Microphytobenthos from two subtidal sediments from North Brittany. II. Variations of pigment compositions and concentrations determinded by HPLC and conventional techniques

Abstract

Pigment composition and concentration of 2 temperate subtidal sediments, a mud and a sand from North Brittany, were studied using HPLC and conventional fluorometric methods. Pigment diversity, found using HPLC, was considerable, particularly in the mud (around 15 identified pigments). Pigment composition in the sand was dominated by Bacillariophyceae pigments, whereas in the mud pigments characteristic of Chlorophyceae were also found. Freeze-drying significantly reduces pigment concentrations.

Monthly HPLC measurements of pigment concentration from an intertidal muddy sediment of Marennes-Oléron Bay, France

“…The complete absence of chl b in our samples excludes the possibility that Chlorophyceae and/or Euglenophyceae contributed to the microphytobenthic community of this intertidal mudflat. This is an important characteristic since chl b has been frequently detected in coastal sediments (Riaux-Gobin et al 1987, Klein & RiauxGobin 1991, but our observations corroborate those of Barlow et al (1990), who studied sediments of salt marshes in the same area (46" 10' N, 1" 15' W). Lutein, which is associated with chl b (Jeffrey 1974), was not detected in our samples whereas 1 unidentified peak might be zeaxanthin, which has been proposed as a taxonomic marker of Cyanophyceae (Guillard et al 1985, Gieskes et al 1988).…”

“…There were nevertheless large amounts of degraded p~gments which probably derived from the breakdown of autochthonous material. We have indeed detected many forms of phaeopigment a, which is consistent with findings of other studies concerning sediment (Brown et al 1981, Riaux-Gobin et al 1987, Klein et Riaux-Gobin 1991, Yacobi et al 1991. The 4 phaeophorbides, which represented about 7 5 % of total phaeopigments, are markers for macrobenthic deposit-feeding processes (Bianchi et al 1988(Bianchi et al , 1993 and more generally for metazoan grazing activity (Brown et al 1981, Welschmeyer & Lorenzen 1985, Abele-Oeschger et al 1992 Based on their order of elution and retention times, the 2 major phaeophorbides a-like:, and a-like, (accounting for about 50 % of total phaeophorbides) correspond very likely to the phaeophorbides a-like in Hawkins et al (1986) study and to phaeophorbides a, and a3 reported by Plante-Cuny et al (1993).…”

“…It also indicates the dominance of diatoms in the microphytobenthic community (confirmed by microscopic observations), which is now well established (Colijn & d e Jonge 1984, Riaux-Gobin et al 1987, Barlow et al 1990). The carotenoids identifiedfucoxanthin, diadionoxanthin and p-carotene -are all present in diatoms [see Stauber & Jeffrey (1988) concerning 51 diatom species].…”

“…High-performance liquid chromatography (HPLC) analysis is now commonly used in ecological studies concerning the sediment, which have largely focused on the problem of method intercalibration (usually between HPLC and the nonseparative spectrophotometric and fluorometric methods) for chloropigment measurements (Brown et al 1981, Daemen 1986, Barlow et a1 1990, Neveux et al 1990, Plante-Cuny et al 1993. Apart from these methodological works, investigations on sediment pigment measurements by HPLC h a r e also been conducted to estimate algal pigment diversity in coastal sediments (Riaux-Gobin et al 1987, Klein & RiauxGobin 1991, to trace the origin and the fate of plant material (Bianchi & Findlay 19W. Abele-Oeschger 1991, Levinton & McCartney 199311 or, more specifically, to follow the degradation of chlorophyll a through macrobenthic grazing [Bmnchi et al 1988, Abele-Oeschger & Theede 1991.…”

Dynamics of microphytobenthos biomass in the Ems estuary

“…It is known (Daemen 1985) that for Dutch estuarine sediments the method of Lorenzen (1967) overestimates chl a content by ca 30% compared with results of HPLC. However, in the late 1970s the HPLC technique (Riaux-Gobin et al 1987) was not available to separate chl a from other pigments in estuarine areas. This was the main reason for application of a conversion procedure to obtain the best possible estimate of the chl a in vital microphytobenthos.…”