Absorption coefficient of phytoplankton:regional variations in the North Atlantic

Abstract

The effect of major pigments on the absorption characteristics of phytoplankton were evaluated by comparing the in vjvo absorption spectra of phytoplankton with pigment data obtained using high-performance liqu~d chromatography (HPLC) for samples of phytoplankton collected in the northwestern Atlantic Ocean, during spring. Four groups of spectra having distinct absorption characteristics and well-defined regional distributions were identified. The result of using general parameters to estimate the absorption coefficient of phytoplankton from any region, the 'general approach', was compared with the result of using specific parameters for each region, or the 'regional approach' Two methods of estlrnating the absorption coefficient were tested for each approach. These were: a 'slnglepigment' method (Prieur & Sathyendranath 1981, Limnol Oceanogr 26:671-689), and a 'multi-pigment' method (Hoepffner & Sathyendranath 1991, Mar Ecol Prog Ser 73:ll-23). It was shown that the regional approach performed better (<10% average error) than the general approach (~2 0 % average error). Nevertheless, the results given by the general approach could be acceptable for some applications. The multi-pigment and the single-pigment methods performed equally well in the context of the reglonal approach, whereas in the general approach, the s~ngle-pigment method gave better results than the multi-pigment method. Overall, it appears that part~tioning the oceans into regions according to their absorption characteristics should improve regional models of light transmission and the algorithms for detection of pigments by remote sensing.

Geochemistry of marine sediments of the Brazilian Northeastern continental shelf

“…The co-assimilation with carbonates, which can occur during the formation of algal carbonate accumulations, can remove chemical substances from the interstitial solutions of the mainly superficial inshore platform sediments, released by more intense fluxes of the interstitial waters in this zone (FREIRE 1985). However, interstitial adsorption in the biominerals of these organisms (or other extracellular points or non-metabolic components) seems to play no important role regarding Fe, probably due to its ability to act as an inhibitor of calcium carbonate precipitation (LUTZ et al, 1996;YASUSHI;YASUSHI 1986;WILSON et al, 2004;ARYAL et al, 2006, EHRLICH, 1996MARCADAM;PARSON, 2004). Metals can be passively (bioabsorption) and actively (bio-accumulation) captured by algae (MORSE, 2003;JAHAN et al, 2004).…”

Bio-optical characteristics of diatom and prymnesiophyte populations in the Labrador Sea

“…where a m is the asymptotic maximum value of the absorption coefficient, a* m is the initial slope of the curve near the origin (maximum specific-absorption coefficient) and C is the HPLC-derived chl a concentration (see Lutz et al 1996, Stuart et al 1998, Sathyendranath et al 2000. Parameters for this function are presented in Table 2 for various wavelengths used in standard remote-sensing algorithms (443, 490, 550, 555 nm) as well as for 623 nm.…”

“…Specific-absorption coefficients of phytoplankton (absorption coefficients per unit concentration of chlorophyll) are known to vary regionally as well as seasonally (Bricaud & Stramski 1990, Hoepffner & Sathyendranath 1992, Lutz et al 1996, Arrigo et al 1998, Stuart et al 1998, Sathyendranath et al 1999 in response to changes in species composition, light history and nutrient conditions. Mitchell & Holm-Hansen (1991) noted that specific absorption coefficients of phytoplankton from high-latitude areas were significantly lower than those from temperate waters.…”

Light Absorption by Phytoplankton in the Upper Mixed Layer of the Black Sea: Seasonality and Parametrization

“…Inherent optical properties (IOPs) vary throughout the world ocean. Due to high variability in light absorption and scattering by optically active components, the world ocean needs to be subdivided into various provinces based on regional IOPs, and their features could be used to improve remote-sensing algorithms for each province (Hoepffner and Sathyendranath, 1992;Lutz et al, 1996;Suzuki et al, 1998). Originally the standard NASA algorithm could be applied if there was a high correlation between a ph (λ) and absorption by colored dissolved and suspended organic matter (a CDM (λ)) (Morel and Prieur, 1977).…”