IMIS

Publications | Institutes | Persons | Datasets | Projects | Maps
[ report an error in this record ]basket (1): add | show Print this page

one publication added to basket [260064]
Effects of diurnal variations in phytoplankton photosynthesis obtained from natural fluorescence
Yoshikawa, T.; Furuya, K. (2006). Effects of diurnal variations in phytoplankton photosynthesis obtained from natural fluorescence. Mar. Biol. (Berl.) 150(2): 299-311. http://dx.doi.org/10.1007/s00227-006-0331-3
In: Marine Biology: International Journal on Life in Oceans and Coastal Waters. Springer: Heidelberg; Berlin. ISSN 0025-3162; e-ISSN 1432-1793, more
Peer reviewed article  

Available in  Authors 

Keyword
    Marine/Coastal

Authors  Top 
  • Yoshikawa, T.
  • Furuya, K.

Abstract
    Effects of diurnal variation in phytoplankton photosynthesis on estimating daily primary production (DPP) were examined using field data from Sagami Bay, Japan. DPP at 5 m depth was calculated from the continuous data of chlorophyll a (Chl a) and light intensity monitored by a natural fluorescence sensor with and without considering time-dependent changes in the photosynthesis–irradiance (P–E) relationship. Chl a could be estimated from natural fluorescence examining the variations in the quantum yield of fluorescence (f f) and Chl a-specific light absorption coefficient (a*ph), and relating them to Chl a. The P–E relationship was determined by water sampling three times daily. A distinct diurnal pattern was observed for the maximum photosynthetic rate (P*max), being maximal at noon, while periodicity of the maximum light utilization coefficient (a*) was less obvious. The actual DPP was calculated by interpolating the P–E parameters from those obtained at dawn, noon, and dusk. For comparison, DPP was calculated by fixing the P–E parameters as the constants measured at dawn, noon or dusk for a day. The difference from the actual DPP was small when the P–E parameters measured at dawn (3% on average) and noon (5%) were used as the constants for a day. The difference was largest when the values at dusk were used (-43%). The medium values of P*max at dawn, its low values at dusk, and the fact that a major part of the DPP was produced around noon were responsible for these results. The present study demonstrates that measurement of the P–E parameters at dawn or noon can give a good estimation of DPP from natural fluorescence.

All data in the Integrated Marine Information System (IMIS) is subject to the VLIZ privacy policy Top | Authors