"The greatest risk is that the clams could clog in-water infrastructure. It’s uncertain how quickly that may occur. As far as we know, the clam hasn't caused any issues for infrastructure in the time it’s been here - but that doesn’t mean it won’t cause problems in future,” she says.
The clam is well established in the USA and parts of Europe. In the USA, it’s even been known to clog cooling water intakes for nuclear power plants.
Emily says water infrastructure owners on the Waikato River should watch out for the clam during routine maintenance and monitoring. Those who are designing or upgrading existing water infrastructure may want to consider building in first lines of defence based on the biological characteristics of the species.
“Many organisations dealing with other invasive molluscs have monitoring boxes, plates, or screens placed before their key infrastructure. These act as sentinel monitoring points. If you see the pest species attaching to the monitoring point, it’s an indication you should be looking closely further up the pipe.”
Overseas, a range of control methods have been tried to combat the clam, including heat and chlorine treatments. But because the clam behaves differently in different environments, solutions that work well in one place may not be easily repeatable elsewhere.
Emily says different removal approaches have different implications – depending on whether the clam is being removed from drinking water or industrial water intakes. Manual removal with a scraping or pigging technique is usually the most effective way of removing build-up of invasive species in pipe infrastructure.
Controlling the impact of the clam will likely already be on the radar for environmentally conscious infrastructure owners who understand that this type of biofouling can be a significant risk to their business. Frameworks such as the Taskforce on Nature-related Financial Disclosure (TNFD) can help to quantify such risks.
TNFD is an international initiative launched in 2022 to develop and deliver a risk management and disclosure framework for organisations to report and act on nature-related risks and opportunities.
“For a power plant operator that has infrastructure in the water and must invest in additional monitoring and cleaning regimes, that’s a cost to their business. Identifying the risk of the clam to their infrastructure in the context of TNFD will be important,” says Emily.
Any sightings of the clam should be reported to MPI as soon as possible.
