Restoration Project

Universidad Católica del Norte - Point Loma

Restoration Objective:

The study evaluated whether artificial plants could be used for protection and restoration of giant kelp forests in southern California.

Site Selection Criteria:

A site was selected in an urchin barren near existing kelp beds.

Cause Of Decline:

Forests of giant kelp (Macrocystis pyrifera) provide substrate, food and habitat for a wide variety of marine organisms, and support fisheries for fin fish, invertebrates and kelp. Forests of giant kelp also provide the basis for an alginate industry which has sales exceeding US$230 million annually. Sea urchins that live in forests of giant kelp typically feed on kelp debris that drifts down from the forest. However when sea urchins become abundant, they can have devastating effects on populations of marine plants, including giant kelps.

Key Reasons For Decline:


Scientific Paper

A new tool for kelp restoration

J.A. Vasquez, R.H. McPeak, , California Fish and Game, Vol. 84.


Universidad Católica del Norte

Site Observations:

Observation Date

1st Jan 1995 – 12th Mar 1995

Action Summary:

Artificial plants were constructed using 17kg cement bricks for the holdfast and low-density, 2-mm thick plastic sheets for the blades. Ten blades, each measuring 1.07m long and 10cm wide, were attached to each brick. Each blade had 4 holes punched in it and several small pieces of lead (15g fishing sinkers) attached to help it settle to the bottom. The artificial plants mimicked bottom kelps and were used to reduce sea urchin numbers or function as sea urchin barrens. Giant kelp transplants were secured to the bottom using 4 concrete nails, 4 tie wraps, and 1 rubber band 1.2cm wide per plant.

Lessons Learned:

Artificial plants reduced red and purple sea urchin densities.

Project Outcomes:

Artificial plants reduced red and purple sea urchin densities.

Key Reasons For Decline:


Area of Restoration (In Square Metres)


Indicator Data:


Ending Value:

Starting Value:

Adult Kelp Count

Cost Currency:USD