Culturing And Utilization Of Large Brown Seaweeds (Kelps)

Kelp species, the larger members of brown-colored marine plants, are widely cultivated and have been utilized by many peoples as food, fertilizer, a source of chemicals, and as fodder for domestic animals. Interest has recently developed in usage as alternative energy sources (kelp tissue would be converted to methane via bacterial fermentation). Kelp life cycles involve an alternation of generations from an entirely microscopic phase to a phase that includes the large macroscopic plant utilized by humans. The complex life history imposes culturing requirements beyond the usual degree of care needed for propagating terrestrial plants. These difficulties notwithstanding, kelp cultivation is successfully practiced, particularly in the Orient. Culturing techniques range from artificially "seeding" an artificial substrate which may eventually be outplanted to the sea, to transplanting large mature individuals to desired locations, allowing them to "seed" naturally and establish their populations. Giant kelp, Macrocystis, is the principal brown alga utilized commercially in the United States. Culturing techniques have been developed for growing Macrocystis. Depleted kelp beds in southern California have been successfully restored utilizing these methods.