Rakes, Ropes and Underwater Hockey: Fighting Azolla on the Moorabool

PALM (People for a Living Moorabool) recently circulated a post about the Azolla outbreak on the Moorabool River at Batesford that had persisted through the winter at a major refuge pool.

What is Azolla?

Azolla caroliniana

Azolla a small, native freshwater aquatic fern that floats on the surface of still or slow-moving bodies of water. It can form dense mats that appear as a green or red carpet, depending on sun exposure. It has a high growth rate and can be an invasive weed in some areas including the recent Moorabool outbreak (but it can also be used as a sustainable food for livestock or as an organic fertiliser).

Why the winter azolla outbreak on the Moorabool River is so concerning
(PALM post)

Given the prospect of warming water and the risk of a black water event, a few of us – PALM (Cameron), Geelong Landcare Network (Stuart) and BFS Landcare (Peter and Felicity) – decided to have a crack at a hands on solution.

With the help of a few members from Stuart McCallum’s local underwater hockey club (a big thanks Stuart and his team) we attempted to see if we could deal with the problem through raking, creating flow paths and breaking up the large clump of Azolla which had thus far proven to be so stubborn.

And it looks like we have had a win!

It doesn't solve the long term problem but is a good story of community action on a waterway.

Azolla removal - Cam on the rake

Azolla removal - Icebreakers S and T

Azolla removal success - NE end Moorabool River Batesford

Azolla removal success - SE end Moorabool River Batesford