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Aquatic pests

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Unwanted freshwater pests, such as the invasive catfish, algae didymo, pose a serious threat to our rivers, streams and lakes. Once in a waterway they 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 catfish

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Catfish are an unwanted pest threatening to ruin the renowned Rotorua lakes andtributaries. They prey on trout, native fish,

and they also lower water quality by churning up mud. Catfish have already made it in to Lake Rotoiti and if they spread to our other lakes, it could be devastating.


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.

Watch this video or download these brochures to find out how:

Find out about aquatic pests

Flyers on what to look for in your pond:

View fact sheets on:

Find out what aquatic plants are safe to use in your pond or water feature:

Find out more about pest management

View other fact sheets on animal and plant pests

Aquatic pest research

Check out our library for a range of research and monitoring reports about aquatic pests.

Here  are some of our most recent research reports: