title: Carbon, nitrogen, and phosphorus stoichiometry of plankton and the nutrient regime in Cabo Frio Bay, SE Brazil.
abstract: This long-term study, performed during the years 2003-2005 and 2008-2009, investigated the carbon (C), nitrogen (N), and phosphorus (P) contents of the phyto- and zooplankton communities and the nutrient regime of Cabo Frio Bay, SE Brazil. The information intends to serve as baseline of the plankton C, N, and P stoichiometry for the calibration of biogeochemical and ecological models in support to future findings related to the local and regional phenomena of climatic change. Cabo Frio Bay is a small semienclosed system set adjacent to a region subject to sporadic coastal upwelling. Zooplankton exhibited average annual C, N, and P contents of 11.6 ± 6.9 %, 2.8 ± 1.8 %, and 0.18 ± 0.08 %, and phytoplankton (>20 μm) 6.8 ± 6.0 %, 1.6 ± 1.5 %, and 0.09 ± 0.08 %, respectively. The C/N/P ratios correspond to the lowest already found to date for a marine environment. The low C contents must have been brought about by a predominance of gelatinous zooplankton, like Doliolids/ Salps and also Pteropods. Average annual nutrient concentrations in the water were 0.21 ± 0.1 μM for phosphate, 0.08 ± 0.1 μM for nitrite, 0.74 ± 1.6 μM for nitrate, and 1.27 ± 1.1 μM for ammonium. N/P ratios were around 8:1 during the first study period and 12:1 during the second. The plankton C/N/P and N/P nutrient ratios and elemental concentrations suggest that the system was oligotrophic and nitrogen limited. The sporadic intrusions of upwelling waters during the first study period had no marked effect upon the systems metabolism, likely due to dilution effects and the short residence times of water of the bay.
authors.affiliation: Departamento de Geoquímica, Instituto de Química, Universidade Federal Fluminense, Outeiro São João Batista s/n, 24020-141, Niterói, Brazil, viniciuskutter@yahoo.com.br.
authors.forename: Vinicius T
authors.initials: VT
authors.lastname: Kütter
authors.forename: Monica
authors.initials: M
authors.lastname: Wallner-Kersanach
authors.forename: Silvia M
authors.initials: SM
authors.lastname: Sella
authors.forename: Ana Luiza S
authors.initials: AL
authors.lastname: Albuquerque
authors.forename: Bastiaan A
authors.initials: BA
authors.lastname: Knoppers
authors.forename: Emmanoel V
authors.initials: EV
authors.lastname: Silva-Filho
mesh_terms: D061006:Bays; D001938:Brazil; D002244:Carbon / Q000032:analysis* / Q000378:metabolism; D017753:Ecosystem; D004784:Environmental Monitoring; D009584:Nitrogen / Q000032:analysis* / Q000378:metabolism; D010758:Phosphorus / Q000032:analysis* / Q000378:metabolism; D010933:Plankton / Q000502:physiology*; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000378:metabolism
chemical_list: D014874:Water Pollutants, Chemical; D010758:Phosphorus; D002244:Carbon; D009584:Nitrogen