Distribution of living coccolithophores in the California Current system, southern California borderland

Abstract

The distribution of living coccolithophores in the California Current system of southern California at 10 m water depth was investigated on two dates in March and June, 1982. Six closely spaced stations were sampled in March, of which three were resampled in June. Thirty-six euphotic species were identified of which four, Emiliania huxleyi, Umbilicosphaera sibogae, Gephyrocapsa oceanica, and Rhabdosphaera longistylis, respectively, were the most abundant. Both the “cold” and “warm” morphotypes of E. huxleyi were present, in varying proportions. Large ranges in community structure, diversity (0.35–2.64 natural bels), and standing crop (1.0 × 10 4–6.2 × 10 5cells/l) were recorded. This range of end-member values is approximately that found in the open ocean from 0° to about 65° latitude. The distributions of four coccolithophore assemblages recognized in March samples from the Borderland area appear to reflect the following distinct water masses: (1) California Current; (2) Southern California Counter Current; (3) Transitional Zone; (4) Near Shore. The coccolithophore assemblages from the June stations were more uniform, indicating that the Borderland was experiencing more stable conditions than in March.