Why Didymo is bad

By Jessica

What is Didymo?

Didymo was discovered in NZ, the first time it was found was in the southern hemisphere. To restrict its spread, the whole of the south island of NZ was declared a controlled area in Dec 2005. Extensive publicity was carried out to limit the spread but it was found in an increasing number of rivers.

Why is Didymo a pest?

Didymo is also known as “rock snot”. It is a freshwater diatom (a type of algae). It can form massive blooms (a massive explosion) on the bottom of streams, rivers, and lakes, and its spread is highly undesirable. This microscopic pest can be spread by a single drop of water. Even if you can’t see it, you could be spreading it. The alga is a native of northern Europe and north America and was first reported in NZ in 2004.

How do we stop Didymo?

To prevent the spread of Didymo you need to check, clean and dry your gear when going from one river to another, everywhere in NZ. It is in NZ’s to interests for you treat every waterway like it is infected with didymo. If we don’t do something about now then didymo will keep spreading it will kill our Eco-Systems.

Bio security NZ has since declared the entire south island an outbreak control area for Didymo. This means rivers and lakes remain open to angling, boating and other recreational activities, but all gear should be cleaned before going from one waterway to another. In Otago, Didymo is found in lake Hawea and lots more.