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Biosecurity tools

We have both weed and fish risk assessment models.

Diquat use for submerged weeds

Frequently asked questions and answers

What is diquat and what is it used for?

Diquat is a herbicide (chemical) that has been used in New Zealand for many decades for submerged (underwater) weed control and also on agricultural crops. It is registered for freshwater use in New Zealand.

Why do we need to control submerged freshwater weeds?

Fish risk assessment model

FRAM is powerful and simple to use - series of straight-forward questions about the biology and behaviour of any alien species lead to it being ranked and categorised as a high, intermediate, or low ecological risk.

Weed risk assessment

NIWA has developed a model to assess the potential weed risk of aquatic plants.