The Distribution and Seasonality of Phytoplankton in Sombreiro River, Niger Delta, Nigeria
E.N. Ezekiel, E.N. Ogamba and J.F.N. Abowei
Corresponding Author: Abowei Jasper
Key words: Distribution, Niger Delta, Nigeria, Phytoplankton, seasonality, Sombreiro River,
Vol. 3 , (3): 192-199
|2011 February, 15
||2011 March, 21
||2011 May, 25
The distribution and seasonality of phytoplankton in Sombreiro River of the Niger Delta area in
Nigeria was studied for a period of two years (August, 2007 July, 2009). Forty-one species were recorded in
stations 1 (Degema), 3 (Ihuaba) and 4 (Odiemudie) while station 2 (Ogbele) recorded 42 species. Among the
Bacillariophyceae, Pinnularia horealis occurred only in station 1 (Degema) 79.4% and 2 (Ogbele) 20.6%.
Stephanodiscus asroea was recorded only from Degema and was absent in stations 2, 3 and 4. All the other
species were fairly distributed in all the stations. Among the chlorophyceae Volvox globator was recorded in
stations 2, 3 and 4 and not in station 1. Also Spirogyra sp. was not recorded in station 1 but was found in
stations 2, 3 and 4. The remaining species were fairly distributed in all the stations. All the species of
Cyanophyceae occurred in all the stations and were fairly distributed. Only one specie of Chrysophyceae
(Dinobroyon sertulana) was recorded and this was fairly distributed in all the stations. Xanthophyceae was
represented by two species Tribonema minus and T. viridis which were also fairly distributed in all the stations.
Annual variation result showed that Melosira granulata had the highest mean value 30.083±23.815 (August
2007 - July 2008), 28.917±25.907 (August 2008 - July 2009). This was followed by Cyclotella omta
27.667±19.213 (August 2007 - July 2008); 30.916±23.267 (August 2008 - July 2009); Cyclotella operculata
25.917±21.773 (August 2007 - July 2008), 26.833±20.399 (August 2008 - July 2009) and Melosira distance
26.333±27.327 (August 2007 - July 2008), 25.833±24.255 (August 2008 - July 2009). The least was Amphora
ovalis 4.083±4.077 (August 2007 - July 2008), 5.167±5.859 (August 2008 - July 2009). There was no
significant variation in the mean values of the two years 13.295±0.558 (August 2007 - July 2008),
14.145±0.576 (August 2008 - July 2009). Seasonal variations occurred in the abundance of Melosira granulata
20.059±17.515 (Wet), 52.429±24.240 (Dry); Melosira distance 17.353±19.839 (Wet), 47.286±25.649 (Dry);
Melosira pusilla 10.412±5.831 (Wet), 42.857±20.472 (Dry); Gyrosigma acuminatum 9.529±7.177 (Wet),
27.429±15.020 (Dry); Pinularia horealis 3.117±3.620 (Wet), 12.142±7.776 (Dry) and Netrium digitalus
7.059±9.141 (Wet), 24.000±16.573 (Dry). The mean values of the two seasons also showed significant
variations 11.395±0.407 (Wet) and 19.365±0.876 (Dry). The diversity (S) of the four stations studied ranged
between 41 (Degema, Ihuaba and Odiemudie) and 42 (Ogebele). Abundance of the individual (N) at the stations
ranged between 2562 (Odiemudie) and 4921 (Degema). Margalef index (d) ranged between 4.705 (Degema)
and 5.096 (Odiemudie). Shannon-Wiener index (H) values ranged between 0.922 (Odiemudie) and 1.573
(Ogbele). Pielou’s index of relative density or evenness were between 0.922 (Ihuaba) and 0.973 (Odemudie).
Simpsin’s Dominance Index (C) ranged between 0.029 (Ihuaba and Odiemudie) and 0.033 (Degema).
Cite this Reference:
E.N. Ezekiel, E.N. Ogamba and J.F.N. Abowei, 2011. The Distribution and Seasonality of Phytoplankton in Sombreiro River, Niger Delta, Nigeria.
Asian Journal of Agricultural Sciences, 3(3): 192-199.
|ISSN (Online): 2041-3890
ISSN (Print): 2041-3882