Gas – The Big Bad Bugaboo of Benthic Barriers

In the lingo of lake management professionals — LakeMat Pro is known as a “benthic barrier.”  “Benthic” simply means lake bottom.


Where does all that gas come from?

You kill off some of your lake weeds and quickly, bacteria start digesting them. In the process these bacteria start creating gases during their digestive process — lots and lots of gases.

There are two types of bacteria digesting your lake weeds. Aerobic bacteria, which use “oxygen” and — Anaerobic bacteria, which don’t use oxygen. The whole process is called, “biotic decomposition.”

Aerobic bacteria work in water, where there’s oxygen. They efficiently digest organic material. Anaerobic bacteria work down in the muck with little or no oxygen. They’re very slow at digesting organic material.

As aerobic bacteria digest, they create methane gas, (yes, just like we sometimes do). Methane has no scent. It’s “natural gas,” the same gas that fuels our furnaces and ovens.

As anaerobic bacteria digest, they create hydrogen sulfide — it smells like rotting eggs. This gas is lethal. You’ve probably read about people succumbing to hydrogen sulfide gas.

If you’ve waded in a mucky area and noticed a rotten egg-like smell, your footsteps have released hydrogen sulfide from down in the muck. Don’t do this a lot — it can be dangerous.


Gases why tarps and plastic sheets dont work

But most of the gas released isn’t methane or hydrogen sulfide — it’s nitrogen, the most common gas in our atmosphere. Nitrogen is released as plant cells break down — which also creates ammonia and carbon dioxide. Gases are released continually until decomposition is complete.

When your dead lake weeds decompose they release — oxygen, nitrogen, methane, hydrogen sulfide, ammonia and carbon dioxide — all of which, can get trapped under lake weed control mats.

Knowing this, you can understand why tarps, tarp-like materials and plastic sheeting doesn’t work well for lake weed control mats — they can’t let the gases out. They fill with gas, bubble up, float, get caught in boat props and cause problems.

LakeMat Pro’s patented fabric is gas permeable — lets gases pass directly through it — we add gas-release ports — we use rigid steel frames, augmented with stakes to anchor it on the lake bottom, but…


We designed the best benthic barrier ever made

We designed the best engineered lake weed control mats ever made — yet even LakeMat Pro still gets some gas bubbles.

How can this be? Gas behaves differently under “low pressure.” A party balloon loses helium quickly when it’s full, but much slower as the pressure drops. Without pressure, gas under a LakeMat Pro collects and dissipates slowly — like a party balloon.

If your LakeMat Pro is in deeper water, you probably won’t even notice this. But in shallow water, you might. Many people don’t care about it. I care — because I invented LakeMat Pro.

I’ve work on this and figured out how to eliminate gas bubbles entirely. We’re working on a way to effectively incorporate it into the design.


If you get a gas bubble five things you can do

Meanwhile, If your LakeMat Pro gets a temporary gas bubble, there are six things you can do.

  1. Add temporary weight (like flat patio stones) where the bubble forms.
  2. Walk on it to “burp” the bubble out (it’s kind of fun).
  3. Use the plastic stakes (we provided) to pin the mat fabric down.
  4. Ignore bubbles — they don’t hurt anything and go away eventually.
  5. If it’s a very mucky area — consider using a MuckMat Pro
  6. Poke a small hole in the fabric where the bubble is, (it won’t unravel).

I had a test LakeMat that bubbled in one spot for two seasons. When it showed up the second year, I poked a hole in it the bubble never returned, (turns out, it was over a spring).

Some areas produce a lot of gas — and some don’t. As a general rule, the softer the bottom, the more gas it produces — a result of organic material being digested by anaerobic bacteria deep in the muck.

Biotic decomposition is a complex process — and I know this was a very simple explanation. But I want you to have a basic idea about gas — the big, bad, bugaboo of benthic barriers.