Diel variations in Prochlorococcus optical properties

• DOI: 10.4319/lo.2002.47.6.1637
• Publication Date: 2010-06-30T20:25:29Z
• Authors: Hervé Claustre; Annick Bricaud; Marcel Babin; Flavienne Bruyant; Laure Guillou; Florence Le Gall; Dominique Marie; Frédéric Partensky
• Keywords: Diel vertical migration; Sunrise; Prochlorococcus; Sunset

Prochlorococcus is an important component of phototrophic biomass in oligotrophic areas. In such systems, diel variations optical properties have been reported. order to better understand these natural variations, the (absorption, attenuation, and scattering) biochemical (carbon pigment) axenic clone , PCC 9511, grown a turbidostat set under light conditions that simulated those found near ocean surface, were monitored every 2 h for several consecutive days. All parameters showed pronounced patterns except divinyl‐chlorophyll (Dv‐Chl ) specific absorption coefficient at 676 nm, *(676), which remained stable (0.019 m mg Dv‐Chl 21). The oscillations 440 *(440) (43% increase between sunrise sunset), essentially governed by zeaxanthin ratio (52% this sunset). scattering cross section 555 σ b (555), with largest amplitude (182% Finally, carbon‐specific attenuation 660 c *(660) (1.04 gC −1 less than half other algal groups. This estimation, together fluctuations highlighted present study, discussed context using situ measurements infer biogeochemical stocks (vegetal or detrital biomass) processes (primary production).