Hatchery seaweed cultivation methods need to be optimised to give our native species the best shot at growth out on marine farms.

Image of Ecklonia radiata lifecycle/NIWA.

Seeding twine type affects hatchery and at-sea success, but has rarely been examined for any seaweed species. Seeding density can also influence hatchery outcomes, affecting zoospore settlement, gametophyte growth, and sporophyte formation. Although spore density effects for Ecklonia radiata have been studied in petri dishes, applied research directly on twine remains lacking.

To address these key knowledge gaps, we conducted experiments to identify the optimal seeding twine type, twine diameter, and spore seeding density for Ecklonia radiata.

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.

We’re continually testing new methods to increase the efficiency of the hatchery process. A key advancement has been the development of methods to successfully maintain broodstock in tanks and induce formation of reproductive tissue on demand.