FN Archimer Export Format
PT J
TI Impacts of high-nitrate freshwater inputs on macrotidal ecosystems. I. Seasonal evolution of nutrient limitation for the diatom-dominated phytoplankton of the Bay of Brest (France)
BT 
AF DEL AMO, Yolanda
   LE PAPE, Olivier
   TREGUER, Paul
   QUEGUINER, Bernard
   MENESGUEN, Alain
   AMINOT, Alain
AS 1:1;2:2;3:1;4:1;5:2;6:2;
FF 1:;2:;3:;4:;5:;6:;
C1 Univ Bretagne Occidentale, Inst Univ Europeen Mer, UMR CNRS 6539 Bioflux, F-29280 Plouzane, France.
   IFREMER, Lab Chim & Modelisat Cycles Nat, F-29280 Plouzane, France.
C2 UBO, FRANCE
   IFREMER, FRANCE
IN WOS Ifremer jusqu'en 2018
IF 1.928
TC 82
UR https://archimer.ifremer.fr/doc/00337/44782/44588.pdf
LA English
DT Article
DE ;coastal ecosystem;phytoplankton dynamics;macrotidal;nutrient limitation;silicon;eutrophication
AB The chemical factors (inorganic nitrogen, phosphate, silicic acid) that potentially or actually control primary production were determined for the Bay of Brest, France, a macrotidal ecosystem submitted to high-nitrate-loaded freshwater inputs (winter nitrate freshwater concentrations >700 mu M, Si:N molar ratio as low as 0.2, i.e. among the lowest ever published). Intensive data collection and observations were carried out from February 1993 to March 1994 to determine the variations of physical [salinity, temperature, photosynthetically active radiation (PAR), freshwater discharges] and chemical (oxygen and nutrients) parameters and their impacts on the phytoplankton cycle (fluorescence, pigments, primary production). With insufficient PAR the winter stocks of nutrients were almost nonutilized and the nitrate excess was exported to the adjacent ocean, due to rapid tidal exchange. By early April, a diatom-dominated spring bloom developed (chlorophyll a maximum = 7.7 mu g l(-1); primary production maximum = 2.34 g C m(-2) d(-1)) under high initial nutrient concentrations. Silicic acid was rapidly exhausted over the whole water column; it is inferred to be the primary limiting factor responsible for the collapse of the spring bloom by mid-May. Successive phytoplankton developments characterized the period of secondary blooms during summer and fall (successive surface chlorophyll a maxima = 3.5, 1.6, 1.8 and 1.0 mu g l(-1); primary production = 1.24, 1.18 and 0.35 g C m(-2) d(-1)). Those secondary blooms developed under lower nutrient concentrations, mostly originating from nutrient recycling. Until August, Si and P most likely limited primary production, whereas the last stage of the productive period in September seemed to be N limited instead, this being a period of total nitrate depletion in almost the whole water column. Si limitation of spring blooms has become a common feature in coastal ecosystems that receive freshwater inputs with Si:N molar ratios <1. The peculiarity of Si Limitation in the Bay of Brest is its extension through the summer period.
PY 1997
SO Marine Ecology Progress Series
SN 0171-8630
PU Inter-research
VL 161
UT 000072100100020
BP 213
EP 224
DI 10.3354/meps161213
ID 44782
ER

EF