Phytodetritus on the deep-sea floor in a central oceanic region of the Northeast Atlantic
Phytodetritus on the deep-sea floor in a central oceanic region of the Northeast Atlantic
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东北大西洋中部海洋区域深海海底的植物碎屑菌
DOI：
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发表时间：
1989
期刊：
影响因子：
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通讯作者：
Franz Riemann
中科院分区：
文献类型：
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作者：
H. Thiel;O. Pfannkuche;G. Schrieber;K. Lochte;A. Gooday;C. Hemleben;R. Mantoura;C. Turley;J. Patching;Franz Riemann
1986年7月/8月，在大西洋东北部的一个温带地区，在4500米深的海底发现了新沉积的植物碎屑。植物碎屑的颜色是多变的，并与降解程度明显相关。显微镜分析显示，存在来自真光层的浮游生物，例如，蓝细菌、小型绿藻、硅藻、颗石藻、硅鞭藻、甲藻、锡虫、放射虫和有孔虫。此外，还发现了甲壳类动物的分泌物和大量的小粪球，即“小粪球”。虽然植物碎屑中细菌丰富，但它们的数量不如沉积物中的多。植物碎屑集合体还含有相当数量的底栖生物，如线虫和底栖有孔虫的特殊集合体。色素分析和颗粒有机碳的高含量表明，植物碎屑是相对未降解。蛋白质，碳水化合物，叶绿体色素，总腺苷酸，和细菌的浓度被认为是显着较高的沉积物表面样品时，phytodegritus比同等样品在早春在相同的站前phytodegritus沉积。只有电子传递系统活性在两组样品之间没有显示出显著差异，这可能是由于采样过程中的生理应激（减压、升温）造成的。植物碎屑样品的化学数据显示出很大的变异性，表明碎屑材料的异质性。各种巨型动物（海参、小行星、星虫和海葵）的肠道内容物包括植物碎屑，表明碎屑物质被各种底栖生物用作食物来源。我们的数据表明，碎屑物质的一部分是快速消耗和在沉积物表面的微矿化和部分纳入沉积物。模拟原位条件下的植物碎屑培养和地表水条件下的生物需氧量的测定表明，其部分有机质可以被生物利用。根据测量的植物碎屑现存量，估计春季初级生产的0.3-3%沉积到深海海底。本文讨论了表层沃茨中聚集体的形成方式、沉积作用以及在海底的分布。
In a midoceanic region of the northeast Atlantic, patches of freshly deposited phytodetritus were discovered on the sea floor at a 4500 m depth in July/August 1986. The color of phytodetritus was variable and was obviously related to the degree of degradation. Microscopic analyses showed the presence of planktonic organisms from the euphotic zone, e.g., cyanobacteria, small chlorophytes, diatoms, coccolithophorids, silicoflagellates, dinoflagellates, tintinnids, radiolarians, and foraminifers. Additionally, crustacean exuviae and a great number of small fecal pellets, “minipellets,” were found. Although bacteria were abundant in phytodetritus, their number was not as high as in the sediment. Phytodetrital aggregates also contained a considerable number of benthic organisms such as nematodes and special assemblages of benthic foraminifers. Pigment analyses and the high content of particulate organic carbon indicated that the phytodetritus was relatively undegraded. Concentrations of proteins, carbohydrates, chloroplastic pigments, total adenylates, and bacteria were found to be significantly higher in sediment surface samples when phytodetritus was present than in equivalent samples collected at the same stations in early spring prior to phytodetritus deposition. Only the electron transport system activity showed no significant difference between the two sets of samples, which may be caused by physiological stress during sampling (decompression, warming). The chemical data of phytodetritus samples displayed a great variability indicative of the heterogeneous nature of the detrital material. The gut contents of various megafauna (holothurians, asteroids, sipunculids, and actiniarians) included phytodetritus showing that the detrital material is utilized as a food source by a wide range of benthic organisms. Our data suggest that the detrital material is partly rapidly consumed and remineralized at the sediment surface and partly incorporated into the sediment. Incubations of phytodetritus under simulated in situ conditions and determination of the biological oxygen demand under surface water conditions showed that part of its organic matter can be biologically utilized. Based on the measured standing stock of phytodetritus, it is estimated that 0.3–3% of spring primary production sedimented to the deep-sea floor. Modes of aggregate formation in the surface waters, their sedimentation, and distribution on the seabed are discussed.