Significance of biomass and light availability to phytoplankton productivity in San Francisco Bay

Marine Ecology Progress Series
By:  and 



Primary productivity was measured monthly at 6 sites within San Francisco Bay, USA, throughout 1980. The 6 sites were chosen to represent a range of estuarine environments with respect to salinity, phytoplankton community composition, turbidity, and water depth. Annual net production over the photic zone ranged from 95 to 150 g C m-2, and was highest in regions of lowest turbidity. Daily photic zone net productivity PN,, ranged from 0.05 to 2.2 g C m-2 d-', and was significantly correlated with the composite parameter B I,/& (where B = phytoplankton biomass; I, = daily surface insolation; E = attenuation coefficient). Lnear regression of PN,, against B Io/€ indicated that most (82 %) of the spatio-temporal variability in primary productivity within this estuary is explained by variations in light availability and phytoplankton biomass. We also calculated annual water-column net productivity PN, as a fraction of annual gross productivity PGx The ratio PN,, : PG, was inversely related to the ratio of water depth H to annual mean photic depth Z,. This linear relation indicates that the watercolumn of San Francisco Bay is a net photosynthetic source of organic carbon only when the ratio H : Z, < 6. In deep turbid habitats, where H : Tp > 6, respiratory loss exceeds productivity. Thus, 2 empirical formulations allow us to estimate productivity over the photic zone and water column from
simple properties that are easily measured.

Publication type Article
Publication Subtype Journal Article
Title Significance of biomass and light availability to phytoplankton productivity in San Francisco Bay
Series title Marine Ecology Progress Series
Volume 17
Year Published 1984
Language English
Contributing office(s) California Water Science Center
Description 10 p.
First page 15
Last page 24
Country United States
State California
County San Francisco County
City San Francisco
Other Geospatial San Francisco Bay
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