Iceland Mag

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Iceland Mag


Unexpected good news from lake Mývatn: Large quantities of Marimo wash ashore

By Staff

  • Small marimo balls Marimo is very rare, but is created by a species of filamentous green algae which grows into balls which can become as large as 20-30 cm (8-12 in) in diameter, although the Mývatn marimo rarely grew beyond 12 cm (4.7 in) in diameter. Marimo has not been found in Mývatn since 2013. Photo/Icelandic Environment Agency, Facebook.

Large quantities of small marimo have washed ashore along the shores of lake Mývatn in the past few days. Marimo is only found in a handful of lakes around the world. While it was once plentiful in Mývatn and one of its chief characteristics, it has not been found in the lake since 2013. Scientists had feared it had completely disappeared from Mývatn and gone extinct in the lake.

Read more: Ecosystem of Lake Mývatn feared to be collapsing

Washed ashore in recent days Known as "muck balls" in Icelandic (kúluskítur) marimo was once extremely common in Mývatn. Photo/Icelandic Environment Agency, Facebook

Davíð Örvar Hansson, an expert with the Icelandic Environment Agency, told the Icelandic National Broadcasting Service that the marimo balls discovered along the shores of Mývatn in recent days are tiny, but they are nonetheless an extremely positive sign.  “It’s a welcome surprise. We don’t know exactly this means, but it’s definitely a positive sign.”

Davíð stresses that it’s too early to say whether this indicates that the ecosystem of Mývatn is recovering. The lake has been under growing stress in recent years, due to pollution from growing tourism, hotels and other human activity along its shores. Sewage seepage into the lake has fed enormous bacteria blooms which have suffocated other life, including algae which forms the foundation of the lake’s ecosystem.

“I seriously doubt this means everything is all right. But it cannot be seen as anything other than a positive sign. We have not seen anything like this in recent years.”


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