Hatchery success with Gigartina
Tiny Gigartina on twine as shown under microscope.
July 2024
Our goal is audacious. We are setting up Aotearoa New Zealand seaweed farmers for a new industry that could be a game changer.
It’s a slow, tender process to hatch a new seaweed industry - though our cultivation of Gigartina (Sarcothalia) atropurpurea also needed a bit of ‘treating it mean to keep it keen’.
We’re happy to share that as a result of painstaking work by Greenwave Aotearoa, tiny babies of fertile Gigartina tetrasporophyte have now settled onto twine ready for the next groundbreaking milestone – to be the first commercial out planting of this species in New Zealand.
Envirostrat’s Ryan Marchington has led the hatchery phase for us at Greenwave Aotearoa. Bringing his knowledge and working alongside Peter Randrup from the University of Waikato, we adapted the method developed by marine biologist Kate Neill’s work with NIWA late in 2017.
It’s a rewarding collaborative milestone to reach, and according to Ryan, all went smoother than anticipated.
As anyone in seaweed will explain, species are broadly grouped by red, brown and green.
Ryan describes the red species that he’s worked with in the past as challenging. “Reds are really cool seaweeds, but they can be quite challenging to work with because they are so sensitive.”
Stress-induced reproduction can be a natural response of plants to ensure their survival, so how was it deployed in the case of Gigartina?
At the end of May, tissue of seaweed was gratefully (and under permit) sourced from Tikapa Moana (Hauraki Gulf) and it has been put through its paces at the hands of the Greenwave Aotearoa and University of Waikato teams.
The seaweed source tissue was dried (dessicated) and rehydrated in sea water, in a process that stresses the cells to release their spores.
Greenwave Aotearoa has a commercial hatchery that operates close to the source of where these babies will be coaxed into their next growing phase, back in Tīkapa Moana off the Coromandel Peninsula’s western coastline.
Watch this space as we take these babies out to the next stage, back where they originated in Tīkapa Moana.