Restoration Project

Southern California Edison - North La Jolla

Restoration Objective:

Researchers developed a number of aquacultural techniques for Macrocystis cultivation in order to reverse trends of deterioration

Site Selection Criteria:

A site was selected with historical kelp beds that have declined.

Cause Of Decline:

Giant kelp (Macrocystis spp.) occurs as extensive beds along the coasts of Baja California and California, where it forms desirable habitat for fishes and invertebrates. The kelp plants are harvested and processed to produce food additives and chemicals. Many Californian kelp beds have dwindled or disappeared since 1940. About 90% of the Macrocystis population of southern California disappeared during a period of abnormally high sea surface temperatures from 1957 to 1959. Many of the former kelp areas were colonised by populations of sea urchins, preventing reestablishment.

Key Reasons For Decline:


Scientific Paper

Aquacultural Techniques for Creating and Restoring Beds of Giant Kelp, Macrocystis spp

W.J. North, , Journal of the Fisheries Board of Canada, Vol. 33.


Southern California Edison

Site Observations:

Observation Date

1st Jan 1973 – 15th Apr 1974

Action Summary:

Four techniques were employed to rehabilitate Macrocystis beds: 1) removing grazing invertebrates and fishes. 2) transplanting adult Macrocystis plants by threading lines through the holdfast, prying plants loose, avoiding desiccation during transport and restoring the anchorage at the new location. A small buoy is usually placed directly beneath the holdfast to prevent abrasion against the bottom. 3) Juvenile Macrocystis plants can be gathered in the field or cultured in the laboratory on plastic rings and moved to desirable sites in the ocean. The juveniles can be attached by fastening them with rubber bands to projections on the bottom. 4) Mass cultures can be initiated from Macrocystis spores on strips of polyethylene film.

Project Outcomes:

Excellent restoration of the Macrocystis bed was observed at North La Jolla.

Key Reasons For Decline:


Indicator Data:


Ending Value:

Starting Value:

Presence / Absence of Kelp

Cost Currency:USD