Pg. Verity et al., COMPOSITION, PRODUCTIVITY AND NUTRIENT CHEMISTRY OF A COASTAL OCEAN PLANKTONIC FOOD-WEB, Continental shelf research, 13(7), 1993, pp. 741-776
A 3 year field study was conducted to investigate patterns, magnitude
and variability of primary production; the abundance, biomass and comp
osition of producers and consumers; and the relative importance of phy
sical and chemical variables associated with these parameters, in inne
r shelf waters of the South Atlantic Bight. Discrete interval, time se
ries and continuous measurements were made along a transect and at two
process-oriented stations during summer and winter 1985-88. A quasi-p
ermanent density front constrains low salinity (<34 parts per thousand
) waters to within ca 10 km of the coast. These waters contain abundan
t autotrophic and heterotrophic communities. Primary production is hig
h, 6-7 x 10(2) gC m-2 year-1, and is apparently subsidized by rapid nu
trient recycling in the water column, sediments and adjacent salt mars
hes. Silicate is notable for its excess concentrations year-round and
supports substantial diatom productivity. Correlation analyses suggest
that Si strongly influences phytoplankton biomass, whereas growth rat
es are coupled to availability of light and NH4. Despite evidence of c
onsiderable variability in primary production over daily to interannua
l scales, plankton biomass is relatively constant. Experimental studie
s suggest a tight coupling between primary producers and microconsumer
s, and support the hypothesis that substantial fractions of primary an
d secondary production are recycled within the water column.