Monroe Lake is home to a wide array of beautiful native plants and animals that make the reserve a popular place to visit for hikers, fishers, naturalists, researchers, and anyone just looking for a place to cool off on a hot summer day. However, like most large bodies of water, the Lake and its surrounding lands have begun to be negatively impacted by the spread of invasive species. These species pose a threat to the native ecosystems and waterways that play a key part in the lives of Monroe County citizens.

Many obstacles stand in the way of clean and clear waterways, biodiversity, healthy ecosystems, and more. However, one threat stands among the rest as one of the greatest potential threats to our waterways – invasive species. These invasive species can dominate ecosystems, harm native species, forestry, and fisheries, and their presence is rapidly growing in Monroe Lake.

Until the early 1700s, the land of Lake Monroe was actually occupied by the Miami and Delaware tribes. The land that’s under the water was predominantly agriculture until the late 1950s. On March 24, 1954, the first announcement came out about the plans to make a 5600 acre lake. At the time, the major purpose of the creation of the lake was flood control. Approval was granted for the project by the Army Corps of Engineers in 1958, and then ground was broken on October 25 1960. The lake was actually fully functional by 1965. Today Monroe Lake serves as the primary water source for the City of Bloomington. 

The Lake is home to many native plant species such as yellow lady slippers and puttyroot orchids, an array of wildflowers, and trees such as yellowwood. Within the water, bluegill, walleye, yellow perch, and large and smallmouth bass, call the Lake their home. 

However, their homes are becoming threatened. On land, a variety of invasive species are beginning to take over. Martha Miller, the district manager at the Monroe County Soil and Water Conservation District talks about some of the invasive species near the Lake.

Miller commented, “The most prominent species near the lake are the standard ones that we find throughout most of Monroe County and predominantly Indiana- the autumn olive, the bush honeysuckle, the garlic mustard, the multiflora rose – those are all ones that are pretty common and grapevines inside the wooded areas, those kinds of things.”

These species all negatively impact the native biodiversity by disrupting ecosystems, altering habitats, and outcompeting native species for resources, all of which lead to the decline of native species in the area.

But how exactly do these species harm ecosystems?

“Again, that question sort of answers itself. It’s not natural. It’s not native. It doesn’t belong. When a germ or a virus enters a human cell, what happens? We get sick. We need medicines to help us take care of the problem. Same is true here as for the long term effect. We don’t really know what the long term effect will be. We only know what damage and concern has been done up to this point in time, and how these non native plants are working so hard to destroy and take over our native lands,” says Miller.

WFHB News spoke with Jill Vance, a Monroe Lake Interpretive Naturalist, who spoke more on their threat.

Vance states, “One really easy to see is that they just out-compete native plants, and then we end up with a monoculture of just that plant. And you know, particularly for some of the shrub or herbaceous layer stuff, that’s going to be really evident when you look around. This is nothing but this, and if you have nothing but that, you are limiting food options for our native wildlife, because they’re not adapted to eat that stuff. And lot of these invasives are things that become able to out compete our natives because the animals aren’t interested in them. And then also you have effects that are even more pernicious, that may not be immediately obvious. There are some, some of these non native plants can actually change to soil chemistry itself, to actually block native species from growing and make it even easier for them to out compete. And so then the net effect that you end up here is just an overall decline in diversity and support for our native animals, and, you know, a reduction of available space that our native flora species can thrive in.”

Vance also commented on how these species spread, even when it may appear like they are not.

“They keep growing back, and people keep planting them. So, we keep seeing them escaping. A lot of invasives that enter natural areas were not planted there deliberately, but they have escaped from landscaping, and people may think their invasives, like burning bush and such are not escaping. I guarantee they are. You’re just not seeing that escape happening right in front of you. You know that with berries, that berry is getting carried several yards over, or even a county over, and being dropped there and spreading it, and so that’s that’s a big problem that we get with invasives,” remarks Vance.

The easy spread of these invasives is part of the reason why they are extremely hard to control. Currently at Monroe Lake, there is no formal program for the removal of these species. However, Vance still has hopes.

“We do what we can. We do have some volunteers working who’ve worked in the past on autumn olive in particular, and trying to tamp it down. I would love to have people who really want to go after bush honeysuckle. I got plenty for them to work on, certainly people. So you know, please contact me if that’s something you’re passionate about, because it is a matter, really, of just hours and hours, and you gotta keep going back and keep tackling it. And you know, unfortunately, we don’t have any staff who are dedicated just to that effort. And so we really have to rely on volunteers who are passionate about doing something in that area. And I’m always happy to find volunteers who would love to help kill an invasive species and get rid of the honeysuckle and the autumn olive and other stuff.”

More information on volunteering can be found at IN.gov/DNR under volunteer and internship opportunities. 

The Lake itself is not immune to its own set of invasive species.

Dave Kittaka, the District 5 fish management biologist for the DNR, said, “The predominant invasive fish species in Monroe Lake are Gizzard Shad and Common Carp.  Both of these species have established fish populations since the mid-1980s.” 

Invasive Asian carp, more specifically silver carp, have been found in Salt Creek, directly downstream of Monroe Lake’s dam. Craig Jansen, the invasive carp biologist for the Indiana DNR, spoke more on the carp.

“There’s four invasive carp species: silver carp, black carp, bighead carp and grass carp. Of those four, basically all of them got brought into the US in the 60s and 70s, and they primarily got brought here for aquaculture purposes, so like fish farms down south. They brought them in to help clean up water quality and various issues in those fish farm ponds. And then, you know, over the years, floods happen and levees can break, and fish got out, started making their way up the Mississippi River. Today, silver carp are definitely the biggest issue. They’re the ones that jump. They’re in super high numbers.”

Kittaka also spoke on the carp stating, “To date, we have only documented 3 Grass Carp and have not documented other invasive carp species like the Silver and Bighead Carp.  Silver and Bighead carp can be found below the dam in Salt Creek, which is too close for comfort.” 

And too close for comfort is correct. Jansen states this concern clearly: “Whenever they can swim there, they can eventually get there.”

Similar to the terrestrial invasives, these carp were introduced into the ecosystem by humans, and humans still play a key role in their spread.

“Initially they were just brought here, so it was kind of a man made introduction, not intentional, obviously, but they did get out. One of the big ways that they can be spread is through what we call bait bucket introductions, so anglers could be cast netting. They’ll use just a net. They’ll throw it out to catch bait fish, so that they can take those bait fish, put them on a hook and then go fish for whatever else they’re fishing for, catfish or bass or crappie. Well, at the end of the day, if they still have minnows in their bucket, they may just dump them out wherever they’re at, and if they caught something like silver carp, and then they transported it to a different water body, and then at the end of the day, they dumped it out – that could be a potential pathway to spread these things,” says Jansen.

Kittaka also commented, “Small Invasive Carp look just like small Gizzard Shad, and it would be easy for anglers to mistakenly use them for bait and release them into the lake.” 

The Indiana DNR also has some regulations in place that are specifically aimed at limiting the spread of these invasive carp. Jansen talks: 

“So Indiana addressed that fairly early on. You’re not supposed to use a cast net within 500 yards of a dam, because a lot of bait fish congregate right below dams. And in the case of like Lake Monroe, a lot of folks maybe would go down there throw a cast net to catch a bunch of what they thought were shad or or other minnow species and and they would catch them, put them in their bucket, and haul them up to the lake to go fish for bass or crappie or whatever. And then, you know, that would obviously be a potential way that carp could get into the lake, if somebody dumped some live minnows out that weren’t from the lake itself.”

Kittaka also states, “Prior to this it was common for anglers to net bait below the Monroe Lake Dam and use them for bait in the lake.” 

In addition to this regulation, carp cannot be hauled alive. Jansen summarizes: 

“Another thing that we’ve done years ago was basically say you cannot haul carp alive. So that kind of regulations to make sure that, or to try to stop people from spreading these fish. So, you know, there are certain cultures that want to see live fish in a fish market, to take it home to eat it. They want to see that fish live first. And if you do that, if you’re allowed to do that, and have live fish that would be in a fish market, and those be invasive carp, obviously that’s not an ideal situation, because if, if one would get out or or be intentionally released, or whatever that could cause issues.”

In other states, where the issue of invasive carp has increased rapidly, other carp management tactics have been employed. Jansen talks about some management initiatives being done in surrounding states.

“Aside from those regulations we’re doing, there’s other states that have been doing a lot of stuff to lower and limit the spread of carp. So for example, like Illinois, there’s that electric barrier that you may or may not have heard of. It’s been in the news over the years, and they’re trying to get a new project off the ground. It’s called The Brandon Road Project, to put more of a permanent type barrier between Lake Michigan and then the Illinois River and using different technologies to keep fish from moving up through that stretch of the river. And they’ve done a similar one of that down in Kentucky, at Barkley Lake. Kentucky and Barkley Lakes are like multi billion dollar recreational fisheries, and there’s a lot of concern down there about carp getting in there. So they put up an experimental fish fence that puts out CO2 bubbles like it basically makes a bubble curtain, and then it also emits some sound and light. And since silver carp are very sensitive to those things, it has been having an impact on limiting the number of silver carp to come up in there.”

These initiatives are expensive and were not guaranteed to work during their installation. So, are they working? 

“So Kentucky hit it really hard in the Kentucky and Barkley lakes, because there’s a lot of bass angling and crappie it’s a really popular fishery, and I’ve heard a lot of reports from fishermen down there that are saying that, yeah, they don’t see nearly the amount of carp that they that they used to. The data from the commercial fishery itself, the fishermen are having to put a lot more effort in to find and remove carp. So we are starting to see those impacts. Obviously, it takes several years to to start whittling away that population, but if you get a barrier in like that, that fish fence that I was talking about, and then you add harvest above that fish fence,  you keep the majority of fish out. Then with harvesting the fish that are in the system, you can have an impact. And we’re starting to see that the Illinois River as well, Illinois has put a lot of fishing pressure in, like downstream of that barrier. So that way you just kind of keep that source population knocked back. So obviously, the less fish you have knocking at the gate of that electric barrier, the less likely they are to pass through the electric barrier. So and their data is looking pretty good, they’re starting to have a their harvest is fairly steady, but they’re fishermen are having a little harder time finding fish and starting to notice some changes there in the population,” responds Jansen.

This indicates that these initiatives are working, but it also highlights how these invasive species have the potential to reshape an entire ecosystem.

Monroe Lake is a beautiful body of water that has something for everyone, even where you least expect it. 

“You know, Monroe is the third property that I have worked at in the Indiana State Parks. I was at Spring Mill. I spent a little bit of time at McCormick’s Creek as well. Monroe is the first reservoir property that I’ve worked at, and the reservoirs are unique in our state park system, because we do try to take a little bit more of a hands on wildlife management approach. The areas of our property that I particularly like are our wildlife management areas. They’re just, I really love field habitats. I really do, particularly when they’re not filled with autumn olive and those areas, I think, you know, in the fall to go out and they’re just covered with Goldenrod and asters and some of the sunflowers. And you know, you’ve got that that fall, the fall sunlight coming across, and it’s just, it’s beautiful out there. And I like those areas. I think those are under-appreciated areas of our property and but for me there, that’s my favorite spots,” shares Vance.

Kittaka spoke on his experience saying “I have worked on Monroe Lake since 2004. I live in Bedford and raised 3 kids fishing and swimming at Monroe Lake.  Managing the fish population on this lake for all these years I have seen the highs and lows that come with these programs and also seen the things mother nature can do and how the lake reacts to those events.”

However, not all thoughts on the Lake hold the same sentiment. Miller shares some of her personal thoughts on Monroe Lake: 

“Honestly, Lake Monroe is a beautiful body of water that provides one of the opportunities to enjoy water recreations of various kinds, but it’s not that special to me. In fact, the development of this body of water is really no different than the invasive plants that you asked about earlier. While it is a wonderful natural attraction for hundreds of thousands of people to our area, offering an incredible boost to our local economy, the lake itself is not native. It is man made and was placed into a location that was never really intended for it to be as with invasive species. We have yet to see the outcome of the lake, cost to maintain loss of native wetlands, possible flooding in the future. All we can do is enjoy its beauty and nature at the moment and do what we can to protect it from where it’s actually at today.”

Here is just another example of humans drastically altering their environment.

The spread of invasive species is just one reason that conservation is desperately needed. Individuals like Vance, Kittaka, Jansen, and Miller focus on these efforts to study and ensure that our ecosystems are protected.

Miller describes her own connection with conservation as “instilled in her by her parents from a young age. They told her, taught her and showed her how to be a good steward of the land through gardening, food preservation, walks in the woods, health management of the herd, and protection of the grazing and forested lands.  These life lessons laid the foundation, proving to be a valuable segway into her position at soil and water.” 

As for Jansen’s passion for tackling carp, he speaks on his own personal path: 

“Well, I guess I didn’t really get into the job initially for carp. It just sort of happened. I guess I started here at Indiana DNR about 12 and a half years ago, and I was a big rivers assistant biologist at the time. Within a year or two, I got promoted to the big rivers biologist. And basically since that time, I was the big rivers biologist for like, six or seven years. And during that time, we just kept getting more and more involved in all this carp work, because all the states were also concerned. We actually, in the Ohio River Basin, started getting a lot more federal funding for tackling this problem. So we kept getting more and more funding, and I kept getting more and more involved in carp. And then in 2020 we got a big pot of money, and it was enough to justify, like us [the Indiana DNR], starting our own work unit. So we hired dedicated staff, so I kind of just sort of transitioned into that carp role, and now I’ve got two assistant biologists, and we just hired a program director that is overseeing some of our carp harvest initiatives. We’re really trying to ramp up and promote the carp harvest in Indiana. There’s a few barriers that we’re trying to get past to get more people in here and let more carp harvest occur. So yeah, it was kind of just this natural progression of getting more involved.”

Jansen also states:

“I mean, personally, it’s, it’s nice to finally, like, whenever you tell people that you’re dealing with invasive carp, they’re just like, yeah, go get them. Like, it’s always a positive reception. You don’t get that sometimes. In the other biologist roles, there’s a lot of anglers that are never happy with the fishery, and they’re always complaining. And with carp, there’s not a whole lot of people complaining about things other than wanting to get more of them out of the rivers.”

And after all the work these individuals have put in to tackle the problem of invasive species, they deserve some praise. Their efforts have begun to address the dangers of invasive species in our waterways, protect our ecosystems, and share their knowledge with their community.

More information on the invasive species in Monroe Lake and surrounding areas is available at IN.gov/DNR.

For WFHB News, I’m Amelia Bucher.