Variability of primary and bacterial production in a coral reef lagoon (New Caledonia).
We assessed the temporal variability of nutrients, phytoplankton and bacterioplankton at two sites of different trophic status in New Caledonia's South-West lagoon, a tropical coastal ecosystem. During stable meteorological conditions, Chl.a, bacterial production and nutrient concentrations experience weak but consistent daily variation. Short-term (1-2 week interval) fluctuations of planktonic variables are in the same range as annual variations at both sites. A part of these short term variations is linked to local meteorological events (wind in the main channel, precipitation at the coastal station). Although annual variations are weak compared to short term variations, phytoplankton and bacterioplankton production show consistent temporal patterns, with maxima in December-January and April-May and minima in August. Annual bacterial production represents 21% and 34% of particulate primary production at the oligotrophic and mesotrophic sites, respectively. Mineral nutrient availability indicates that nitrogen is probably the primary limiting factor of phytoplankton throughout the year.
Torréton
Jean-Pascal
JP
UR 103, CAMELIA, UMR 5119 ECOLAG, Université Montpellier II, Case 093, 34095 Montpellier, France. jean-pascal.torreton@ird.fr
Rochelle-Newall
Emma
E
Pringault
Olivier
O
Jacquet
Séverine
S
Faure
Vincent
V
Briand
Enora
E
D018407:Bacterial Physiological Phenomena; D018533:Biomass; D002734:Chlorophyll / Q000032:analysis; D000077194:Chlorophyll A; D017753:Ecosystem; D004784:Environmental Monitoring; D057446:Hydrodynamics; D009584:Nitrogen / Q000032:analysis / Q000378:metabolism; D010839:Phytoplankton; D010933:Plankton / Q000382:microbiology*; D011891:Rain; D012621:Seasons; D012623:Seawater / Q000737:chemistry / Q000382:microbiology; D013997:Time Factors; D014871:Water Microbiology; D014919:Wind
D002734:Chlorophyll; D009584:Nitrogen; D000077194:Chlorophyll A