scholarly journals Spatial and temporal phytoplankton species diversity in Southern Gulf of Lake Tana, northwestern Ethiopia

2016 ◽  
Vol 8 (10) ◽  
pp. 224-232
Author(s):  
Gashaye Dilnessa
Author(s):  
P.Y. Guo ◽  
H.T. Shen ◽  
J.H. Wang

This paper reports on the phytoplankton community, its composition, structure and distribution in Changjiang estuary from February 1999 to March 2000. Two hundred and eight species were identified in the dry and flood periods. Diatoms, with 143 species observed, was the most abundant phytoplankton group, accounting for 68.75% of the total phytoplankton species number. Skeletonema costatum was dominant among all the species. The phytoplankton of Changjiang estuary in China was divided into five ecological categories: freshwater species, estuary brackish water species, inshore low salinity species, inshore widespread species and off-sea high salinity species. During the dry period, the major phytoplankton populations in the surface layer were estuary inshore and offshore populations, distinguished from the composition of the bottom layer. The community structure was similar in the two layers during the flood period. The phytoplankton species diversity was calculated for Simpson, Shannon–Weaver diversity and evenness indices, and found to be higher in the dry period, due to the simple dominant species and low spatial heterogeneity in the flood period. Higher phytoplankton abundance was observed in the surface layer during the flood period. The phytoplankton species distribution, coinciding with the dominant species distribution, varied with salinity, and their abundance correlated significantly with nutrients and light.


2018 ◽  
Vol 6 (1) ◽  
pp. 123
Author(s):  
I Gede Bagus Indradewa ◽  
Rose O.S.E Mantiri ◽  
Jan F.W.S. Tamanampo

The research was conducted in four rivermouths surrounding city of Manado. The first location is Bahu rivermouth, second location is Sario rivermouth, third location is Jengki rivermouth and the fourth location is Bailang rivermouth. Objectives of this study were to reveal the composition of phytoplankton and its ecological indices in those four rivermouths.Method used was considered as descriptive and explorative study. Plankton net with 60 µm mesh size used for samples collection. The volume of water on the cod end was 50 ml which then  brought into the laboratory for further identification and density calculation.Fourtyfive in total of phytoplankton species identified on those four rivermouths comprise of 23 marine species and 22 freshwater species. The highest density value (5.99 individu/l) was found in Jengki rivermouth while the lowest found in Bahu rivermouth (0.65 individu/l). Those four rivermouths have diversity index ranging from 0.94 to 2.03 that considered high. This index value shows that there is no dominant species recorded in the study areasKeyword: Phytoplankton, Rivermounth, Manado bay AbstrakPenelitian ini dilaksanakan di empat muara sungai yang terdapat pada Kota Manado. Lokasi pertama di muara sungai Bahu, lokasi kedua di muara sungai Sario, lokasi ketiga di muara Sungai Jengki dan lokasi keempat di muara sungai Bailang. Tujuan penelitian yaitu mengetahui jenis-jenis fitoplankton di keempat muara sungai di Kota Manado kawasan Teluk Manado dan mengetahui kepadatan spesies dan indeks ekologis fitoplankton di keempat muara sungai tersebut.            Penelitian ini menggunakan metode deskriptif dan eksploratif. Sampling plankton menggunakan plankton net ukuran 60 µm. Air yang tersaring dan tertampung di cod end  sebanyak 50 ml kemudian diidentifikasi dan dihitung kepadatannya.Diperoleh 45 spesies fitoplankton di empat muara tersebut terbagi atas 23 spesies air laut dan 22 spesies air tawar, dengan kepadatan tertinggi sebesar 5,99 ind/l yang terdapat pada muara Jengki dan kepadatan terendah sebesar 0,65 ind/l terdapat pada muara Bahu. Keempat muara tersebut memiliki indeks keanekaragaman 0,94-2,03 yang berarti memiliki tingkat keanekaragaman yang tinggi. Angka ini juga menunjukan bahwa pada daerah ini tidak ada spesies yang terlalu mendominansi suatu wilayah.Kata kunci: Fitoplankton, Muara sungai, Teluk Manado  


1990 ◽  
Vol 47 (7) ◽  
pp. 1378-1386 ◽  
Author(s):  
D. L. Findlay ◽  
S. E. M. Kasian

Additions of sulfuric acid to the South Basin and nitric acid to the North Basin of Lake 302 caused major changes in the phytoplankton communities. The basins were separated by a nylon-reinforced vinyl sea curtain. In the South Basin, below pH 5.6, species composition shifted from chrysophycean dominance to one of Dinophyceae. Diatoms and cyanophytes were eliminated below pH 5.3. Phytoplankton species diversity decreased as pH decreased. Total epilimnetic biomass was unchanged, except in late fall, when entrainment of dense layers of hypolimnetic species caused increases. The assemblage in the North Basin changed immediately upon additions of HNO3 to resemble systems experimentally fertilized with nitrogen. Chrysophycean dominance gave way to chlorophytes and dinoflagellates. Once pH decreased below 6.0, diatoms and cyanophytes were eliminated from the assemblage, as in the South Basin. Phytoplankton species diversity decreased, but total epilimnetic biomass remained unaffected.


Ecoscience ◽  
2009 ◽  
Vol 16 (4) ◽  
pp. 429-440 ◽  
Author(s):  
Anita Narwani ◽  
Julie Berthin ◽  
Asit Mazumder

Author(s):  
Ewa Dembowska

Phytoplankton species diversity of the Lower Vistula from Wyszogród to ToruńIn this paper, the results of research on phytoplankton species composition along the 145 km section of the Lower Vistula are presented. The research was carried out during the growing season in 1998. All sites were located in the mainstream, both in the river and in the dam reservoir, which is situated in the middle part of the studied river section. As regards the number of species, diatoms and green algae were the most numerous. Most of the species were identified at the site located above the dam reservoir. The fewest number of species were identified at the sites below the reservoir. Damming the river, and therefore changing the water flow velocity, had a clear effect on the species composition and diversity of plankton algae.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Muzamil Bashir ◽  
Sheema Zaffar ◽  
Javid Ahmad Malik ◽  
Mohammad Farooq Mir

The most significant biotic constituent in a lake ecosystem is represented by phytoplankton in their diverse forms. phytoplankton because of their capacity to integrate environmental changes over periods of a few years, and reflect the cumulative effects of successive disturbances, are considered excellent biomass ecological state of water bodies Biodiversity to the aquatic ecosystem is quite varied starting from plankton (phytoplankton and zooplankton) to higher vertebrates like fishes. Study of plankton (phytoplankton and zooplankton) diversity and their ecology greatly contribute to an understanding of the basic nature and general economy of an aquatic habitat. In the present study overall, six broad groups of phytoplankton were observed during the present study, which include Bacillariophyceae, Chlorophyceae, Cyanophyceae, Euglenophyceae, Dynophyceae and Cryptoceae


2021 ◽  
Vol 958 (1) ◽  
pp. 012002
Author(s):  
A Kostryukova ◽  
I Mashkova ◽  
S Belov ◽  
E Shchelkanova ◽  
V Trofimenko ◽  
...  

Abstract The current paper aims at analyzing the species structure of the phytoplankton community of two reservoirs on the territory of South Ural. The given water bodies are of different trophicity, namely, oligotrophic Lake Turgoyak and oligomesotrophic Lake Uvildy. Both lakes, being natural monuments, are subject to intensive recreational use. A large flow of tourists is a serious problem for the ecological state of the water bodies coastal areas. Also, tourist activities can affect the state of aquatic biocenoses. In this work, the degree of recreational degression of the selected study sites was assessed. The analysis was carried out according to the state of landscapes, vegetation and trampledness of the surveyed area. Based upon the research the current paper reveals spatial patterns in the distribution of recreational load on the coastal geosystems and the level of anthropogenic transformation of the territory. Mainly due to the high density of recreational centres and camping areas, the coastal area is characterized by a high degree of regression. Some signs allow forecasting changes in the species composition of phytoplankton communities and the trophic status of the lakes depending on the degradation of the coastal zones. Diatoms (Bacillariophyta) have been dominant in plankton phytocoenosis of Turgoyak and Uvildy. At the same time, in the oligomesotrophic lake (Uvildy), the number of diatom species is significantly reduced in areas with a higher degree of regression. Thus, diatoms are sensitive indicators of anthropogenic impact on aquatic ecosystems. Green and blue-green algae biodiversity has grown in the water body. However, no relationship was found between their species diversity and the level regression. But the following tendency is observed for the oligotrophic Lake Turgoyak. The species diversity of green algae grows with an increase in the degression degree. To forecast the further state of the studied water bodies, the revealed patterns in the change of the phytoplankton species structure depending on the degradation level of the coastal territories can be used as eutrophication signs.


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