University of California institute of Marine Science - Point Loma

Restoration Project

University of California institute of Marine Science - Point Loma

Restoration Objective:

Restoration was undertaken to restore a historical kelp bed.

Site Selection Criteria:

The selected kelp bed was heavily utilised due to its size and proximity to an urban centre, and has experienced historical kelp losses.

Cause Of Decline:

The Point Loma kelp bed, because of size and proximity to a large population centre, was probably the most heavily utilised kelp area in southern California. Records show that formerly the bed extended over about six square miles. Following World War I its size decreased steadily, reaching a minimum value of about 1/100 of a square mile in 1961. During this period the volume of kelp harvested here also decreased. Investigation showed large numbers of sea urchins dominated areas where kelp had formerly existed and that intense grazing by the dense urchin populations was preventing natural kelp regrowth.

Key Reasons For Decline:


Scientific Paper

Kelp Habitat Improvement Project. Annual Report 1

W.J. North

Site Observations:

Observation Date

1st Jan 1963 – 1st Jan 1967

Action Summary:

Quicklime was used to destroy urchin populations in selected areas. Lumps of quicklime were dribbled into the wake of a moving vessel travelling back and forth in a grid pattern. Between 1964 and 1966 quicklime was spread farther north in central and northern Point Loma.

Lessons Learned:

Urchin culls were repeated throughout the study period, and restoration occurred despite heavy urchin grazing in some areas.

Project Outcomes:

By Fall 1967, the canopy area of the Point Loma kelp bed had expanded by 75%, almost reaching its maximum historical coverage despite substantial grazing by urchins in some areas.

Key Reasons For Decline:


Area of Restoration (Ha)


Indicator Data:


Ending Value:

Starting Value: