Diversity of planktonic organisms in selected areas of Panay Island, Philippines

A total of 47 planktonic organisms were identified in selected inland waters and coastal areas around Panay Island, Philippines from June 2013 to February 2014. Of this number, 39 species were phytoplankters belonging to six divisions, namely Cyanophyta, Dinophyta, Ochrophyta, Bacillariophyta, Euglenophyta, and Chlorophyta. There were eight zooplankters identified, which belonged into four phyla; most belonged to the phylum Ciliopora. Among the six collection sites, the highest phytoplankton density was observed in Batan, Aklan (3,101 cells/mL), while the least number was noted in the University of the Philippines Visayas Hatchery (UPV Hatchery) (210 cells/mL). About 56% of the total phytoplankton enumerated belonged to marine centric diatoms (15 genera) with Coscinodiscus having the highest density, followed by (in decreasing order) Skeletonema, Biddulphia, Thalassionema, Melosira, and Chaetoceros. The Shannon-Wiener’s species diversity index (H′) estimated for the area was 3.06.