A Bay of Plenty Regional Council contractor is starting checks on ornamental ponds in the Omokoroa and Maungatapu areas this month, in an effort to stop the spread of freshwater pests into local waterways.

Regional Council Biosecurity Officer Donna Watchman says they are searching for invasive weeds and pond fish such as koi carp and rudd that can eat and out-compete native fish.

'In the wild, koi and rudd can make water murky and unhealthy when they stir up sediments and reduce oxygen levels," says Donna.

"Invasive weeds like salvinia and water hyacinth grow as thick floating mats and can choke waterways, clog irrigation intakes and aggravate flooding."

Regional Council last completed pond pest checks in 2016, in the Katikati, Oropi, Ohauiti, and Welcome Bay areas.

'We found at least one pest plant in 27 percent of the 303 ponds we checked in 2016, and fortunately no pest fish. Pests that seem safely contained in a pond can easily be spread elsewhere by birds, pond overflows, earthworks machinery, or if they're shared with neighbours and friends.

'People often have no idea that they have pests in their ponds. By casting an expert eye over them we can help people understand what to look for and minimise the risk of liberation into natural waterways.

"A new property owner who knew what to look for was a huge asset in helping us find and remove koi carp from the Katikati area last year, in partnership with Department of Conservation,” she says.

Regional Council's Authorised Contractor will be carrying identification and will be visiting Maungatapu and Ōmokoroa properties to check outdoor ponds from October 2018 to June 2019.

A notice about the visit will be left in the letterbox or posted out after the visit to each property and occupiers will be advised if pests are found or further action is needed.

To discuss the pond checks or find out more about pond pests, people can chat to the contractor when they visit, or contact a Regional Council Biosecurity Officer ph: 0800 STOP PESTS (0800 786 773), email [email protected].

Information about aquatic pests is also available at: www.boprc.govt.nz/aquaticpests