Restoration Project

MBC Applied Aquatic - Corona Del Mar

Restoration Objective:

The aim of restoration was to reseed kelps where they had exhibited little or no recovery in order to improve biological and commercial outcomes.

Site Selection Criteria:

Transplant sites were selected where giant kelp was once present. Ideal transplant sites had many attachment points, no competing macroalgae and were in less than 13m of water.

Cause Of Decline:

Historically, beds of giant kelp (Macrocystis pyrifera) along the Orange County coastline were dense and covered much of the available rocky substrate from the shallow subtidal area down to 20m and deeper. These beds supported a diverse assortment of fish, invertebrates, and other plants, many of which were of significant interest to commercial and sport fisherman. The warm waters brought by the El Niño of 1982-1983 caused the loss of most giant kelp stands leaving only a few surviving patches along the Orange County shoreline. Additional stressors to kelp populations included urbanisation, low water quality, storms and overfishing.

Key Reasons For Decline:

Heatwave

Scientific Paper

Orange County Kelp Restoration Project

M.B.C.Applied Environmental Sciences, , p.93.

Organisation:

MBC Aquatic

Site Observations:

Observation Date

4th Jul 1988 – 15th Feb 2007

Action Summary:

Adult and juvenile Macrocystis pyrifera plants were transported from the donor site quickly, covered in a tarp and kept cool and moist. Juveniles were also grown in lab culture. Kelps were attached using rope sewn through the holdfast with needles. Adult and juvenile kelps were transplanted to 12 sites. Sites were monitored, maintained, and sometimes expanded with additional juvenile kelps over three years.

Project Outcomes:

At Corona Del Mar, canopy was sparse in surveys conducted in July and September 1989, although subsurface plants were abundant. 90 adults, 13 subadults and 34 juveniles were counted in July. Subsurface coverage was approximately 0.75 acres in September, and kelp plants appeared healthy and the bed was expanding despite large sea urchin numbers.

Key Reasons For Decline:

Heatwave

Area of Restoration (In Square Metres)

3,000

Indicator Data:

Indicator:

Ending Value:

Starting Value:

Adult Kelp Count

134275
Costings:
Cost Currency:USD