General description

Olive green-bronze fish (30-70 cm) with red eyes, two barbels, large soft-rayed fins and copious mucous.

What you need to know

To help protect our environment:

Soft substrates of still or slow-moving waterbodies, lakes, ponds.

Can cause flipping of lakes to alternative turbid state devoid of vegetation through uprooting submerged macrophytes, re-suspending sediment and exacerbating algal blooms by consuming zooplankton. Impacts native fish species through transmission of parasites, competition for prey and reduction of water clarity.


Check equipment and vessels for freshwater pests, clean everything that has been in contact with the water and dry everything thoroughly.

Find out more:

For more information about tench and how to manage them, please contact Auckland Council at pestfree@aucklandcouncil.govt.nz.

Search tags

RPMP status

Aotea (Exclusion)
Lakes Tomarata and Rototoa
Whole region (Sustained Control)
Hauraki Gulf Controlled Area Notice pest
Tench - Main species image