Where exotic freshwater clams have been found
Two species of Corbicula have been found in New Zealand.
Corbicula fluminea (commonly known as 'gold clams' or 'freshwater gold clams') was found in the Bob’s Landing area of the Waikato River near Lake Karāpiro in May 2023. Later, it was also found in the Waikato River from Lake Maraetai Landing to Tuakau.
Corbicula australis was found in March 2024 at the Lake Taupō Aqua Park in a small man-made lagoon.
Biosecurity measures for the clam
Corbicula fluminea and Corbicula australis have been given the legal status of an Unwanted Organism under the Biosecurity Act 1993.
This means that people must not knowingly move them or water that may contain them. To do so would be an offence under the Act. People can still use the Waikato River for recreation, including boating and fishing, or gathering of kai (food) if they follow the requirements of the controlled area notices, including 'Check Clean Dry' procedures, before moving their equipment or craft.
Controlled area notices for exotic freshwater clams
Biosecurity rules are in place to stop the spread of the clam through a mechanism under the Biosecurity Act called a Controlled Area Notice (CAN).
Two CANs are in force – one for the Waikato River and another for the Te Arawa lakes with additional protections for Lake Ōkataina.
Most consent holders with consent to take water from the Waikato River under the Resource Management Act (RMA) – such as for irrigation, municipal water supply, or other commercial uses – will notice no impact.
Waikato River Controlled Area Notice and amendments
A CAN with specific rules for all wake boats applies to the Waikato River from the Whakamaru Dam to the river mouth at Port Waikato. Wake boats are defined as any craft with an internal tank or bladder that cannot be completely drained. This came into effect at 11.59pm on 24 November 2023.
Amendments to the CAN came into effect on 1 December 2024 and will be in place until further notice.
Waikato River Controlled Area Notice [PDF, 828 KB]
Notice of Amendment to Controlled Area Notice [PDF, 229 KB]
Waikato River CAN requirements
- All wake boats that have been in the controlled stretch of the river must not be used in any other waterways, including parts of the river outside the controlled area.
- Recreational river users that have been in the controlled stretch of the river must continue to follow 'Check Clean Dry' requirements for any craft, gear (such as fishing and other equipment used to gather kai) and equipment (including water skis, wakeboards, and inflatable pool toys).
Te Arawa lakes Controlled Area Notice
A CAN applies to the 14 Te Arawa lakes in the Bay of Plenty with additional protections for Lake Ōkataina. This came into effect from noon on Friday 10 November 2023. The notice of amendment to the CAN came into effect at 11.59pm on Tuesday 18 March 2025 and will be in place until further notice.
Te Arawa lakes and Lake Ōkataina Controlled Area Notice [PDF, 340 KB]
Amended version of the Te Arawa lakes and Lake Ōkataina Controlled Area Notice (March 2025) [PDF, 401 KB]
Notice of amendments to Corbicula fluminea Controlled Area Notice (March 2025) [PDF, 298 KB]
Designated wash station
A designated wash station is The Wash Place, 338 Te Ngae Road, Rotorua.
The Wash Place is a commercial facility and there is a cost for washing a boat and trailer – the cost varies depending on the length of the cycle chosen. Payment is by card or coins.
The station is open 24/7 and detailed instructions about how to complete the wash are provided.
For Lake Ōkataina
All boats must be cleaned at the designated wash station before entering the lake. This is in addition to Check Clean Dry requirements
At the wash station, boaties need to:
- Wash down the boat and trailer, and drain any remaining water.
- Scan the QR code in the wash bay using a phone camera, which will take you to an online form.
- Fill out and submit the form while at The Wash Place to receive 2 PIN access codes for the Lake Ōkataina boat ramp gate (this area is geo-fenced).
- Use the first 4-digit PIN received by email or text to open the gate at the boat ramp. You must use this PIN within 2 hours of receiving it.
- Use the second PIN when exiting the lake.
Contact details are available on a sign at the lake if users have issues gaining access.
Note, there is no overnight parking or camping allowed at the Lake Ōkataina Scenic Reserve.
For all 14 Te Arawa lakes
Any boat that has been in the Waikato River in the previous 30 days must be cleaned at the designated wash station before entering the water. This is in addition to Check Clean Dry requirements
At the wash station, boaties need to:
- Wash down the boat and trailer, and drain any remaining water.
- Scan the QR code shown on signage and complete the online form to prove wash-down has been completed.
Special permissions
Special permissions are considered for the taking of water likely to contain the freshwater clam. This could include, for example, research, sampling, or taking of water not previously consented under the RMA. Consent holders who want to carry out movements that differ from their usual business should also seek a special permit.
To apply for a special permit, email corbiculalongterm@mpi.govt.nz
Section 52 permissions of the Biosecurity Act 1993 [PDF, 191 KB]
Report any suspected sightings of Corbicula to Biosecurity New Zealand. Note the location and take a photo. Do not handle the clams. Because they are an unwanted organism, permission to handle them is required from MPI.
Find out about getting permission to handle unwanted organisms
Check Clean Dry
When you move from the controlled stretch of the Waikato River (which is from Whakamaru Dam to the river mouth at Port Waikato) to another part of the river or its lakes, you must follow the 'Check Clean Dry' procedures for the exotic freshwater clam for all watercraft, gear, or clothing that has come into contact with river water.
Note, 'Check Clean Dry' procedures to prevent human spread of the exotic freshwater clam will also manage other freshwater pest species.
