Research Technical Report

California Coastal Kelp Resources, Monterey Bay National Marine Sanctuary, Summer 1999

Van Wagenen, R.F. (Feb 2000)

Final Report, 87pp.

PRINCIPLE FINDINGS

The principle findings from the 1999 Monterey Bay National Marine Sanctuary kelp resource inventory were summarized, by CDF&G kelp bed numbers, as follows:

1. 1999 kelp resource extent,
2. 1989 kelp resource extent, and
3. Comparisons of the 1989 and 1999 sanctuary-wide coastal kelp resource.

1) Summary of the 1999 Sanctuary-wide Kelp Resource Extent

The total 1999 surface kelp canopy resource, within the MBNMS (CDF&G kelp beds 208-225), occupied canopy/planimeter areas of 14.053 sq. mi. and 22.358 sq. mi., respectively. The relative density index was measured at .63.

2) Summary of the 1989 Sanctuary-wide Kelp Resource Extent

The total 1989 surface kelp canopy resource, within the MBNMS (CDF&G kelp beds 208-225), occupied canopy/planimeter areas of 16.918 sq. mi. and 25.814 sq. mi., respectively. The relative density index was measured at .66.

3) Summary Comparisons of the 1989-99 Sanctuary-wide Kelp Resource

The total sanctuary-wide kelp resource canopy area significantly decreased (p=,05) from 16.918 sq. mi. to 14.053 sq. mi., which represented a 17% loss of surface canopy from that measured in 1989. The 1989-1999 total kelp bed planimeter area also significantly decreased from 25.814 to 22.358 sq. mi., which represented a 14% loss of perimeter extent. The relative density index also decreased from .66 (1989) to .63 (1999), but was statistically unchanged.

The greatest loss in kelp canopy extent between the two inventories was observed within the Monterey Bay itself (CDF&G canopies 222, 221 and 220), and the greatest gain in kelp resource extent was noted in canopy 217, between Yankee Pt. and Pt. Sur.