Distribution and diversity of phytoplankton in a tropical man-made lake, Putrajaya, Malaysia
A study on phytoplankton community in a tropical man-made lake, Putrajaya Lake was carried out from October 2009 to September 2010. The study was conducted to examine the phytoplankton composition, distribution and diversity in different zones of the lake, and in different seasons. Monthly phytop...
Saved in:
| Main Author: | |
|---|---|
| Format: | Thesis |
| Language: | English |
| Published: |
2015
|
| Subjects: | |
| Online Access: | http://psasir.upm.edu.my/id/eprint/66885/1/IB%202016%2028%20IR.pdf |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | A study on phytoplankton community in a tropical man-made lake, Putrajaya Lake was
carried out from October 2009 to September 2010. The study was conducted to
examine the phytoplankton composition, distribution and diversity in different zones of
the lake, and in different seasons. Monthly phytoplankton samples were collected at
three selected stations representing three different lake zones, namely Station 1 (littoral
zone), Station 2 (sub-littoral zone) and Station 3 (limnetic zone). Phytoplankton
samples from each station were preserved, identified and enumerated. Physicochemical
parameters such as water temperature, pH, conductivity and dissolved oxygen
were measured in situ. Meteorological data were obtained from the Putrajaya
Corporation Database Centre.
Differences in the composition and diversity of the community across zones spatially
and vertically were analysed by using multivariate test procedures. A total of 148
species from 77 genera were recorded for the Putrajaya Lake during the study period.
The seven identified groups were Chlorophyta (59% of the total abundance),
Pyrrhophyta (15%), Cyanobacteria (11%), Bacillariophyceae (9%), Chrysophyceae
(3%), Cryptophyta (2%) and Euglenophyta (1%). The highest total mean density of
phytoplankton was recorded in the limnetic zone (433.94 ± 18.29 cells ml-1), followed
by sub-littoral (292.94 ± 18.61 cells ml-1) and littoral zone (199.58 ± 13.56 cells ml-1).
Average similarity within zones in descending order was limnetic zone (58.5%), sublittoral
zone (53.7%) and littoral zone (52.1%). According to zones, Peridinium had the
highest density in littoral and sub-littoral zones although the dinoflagellates were not
the dominant phytoplankton group, whereas Staurastrum dominated the limnetic zone.
There was a significant difference in the Shannon-Wiener diversity index for
phytoplankton diversity and abundance in all three zones (p < 0.05). Limnetic zone
demonstrated the highest species diversity (H’=3.48 ± 0.021) compared to other zones.
In terms of depth distribution, the highest phytoplankton density was found at 1.5 m
depth (366.03 ± 33.37 cells ml-1) combining all stations. However, the highest species diversity was observed at 2.0 m depth (3.54 ± 0.04). Nonetheless, densities and species
diversity values at different depths were not significantly different (p > 0.5).
Two distinct groups consisted of limnetic and littoral-sub-littoral zones at 83% were
obtained from the dendrogram. SIMPER average dissimilarity was highest between
littoral and limnetic zone (50.8%) with Staurastrum as the most discriminating genus
(6.7%). Sub-littoral species dominated both littoral and limnetic phytoplankton
communities suggesting that sub-littoral zone acts as an interphase for phytoplankton
adaptation and migration between the two different zones.
Phytoplankton community in Putrajaya Lake did not show distinct seasonal pattern.
Rainfall had low influence on the phytoplankton community structure (r = 0.168) and
the ANOSIM R value (R = 0.21) indicated strong overlapping of phytoplankton
communities found during the wet and dry seasons. Average dissimilarity between the
two seasons was 49.8% whilst average similarity within each wet and dry seasons were
55.0% and 58.5%, respectively. Shannon-Wiener diversity index during the wet season
was higher than the dry season, but not significantly different (p > 0.05).
Physical parameters such as water transparency, temperature, pH, dissolved oxygen,
and conductivity were found to be important factors characterizing each zone and
influencing the phytoplankton composition (p < 0.01). The genus Staurastrum and
Peridinium which were found dominant in the present study may indicate the water
trophic as oligotrophic. Nevertheless the rise and sink of chrysophytes at a certain
period of time may suggest the interchanging trophic water between oligotrophic to
mesotrophic. The findings suggest that spatial and temporal distribution and diversity
of the phytoplankton community can be affected significantly by local lake zonation
characterized by environmental variations. |
|---|