| dc.creator |
Kyaruzi, Jasson J. |
|
| dc.creator |
Kyewalyanga, M. S. |
|
| dc.creator |
Muruke, Masoud S. H. |
|
| dc.date |
2016-06-02T13:42:29Z |
|
| dc.date |
2016-06-02T13:42:29Z |
|
| dc.date |
2004 |
|
| dc.date.accessioned |
2018-03-27T08:19:33Z |
|
| dc.date.available |
2018-03-27T08:19:33Z |
|
| dc.identifier |
Kyaruzi, J.J., Kyewalyanga, M.S. and Muruke, M.H.S., 2004. Cyanobacteria composition and impact of seasonality on their in situ nitrogen fixation rate in a mangrove ecosystem adjacent to Zanzibar Town. Western Indian Ocean Journal of Marine Science, 2(1), pp.35-44. |
|
| dc.identifier |
http://hdl.handle.net/20.500.11810/2344 |
|
| dc.identifier |
10.4314/wiojms.v2i1.28427 |
|
| dc.identifier.uri |
http://hdl.handle.net/20.500.11810/2344 |
|
| dc.description |
To investigate the input of combined nitrogen by cyanobacteria in mangrove
ecosystems and the seasonal fluctuation of this biological process, in situ nitrogen fixation
activity was measured in day and night experiments carried out at Maruhubi mangrove ecosystem
adjacent to Zanzibar town. Sampling was done for 12 months at two stations: Station I covering
sandy sediments and Station II muddy sediments. Associated cyanobacteria genera were
identified and environmental variables were measured throughout the study period. A total of
10 genera of cyanobacteria were encountered, two of which were the heterocystous cyanobacteria
genera Anabaena and Rivularia and eight the non-heterocystous genera Aphanocapsa,
Merismopedia, Lyngbya, Microcoleus, Oscillatoria, Phormidium, Schizothrix and Spirulina.
At both stations N2 fixation during the night was significantly higher (P ≤ 0.05) than during the
day. The average N2-fixation rates at stations I and II were 1.64 and 1.34 nmole N2/hr/m2
respectively, with no significant differences (P ≤ 0.05) observed between seasons at both stations,
or between stations in the rainy season. There was no significant correlation (P ≤ 0.05) between
nitrogen fixation and physical-chemical variables, except sediment temperature, which showed
a significant direct relationship with N2
fixation rate at Station I only. The results suggest that
in the investigated ecosystem cyanobacterial diversity and nitrogen fixation are high; and
generally seasonal changes do not have a significant influence on nitrogen fixation. It is therefore
concluded that cyanobacterial diversity and nitrogen fixation process may contribute in the
promotion of primary productivity in the mangrove ecosystem adjacent to Zanzibar town. |
|
| dc.language |
en |
|
| dc.subject |
Cyanobacteria composition |
|
| dc.subject |
Nitrogen fixation |
|
| dc.subject |
Seasonality |
|
| dc.subject |
Mangrove ecosystem |
|
| dc.title |
Cyanobacteria Composition and Impact of Seasonality on Their In Situ Nitrogen Fixation Rate in a Mangrove Ecosystem Adjacent to Zanzibar Town |
|
| dc.type |
Journal Article, Peer Reviewed |
|