Seasonal variations of metal concentrations in periphyton and taxonomic composition of the algal community at a Yenisei River littoral site

2010 ◽  
Vol 5 (1) ◽  
pp. 125-134 ◽  
Author(s):  
Olesya Anishchenko ◽  
Michail Gladyshev ◽  
Elena Kravchuk ◽  
Elena Ivanova ◽  
Iliada Gribovskaya ◽  
...  
Keyword(s):  
Seasonal Variations ◽  
Early Spring ◽  
Taxonomic Composition ◽  
Early Summer ◽  
Algal Community ◽  
Yenisei River ◽  
Algal Communities ◽  
Metal Contents ◽  
Middle Stream ◽  
A Site

AbstractThe concentrations of metals K, Na, Ca, Mg, Fe, Mn, Zn, Cu, Ni, Pb, Co and Cr, in the water and periphyton (epilithic algal communities) were studied at a site in the middle stream of the Yenisei River (Siberia, Russia) during three years using monthly sampling frequencies. Despite considerable seasonal variations in aquatic concentrations of some metals, there was no correlation between metal contents in the water and in periphyton. Seasonal concentration variations of some metals in periphyton were related to the species (taxonomic) composition of periphytic microalgae and cyanobacteria. Enhanced levels of Ni and Co in periphyton in late autumn, winter, and early spring were likely caused by the predominance of cyanobacteria in the periphytic community, and annual maximum levels of K in periphyton in late spring and early summer were attributed to the domination of Chlorophyta, primarily Ulothrix zonata.

Seasonal succession of diatom epiphyton on dense mats of Lemna minor

1985 ◽  
Vol 63 (12) ◽  
pp. 2332-2339 ◽  
Author(s):  
L. G. Goldsborough ◽  
G. G. C. Robinson
Keyword(s):  
Lemna Minor ◽  
Algal Growth ◽  
Seasonal Succession ◽  
Ambient Air ◽  
Early Spring ◽  
Early Summer ◽  
Algal Community ◽  
Light Limitation ◽  
Total Biomass

Annual sequences of biomass, species diversity, and community composition of epiphytic diatoms on a dense mat of Lemna minor L. growing in a freshwater marsh are described. In 2 successive years, maximum biomass occurred in early spring prior to occlusion of the water surface by the mat, while diversity reached relative maxima in the early summer (during a period of declining total biomass) and late fall. Ambient air temperature (possibly through a relationship with in situ metabolic activity and nutrient availability) was significantly correlated with community ordination scores on a temporal basis. Depth profile maxima of diatom abundance on vertically positioned artificial substrata occurred below the mat, suggesting that light limitation of algal growth within dense mats may be of lesser importance. Dominant diatom species in the spring and fall were generally ubiquitous in the surrounding marsh, while the major taxa in midsummer, Achnanthes hungarica, Amphora veneta, and Navicula twymaniana, may be specific to the Lemna microhabitat. The development of algal community specificity within a defined seasonal range is discussed in terms of the relative importance of host exudates versus exogenous nutrients as the basis for algal-substratum associations.

Algal Communities as a Biological Indicator of Stormwater Management Pond Performance and Function

2000 ◽  
Vol 35 (3) ◽  
pp. 489-504 ◽  
Author(s):  
Daniel D. Olding
Keyword(s):  
Green Algae ◽  
Stormwater Management ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Biological Indicator ◽  
Taxonomic Composition ◽  
Algal Community ◽  
Algal Communities ◽  
Blue Green Algae ◽  
Biological Communities

Abstract An investigation into phytoplankton and periphyton algal communities of two recently constructed Stormwater management ponds suggests that Stormwater impacts on biological communities are reduced during passage through the ponds, providing a degree of protection for biological communities in their receiving waters. In both ponds, disturbance effects from the incoming Stormwater on algal community richness and evenness appear to be greatest in the sediment forebay and are reduced in the main pond. However, the nature of the disturbance in the two systems can be seen to be fundamentally different from a biological perspective, with Rouge Pond functioning primarily to reduce toxins harmful to algal communities (e.g., heavy metals), and Harding Pond acting to reduce nutrients. The taxonomic composition of the two sites provides an indication of the quality of the incoming Stormwater. Rouge Pond, which contains many marine and brackish water species, receives Stormwater runoff from a major highway, while Harding Pond, containing more nutrient rich species, receives Stormwater primarily from residential properties. Despite the nutrient-rich conditions present in both ponds, nuisance blue-green algae (cyanobacte-ria) are conspicuously absent, and the ponds appear to have little potential for developing harmful algal blooms. The lack of blue-green algae can be linked to the hydraulic functioning of the ponds, suggesting that Stormwater facilities may be engineered to inhibit undesirable algal communities.

scholarly journals Water quality drives the regional patterns of an algal metacommunity in interconnected lakes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Min Sung Kim ◽  
Seok Hyun Ahn ◽  
In Jae Jeong ◽  
Tae Kwon Lee
Keyword(s):  
Water Quality ◽  
Community Assembly ◽  
River Flow ◽  
Geographical Area ◽  
Oxygen Demand ◽  
Algal Community ◽  
Regional Patterns ◽  
Algal Communities ◽  
Species Sorting ◽  
Metacommunity Structure

AbstractThe metacommunity approach provides insights into how the biological communities are assembled along the environmental variations. The current study presents the importance of water quality on the metacommunity structure of algal communities in six river-connected lakes using long-term (8 years) monitoring datasets. Elements of metacommunity structure were analyzed to evaluate whether water quality structured the metacommunity across biogeographic regions in the riverine ecosystem. The algal community in all lakes was found to exhibit Clementsian or quasi-Clementsian structure properties such as significant turnover, grouped and species sorting indicating that the communities responded to the environmental gradient. Reciprocal averaging clearly classified the lakes into three clusters according to the geographical region in river flow (upstream, midstream, and downstream). The dispersal patterns of algal genera, including Aulacoseira, Cyclotella, Stephanodiscus, and Chlamydomonas across the regions also supported the spatial-based classification results. Although conductivity, chemical oxygen demand, and biological oxygen demand were found to be important variables (loading > |0.5|) of the entire algal community assembly, water temperature was a critical factor in water quality associated with community assembly in each geographical area. These results support the notion that the structure of algal communities is strongly associated with water quality, but the relative importance of variables in structuring algal communities differed by geological regions.

TEMPERATURE RESISTANCE OF GOLDFISH MAINTAINED UNDER CONTROLLED PHOTOPERIODS

1959 ◽  
Vol 37 (4) ◽  
pp. 419-428 ◽  
Author(s):  
William S. Hoar ◽  
G. Beth Robertson
Keyword(s):  
Temperature Change ◽  
Seasonal Variations ◽  
Rapid Growth ◽  
Endocrine System ◽  
Early Spring ◽  
Late Winter ◽  
Thyroid Activity ◽  
Temperature Resistance ◽  
Sudden Temperature Change

Goldfish maintained under controlled photoperiods for 6 weeks or longer were relatively more resistant to a sudden elevation in temperature when the daily photoperiods had been long (16 hours) and relatively more resistant to sudden chilling when they had been short (8 hours). The magnitude of the effect varied with the season. Thyroid activity was slightly greater in fish maintained under the shorter photoperiods. The longer photoperiods stimulated more rapid growth of ovaries during late winter and early spring. The endocrine system is considered a link in the chain of events regulating seasonal variations in resistance to sudden temperature change.

scholarly journals Seasonal variations in response of periphytic algal community to nutrient enrichment in the river Ganga (Varanasi, India)

2018 ◽  
Vol 54 ◽  
pp. 32 ◽  
Author(s):  
Arpana Yadav ◽  
Dhananjay Kumar ◽  
Ram Sharan Singh ◽  
Lalit K. Pandey ◽  
Jyoti Rai
Keyword(s):  
High Temperature ◽  
Species Diversity ◽  
River Water ◽  
Green Algae ◽  
Nutrient Enrichment ◽  
Seasonal Variations ◽  
Algal Community ◽  
Phosphate Limitation ◽  
River Ganga ◽  
Time Periods

Effect of nutrient enrichment on periphyton was studied using chemical diffusing substrates that released, singly or in combination, PO43−-P and nitrogen, both NO3−-N and NH4+-N. The study was carried out in March and June 2014 as these two time periods showed abundance of different groups of algae. Whereas diatoms and green algae were abundant in March, cyanobacteria dominated in June. Nitrogen was primarily growth limiting in river water as its enrichment enhanced the growth of periphyton. Phosphate limitation was secondary in nature. Enrichment of NH4+-N caused greater enhancement of periphytic growth than that of NO3−-N. Nutrient enrichment reduced species diversity, further enhancing total biovolume of the periphytic group that was predominant at that particular point of time. Nutrient enrichment markedly increased cyanobacterial populations in June due inter alia to high temperature. In spite of nutrient enrichment, the periphytic biomass did not reach the level (chla≥ 100–150 mg m−2) considered as the nuisance, except in March when combined enrichment of PO43−-P and NO3−-N greatly enhanced the periphytic biomass.

scholarly journals MANAGEMENT OF LATE SPRING-EARLY SUMMER PASTURE SURPLUSES IN HILL COUNTRY

1984 ◽  
pp. 199-206 ◽  
Author(s):  
G.W. Sheath ◽  
R.W. Webby ◽  
W.J. Pengelly
Keyword(s):  
Early Spring ◽  
Early Summer ◽  
Late Spring ◽  
First Year ◽  
Hill Country ◽  
Continuous Grazing ◽  
Summer Pasture ◽  
Animal Performances ◽  
Grazing Policy ◽  
Made In

Comparisons of controlling late spring to early summer pasture growth on either easy or steep contoured land with either a fast rotation or continuous grazing policy were made in self-contained farmlets for two years. Pasture control was maintained over more land by controlling steep land first and with continuous grazing. Animal performances (ewes, steers) were generally similar for the mid-November to early January treatment period, and subsequently until May shearing. In the first year better animal performances occurred in "steep control" farmlets during winter and early spring, but this was less evident in the second year. Priority control of steep land during late spring-early summer is recommended because of likely longer-term benefits in pasture composition,density and production. Quick rotation grazing through the period provides a better ability to recognise and manage pasture quantities and should be adopted if summer droughts are anticipated. For well fenced properties in summer-wet areas and with integrated stock grazing, continuous grazing during late spring-early summer may be equally suitable. Keywords: hill country, grazing management, pasture control

scholarly journals Seasonal patterns of pasture production in the Bay of Plenty and Waikato

1991 ◽  
pp. 67-72
Author(s):  
J.A. Baars ◽  
G.J. Goold ◽  
M.F. Hawke ◽  
P.J. Kilgarriff ◽  
M.D. Rolm
Keyword(s):  
Growth Rates ◽  
Early Spring ◽  
Early Summer ◽  
Growth Patterns ◽  
Climatic Data ◽  
Large Contribution ◽  
Pasture Production ◽  
Summer Peak ◽  
The Difference

Patterns of pasture growth were measured on 3 farms in the Bay of Plenty (BOP) and at No2 Dairy (Ruakura Agricultural Centre) in the Waikato from 1989 to 199 1. A standardised trim technique with cages and 4-weekly cutting under grazing was used. Long-term seasonal growth patterns, using a predictive pasture model, were also simulated. Simulated pasture growth from long-term climatic data shows that pasture growth rates are higher in winter, early spring and late autumn in the BOP than the Waikato. However, the actual measurements over the 2 years show that pasture growth over the latter periods is lower at the BOP sites than at the Waikato site. In the BOP the spring peak is much later than in the Waikato while an early summer peak, with higher growth rates than in the Waikato, occurred in the BOP. No such summer peak was evident in the Waikato. The difference between the two regions is caused by the large contribution of subtropical grasses to sward production in summer and autumn, The prolific summer growth of subtropical grasses may explain the low ryegrass content and low pasture production in winter. The lower than expected autumn, winter, spring production may also becaused by low clover content, possibly a result of competition from subtropical grasses and a sulphur deficiency. The apparent low amount of nitrogen fixed by clover may explain the low rates of pasture production over the cooler season. Applications of nitrogen fertiliser may substantially increase dry matter production from April to September. Keywords pasture,simulation,subtropical grasses, Paspalum, Digitaria sanguinalis, growth rates

The diet of grizzly bears in the Flathead River drainage of southeastern British Columbia

1995 ◽  
Vol 73 (4) ◽  
pp. 704-712 ◽  
Author(s):  
Bruce N. McLellan ◽  
Fred W. Hovey
Keyword(s):  
National Park ◽  
Ursus Arctos ◽  
Handling Time ◽  
Early Spring ◽  
Early Summer ◽  
Grizzly Bears ◽  
Green Vegetation ◽  
Heracleum Lanatum ◽  
Shepherdia Canadensis ◽  
Food Consumed

Based on the analysis of 1100 feces or scats, the seasonal diet of grizzly bears (Ursus arctos) in the Flathead drainage between 1979 and 1991 was estimated. In the early spring, major foods included ungulates and hedysarum roots (Hedysarum sulphurescens). Later in the spring and early summer, green vegetation that mainly included horsetails (Equisetum arvense), graminoids, and cow parsnip (Heracleum lanatum) dominated the diet. Later in the summer, berries, particularly huckleberries (Vaccinium spp.) and soopolallie (Shepherdia canadensis), were most common. In the autumn, berries, ungulates, and hedysarum roots were major foods. Seasonal changes in nutrients were measured for major foods. The volume of a food consumed within a season was inversely related to food quality, suggesting that food availability and handling time may have been more important factors influencing diet selection. The proportions of food items in the scats, and species of fruit in particular, varied among years. The Flathead and contiguous Waterton Lakes National Park are so far the only study areas in North America that contain all major bear foods found across the interior of the continent, and in particular, both major berry species, huckleberries and soopolallie. This observation supports the hypothesis that a favourable food base in the Flathead is partially responsible for the high density of bears found there. It is important for managers to realize the possible uniqueness of the Flathead area and not extrapolate information without due caution.

scholarly journals Resilience of benthic diatom communities in Mediterranean streams: role of endangered species

2019 ◽  
Vol 70 (2) ◽  
pp. 212 ◽  
Author(s):  
E. Falasco ◽  
E. Piano ◽  
A. Doretto ◽  
S. Fenoglio ◽  
F. Bona
Keyword(s):  
Endangered Species ◽  
Global Climate ◽  
Resistance Mechanisms ◽  
Taxonomic Composition ◽  
Change Scenario ◽  
Mediterranean Streams ◽  
Development Of Resistance ◽  
Diatom Communities ◽  
Experimental Treatments ◽  
A Site

The extent of drought in Mediterranean streams has been intensifying recently, and the mean annual discharge is expected to experience a decreasing trend in coming years, with significant effects on aquatic ecosystems. The aim of this study was to analyse colonisation patterns of diatom communities that differed in terms of taxonomic composition and percentage of endangered taxa exploring the possible development of resistance mechanisms. To this end, we selected three Mediterranean streams comparable in terms of water quality, but different in terms of surrounding land use, and we performed two experimental treatments. The first treatment consisted in artificially drying and cleaning of substrates (cobbles) to analyse the post-drought recolonisation process that is only driven by drift and immigration. In the second treatment cobbles coming from a site experiencing a seasonal drought were transplanted upstream in a perennial stretch to explore the possible development of resistance mechanisms within diatom communities periodically exposed to droughts. We observed that stream identity played an important role in determining diatom assemblage composition. Highly natural stretches had a high abundance of endangered species, which were less resilient to drought than assemblages composed of general and widespread taxa. Moreover, according to our results, resistance mechanisms did not play a significant role in recovery patterns. Improving our knowledge of diatom resilience mechanisms is very important in a global climate change scenario, especially in Mediterranean streams.

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