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Phosphorus and nitrogen limitation of primary production in a simulated estuarine gradient

1995; Inter-Research; Volume: 124; Linguagem: Inglês

10.3354/meps124271

1616-1599

PH Doering, CA Oviatt, BL Nowicki, E. Klos, LW Reed,

Marine Bivalve and Aquaculture Studies

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 124:271-287 (1995) - doi:10.3354/meps124271 Phosphorus and nitrogen limitation of primary production in a simulated estuarine gradient Doering PH, Oviatt CA, Nowicki BL, Klos EG, Reed LW The transition between phosphorus limitation of primary production in freshwater and nitrogen limitation in seawater was examined along an estuarine gradient simulated in 4 large 13 m3 enclosures connected in a series and containing pelagic and benthic subsystems. Nominal salinities of 0, 5, 10 and 25 ppt were maintained by exchanging appropriate volumes of water between enclosures. River water, which served as a freshwater endmember, was naturally high in N relative to P, while the oceanic endmember (water from Narragansett Bay, RI, USA) was low in N relative to P. Production in the water column was supported by external inputs and recycled nutrients. Bioassays, inorganic nutrient concentrations and N:P ratios of the seston and inorganic nutrients indicated that phosphorus was limiting at 0, 5 and 10 ppt, while nitrogen was limiting at 25 ppt. Coincident with this shift in limiting nutrient was a shift in the N:P ratio of nutrient supply from greater than the Redfield ratio of 16 to less than 16. External inputs established relative rates of supply in each enclosure. The relative proportion of N and P in external inputs was largely a function of the hydrodynamic mixing of fresh (high N, low P) and salt water (low N, high P) endmembers. At the scale of the estuarine segment or enclosure, neither recycled inputs from the benthos and water column, nitrogen fixation nor internal losses of N and P to sedimentation and/or denitrification materially altered relative supply rates, despite a hydrodynamic residence time of 27 d. Estuaries . Primary production . Nutrient limitation . Nitrogen . Phosphorus Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 124. Publication date: August 10, 1995 Print ISSN:0171-8630; Online ISSN:1616-1599 Copyright © 1995 Inter-Research.