Phytoplankton and Bacterial Communities in South Harbour, Manila Bay, Philippines

In line with the ASEAN-India project “Extent of Transfer of Alien Invasive Organisms in South/Southeast Asia via Shipping”, phytoplankton and bacterial communities in the waters off South Harbour, Manila Bay were investigated. Sampling was done in July and August 2012 and in April and May 2013. A total of 67 phytoplankton species including 29 diatoms and 38 dinoflagellates were identified. Potentially toxic Pseudo-nitzschia spp. were among the diatoms found as well as dinoflagellates Alexandrium spp., and Gymnodinium spp. The diatom Skeletonema costatum appeared to be the dominant species in July and August 2012, whereas Chaetoceros spp. constituted over 85% of the total phytoplankton assemblage in April and May 2013. Mean bacterialabundance ranged from 9.53 x 102–3.18 x 105 cells/mL in July 2012. In addition, 93 bacterial isolates were identified using 16S rDNA, several of which belonged to the following phyla: Actinobacteria, Bacteriodetes, Firmicutes, and Proteobacteria; whereas, others were determined as uncultured bacterial clones. These results will serve as a valuable baseline for future studies on phytoplankton and bacterial community structure in Manila Bay.

PHYTOPLANKTON SPECIES COMPOSITION IN SEAWATER AND TISSUE OF GREEN MUSSELS (PERNA VIRIDIS), AT KALI BARU-CILINCING, NORTH JAKARTA

Species composition and abundances of phytoplankton in the shellfish farming area in Jakarta Bay, Kali Baru-Cilincing, were examined in order to identify harmful algae species. Phytoplankton contained in the shellfish was also observed to detect the presence of toxic species, as well as the phycotoxin contained in visceral of green mussel (Perna viridis) collected from the farming area using brine shrimp lethality test (BSLT). We detected the presence of Alexandrium spp. (PSP causing species), Dinophysis caudata, D. miles and D. rotundata (DSP causing species), and Pseudo-nitzschia spp. (ASP causing species). The last mentioned species was also detected in thestomach content of green mussel. The toxicity of green mussels tested was recorded LC 50 ≤ 1,000 ppm and indicatedthe presence of an active compound in the green mussel viscera. Meanwhile, preliminary PSP test of shellfish did not showed any toxin.