Fish Like a GIRL

I would be remiss if I did not mention that this week is National Invasive Species Awareness Week. This is a topic about which I have written quite a bit. But, as I have learned about other topics I cover (neonicotinoids, for one), although I write about it, there are still plenty of people who have limited knowledge of these things. That said, I believe this is a good time to take a look at a few invasive species found in the Northwoods, and a few that are knocking on our door.

CBCW and WHIP

No conversation about invasive species can be complete without speaking about these two groups: Clean Boats Clean Waters (CBCW) volunteers and the folks at Wisconsin Headwaters Invasives Partnership (WHIP). Each group targets invasive species, with the former most concerned with Aquatic Invasive Species (AIS) the latter Terrestrial Invasive Species (TIS).  Both groups work toward a common goal, and that is the goal of stopping the spread of invasive species. Both groups are also big on education and outreach — helping people better understand why invasive species are bad and how to help to keep from moving them, or even working on getting rid of them where they are found.

Most boaters have come in contact with a CBCW volunteer or intern working in that same capacity. They are the people in the blue shirts at the launch ramp that ask a variety of questions such as:

“Have you had your boat in any other body of water in the last seven days?”

I am a trained Clean Boats Clean Waters volunteer. While a bunch of my weekends in the summer are taken up with fishing tournaments, I do still have some weekends open, and even some weekdays. (I mention this in case there is a lake association out there that might need a hand. Feel free to reach out and I’ll see what I can fit into my schedule!)

EWM

One of the most widespread aquatic invasives that many lake groups fight is Eurasian Water Milfoil (EWM). The thing with EWM is that it’s been determined that it does not act the same in all water bodies. In some cases, it can take over and making swimming and even boating impossible. In other lakes, it seems to be more “well behaved,” if you will. 

Eurasian water milfoil grows early in the year, often starting to grow while there is still ice on the lake. It grows quickly up through the water column and can form dense mats on the top of the water. This leaves no light for native plants to grow, especially those that get a later start. In many areas where EWM is prolific, it can do away with biodiversity and may not even make good habitat for fish and other wildlife.

For many years, an herbicide called 2,4-D has been used to combat EWM. However, with concerns to non-target species, Procellacor has come to the forefront as a replacement. While studies have shown this particular chemical compound to be less detrimental to other species, many still wonder whether adding chemicals to their lake is the right thing to do.

Rusty Crayfish

Rusty crayfish are another seemingly ubiquitous aquatic invasive species. Rusty crayfish have found their way into Wisconsin lakes in a few different ways. Some were “set free” from classroom where they were kept as pets or teaching tools. Others may have been dumped by fishermen back in the day who were using them for bait. Because they were bait, anglers would have assumed the excess they put back into the lake would quickly be consumed by the fish in the lake. Unfortunately, that did not prove to be true.

Rusty crayfish are voracious eaters, capable of cleaning all of the vegetation out of a bay in a short time. Again, these invaders outcompete native crayfish in areas where they are introduced. They do not always make good food for those species that have traditionally dined on native crayfish species.

Rusties, as they are called, are larger and more aggressive than native crayfish. There is evidence, of course, that fish will eventually learn that rusty crayfish can be a source of food, which may keep them under control somewhat.

There has been some recent research done at Trout Lake Station looking at the decline of rusty crayfish in Trout Lake. These aquatic invasive species seem to be succumbing to a parasite that only affects rusties and not native crayfish. Indeed, there has been anecdotal evidence on several other lakes that rusty crayfish are either in decline or completely missing in areas where they were once abundant.

Buckthorn

Buckthorn is a terrestrial invasive species that many landowners have found on their property. Buckthorn was planted on purpose, for the most part, before it was known to be problematic. Landowners used it as a “natural” fence or barrier or in other places where a dense, natural “wall” of sorts was felt to be needed.

Buckthorn is problematic in that it does not make good habitat for most native wildlife. It also takes over areas and does not allow native tree regrowth as well as shading the understory, making it impossible for smaller native plants to grow in an area. 

Small stands of buckthorn can be manually controlled through hand-pulling. However, larger plants are normally cut down and the stumps treated with an herbicide. Interestingly, goats have also been used as an eco-friendly alternative with some success. A herd of goats is capable of knocking back some buckthorn, as they will eat just about anything. In the last couple of years, I have heard of goats being used to fight invasive species, and I think that is pretty awesome that people thought to give goats a try.

Garlic mustard

Many in the Northwoods have had battles with garlic mustard as well. The only saving grace of this terrestrial invasive species is that it is edible. It tastes much like mustard, as its name implies. Unfortunately, I would say a person really needs to love mustard in order to eliminate this invasive species solely by eating it. I should say though, that it should only be eaten when it is younger. It requires full cooking when older to reduce toxicity.

Like other invasive species, this species is native to Europe. It was originally planted for erosion control and for herbal uses. Then it was found to be invasive and to cause problems in just about every place where it had been planted. It can take over an entire area and push out native plants. 

Like other invasive species, garlic mustard grows early in the year, meaning it takes over the space, and the sunlight, that native plants need in order to grow successfully. Invasive species also weaken the entire ecosystem by changing the understory of a forest. That understory is important to native, beneficial insects, meaning once that has changed, it could conceivably throw off the entire food web.

Canada thistle

Of course, I also have to talk about Canada thistle, a terrestrial invasive species that is not only bad for the areas where it is introduced, but I can say from personal experience is also a pain (literally) for humans who have to deal with it.

As many readers know, the home Chet and I bought last year was surrounded by several invasive species. Rosie Page, the coordinator for WHIP, helped me identify a few things. She was my “phone a friend” for several species. I would text her a photo and she would tell me what to do to get rid of my invaders.

One of those was Canada thistle. Some of the thistle on the property line was huge. When I say huge, I mean I could not even take it down with a machete. I had to get out the electric chain saw to take care of it. Then we dug it out by the roots. That area was part of what we disturbed in the garage build, so the hope is to have natives in place in the spring, although I would imagine there is still a seed bank from some of the pests I pulled and dug up last year. 

I hand-pulled some Canada thistle in my flower garden. I used Chet’s welding gloves, which seemed to work pretty well. I would not recommend it with normal gardening gloves. I was stabbed several times using those before I got smart and pulled out the “big guns.”

There are so many people who are active in the fight against both aquatic and terrestrial invasive species. Some of these invaders, such as EWM, seem to be here to stay. Others, such as spiny water flea and European frogbit do not have large, established populations in the Northwoods at this time. But people today are more mobile than ever, and there has been much more talk of late about more and more people potentially heading to the Northwoods. That leads to the potential for more invasive species to be moved around. 

I firmly believe that outreach and education efforts are imperative when it comes to stopping the spread of invasive species. 

Beckie Gaskill may be reached at [email protected].