Nature and ecological implications of algal pigment diversity on the Molenplaat tidal flat (Westerschelde estuary, SW Netherlands)
Nature and ecological implications of algal pigment diversity on the Molenplaat tidal flat (Westerschelde estuary, SW Netherlands)
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DOI：
10.3354/meps180051
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发表时间：
1999-05
影响因子：
2.5
通讯作者：
C. Lucas;P. Holligan
中科院分区：
文献类型：
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作者：
C. Lucas;P. Holligan
叶绿素a、其降解产物和辅助色素标记物的深度剖面显示了物理和生物过程在Molenplaat潮滩周围微藻生物量水平和垂直再分布中的作用。chl a的中尺度分布与沉积参数高度相关，在粉砂质站点生物量最大。岩藻黄质：chl a比值为0.35 ~ 1.60，表明粉质和砂质沉积物中微底栖植物群落均以硅藻为主。蓝细菌（玉米黄质）也存在，主要在9月份。藻类的其他来源以沉积的水柱物质的形式出现。紫红素、19′己氧岩藻黄质和少量的chl b是主要的色素，主要存在于粉砂质位点。在6月至9月期间，辅助色素的相对数量增加，表明在此期间有来自水柱的物质输入。粉砂质和砂质样地表层均发现底栖生物和水柱色素，但在生物量和垂直分布上存在显著差异。在沙质地点，沉积物上部2cm的chl a垂直分布均匀，且表层以下缺乏水柱色素，表明原位和异地微藻源的积累不显著。在每个潮汐周期中，通过诸如Arenicola marina等生物搅拌器的作用，材料受到掩埋和再悬浮的连续循环。粉砂质样地chl - a生物量在6月有明显的高峰。顶部1cm的chl a迅速下降，表明降解比泥沙混合更快。随着草食性群落在chl - a循环中的作用变得更加显著，叶绿素的相对贡献从3月/ 4月的褐藻类转向9月的褐藻类。在春季和秋季之间，表层和深层的辅助色素的相对贡献都有所增加，这表明粉砂质地点是在此期间从水柱中沉积藻类的水池。在秋末-冬季，叶绿素生物量和色素多样性显著下降，与生物活性降低和物理混合增加相一致。
Depth profiles of chlorophyll a (chl a), its degradation products, and accessory pigment markers from 5 sites with differing sediment properties highlighted the role of physical and biological processes in re-distributing microalgal biomass both horizontally and vertically around the Molenplaat tidal flat. Intermediate-scale distribution of chl a was highly correlated with sedimentological parameters, with biomass greatest at siltier sites. Fucoxanthin:chl a ratios of 0.35 to 1.60 indicated that the microphytobenthos community was dominated by diatoms in both silty and sandy sediments. Cyanobacteria (zeaxanthin) were also present, mainly in September. Other sources of algae came in the form of deposited water column material. Peridinin, 19'hexanoyloxyfucoxanthin, and to a lesser extent chl b were the main pigments, primarily found at silty sites. Between June and September, the relative amounts of accessory pigments increased suggesting that inputs of material from the water column occurred during this period. Although benthic and water column pigments were found in the surface layers of silty and sandy sites, there were pronounced differences in biomass and vertical distribution. At sandy sites, homogenous vertical distributions of chl a in the upper 2 cm of sediment, together with low phaeopigment levels and the absence of water colum pigments below the surface layer, suggest that accumulation of in situ and allochthonous sources of microalgae is insignificant. Material is subjected to a continuous cycle of burial and resuspension during each tidal cycle and through the action of bioturbators such as Arenicola marina. There was a pronounced peak in chl a biomass at the silty sites in June. Rapidly decreasing chl a over the top 1 cm suggests that degradation was more rapid than sediment mixing. Large amounts of phaeopigments were produced, with the relative contribution switching from phaeophytins (March/April) to phaeophorbides (September) as the role of the herbivorous community in chl a cycling became more significant. An increase in relative contributions of accessory pigments both at the surface and in deeper layers between spring and autumn suggest that silty sites are a sink for sedimenting algae from the water column during this time. During the late autumn-winter, chl a biomass and pigment diversity decreased considerably, coincident with reduced biological activity and increased physical mixing.