Bay of Plenty Regional Council contractors will be door-knocking in Oropi, Ohauiti and Welcome Bay this month, to check ponds and water features for aquatic pests.
Regional council land management officer Donna Watchman said that pest plants such as water hyacinth and pest fish such as koi carp, are a threat to water quality, access and native wildlife in the region's streams, lakes and wetlands.
"Pest fish and weeds 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," Mrs Watchman said.
"People often don't realise they're harbouring pests. We found a single water hyacinth plant in a small water lily pond during pond checks in Katikati last month. The landowner had recently bought the property and was surprised to find that water hyacinth was in the pond. She was happy for our contractor to remove it," she said.
Pest fish such as koi carp and catfish can eat and out-compete native fish. They make water murky and unhealthy when they stir up sediments and reduce oxygen levels. Pond weeds like salvinia and water hyacinth grow as thick floating mats that can choke waterways, clog irrigation intakes and aggravate flooding.