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.

In collaboration with Cawthron Institute, we’re undertaking environmental monitoring at both the Esk Point and Pōnui farm sites. Purpose-built ocean going sensors have been deployed and are measuring water temperatures and light penetration throughout the water column to monitor the growing environment at various depths. This will help us get a better understanding of whether high light intensity and warmer water temperatures are impacting the survival of the seedlings.