Abstract:
Diversity and abundance of phytoplankton at Tanjung Kuala waterway was examined
during a tidal cycle in September 2007. Water sample (42L) was collected every hour
within 24 hours, and filtered through 20 μm mesh size plankton net. Filtered water
sample was concentrated to 200rnL and preserved with Lugol's solution. The preserved
water sample was concentrated to 1 OmL subsamples and kept in glass bottles in the
laboratory. Identification of phytoplankton to the genus level and cell counting using
Lackeys Drop method was done under light microscope. Calculation was done for
density (cell.L- 1), diversity index and evenness index. From the results, 80 genera were
found within 24 hour observation. During high tide 71 genera were found, and 67 genera
were found during low tide. Average diversity index during high tide at 3.8565, and low
tide at 3.8397. Average evenness index during high tide was 0.8019, while low tide was
0.7972. Density of phytoplankton during high tide was recorded at 2206 cell.L-1, whereas
the average density during low tide was 2859 cell.L-1 • Bacillariophyta was a major
division followed by Dinophyta, Cyanophyta, Cholorophyta and Euglenophyta.
Chaetoceros and Rhizoso/enia, were found abundantly at the sampling site during high
tide, while the Peridinium and Closterium increased the density of phytoplankton during
low tide drastically. From statistical analysis, there was no correlation between salinity
and diversity index of phytoplankton at the sampling site. No significant difference were
found between diversity index and evenness index with tidal cycle and day or night
