At the ramp today, I had an interesting conversation with the DEC boat inspector. He was inspecting the boat for invasive aquatic weeds, namely Eurasian milfoil and hydrilla, as is standard in NYS if you’re fishing waters with these invasive weeds and he mentioned how the milfoil is really affecting the bass fishing in this particular lake. I’ve always understood that milfoil and hydrilla are bass magnets. It can be hard to fish when it mats up, but that doesn’t mean the bass don’t love the stuff. But this gentleman explained to me that because the milfoil is matting up so bad, it’s pushing the bass to spawn deeper. That deeper spawn makes the eggs non-viable in some cases, which of course would affect the bass population negatively.
 

I had never heard of something like this happening. Sure milfoil and hydrilla can completely choke out a body go water, but I’ve never heard of that affecting the fish population negatively. The fish-ability of a lake? Sure I could see how having milfoil as thick as butter could make it hard to fish. But I still can’t wrap my head around it negatively impacting the bass population. But then again I’m no DEC biologist, just a bass head. 
 

Has anybody heard of this before? Milfoil or hydrilla reducing the population of bass? 
 

On another note, I probably should have told the inspector about all the invasive water chestnut and maidencane I saw on the water as well. Water chestnut is the actual worst. 

I’ve never heard anything like that before.  I’ve seen in multiple lakes a direct correlation between the amount of aquatic grass and the quality of the fishing.   I’ve also fished for fish on beds on Guntersville where the weeds were so thick it was difficult to run my trolling motor.  The bass found holes in the grass where they made their beds.  I never assume that what I observe here is the same everywhere else.  I’m sure weeds affect other species differently as well.

Usually up here there isn't much weed growth by the time the bass spawn, which is usually from mid May until mid June, depending on the size of the lake and how far north it lies.

 

We have milfoil in many lakes here.  It gets so thick in some areas its almost unfishable.  But its not present in thick mats when the bass spawn, so I don't see how it could be affecting their spawning cycle.

@gimruis that’s another thing I thought about. The bass spawn is wrapped up before any vegetation becomes matted here as well. 

For a bit of change, I sometimes do an history tour in the morning and then, in the first part of the afternoon, I  choose a part of the lake that I have not visited or a section that doesn't look to good and try to get the most out of it.  You often get surprises.  

I have observed large concrete stepping stones covered with gravel  and tires filled with gravel placed in 3’ of water where weed beds are thick to attract bass to spawn. 

Tom

 

Never heard of that

 

Hydrilla, Coontail & Milfoil die back during winter.

 

Even when matted there are tunnels & caverns under the mat.

The lake I fish close to here is having one of its best years ever in the history of the reservoir for bass fishing. It is snotted with hydrilla in most places shallow. Like Catt said, there are tunnels and caverns underneath. But also, there are some places shallow with a different bottom composition where the hydrilla is greatly decreased. These have actually been places that I look for when I go fishing

Like the Marines, bass will improvise, adapt, and overcome all obstacles in all situations.

Two thoughts come to mind.

 

The first is that heavy vegetation will filter the water, usually leading to clearer water and subsequently allow the bass to spawn deeper since sunlight can penetrate deeper, so the two kind of work in tandem.

 

The other thought is more commonly, bass will spawn along the inside milfoil weedline as the stuff rarely grows all the way into the shallows. Plus as others have mentioned, hard bottom areas inside the milfoil from roadbeds, rock or gravel or even shell beds will all create openings where bass can spawn.

 

Plus, weedgrowth allows lots of spaces for the juvenile largemouth to hide, leading to less predation and greater survivability, hence stronger bass populations in most cases.

3 hours ago, Jar11591 said:

The bass spawn is wrapped up before any vegetation becomes matted here as well. 

Exactly. I'm a little south of you, and they're off beds no later than the 1st week of June at the very, very latest. Usually, a few weeks before then. The weeds don't hit their fullest until about now and going forward.

The only thought I have about that is maybe a dissolved oxygen thing, the invasive milfoil where I'm at will die off when it gets to a certain thickness and the water around it will get gross. There's times and places where that essentially turns it into a feeding frenzy for microorganisms and the things that follow, but after a time the decomposing grass will rob some oxygen from an area. I'm not a biologist though.

Around here the water is very clear which allows sun penetration and the abundance of hydrilla, especially the more shallow lakes.

Does not effect the reproduction of bass.

My experience on a northern, clear water, natural lake with both milfoil and hydrilla says that DEC officer has incomplete facts or is just wrong, but this also applies to me.

 

scott

So, there is a pond near me in CT, where the bass fishing was incredible for years. Then millfoil took over. And I’m not talking about MOST of the lake. I’m talking ALL. All the edges, even in the middle. I’ve fished the entire lake (it’s small) and not found a single spot without mill foil and hydrilla. It’s so bad you can’t even stick your hand through it. Even tying a massive 5oz saltwater sinker and trying to drop it through does nothing. Lo’ and behold, the fishing there is terrible now. My thoughts were exactly what that biologist said. There used to be specific sandy/rocky bottom spots they would spawn in that lake. They are now overgrown and there are no fish in those spots spawning. They’ve been pushed back into this one cove area that is about one foot deep at the deepest, and that cove gets INSANE wind, so the eggs can’t hold their ground. Bad situation.

I talk to your local DNR or whomever is responsible to manage the lake.

The aquatic plants will die back during the winter a good time for some habitats restoration.

Tom