Organic films on particulate matter in surface waters off eastern Asia

SEM examination of suspended material collected by filtration from samples of surface waters over continental shelves and deeper areas off eastern Asia reveals the presence of irregular organic films that are longer, cover more filter area, and have more tapered edges in samples from nearshore than offshore regions. Associated diatoms include species diagnostic of coastal environments. Films and coastal diatoms are most abundant in waters above continental shelves where river discharges cause the waters to be more dilute than 33.5‰ salinity. Farther from shore, both films and skeletal elements are broken and partly dissolved. Skeletal elements, faecal matter, and other debris are trapped or adhere to the films, which therefore provide a concentrated food source for small organisms beyond nearshore regions of high primary productivity. The films contribute an unknown percentage of the total organic matter that reaches bottom sediments.     

Surface suspended matter off western Africa: relations of organic matter,skeletal debris and detrital minerals*

Components of suspended matter in surface waters between western Africa and the Mid-Atlantic Ridge were removed by filtration and measured by scanning electron and optical microscopy. Skeletal debris from diatoms, dinoflagellates, and other plankton are most concentrated in Antarctic surface water and in regions of coastal upwelling. Detrital mineral grains are most concentrated in nearshore regions, from discharge of major rivers, erosion of sea cliffs, and deposition from offshore winds. Farther offshore are high concentrations of mineral grains brought by trade winds from deserts in both northern and southern Africa. The winds also bring freshwater diatoms and woody tissue. The remaining component on the filters is marine organic matter, mostly in thin films. These films trap skeletal debris and mineral grains. Presumably, animals that graze upon the films further concentrate the grains into faecal pellets whose rapid settling carries the grains into deeper waters and to the bottom. The films were found in all other areas of the world ocean from which surface samples were spot-checked: off eastern Asia, off eastern North America, and the central Pacific. Thus they appear to be a major factor in marine sedimentation. In areas of upwelling off western Africa, the total suspended matter in surface waters averages about 0.1 mg/1 of filtrate, about five times that present in the open ocean. It consists of about 70% organic matter, 29.6% skeletal debris, and 0.4% mineral grains, in contrast with concentrations in the open ocean of 90%, 8% and 2%, respectively.     

Suspended matter in surface waters: influence of river discharge and of upwelling*

About 4100 samples of suspended matter were collected by filtration of surface ocean waters in three large regions on the western sides of oceans and two on the eastern sides. Comparison of results shows that the non-combustible fraction (chiefly detrital clays and silts with some siliceous and calcareous skeletal debris) generally dominates along the western sides of oceans, where large contributions of solid detrital sediment are made by rivers that drain much of the adjacent continents. The combustible fraction also is important off these rivers, but it is more important (both relative to the non-combustible fraction and in absolute terms) along the eastern sides of oceans, where upwelling is intense.     

Nepheloid and suspended particulate matter in south-eastern Lake Michigan*

A persistent benthic nepheloid layer with high total suspended matter (TSM) and high total particulate surface area was observed in south-eastern Lake Michigan. The layer thickens from a few metres near the shelf-slope boundary to greater than 10 m at the base of the slope. When compared to the hypolimnion, TSM increases by a factor of 2-20 at 1 m above the bottom, the greatest increase detected at the slope-basin boundary. Sediment trap profiles within the nepheloid layer show that the particulate flux increases exponentially from about 10 m above the bottom to 1 m above the bottom, suggesting that a large fraction of the collected material came from resuspension. A nepheloid layer is created during the formation of the thermal bar and maintained during the stratified period, apparently through the action of weak but persistent currents. This layer is supplemented by lakeward transport of fine particles resuspended near the shelf-slope boundary due to impingement of the thermocline on the bottom, or during higher energy events.     

Geochemistry of suspended matter and sinking material in the eastern Norwegian Sea

This paper reports the results of a geochemical study of suspended particulate matter and particle fluxes in the Norwegian Sea above the Bear Island slope. The concentrations of suspended particles and the main components of suspended matter were determined in the euphotic, intermediate (“clean water”), and bottom nepheloid layers. It was shown that biogenic components are predominant in the water above the nepheloid layer, whereas the suspended matter of the nepheloid layer is formed by the resuspension of the lithogenic components of bottom sediments. The chemical compositions of suspended matter and material collected in sediment traps are identical.     

Comparison of components and distribution of heavy metals in sediments, suspended particulate matter and surface coatings in natural waters

Solid phases, such as surface coatings （SC）, suspended particulate matter （SPM） and deposited sediments （DS）, contribute to the pool of heavy metals in natural waters. Their existing and forming conditions lead to potential differences in enrichment capacity of pollutants, chemical compositions and crystals. In this study, the contents of heavy metals in SC, SPM and DS were determined by GF-AAS after digestion with a mixture of concentrated HNO3 and HClO4. The selective extraction method was employed to remove Fe, Mn oxides and organic matters and associated heavy metals （Cu, Pb, Zn）. X-ray diffraction analyses were performed to characterize the crystals in the samples. The results showed that no significant difference in the contents of Fe-oxides in DS, SPM and SC was found, but the contents of Mn-oxides and organic matter follow the order of SC〉SPM〉DS. The significant crystal characters were observed in DS, SPM and SC, and the kinds of minerals and crystallization degree follow the order of DS〉SC〉SPM. In addition, quartz was the most important matter of crystals in the solid phases. Enrichment capacity follows the order of SPM〉SC〉DS for Pb, Cu and Zn. Organic matter was the major sorbent for Cu, and Mn oxides and organic matter played an important role in the enrichment of Zn. However, Pb was absorbed mainly by Fe oxides. Moreover, compared with Fe oxides and organic matter, Mn oxides had a great enrichment capacity for these metals. Although DS, SPM and SC were formed in the same water system, contents of chemical components, crystals and enrichment capacities to heavy metals were obviously different.     

Concentrations and composition of aerosols and particulate matter in surface waters along the transatlantic section

Along the transatlantic section from Ushuaia to Gdańsk (March 26–May 7, 2015; cruise 47 of R/V Akademik Ioffe), data were obtained on the concentrations of aerosols in the near-water layer of the atmosphere and of particulate matter in surface waters, as well as of organic compounds within the considered matter (C_org, chlorophyll a, lipids, and hydrocarbons). The concentrations of aerosols amounted to 1237–111 739 particles/L for the fraction of 0.3–1 μm and to 0.02–34.4 μg/m²/day for the matter collected by means of the network procedure. The distribution of aerosols is affected by circumcontinental zoning and by the fluxes from arid areas of African deserts. The maximum concentration of the treated compounds were found in the river–sea frontal area (the runoff of the Colorado River, Argentina), as well as when nearing the coasts, especially in the English Channel.     

Sedimentary matter and organic compounds in the aerosols and surface waters along the Transatlantic section

Concentrations and composition of suspended particulate matter and organic compounds (OC), including Сorg, lipids, hydrocarbons (HC), and pigments, were determined in the near-water aerosol layer and in surface waters on the meridional section across the Atlantic Ocean from the port of Ushuaia to the port of Gdansk (Cruise 47^th of the R/V Akademic Ioffe, March 26–May, 7, 2015). It was established that the distribution of OC (except for pigments) in aerosols, in general, repeats the distribution of particle number and weight concentrations of aerosols, with maximums in the influence zone of fluxes from Patagonia and African deserts. The concentrations of aerosols changed within wide ranges: from 1237 to 111739 particles/L for 0.3–1 μm fraction; and from 0.02 to 19.890 μg/m³ for aerosols collected by network method (flux of 0.02–34.4 mg/m² day). The contrasting mineral composition of aeolian material reflects the diversity of its provenances. In surface waters, the studied compounds were accumulated in the frontal river–sea area (runoff of the Rio-Colorado River) and with approaching the coast, especially in the English Channel. A simultaneous change of concentrations of suspended particulate matter and OC is observed only in open oceanic waters.     

Copper,zinc and lead minerals suspended in ocean waters

Individual particles of malachite, tenorite, paratenorite, laurionite and sphalerite, as well as several intermediate compounds of Cu, Zn, Pb, Cl, S, OH and CO₃ have been identified among paniculate matter filtered from Atlantic and Pacific deep water samples. These particulate matter samples were provided mainly by the GEOSECS 1972 and 1974 cruises. The detection and the identification of the individual heavy metal compounds were made by a combination of light microscopy, SEM, EMP and XRD. The highest frequency of heavy metal compounds has been found at several North Atlantic, and at one Antarctic stations. Their origin can, at least partly, be ascribed to technological influences, since metallic copper and brass particles are sometimes found associated with, or included in the heavy metal compounds. Others, however, result clearly from growth in the water.     

Elemental composition of suspended particles from the surface waters of Lake Baikal in the zone affected by the Selenga River

The elemental composition of suspended particles in surface waters of Lake Baikal has been studied by ICP MS along a transect of the zone affected by the Selenga River. The amount of terrigenous suspension in water was estimated from Al content, which decreases in a saltatory manner along the transect: 6.5–8.3 km offshore it decreases by an order of magnitude; 11–14 km offshore, by other 20 times; in the pelagic zone it remains almost unchanged. During the study period (late June 2001), the distribution limit of suspension from the Selenga River in the lake’s surface waters lays 11–14 km offshore.It has been found that pelagic suspension is more than 20 times richer in Ca, P, Zn, Cu, Ni, Sn, Mo, Bi, S, and Cd than littoral one (6.5 km offshore) in the zone affected by the Selenga River. This is mainly due to fine suspension (<1.2 μm), which was considerably richer in Ca, P, Zn, Cu, Ni, Sn, Mo, Sb, and Cd than coarser ones in the river.Fine suspension in Lake Baikal, both in the zone affected by the river and in the pelagic zone, is considerably (2–35 times) richer in most elements, except for typical terrigenous ones, than river one. This suggests that element enrichment takes place in the lake, probably owing to bioaccumulation and chemisorption. These processes may be affected by additional factors, because fine suspension from the zone affected by the river differs significantly from pelagic one in elemental composition.     

Manganese and suspended matter in the Yaquina Estuary,Oregon

The longitudinal distribution of total suspended matter and total, dissolved, and particulate manganese in a small coastal plain estuary is described. The distribution of manganese is a consequence of estuarine circulation; a within-estuary maximum is inversely correlated with river flow, and is a function of residence time in the estuary, resuspension in the upper estuary, and desorption from particles introduced from within the estuary or from the river. The turbidity maximum is similarly most pronounced during low river flows. The upper estuary (salinity <15‰), comprising a small percentage of the total estuary volume during low flow, receives material from the river and along the bottom from the lower estuary; this material is returned to the water column by resuspension and desorption from estuarine and riverine particles. The lower estuary tends to damp out these processes because of the greater volume and (residence) time available for mixing.     

The major-element chemistry of suspended matter in the Amazon Estuary

Suspended matter from the surface waters of the Amazon Estuary were collected during May and June 1976 on the ‘R/V Alpha Helix’, and their major-element compositions (Al, Si, Ti, K, Mg, Ca, P, Fe and Mn) were measured.Between salinities of 0 and 10%. the suspended material, predominantly terrigenous in derivation, decreases in load from 500 to 3 mg/l, but has a chemical composition which remains essentially constant. With the onset of a large amount of biological productivity at approximately 10%. salinity, there are large increases in the ratios of $\text{Si}\text{Al}$, $\text{P}\text{Al}$, $\text{Ca}\text{Al}$, $\text{Mg}\text{Al}$, $\text{Ti}\text{Al}$ and $\text{Mn}\text{Al}$ which are maintained at higher salinities. Calculations of “excess” concentrations of elements held in the non-terrigenous components of the suspended material further support our main conclusion that Si, P, Ca, Mg, Ti and Mn are incorporated into the skeletal and organic phases of marine phytoplankton (predominately diatoms) of the Amazon Estuary. The data suggest, but with less certainty, that Fe and K follow the above elements.This study has demonstrated that the chemical composition of river-introduced suspended matter can be significantly altered by biological activity within estuarine waters as can be the geochemical cycle of inorganic elements.     

长江悬浮颗粒物中磷的赋存形态

2006年9~10月在长江采集悬浮颗粒物样品,应用改进后的SEDEX法对磷的赋存形态进行了分析.结果表明,自生磷灰石磷是长江悬浮颗粒物中磷的主要赋存形态.涪陵至万州江段,碎屑磷灰石磷的含量较高,弱吸附态磷和有机磷含量较低,磷的赋存形态主要受悬浮颗粒物含量的影响;香溪至葛洲坝下江段,弱吸附态磷和有机磷含量较高,碎屑磷灰石磷含量较低,磷的赋存形态主要受浮游植物生长及泥沙粒径的影响;城陵矶至大通江段,有机磷、碎屑磷灰石磷和铁结合态磷含量较高,弱吸附态磷含量较低,磷的赋存形态主要受泥沙粒径和洞庭湖输入的影响.长江悬浮颗粒物中生物可利用磷占颗粒态磷的45.6%,长江上游水体中生物可利用磷含量较低,下游含量较高.     

Organic matter in ground- and surface waters in the area of the Annenskii geothermal field,Russian Far East

The paper presents author’s data on the composition of water-soluble organic matter in thermal, cold groundwaters, and surface waters in the Annenskii geothermal field. The waters contain 75 organic compounds of 13 homologous series, with 72 of these compounds identified in the thermal waters. The compounds are mostly of biogenic origin. Organic matter in the thermal waters differs from that in the cold groundwaters in containing nitrogen-bearing compounds, isoalkanes and alkenes. The compositional specifics of the saturated hydrocarbons suggests their partly abiogenic origin.     

Importance of heavy metal-organic matter interactions in natural waters

The role of organic ligands in metal complexing in natural waters has received little attention because of uncertainties regarding both the abundance and nature of dissolved organic carbon compounds. Recent data show that the bulk of dissolved organic matter in natural waters consists of highly oxidized and chemically and biologically stable polymeric compounds closely resembling soil humic substances. Average molar concentrations of these aquatic humics in major U.S. rivers range from 5 × 10^?6to 3 × 10^?5 moles 1^?1. Fractional elution of soil organic matter by meteoric waters may be considered to be the main process contributing to the presence of humic matter in rivers. The aquatic humic polymers participate in complex formation through ionizable functional groups with a range of differential acidities. The stabilities of metal-humic complexes in natural waters are higher than those of the corresponding inorganic metal complexes. Quantitative evaluation of the metal-organic interactions can be approached by applying variable equilibrium functions which take into account the differential physico-chemical characteristics of the active complexing sites on the polymer molecule. Assuming an average humic concentration of 10 mg 1^?1, complexation of trace metals can be significant even in the presence of excess concentrations of major cations.     

Organic geochemistry of suspended and settling particulate matter in Lake Michigan

Organic matter contained in particulate matter in Lake Michigan waters and sediments has been characterized by $\text{C}\text{N}$ ratios and by distributions of biomarker fatty acids, alkanols, sterols, and aliphatic hydrocarbons. Differences in organic constituents of particulate matter from various depths and distances from shore indicate a complex interaction of production, transformation, and destruction of the organic matter contained in sinking particles. Near-surface material contains important contributions of landderived organic matter, presumably of eolian input. Midwater particles have predominantly aquatic organic material of algal origin. At the sediment-water interface, selective suspension of the finer fractions of surficial sediments enriches bottom nepheloid layers with these sediment size classes. As a result, near-bottom particulate matter has an aquatic biomarker character. Organic matter associated with sinking particles undergoes substantial degradation during passage to the bottom of Lake Michigan, and aquatic components are selectively destroyed relative to terrigenous components.     

Composition of subsurface waters in certain mercury-antimony deposits in Central Asia

In the Khaydarkan and the Karasu ore fields, mercury is present in outcropping subsurface waters (fractions of one microgram per liter), and is enriched significantly in sediments of the springs. The fig content of waters circulating in carbonate rocks is higher, almost by a whole order of magnitude, than in aluminosilicate rocks. The waters are of the HCO₃ and SO₄ type, low in Na and Cl, at pH 5 to 6. 5, T. S. at 200 to 600 ppm; traces of Sb, As, Zn, Cu, Sr, Ba, others are present. -- V. P. Sokoloff.     

近岸强海流切变锋作用下悬浮沉积物的输送和沉积--以山东半岛东端外海为例

利用2007年国家908专项ST02区块（渤海海峡及北黄海）水体专项夏季和冬季两个航次调查的温度、浊度和悬浮体浓度数据,选取了跨越山东半岛东端外海泥质沉积体的B1和B2两个断面,结合该区浅地层剖面资料,辅以研究海域的冬季环流数值模拟,着重分析了山东半岛东端外海强海流切变锋作用下的悬浮体输送和沉积特征。结果表明山东半岛东端外海悬浮体向外海输送存在类似“夏储冬输”的规律:夏季,北黄海海水浊度普遍小,不仅北黄海温跃层抑制了底层悬浮体向中上层水体扩散,而且北黄海冷水团在中底层与山东半岛东部沿岸水也形成了显著的温度和悬浮体锋面,阻碍了悬浮物的纬向输送,故夏季应是悬浮体沉积的主要时节;冬季,温跃层消亡,在强风的作用下,山东半岛东部悬浮体浓度高且垂向混合较好,然而在泥质沉积体顶积层两侧,山东半岛东部沿岸中下层北上的逆风补偿流和北上的黄海暖流与位于顶积层上方表中层南下的沿岸流构成了两道显著的强海流切变锋,使得底积层上大量的再悬浮沉积物不能越过山东半岛东部陆架末梢,从而有助于形成山东半岛东端外海特有的Ω状泥质沉积体。