Commercial mariculture of macroalgae and sessile animals, as currently practiced, involves laborintensive, controlled settling of spores or larvae on clean rope, netting, or shells. These substrates are then placed on farms in the sea. In contrast, natural propagation of nearly all marine organisms involves the broadcasting of microscopic spores, gametes, or larvae, that are adapted to attach and survive in the calm boundary layer adjacent to the sea floor. Sea grasses are exceptional in that they produce morphologically distinctive fruits that disperse and sometimes become hooked on particular "target" organisms. During the Phase I research period, we created artificial "seeds," or sea grass fruit analogs, of the giant kelp, Macrocystis, by encapsulating gametophytes in calcium-alginate gels. The feasibility of planting natural marine habitats with kelp was demonstrated in the laboratory by testing the structural integrity, attachment success, and growth potential of several designs of kelp seeds. During Phase II, these studies will expanded to ocean testing. In view of the likely cost advantages of broadcast seeding, and the availability of natural target substrates in many near-shore habitats, there is likely to be considerable commercial interest in a new, broadcast seeding technology, both in the U.S. and abroad.
Anticipated Results:This technology has both maricultural and environmental applications. If it is possible to devise an effective broadcast-seeding method, using living microencapsulated propagules, then large areas of near-shore waters could be "planted" with specific plants or animals. Low cost broadcast seeding will be particularly useful where near- shore ecosystems have been damaged, and mitigation "in kind" is required.
