William H. Klingbeil1, Job Schipper2, Courtney Schatzman1, Eliza Harrison1, Javier Infante3
1Ocean Rainforest Inc., 1117 State St., Santa Barbara, California, USA
2Seawiser, Schagen, North Holland, Netherlands
3Patagonia Seaweeds, Los Ulmos de Molino Viejo, P. 124, Puerto Varas, Llanquihue, Chile
The utilization of novel seeding techniques can reduce the economic barriers associated with upscaling kelp aquaculture in the United States. The traditional method of twine seeding is labor intensive and requires a large hatchery footprint when compared with direct seeding. Direct seeding involves the binding of gametophyte and or juvenile sporophytes onto a substrate (i.e., rope) for later out planting, requiring far less labor and hatchery space. For the first time, we use a direct seeding approach to cultivate Giant kelp (Macrocystis pyrifera) in Southern California and compare three methodologies that have the potential to reduce labor and improve the efficient use of seed stock. In this study we propagate and seed nylon ropes with a collection of locally sourced gametophytes and compare a hand massage seeding technique, a mechanical two-step direct seeding approach and a mechanical interval spot seeding approach. Both mechanical methods utilize the novel Seawiser seeding machine. Using a partial factorial design, we assess long-term differences in biomass between a traditional twine method and the three direct seeding methodologies. All direct seeding methodologies produced viable seedlings and we observed no difference in long-term success of the twine, massage, two-step, and spot seeding techniques. These results support the efficacy of using a direct seeding approach to cultivate Giant kelp and suggest machine seeding is the most efficient methodology based on labor-time comparisons. Future work should focus on fine tuning the seeding machine, with an emphasis on spot seeding to further optimize efficient use of seed material.