Nanobubbles: A new approach to Algae

Across Wisconsin, blue-green algae can be found in many lakes. This growth sucks the life right out of the water, killing lake towns. However, advances in technology are giving lakes across the state a fighting chance. California-based tech company Moleaer has a non-chemical answer to this toxic alga: minuscule bubbles. 

 They’re called Nanobubbles, and they are 2500 times smaller than a grain of salt. Their size causes them to have many properties that help remove algae and contaminants. While the technology is still relatively new, there seem to be very few downsides associated.  

Moleaer introduces nanobubbles into lakes with a series of machines. A nanobubble machine can be temporarily wheeled in on a trailer, or it can be installed just offshore. The average machine takes up about as much space as a pontoon. They are comprised of the Nanobubble Generator, a pump system, two large tubes for sucking in lake water and shooting out nanobubble-charged water, and a gas fuel source. These machines vary in size and power, but they can often run for several days without interruption. A larger container unit can pump over 2,400 gallons of water per minute and are estimated to cost about $600,000 each. 

Nanobubbles greatly increase dissolved oxygen levels, helping fight back against algae. Higher oxygen means fewer nutrients are released from low-oxygen. It also allows beneficial bacteria to thrive and collect what remaining nutrients there is. So there is far less food available to fuel algae blooms. In addition to this, when nanobubbles collapse, they create small amounts of reactive oxygen. This reactive oxygen actively damages algal cells and other harmful bacteria. So blue-green algae has its food source slashed, gets outcompeted for what food there is, and is damaged on a cellular level by nanobubbles. 

Declining algae levels go hand in hand with clearer water. Nanobubbles also have negative charges, keeping them from clumping together. However, it does help them latch onto contaminants and prevent them from spreading out. This creates big clumps or particles that fall to the lakebed. This reduces floating muck. Even more so, nanobubbles reduce further nutrients from being rereleased back into open water. 

Nanobubbles are effective at fighting blue-green algae, and there appear to be very little side effects. So far, there is no evidence that shows nanobubbles can harm an ecosystem. Some testimonials say that they have even helped fish numbers return. It seems that they help shift the ecosystem of inland lakes towards beneficial microbes. However, the Department of Natural Resources has ordered more extensive studies be done before these treatments can be made available to the public. It’s understandable why the DNR would want this, as the technology is new. However, things are looking good. 

Nanobubbles could be the next big breakthrough in lake conservation. Could such a technology be seen in our lakes? Follow us on social media for more on Paw Paw Lake preservation. 

Sources

Central Wisconsin lakes try nanobubble technology to stop algae blooms

What are Nanobubbles? | Moleaer

Research & Development | Moleaer | Advancing Nanobubble Technology

Wisconsin community experiments with nanobubbles to clean up lakes - WPR

Comprehensive Lake Management Plan - Nanobubble Treatment

Ongoing research into Powerboats and their Wake

Power boats are some of the most popular watersports commodities at the moment. Their robust engines and unique design bring a new life to sports like surfing. Any powerboat owner will tell you that these machines are incredibly powerful and need to be used responsibly when surfing or towing. Historically, wakeboard boaters have had to take additional care to prevent damage to property and persons. However, recent studies suggest that these additional precautions might not be enough. 

Powerboats can plane just like every other boat, with minimal effect on wake. They can also use a semi-displacement mode (or surf mode) to maximize the waves at the bow of the boat. In shallow waters, the wake made by surfing can cause damage to property and the local ecosystem. Most boaters know this already, as many powerboats stay 200 feet away from shores, property, or other watercraft. However, recent studies have challenged our previous understanding of what was happening under the water. 

Under the water

When operating at semi-displacement mode, these boats have the power to disturb the lakebed at depths over 20 feet. A recently published study done by the University of Michigan shows what type of damage this can cause at shallow depths. Cameras placed at 14 feet below a wakesurf boat show that the force generated creates an upheaval of the lakebed. Sediment is thrown violently upward, and plant life is uprooted. At 9 feet, the lakebed is almost unrecognizable from what it was a few seconds prior.  

There are three big takeaways as to why disturbing the lakebed lie this is harmful: 

1. The uprooting of vegetation will kill it. These plants cannot always regain composure, and often can no longer provide shelter and food for local wildlife. This also leaves the bed weaker and susceptible to erosion.  

2. This can weaken thermal stratification, or the process by which a lake forms different layers of water based on temperature and depth. When this happens, it upsets how oxygen cycles throughout the lake. This can kill aquatic life and stress the balance of the lake’s ecosystem. 

3. The upheaval of sediment scatters nutrients throughout the lake, nutrients like phosphorus. The result fuels rapid algal blooms.  

Conclusion

Many powerboat owners are aware of the impact of their watercraft, but this research suggests the previous recommendations for powerboating may not be enough to preserve the lake. This study suggests the following: 

1. Remain in a depth greater than 10 feet when planing. 

2. Do not exceed no-wake speeds when at a depth below 10 feet. 

3. Keep an even further distance from shores and plant life. 

4. Only surf (or use semi-displacement mode) when in a depth of at least 20 feet. 

The Paw Paw Lake Association recommends that all wake surfing be done in the center of the lake where the water is deepest. You’ll find a map of our suggested surfing locations below. 

This study shines a new light on all boaters; we can affect our lake every day. What kind of an impact are you making?

Sources

UMN researchers study waves created by recreational boats | St. Anthony Falls Laboratory | College of Science and Engineering 

minnesota-phase-2.pdf 

Data used in St. Anthony Falls Laboratory Project Report No. 611 A Field Study of Recreational Powerboat Hydrodynamics and their Impacts on the Water Column and Lakebed 

Off the Lawn and Out of the Lake

The conservation of our lake is an ongoing effort that can be impacted by anyone. You might think that a couple of leaves and few blades of grass isn’t enough to do serious damage to our lake, and you might be right on a small scale. However, if everyone dumped small amounts of yard waste into the water, we would all face the consequences. 

The introduction of yard waste into lake water brings excess nitrate, phosphorus, and unwanted chemicals into where we swim. These undesirable additions can deplete oxygen in wildlife habitats, killing fish and aquatic animals that live there. Pesticides and other yard treatment chemicals can often cause skin irritation to recreational swimmers. In addition to being generally unpleasant to look at, this waste can also clump together and cause clutter in channels, boat docks, ponds, and streams. 

One of the biggest nitrate causes is from Animal waste. Our lake primarily deals with waste from dogs and Canadian geese, as these are most prevalent on our lawns. If left unattended, runoff from these will find their way into our water. It’s not feasible to try to stop aquatic birds from leaving waste in the water, but we can stop it from getting from the land to the lake. Throwing animal waste of any form into the lake is not acceptable. 

All pet and yard waste should be disposed of properly with local sanitation departments or proper disposal locations. Under Michigan’s litter laws, fines for improper disposal of waste into public waters can range anywhere between $800 and $5,000, depending on the circumstances. This does not include additional fines that could be enforced by the Michigan Department of Environment, Great Lakes, and Energy (EGLE). 

We all make decisions that can help or harm the lake shed. It’s up to us to keep it healthy. Please remember that if it comes off your lawn, it doesn’t go into the lake. 

Sources:

Leaf litter and yard waste 

Stormwater Best Management Practice, Pet Waste Management