Don't let clams hitch a ride
Did you know that freshwater weeds and pests, like the invasive clam, can spread through your activities in lakes and rivers?
Clam larvae grow into sand-grain sized juvenile clams that produce a sticky thread of mucous which attaches to surfaces like boats, wetsuits, and other gear. Because they are invisible, the juveniles and mucous can be moved between waterways undetected.
If you’ve recently visited a lake, river, stream, or wetland and plan to head to another, it’s important to 'Check Clean Dry' your gear and your boat, or kayak or paddleboard to prevent harmful species from hitching a ride with you.
Note that there are different treatment requirements for the North and South Island.
You need to meet the requirements of Controlled Area Notices (CANs) that are in place for the Waikato River, Te Arawa lakes, and Lake Ōkataina. The CANs have specific requirements for each area.
Rules to stop the spread of invasive clams
These rules are in place because any movement of craft between waterways poses a risk of spreading the freshwater clam to areas that are not infested.
Don’t move or eat clams
While they are a delicacy in some places overseas, the invasive freshwater clam Corbicula should not be moved or eaten.
It’s an offence under the Biosecurity Act 1993 to move the clam as it is an unwanted organism.
They also aren’t safe to eat as they are filter-feeding shellfish that eat deposits from the river or lakebed. During feeding clams may consume harmful algae or other toxins that may make people sick.
Follow this 'Check Clean Dry' guide for all North Island lake and river users
Tell us if you find freshwater clams
Keep an eye out for Corbicula and report suspected sightings to us. Take a photo, if possible, and note the location. Then either:
- freephone 0800 809 966
- or complete the online form at report.mpi.govt.nz
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