Quantitative and qualitative observations on Laminaria dentigera and other subtidal kelps of southern Kodiak Island, Alaska

Abstract

Observations were made and quantitative samples of non-canopy kelps were collected, using SCUBA, at 9 subtidal sites off southern Kodiak Island in May, 1976. At a 10th site, only observations were made. The most abundant species in the quadrats were Laminaria dentigera, L. yezoensis, Pleurophycus gardneri, Agarum cribrosum, and Alaria marginata. We found fertile plants of all these species. L. dentigera dominated at all sampled sites except one within a bed of Nereocystis luetkeana, where P. gardneri was dominant. L. yezoensis was dominant at the site which was visited but not sampled. The average wet weight of non-canopy kelps in the 55 samples was 12 kg m-2, and the quadrat range was 2 to 35 kg m-2. The reported ranges of P. gardneri and Alaria marginata are extended westward from Montague Island (147°22′W) to Bumble Bay, Kodiak Island (154°43′W), where A. marginata was found at a depth of 8.5 m.