A Regional Approach to Kelp Restoration and Monitoring in the Southern California Bight

摘要

The California Coastkeeper Alliance (CCKA), in a partnership with the National Oceanic and Atmospheric Administration (NOAA) Fisheries' Community-Based Restoration Program, has launched a regional-scale project to restore giant kelp (Macrocystis pyrifera) to depleted reefs in Southern California, which previously supported mature kelp forests. The Southern California Regional Kelp Restoration Project (SCRKRP) plans to establish three Restoration Areas (RAs) in each of the five coastal counties from San Diego to Santa Barbara from 2001-2004 to support long-term kelp persistence. Each RA consists of three 500m~2 restoration sites and one 500m~2 control site. Site selection criteria require identification of naturally occurring, low-relief rock reefs, which historically supported giant kelp. Prospective sites are surveyed by SCUBA divers to evaluate the suitability of physical and biological factors to support kelp restoration. Reference sites (500m~2) are also being established in naturally existing kelp forests in each county. Volunteer SCUBA divers are trained by and work alongside Coastkeeper biologists to replant, monitor and maintain kelp forests. SCRKRP restoration techniques combine outplanting laboratory-reared juvenile kelp sporophytes, seeding with M. pyrifera spores, relocating grazing sea urchins and opportunistic transplanting of drift kelp. Juvenile sporophytes are cultivated in the CCKA Regional Kelp Mariculture Laboratory at the Southern California Marine Institute. Regional monitoring of in situ temperature fluctuations and species diversity and abundance combined with aerial kelp canopy surveys will facilitate evaluation of Bight-wide kelp resources and the progress and success of the project. Preliminary results from the first outplanting of laboratory-cultivated sporophytes in summer 2002 are promising. Surviving juvenile sporophytes have grown from 2-4cm at the time of outplanting to 30-45cm, three months post-outplanting, with excellent holdfast and pneumatocyst development and blade differentiation.