So What Are These Shitballs I Keep Hearing About?

If we are to have any hope of discussing the very serious matter of an ecological collapse in the unique natural wonder of Lake Mývatn, we will have to get the terminology right. The spherical form of the algae species Aegagropila linnaei is called “marimo” in Japan, which means “round weed,” but the Icelandic name for it, “kúluskítur” means “sphere shit” or “shitball.” The most commonly used English name is, however, lake balls.

If it were up to me I’d call them “freshwater cojones.”

Lake balls, please stop giggling, are not strictly speaking a species of algae, but simply one of three growth forms of A. linnaei. One is a free-floating filament. Another is when the algae attach itself to rocks and form patches on the shadowy side. The latter starts to grow little spherical tufts that then break free and become proper lake balls, growing up to 10–15 centimetres in diameter and even 30 centimetres under ideal conditions.

So these algae grow some balls.

Maybe it is better to stick to calling them marimo which might be all too appropriate, as we may have seen the last of the algal spheres in Mývatn. Icelanders may need to visit Lake Akan in Japan to see marimo, for the “kúluskítur” has disappeared in Mývatn.

Save the shitballs!

It might be too late for that. An English-language report published in May this year by Dr. Árni Einarsson, director of the Mývatn Research Station, has the stark title: “The Lake Balls of Mývatn — In Memoriam.” The report is full of sentences like: “While some isolated lake balls may still exist in Mývatn it is by now (2013) clear that the communities of lake balls have vanished.” And: “Now, when they have disappeared, there is room for some nostalgic thoughts.”

I’m gonna miss the little shitballs.

Honestly, marimo is a perfectly good word. In Japan you can even buy little marimo dolls. The algal sphere is soft, fluffy and a pretty, dark green colour. If you Google for marimo photos, and I advise using the word marimo here and not shitballs, you will notice that they look like ornamental shrubs, or bright green Tribbles from the TV show Star Trek.

But in Star Trek Tribbles grow really quickly and are impossible to get rid of. Can the marimo make a comeback?

According to the Mývatn Research Station, we should proceed to: “(1) Reduce nutrient release from the human settlements as much as possible, (2) map and monitor nutrients in the groundwater and (3) map the situation of lake balls in other lakes in Iceland.”

Uh… does the phrase “nutrient release from the human settlements” mean that the shitballs are being killed by human shit?

Sort of, but not the way you’re picturing it. Essentially, the system of septic tanks and filtering used in the Mývatn area does not remove enough nutrients from the sewage and other waste, which then runs off into the lake. If there is an overabundance of nutrients in the water, other organisms thrive which makes life for the marimo, and all other forms of A. linnaei, very difficult. Now they are gone.

Stop the shitflow and the shitballs will be okay, right?

The abundance of nutrients is not the only cause. For decades the lake was mined for diatomite, a type of silicate that has lots of different applications, from agriculture to dynamite. This left a large hole in the lake bottom which has destabilised the ecosystem of Mývatn, and now both A. linnaei and another algae species, Cladophora glomerata, have disappeared almost completely. Both are important sources of food for many animals, from invertebrates to ducks.

I thought this would be a funny story about aquatic plants with a silly name but now I’m depressed.

This is the second summer that there have been reports of large-scale ecological disasters in Iceland. Last year the ecosystem of the river Lagarfljót and its lake collapsed due to a hydroelectric dam. Recently there has also been news about sewage disposal problems in Þingvallavatn, the lake at Þingvellir, but hopefully that will not lead to anything terrible.

Two aquatic ecosystem collapses is plenty, thank you very much.

As Dr. Árni Einarsson makes clear in his report, this is a worldwide phenomenon. Marimo, and indeed A. linnaei itself, has been vanishing in many lakes around the world. Lakes with marimo populations have seen an increase in nutrients because of human activity. In the heart-breaking final chapter, titled “Canary in the Mine,” he sets out a personal history of his first encounter with and studies of marimo, and how it was to be a witness to their disappearance. The final words are simply: “The canary has died.”

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See Also:

Mývatn’s Marimo Are Disappearing

Ode To Nature’s Fuzzy Balls