Annual Primary Production in Narragansett Bay with no Bay-Wide Winter–Spring Phytoplankton Bloom

Abstract

Primary production was estimated over the annual cycle from 14C incubations conducted in 5m deep enclosures and modeled for 16 stations in Narragansett Bay with data from biweekly surveys in which light, chlorophyll, attenuation coefficients and other parameters were measured. Annual values ranged from 160gCm−2 y−1 in the lower West Passage to 619gCm−2 y−1 at the mouth of the Providence River. The annual bay-wide, area mean fell near the middle of this range at 323gCm−2 y−1 and was not apparently different from previous surveys. In the 1998 warm, El Niño winter, no bay-wide winter–spring phytoplankton flowered. Bloom limitation was correlated with warm temperatures which may have stimulated grazing rates. The lack of a bloom did not change annual levels of primary production but this alteration in carbon flow may impact macrofauna in the benthic infauna community.