Variability of Trophic State of Bottom Biotopes of the Gorky Reservoir by Sedimentary Pigments

Water Resources - New data on the contents of plant pigments and organic matter in bottom sediments of channel, floodplain and estuarine biotopes of the Gorky Reservoir (upstream Volga, Russia) are...     

Plant pigments as indicators of water transformation in the upper Volga Chain of reservoirs

Results of studying spatial and temporal variability in plant pigments in the Volga River water from the upper sections of the Ivankovo Reservoir downstream to the Rybinsk Reservoir Main Reach, as well as the applicability of different groups of indices of the absolute and relative concentration of pigments (chlorophylls, phaeo-pigments, and carotenoids) are presented. To differentiate water masses, these pigments have been assessed using the standard spectrophotometric method. It has been found that waters of individual river sections, singled out according to their hydrological features, and waters of different reservoirs on the whole can be reliably distinguished according to the concentration of pigments in the plant suspension.     

Plant Pigments in the Ivankovo Reservoir Silts as Indicators of Destruction Processes

The trophic state of the Ivankovo Reservoir is evaluated based on the characteristics of phytoplankton development and silt accumulation. Data on the space and time distribution of plant pigments in silt deposits are examined. Correlation between plant pigments and the main characteristics of silts are established. The ratio of chlorophyll content of the normal annual layer of sediment accumulation to the annual primary production of phytoplankton is calculated. The bedding of gray clayey silts onto gray sandy silts is shown to correlate with an increase in pigment concentrations in the top sediment horizons.     

Sedimentary Pigments as Production Characteristics of the Shallow Kostromskoe Widening of the Gorky Reservoir

Water Resources - First data on the concentrations of plant pigments in the top layer of bottom sediments are given for a large, shallow, moderately overgrown by macrophytes (21.5%) the Kostromskoe...     

Sediment pigments and silting rate as indicators of the trophic condition of the Rybinsk Reservoir

The results of studies of the vertical distribution of SP (the sum of chlorophill a and pheopigments) and the rate of silting of the Rybinsk Reservoir since its filling in 1941 up to 2009 are studied. The range of pigment concentrations (7–232 μg/g of dry residue) in core sample layers includes the values typical of all types of trophic conditions of water bodies, but the majority of values (81%) refers to the categories of mesotrophic and eutrophic. The mean concentrations of pigments in core samples over the periods between soil surveys, which were carried out in 1955, 1978, 1992, and 2009, averaged 525.4, 248.8, 200.6, and 142.3 mg/(m² year), respectively. The mean rates of silting at the stations under study decreased from survey to survey from 13.6–17.9 to 3.5–5.3 mm/year. A direct positive relation was found to exist between the mean annual concentrations of pigments in core samples and the rate of silting at higher values of the indices in lakelike reaches in comparison with river-type reaches.     

Evaluation of Microphytobenthos Productivity in Lake Pleshcheevo Based on Plant Pigment Stock

Results of spectrophotometric determination of plant pigments (chlorophylls, phaeo-pigments, and carotenoids) in the upper 3-cm layer of the littoral and sublittoral lake bottom sediments are presented for the depths corresponding to water transparency of 0.2, 0.5; 1, 2, and 3. Pigment characteristics are analyzed for the conditions, theoretically ensuring the possibility of photosynthesis and development of microphytobenthos. The presence of live algae in the bottom sediments is confirmed by directly counting the cells capable of positive photokinesis. The specific character of pigments' horizontal distribution is determined by a circum-bathymetric structure of the lake sediment complex and by illumination conditions. Potentially active, “pure” chlorophyll prevails in the euphotic area in the zone of light saturation, whereas phaeo-pigments prevail in the area of limited illumination. Regression equations describing relations between pigments concentration and depth have been obtained. The ratio between chlorophyll concentration in microphytobenthos and that of phytoplankton in the lake is estimated.     

Physicochemical Properties of Bottom Sediments in Water Bodies in the Central and Southern Vietnam

Water Resources - The physicochemical characteristics of bottom sediments in inland water bodies in the Central and Southern Vietnam are presented for the first time, including particle-size...     

Relationships between the Concentrations of Phyto-Pigments,Nitrogen, and Phosphorus in Bottom Deposits of Water Reservoirs

Samples characterizing the horizontal distribution of bottom deposits of different types in the Upper Volga reservoirs were used to study the statistical relationship between the indicators of the potential and actual trophy of water bodies. These indicators are the amount of biogenic elements (the total nitrogen and phosphorus) and phyto-pigments (in the dry and wet masses of soil and in its organic fraction). The relationship between the above indicators for the channel deposits from the Upper Volga reservoirs and for the deposits in the lake hollows is found to he linear.     

Significance of Pigment Characteristics of Phytoplankton in Water Quality Estimating

Data on water bodies with different trophic status in the Upper Volga basin are used to analyze the relationship between the algological and pigment characteristics of blue-green alga development. The examined relationships for the phytoplankton of highly eutrophic Lake Nero are shown to feature higher correlation coefficients as compared with meso- and mesoeutrophic reservoirs.     

Studying the Correlation between the Vegetable Pigments Content of Bottom Deposits and the Trophic Status Indices of the Gor'kovskoe Reservoir

Data on the distribution of vegetable pigments in bottom deposits and water mass is presented to characterize the ecological zones of the reservoir. The concentrations of pigments in the channel deposits are shown to increase from the reservoir head toward the dam in accordance with the difference in phytoplankton production in the zone of backwater pinching out, transient zone, and near-dam zone. It is shown that the space heterogeneity of the pigment characteristics of deposits is controlled by the soil properties and the pigments content of the top 2.5-cm layer of bottom deposits of the reservoir correspond to the average productivity level.