Wyniki wyszukiwania - BazTech

1

Variations in organic matter bound in fluffy layer suspended matter from the Pomeranian Bay (Baltic Sea)

Pazdro K., Staniszewski A., Bełdowski J., Emeis K. C., Leipe T., Pempkowiak J.

Oceanologia

|

2001

|

No. 43 (4)

405-420

EN

Fluffy layer suspended matter (FLSM) and surface sediment samples from the Pomeranian Bay were examined for fatty acid, lipid and organic matter contents. FLSM is a several-centimetre-thick layer of fairly concentrated particulate matter lying on the sea floor significantly affecting the flux of matter to depositional basins. Analyses of fatty acids were used to establish sources and decomposition rates of labile organic matter along a transect from the shallow, highly dynamic, Odra estuary to the Arkona Basin, a deep, low energy, depositional area. In FLSM and sediments respectively, the ranges of organic matter contents were 4.0-25.0% and 5.1-23.0%, those of lipids 0.1-5.4% and 0.30-1.67%, and those of fatty acids 50-991 žg g-1 dry wt. and 100-546 žg g-1 dry wt. In shallow waters, the contents of these compounds are very variable, mirroring variations in biological activity and hydrological conditions. The high percentage of polyunsaturated fatty acids in shallow areas indicates the presence of fresh, undegraded, labile organic matter of autochthonous origin. Fatty acids, the most labile components, are transported as suspended matter attached to minerals and finally accumulated in the depositional area in the form of condensed organic macromolecules. The intensity of bacterial decomposition of organic matter in this system is reflected in the high percentage of branched fatty acids. The low fatty acid content in the organic matter is attributed to the high rate of decomposition of the labile organic matter. No linear correlation was found between the contents of fatty acids and lipids.

2

Temporal and spatial changes of cadmium in the near-bottom suspended matter of the Pomeranian Bay - Arkona Deep system

Staniszewski A., Pazdro K., Bełdowski J., Leipe T., Emeis K. C., Pempkowiak J.

Oceanologia

|

2000

|

No. 42 (4)

483-491

EN

Owing to the high toxicity of cadmium (Cd) towards biota and the considerable quantities of this element entering the environment from anthropogenic sources, interest in its biogeochemistry is increasing. This is also true for the marine environment, which serves as a sink for both natural and anthropogenic Cd loads entering the hydrosphere and the atmosphere. The distribution of Cd in the coastal zone of the marine environment is governed primarily by the flux of the so-called fluffy layer suspended matter (FLSM), which spreads across the top of the sea floor as a several-centimetre-thick layer containing highly concentrated suspended matter. Both total contents and solid speciation of Cd was measured in FLSM collected in the Pomeranian Bay - Arkona Deep system (Western Baltic Proper) in the course of the three-year-long study. Seasonal changes in the total Cd content (0.5-1.8 žg g–1 dry matter) were attributed to the contribution of organic suspensions originating from algal blooms. The decreasing content of Cd in FLSM offshore is due to the input of Cd-rich suspended matter from the River Odra (Oder), and the decreasing organic matter content in FLSM with increasing depth. The contribution of labile fractions (adsorbed and bound to iron III hydroxides) was found to be from 50 to 75% of the total content. In view of the substantial mobility and bioavailability of the fractions, this is a highly alarming feature.

3

Near-bottom fluxes and composition of suspended matter in the Pomeranian Bay

Laima M. J., Lund-Hansen L.C., Pazdro K., Christiansen C., Emeis K. C.

Oceanologia

|

1999

|

No. 41 (3)

335-353

EN

The quality and composition of suspended organic matter in near-bottom fluxes was determined at a mooring station (Odas Tonne) 20 km north-north-west of the Odra river mouth from June to December 1997. Salinity data and high concentrations of suspended matter near the bottom showed that the material entering the Pomeranian Bay from the Odra flood was recognisable for about three weeks. Vertical sediment fluxes, however, were low ~ 40 g m-2 d-1 compared to those measured later in the year ~ 60 g m-2 d-1. On the other hand, average molar CNP ratios in sediment trap material decreased from June to December 1997. These results may have been a combined effect of dilution and material transport in a layer close to the sediment surface. Fluff layers sampled at Odas Tonne in August 1997 contained a very high proportion of branched fatty acids of bacterial origin, indicating high rates of bacterial degradation. Long-chain fatty acids indicated an origin from higher terrestrial plants. The saturated fatty acid content was high in the surface sediment and the traps, increasing towards the top trap. The percentage composition of fatty acids indicated that the lowest trap was fed mainly by material from the underlying sediment. Low salinities, variability in molar ratios for major elements, higher than usual bacterial activities and detection of fatty acids characteristic of land plants during the June-August deployment show a relationship with the Odra flood of summer 1997.