National Oceanic and Atmospheric Administration - Pendleton

Restoration Project

National Oceanic and Atmospheric Administration - Pendleton

Restoration Objective:

Pendleton Artificial Reef was constructed to determine if man-made reefs could be used to address a possible loss of kelp forest communities due to power plant operations and to improve sport fishing.

Site Selection Criteria:

A water depth of 13m was chosen to optimise Macrocystis growth and recruitment. Sites that were heavily influenced by terrestrial runoff were rejected to avoid excessive turbidity, siltation, and substrate burial. Since the reef was to be constructed on sand, excavations and probes were made to determine if a solid base was present.

Cause Of Decline:

Intensive human use of nearshore waters and associated resources, particularly off southern California, has contributed to the widespread deterioration and/or loss of reef and kelp forest habitat, disruption of trophic relationships, and decline of many living marine resources. Such changes first became evident In the mid-1940's and were related to coastal development, ocean sewage discharges, and Intensive fishing pressure and related Increases In numbers of herbivorous sea urchins. Since that time, the impact of human use on the marine environment has increased significantly.

Key Reasons For Decline:

Physical Disturbance

Scientific Paper

Artificial reef plan for sport fish enhancement

K.C. Wilson, R.D. Lewis, H.A. Togstad

Site Observations:

Observation Date

1st Jun 1980 – 1st Jun 1992

Action Summary:

An artificial reef was constructed on a sandy bottom in 13m of water approximately one nautical mile from shore. It was composed of 9,078 metric tons of quarry rock, ranging in size from 0.3 to 2.0 m in diameter, and consisted of eight modules spaced about 18 m apart. Modules were irregular in shape, averaging 36 m x 20 m x 4.5 m. The modules encompassed an area of approximately 3.5 acres.

Lessons Learned:

No persistent kelp populations were regenerated.

Project Outcomes:

Periodic transect surveys on the Pendleton Artificial Reef from 1982 to 1984 showed only intermittent kelp at very low densities (0.005 plants/m2). Qualitative surveys in the 1990s showed some limited kelp around the edges and on the reef modules, but no persistent kelp populations.

Key Reasons For Decline:

Physical Disturbance

Indicator Data:


Ending Value:

Starting Value:

Presence / Absence of Kelp