Understanding marine connectivity: sampling mussels in the Bay of Plenty

Green lipped mussels are an important aquaculture species in New Zealand valued at over $300M a year. The aquaculture industry largely depends on wild caught seed mussels called spat, but to this date nobody knows exactly which wild mussel beds supply the larvae. The Moana Project aims to better understand the connectivity of mussel spat in Aotearoa, NZ, and has had a successful sampling trip in the Bay of Plenty.

In the video above, Aquaculture technician Ashleigh Anderson employed by the Whakatōhea Māori Trust Board and Dr Kura Paul-Burke, Director of MUSA Environmental are helping us sample mussels in the Bay of Plenty.

Prof. Jonathan Gardner, one of New Zealand’s leading marine biologists and Moana Project He Hono Moana lead is heading this component of the Moana project. He says that where the mussel larvae come from, how they travel, and where they end up is all crucial information that isn’t well understood in Aotearoa.

“In the Moana Project, we are using a unique combination of four types of science to determine where mussel larvae come from.”

Green lipped mussel bed by Joe Burke

Mussel shells during the sampling process, by Ashleigh Browne

Green lipped mussel bed, By Joe Burke

The different genres of science that are being drawn together for this research include:

Population genetics, where samples of the mussels collected will be genotyped – a process that provides a DNA fingerprint of the mussels, allowing the connectivity between mussel populations in different areas to be revealed.

Microchemistry analysis using a laser to take a small sample of mussel shell (producing a little puff of mussel shell dust), which is then analysed to show geochemical tags. Geochemical tags are accumulated incrementally from the surrounding environment into the mussel shell, giving a chemical record of the mussel’s life. The chemicals can be traced to different areas of New Zealand showing the transport of that mussel throughout its lifetime.

Mātauranga Māori providing local ecological knowledge will help corroborate the location of the mussel reefs generating the spat, thus guiding the research. 

Ocean modelling allows the simulation of currents and tides, enabling the project to predict the movements of green lipped mussel larvae in the Bay of Plenty.

More about this research can be found in the latest NZ Herald article on marine heatwaves and mussel larvae and at moanaproject.org