Invasive Species

Since the early 1900's invasive species have really started to pose a serious threat to our wetlands, native fish species and aquatic plants and insects. From fish that produce up to 30,000 eggs annually to algae that spreads rapidly across the riverbed, it’s crucial to understand how we can prevent these impacts and help preserve our wetlands. 

How might you protect your wetland from invasive species?

The most crucial step is the cleaning of all gear before entering any wetland, using the “Check, Clean, Dry” method to stop the spread of pests such as didymo, koi carp eggs, or fragments of plants. Healthy, well-planted wetland edges are also a protection in themselves — thick native vegetation such as harakeke, raupō, toetoe, and mānuka secures the banks and prevents erosion, lessening the possibility of koi carp entry during floods.

Once protected, ongoing monitoring of the wetland is paramount. Regular site visits can help spot invasive species early-meaning when they're easiest to remove-through the use of nets, eDNA tests, and spot checks. If something does turn up, speedy controlled removal, fixing broken culverts, or repairing banks can be the difference in stopping pests taking over. Keeping the water clean and full of plants will help create a robust and resilient ecosystem.

Hear are some invasive species that have taken over our freshwater wetlands: