AN EMILIANIA-HUXLEYI DOMINATED SUBSURFACE BLOOM IN SAMNANGERFJORDEN, WESTERN NORWAY - IMPORTANCE OF HYDROGRAPHY AND NUTRIENTS

Samnangerfjorden is a narrow and sheltered fjord with a pronounced low salinity phosphate-depleted surface layer. The coccolithophorid Emiliania huxleyi (Lohmann) Hay et Mohler bloomed in a nitrate-depleted intermediate layer below the phosphate-depleted surface layer in the inner part of the fjord in May 1992. Maximum cell density was 7 x 10(6) cells l-1, and E. huxleyi accounted for 30% of autotrophic biomass. Both cell density and the calcification rate decreased towards the mouth of the fjord. Production was P-limited in the inner part of the surface layer, while production in the intermediate layer was light-limited. The growth of E. huxleyi in the surface layer was greatly reduced by the low salinity.