International Journal of Fisheries and Aquatic Studies
2019, Vol. 7, Issue 4, Part F
Assessment of phytoplankton species composition, abundance and diversity within the itu bridge-end area of the lower cross river system, NigeriaAuthor(s):
Job Bassey EtimAbstract:
This paper reports on the phytoplankton species composition, abundance and diversity within the Itu bridge-end area of the lower Cross River system, Nigeria, which was undertaken for nine months (February- October, 2018). Surface water samples were collected for phytoplankton studies by filtration method, using a-20L plastic bucket and a-55μm standard plankton net. Samples were concentrated to 10ml, stored in well-labeled plastic bottles and preserved in 4% buffered formaldehyde solution prior to laboratory analysis. Samples were analyzed by addition of 1-2 mls of Lugol’s iodine solution which enhanced phytoplankton cell identification under an inverted microscope of x 10 and x 40 magnification using standard texts and atlases. Total of 57 phytoplankton species spread into 5 taxonomic families (Bacillariophyceae, Chlorophyceae, Cyanophyceae, Euglenophyceae and Chrysophyceae) were identified. All identified species of the phytoplankton were those common in the tropical river system. A total of 36.34% of the phytoplankton were Bacillariophyceae, with 20.54% of Euglenophyceae, 20.38% of Cyanophyceae, 16.47% of Chlorophyceae and 6.27% of Chrysophyceae. There was a predominance of Melosira variance in the Bacillariophyceae, Anaena spiroides in the Cyanophyceae, Euglena gracilis in Euglenophyceae and Ceratium hirudinea in the Chrysophyceae. The complete absence of the genus Coscinodiscus in the Bacillariophyceae interplayed by the low ranges of the Margalef’s index of (2.58 – 3.09) for Bacillariophyceae, (2.11 – 2.62) for Chlorophyceae, (1.44 – 1.86) for Cyanophyceae, (1.24 – 1.90) for Euglenophyceae and (0.79 – 1.18) for Chrysophyceae, and the high values (>1) of the Shannon-Wiener indices which ranged between 1.96 – 2.36 for Bacillariophyceae, 1.63 – 1.95 for Chlorophyceae, 1.73 – 2.05 for Cyanophyceae, 1.92 – 2.05 for Euglenophyceae and 1.34 – 1.60 for Chlorophyceae connote the Itu bridge-end area of the lower Cross River system to be under the threat of pollution. There was a significant relationship (p<
0.05) between phytoplankton abundance and month of sampling. Based on the results of the study, proper management strategies of this area of the river system are outlined and recommended.Pages: 398-405 | 240 Views 19 DownloadsDownload Full Article:
How to cite this article:
Job Bassey Etim. Assessment of phytoplankton species composition, abundance and diversity within the itu bridge-end area of the lower cross river system, Nigeria. Int J Fish Aquat Stud 2019;7(4):398-405.