Human activities in the watersheds of the tributaries of Pamlico Sound (PS) in North Carolina have resulted in increased riverine loading of nutrients. Pamlico Sound is a regionally important aquatic resource, and provides crucial foraging and nursery habitats for Southeast Atlantic fisheries. Changes in phytoplankton community composition that may result from increased frequency and quantity o...

A high performance liquid chromatography (HPLC) system for pigment analysis of marine phytoplankton was established. The characteristic quantification limits of the major photosynthetic chlorophylls a and b were 0.29 and 0.27 ng, respectively. The reliability of this method was verified by resolving the marker pigments in culture extracts from diatoms, blue-green algae and green algae. Fucoxant...

The composition of nascent SSA organic matter changed as a spring phytoplankton progressed.

In terrestrial ecosystems, transitional areas between different plant communities (ecotones) are formed by steep environmental gradients and are commonly characterized by high species diversity and primary productivity, which in turn influences the foodweb structure of these regions. Whether comparable zones of elevated diversity and productivity characterize ecotones in the oceans remains poor...

The ability of bivalve filter feeders to limit phytoplankton biomass in shallow waters is well-documented, but the role of bivalves in shaping phytoplankton communities is not. The coupled effect of bivalve grazing at the sediment-water interface and sinking of phytoplankton cells to that bottom filtration zone could influence the relative biomass of sinking (diatoms) and non-sinking phytoplank...

The relationship between species diversity and ecosystem functioning has been debated for decades, especially in relation to the "macroscopic" realm (higher plants and metazoans). Although there is emerging consensus that diversity enhances productivity and stability in communities of higher organisms; however, we still do not know whether these relationships apply also for communities of unice...

Diatoms constitute a major group of phytoplankton, accounting for ~20% of the world's primary production. It has been shown that iron (Fe) can be the limiting factor for phytoplankton growth, in particular, in the HNLC (High Nutrient Low Chlorophyll) regions. Iron plays thus an essential role in governing the marine primary productivity and the efficiency of biological carbon pump. Oceanic syst...

A CO2 enrichment experiment (PeECE III) was carried out in 9 mesocosms in which the seawater carbonate system was manipulated to achieve three different levels of pCO2. At the onset of the experimental period, nutrients were added to all mesocosms in order to initiate phytoplankton blooms. Primary production rates were measured by in-vitro incubations based on 14C-incorporation and oxygen produ...

The consideration of iron effects on marine ecosystems has focused mainly on high-nitrate low-chlorophyll regions, but iron likely has an equally important regulatory role in coastal waters. Iron requirements of neritic phytoplankton not only are comparatively high but also differ substantially among species, so that iron fluctuations within metal-replete systems should strongly influence the c...

Samples of natural phytoplankton assemblages were taken on 4 occasions between 28 March and 19 April 1990 at 2 stations located to the southwest of Plymouth (UK) and incubated in experimental microcosms under constant light and temperature. 14C incorporation into cell constituents [proteins, polysaccharides, lipids and low molecular weight metabolites (LMWM)] and the biochemical compos~tion of ...