking About Plant Surveys and Healthy Lakes

Aug 13, 2019

Susan Knight of UW-Madison’s Trout Lake Station is enjoying her summer by doing aquatic plant surveys, and she may be coming to your lake soon.

She tells us about it for this month's Field Notes.

It is summer, and lots of folks are out waterskiing, fishing or paddle boarding on our area lakes.  That is all well and good, but for me, the best way to enjoy a lake is to do an aquatic plant survey. Yes, I am a complete plant nerd, but, honestly, these really are fun and even important. There is a bunch of us around the state who spend part of the summer doing plant surveys on our lakes.  You will know us when you see our 15’ long, two-headed metal rake plunge into the lake over and over and over again, pulling up plants from the bottom.  Though it can get a little tiring, I just can’t wait to see what the next rakefull holds; for me it is like a nearly endless pile of Christmas presents waiting to be opened.  Plants are critical to a healthy lake, and the different species and their abundance says a great deal about your lake. During a survey, we’ll visit hundreds of points on a lake, with each site’s location pre-programmed into a GPS unit we use to navigate to each point.  We record every plant species we see, along with other data from each site. Altogether, we end up with a good snapshot of the vegetation of that lake. Because we keep the GPS points, we can return to the same points, at least approximately, and compare the results from a survey done in one year to another to look for any changes.

The plants are not the only things that get our attention on a lake. Hey – we see lots of lakes, and it is only natural that we have become lake snobs.  We know a good lake when we see one. And what we are looking for is a natural shoreline.  We look for vegetation right down to the lake edge, with shrubs and trees arching over the water.  No lawns, please.  The lake shoreline is the most vital part of your lake.  It is simple - the more natural your shoreline, the healthier your lake. The most thoughtful residents live lightly on the shore; they are careful not to intrude on the functioning of the lake. They leave trees that have fallen into the water in place, knowing that the branches will become covered with a scum of algae, which will support an entire food web in the near-shore area. From the lake, you can barely see their house.  A simple pier marks their home, and otherwise, their love of their lake is evident from the lack of a conspicuous presence.  I was on a lake a few weeks ago, and almost the entire lake was like this – the ethic for the all the residents seemed to be one of respect for the lake itself.

Unfortunately, not every lake is like this. Probably you have seen lakes where it is evident that homeowners are mistreating the lake where they live. Many people think of the lake as their lake.  This is great if they are acting as good stewards, but not so good if they think it is their lake to abuse.  But the lakes do not belong to us – they are natural features and as lake lovers, it is our responsibility to try to keep the lakes in as pristine condition as possible. Lake homes with multiple piers, riprap along the bank and lawn to the shore likely have eliminated all the plants and animals that would normally live along the lake edge. This near shore area is one of the richest areas of biological diversity in the Northwoods and should be treated kindly and gently.

The Wisconsin DNR has a program called “Healthy Lakes” and they can help you evaluate your shoreline to make it healthier for everything living in the lake and on the lake margin.  They can help you put in a rain garden, to put all that rain coming off your roof to beautiful use.  They can help you re-engineer the slope down to the lake to prevent erosion from rain gullies.  They can show you how to add wood to your lake to get the same benefits of a natural treefall.   They can help you plant beautiful shoreline plants to provide habitat for all the near-shore animals for your wildlife-viewing enjoyment.  You can turn your lake back into a Healthy Lake.

So, treat your lake right!  Who knows, we might be surveying your lake next and casting our snobby judgement on your plants and shoreline.

And by the way, I would like to thank whoever lost their musky rod, complete with fancy reel and musky lure, into the middle of a certain lake east of Eagle River, that I miraculously snagged on my plant survey rake a couple of weeks ago. So thanks!

For Field Notes, this is Susan Knight of UW-Madison’s Trout Lake Station.