Didymo

Didymosphenia geminata (didymo), also known as rock snot is a freshwater diatom (a type of alga). Didymo is currently found in a number of South Island rivers.

Biosecurity New Zealand has declared the entire South Island a Controlled Area for Didymo. This means waterways are open to recreational activities, but people are legally obliged to prevent the spreading of didymo.

Check, Clean, Dry

CHECK: Before you leave a river or lake, check items and leave debris at site.

CLEAN: There are several ways to kill didymo.

DRY: Drying will kill didymo, but slightly moist didymo can survive for months.

More information on the Check Clean Dry method can be found on the MAF Biosecurity website.

Further Information

• Didymo on MAF Biosecurity website.