Check, Clean & Dry

Unwanted freshwater pests like the invasive catfish and algae didymo pose a serious threat to our rivers, streams and lakes. Once in a waterway these pets can spread rapidly and destroy the environmental, recreational and aesthetic values of our waterways.

Freshwater pests like salvinia can quickly form extensive mats, completely smothering waterways and badly affecting water quality. It can double in area within 10 days. The mats kill off native plants, attract breeding mosquitoes, block dams and irrigation systems, remove oxygen from the water and create a drowning risk for people and animals.

Some freshwater pests are microscopic and can be spread by a single drop of water or a single fish egg. Even very small fragments of many aquatic plants can easily take root and grow into new plants.

Even if you can’t see the danger you could be spreading it. Pests that seem safely contained in a pond can be easily spread elsewhere by birds, pond overflows, earthworks machinery or if they’re shared with neighbours and friends.

Stop the spread of aquatic pests

  • If you have a pond or water feature at home, make sure you know what plants or fish are pests and choose safe species to fill it with.
  • Watch out for pests and dispose of any you find safely - ask us for help by calling 0800 STOP PESTS (0800 786 773) or email

Freshwater pest caught from Lake Rotoiti.

Video - Stop the spread of aquatic pests.

Check, clean, dry

To slow the spread of freshwater pests into local waterways, please CHECK, CLEAN and (when practical) DRY your boat, trailer, prop, fishing, sporting or earthmoving equipment when you're moving from one waterway to another, anywhere in the Bay of Plenty.

Download these brochures to find out how:

Flyers on what to look for in your pond:

View fact sheets on:

Stop the spread of catfish

Brown bullhead catfish (Ameiurus Nebulosos) were discovered in Lake Rotoiti in 2016 and are an unwanted pest that prey on trout, native fish and lower water quality by disturbing sediment.  Currently, catfish have been identified in Lake Rotoiti, and if they spread to other lakes the effect could be devastating.

Catfish grow up to 500mm and are easily identified as dark brown to olive green in colour with four pairs of barbels around the mouth and sharp spines. 

Keep our lakes great banner - stop catfish

Catfish from Lake Rotoiti.

Catfish from Lake Rotoiti.

Geoff managing catfish in Lake Rotoiti.

Geoff managing catfish in Lake Rotoiti.