“Lakespert” – Life in lakes now includes moss balls

Steve Lundt, CLM

Image from WFXRtv.com, Digital Desk – 03/05/21

There are three items on my career to-do list: be a guest on National Public Radio’s “Science Friday,” be invited to join a “think tank” about anything, and coin a term. If I can do all three, then I have done my part.

So far in my 22-year career in lake and reservoir management, I have at least coined a term: “lakespert.”

I will be sharing my experiences and thoughts on various hot topics that relate to the Lakeline theme. For this spring issue, “Life in Lakes” I would like to cover the topic of Marimo Balls, also known on the street as moss ball, Cladophora ball, lake goblin, lake roller, and lake ball.

I will be honest with you. When I first heard about them in the news in March, I was clueless. I now know that people have found yet another way to spread the invasive zebra mussel. I do know about non-native hitchhikers that can mistakenly get into a lake because of people’s attraction to cute or pretty things. I am currently trying to eradicate three non-native plants in a pond because of a grand opening event.

Back to Marimo Balls, which are actually a green, filamentous algal colony that forms into balls in shallow, low light conditions, on sandy lake sediments. These Cladophora balls have been an aquarium favorite for a few years and are a fuzzy novelty that can lead to spreading of non-native aquatic species.

The problem is not the actual algae (Aegagropila linnaaei), which turns out to be rare and protected in some countries (Japan and Iceland). Instead, the problem

threatened unintentionally by these desirable lake balls. It is kind of ironic that the love of water and nature shared through the infatuation for aquariums is often the reason why lakes have invasive species problems.

I have seen, first-hand, Brazilian elodea introduced to two lakes. One was in Oregon because of a backyard water feature and another one in Colorado because of a landscaping effort to get a pond ready for a grand opening. I have yet to find an intentional planting of invasive species.

Similar to these lake rollers, most infestations are caused by accidental hitchhikers. Growing, selling, and displaying aquatic plants needs to be done carefully. Growers need to have clean practices, and distributers need be on the lookout. Sellers need to know what is non-native and what to do when found. Buyers need to properly understand the implications of buying exotic items and how to properly dispose of them. At all levels, prevention is best.

This world economy of online shopping is not changing anytime soon. We need to fully understand our actions when it comes to moving non-native species, from viruses to zebra mussels. Everyone must do their part in protecting the native life in our lakes – understand what you are purchasing, properly dispose of any aquarium materials, keep a look out for aquatic invasive species, and think about your daily actions. We can all be “lakesperts” and help keep our lakes and reservoirs protected and healthy.


Steve Lundt, Certified Lake Manager, has monitored and worked to improve water quality at Barr Lake (Denver, Colorado) for the past 19 years. Steve is active with the Colorado Lake & Reservoir Management Association and is a past Region 8 director for NALMS and an active member since 1998.