scholarly journals A STUDY OF DIATOMS (BACILLARIOPHYTA) IN HOOR-AL-AZIM WETLAND, SOUTH-WEST IRAN, AND THEIR SEASONAL CHANGES

2021 ◽  
Vol 52 (5) ◽  
pp. 1163-1170
Author(s):  
M. Dezhman ◽  
S. Dehghan ◽  
F. M Hassan

This study was aimed to identify the planktonic diatoms and their seasonal change in Hoor-AL-Azim wetlands, Iran. Diatoms are important algal groups in different aquatic ecosystem and considered as bioindicators for water quality and environmental health. Hoor-AL-Azim or Hoor-al-Hawizeh is one of the most extensive and ecologically important wetlands in the Middle East which is shared between Iran (south-west) and Iraq(south). A major part of the wetland area was exposed to drying completely or partially during last few decades due to two Country politics. The samples were taken on a monthly basis from four stations for year from January to end of December, for  identification and seasonal changes of Diatoms (Bacillariophyta). In this study, totally  69 taxa belonging to 28 different genera were identified of which Nitzschia genus had the highest species diversity (13 species) and followed by Navicula genus (10 species) while the highest species diversity observed in autumn. The average density ranged from 4818 cells/ liter  to 58625 cells /liter in spring and winter, respectively.

2001 ◽  
Vol 2 (1) ◽  
pp. 27 ◽  
Author(s):  
S. STOYKOV ◽  
S. UZUNOVA

The paper presents results of analysis of 96 macrozoobenthic samples, collected on a seasonal basis in Bourgas Bay and in open-sea areas offshore Cape Emine (Bulgarian Black Sea) in 1996 and 1998. In total 96 taxa were established, distributed in four groups: Polychaeta, Mollusca, Crustacea and “Diversa”. The average density of populations was 1756 ind.m-2 with a predominating abundance of Polychaeta species. The average biomass estimated was 183.02 g.m-2, formed mainly by representatives of Mollusca. The latter species were measured together with the shells, which appraised their individual weights. Seven of the species found had a coefficient of constancy more than 50%. These were the most adapted species to the environmental conditions of the investigated areas. The quantitative and qualitative assessments in this study demonstrate an increasing tendency in the parameters obtained (density, biomass, species diversity) in comparison with previous investigations in the early 1990-s, when intensive anthropogenic influence was widely perceived to misbalance the Black Sea ecosystem.The method of Warwick (1986) applied to characterize the water quality of the studied areas allowed us to define them as rather clean or moderately polluted aquatories.


2012 ◽  
Vol 63 (9) ◽  
pp. 788 ◽  
Author(s):  
N. E. Pettit ◽  
T. D. Jardine ◽  
S. K. Hamilton ◽  
V. Sinnamon ◽  
D. Valdez ◽  
...  

The present study indicates the critical role of hydrologic connectivity in floodplain waterholes in the wet–dry tropics of northern Australia. These waterbodies provide dry-season refugia for plants and animals, are a hotspot of productivity, and are a critical part in the subsistence economy of many remote Aboriginal communities. We examined seasonal changes in water quality and aquatic plant cover of floodplain waterholes, and related changes to variation of waterhole depth and visitation by livestock. The waterholes showed declining water quality through the dry season, which was exacerbated by more frequent cattle usage as conditions became progressively drier, which also increased turbidity and nutrient concentrations. Aquatic macrophyte biomass was highest in the early dry season, and declined as the dry season progressed. Remaining macrophytes were flushed out by the first wet-season flows, although they quickly re-establish later during the wet season. Waterholes of greater depth were more resistant to the effects of cattle disturbance, and seasonal flushing of the waterholes with wet-season flooding homogenised the water quality and increased plant cover of previously disparate waterholes. Therefore, maintaining high levels of connectivity between the river and its floodplain is vital for the persistence of these waterholes.


CATENA ◽  
2019 ◽  
Vol 173 ◽  
pp. 131-140 ◽  
Author(s):  
Guoce Xu ◽  
Peng Li ◽  
Kexin Lu ◽  
Zhan Tantai ◽  
Jiaxin Zhang ◽  
...  

2016 ◽  
Vol 9 (2) ◽  
pp. 146-157
Author(s):  
Adimasu Woldesenbet Worako

Lake Hawassa is one of the Major Ethiopian Rift Valley Lakes which is situated in southern regional state, which has a closed basin system and receives water from only Tikurwuha River and runoff from the catchment. Quality of the lake water is vital for the surrounding community for proper and safe use of the lake. The present study was designed to examine the physicochemical and biological water quality suitability for multiple purposes and to determine trophic state index of the lake for a period of three months from December to February, 2011/12. Water samples were collected from the lake on monthly basis and analyzed for all water quality parameters by using standard methods. Data analysis was performed by descriptive, multivariate analysis (MANOVA%


Author(s):  
Erwin Theofilius ◽  
Zahidah Hasan ◽  
Asep Agus Handaka ◽  
Herman Hamndani

This study conducted to determine the water quality of Situ Ciburuy based on the structure of the gastropod community as a bioindicator. The survey method used in this study based on collecting data directly at the research area (purpose sampling method).  For instance, species and density of gastropods were descriptively analyzed, using diversity index and evenes index. For instance, The findings showed that level of water quality in  Situ Ciburuy based on gastropods bioindicators was lightly polluted. That is indicated by the low to moderate diversity of gastropods, which ranges from 1.31-1.98. The Shannon evenness index (0,73-0.95) revealed low gastropod species diversity in Situ Ciburuy, indicating low evenness of gastropod in Situ Ciburuy.


2014 ◽  
Vol 48 (1) ◽  
pp. 3-10 ◽  
Author(s):  
O. S. Shevchenko ◽  
L. A. Kolodochka

Abstract Species complexes of oribatid mites in soil and litter in 10 plots in green areas of different parts of Kyiv city in April-September 2011 were studied. In total, 107 species of 76 genera of 44 families of oribatids were found. Trends of seasonal fluctuations of species diversity and dominance structure of oribatids in studied plots were assessed.


2021 ◽  
Vol 267 ◽  
pp. 01035
Author(s):  
Ziqi Zhang ◽  
Lei Yang ◽  
Dongxu Han ◽  
Hongyan Shen

An investigation of phytoplankton community and water quality for M River was conducted in December 2019.The results showed that 38 species of phytoplankton belonging to 6 phyla and 26 genera were collected. Among them, Bacillariophyta is the richest species, which accounted for 34.21%, followed by Cyanophyta with 26.32% and Chlorophyta with 28.95%. The density of phytoplankton was 63.0*106 inds/L which indicated as eutrophic water body. The highest density was Bacillariophyta, accounting for 51.03%. The Shannon-Wiener diversity index (H’) varied from 1.34 to 2.24, the Margalef Species diversity index (d) varied from 2.71 to 3.85, and the Pielou evenness index (J) varied from 0.38 to 0.67. According to the integrative analysis results of H’, d and J, M River water quality belongs to oligo-polluted, but individual sites belong to meso-polluted.


2019 ◽  
Vol 7 (8) ◽  
pp. 243
Author(s):  
Eduard A. Titlyanov ◽  
Tamara V. Titlyanova ◽  
Anna V. Scriptsova ◽  
Yuxiao Ren ◽  
Xiubao Li ◽  
...  

Intensive algal sampling conducted in 2016–2019 in the Xiaodong Hai locality (Hainan Island, South China Sea), yielded a total of 198 benthic macroalgal species and their taxonomic forms (54% reds, 20% browns and 26% greens) and 20 species of Cyanobacteria. The largest number of species belonged to the families Rhodomelaceae, Ceramiaceae and Corallinaceae (Rhodophyta); Sargassaceae and Dictyotaceae (Phaeophyceae); Cladophoraceae and Caulerpaceae (Chlorophyta). The majority (79%) of species inhabiting only the tropics or subtropics were previously recorded and 21% of the species were also inhabiting temperate latitudes. Cosmopolitan algae inhabiting from the tropics to Arctic or Antarctic waters amounted to 14%. The level of maximum similarity of macroalgal species diversity in different years was on average more than 70%, interannual species specificity was observed only in the group of dominating species in algal turf communities. The seasonal variability of floras was manifested in a significant decrease in species diversity from the dry season to the rainy and in the change of dominant species in algal turf communities.


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