Aquaculture of giant kelp
[2] The supply of M. pyrifera for alginate production relied heavily on restoration and management of natural beds during the early 1990s.
[33] Research efforts at the state level to prevent kelp forest collapse in California were announced in July 2020.
[35] Ocean Rainforest, a Faroe Islands-based company, secured $4.5 million in U.S. government funding to grow giant kelp on an 86-acre farm off the coast of Santa Barbara, California.
[38][39] To induce sporulation, plants are dried for up to twelve hours and placed in a seeding container filled with seawater of about 9-10 °C; salinity of 30% and a pH of 7.8-7.9.
[37][40] These strings are either wrapped around or are cut up into small pieces and attached to a larger diameter cultivation rope.
Problems that afflict this method include management of the transition from spore to gametophyte and embryonic sporophyte which are done on a terrestrial facility with careful control of water flow, temperature, nutrients and light.
[37] The Japanese use a forced cultivation method where 2 years of growth is achieved within a single growing season by controlling inputs.
Issues with operational and farm designs plagued deep water cultivation and ended further exploration.
[11][37] M. pyrifera which is artificially cultivated on ropes is harvested by a pulley system that is attached to boats that pull the individual lines on the vessels for cleaning.
[11][37] Other countries such as the US rely primarily on naturally grown M. pyrifera, use boats to harvest the surface canopy several times per year.
Additionally, the kelp would support a fish harvest of 2 megatons per year and reduce ocean acidification.
Large scale open ocean forestry would require engineered substrate and added nutrients.
[43][44] A Maine startup, Running Tide Technologies, seeks to grow large quantities of kelp which would sequester carbon in the ocean floor.
Cultivation techniques using a "kelp elevator" have shown promise for biofuel production using thermochemical liquefaction.
