No abstract

Limited knowledge of native marine biodiversity hinders effective biodiversity management to safeguard South and Southeast Asia’s marine coastal environment against the threat of invasive species transfer through shipping. In particular, sessile marine biofouling organisms in South East Asian ports are poorly known. Through the support of the ASEAN-India Cooperation Project on the Extent of Transfer of Alien Invasive Organisms in South/South East Asia Region by Shipping, a coordinated effort to examine diversity of biofouling organisms in major port areas in Southeast Asia and India was made using polyvinylchloride (PVC) panels as recruitment surfaces in a static immersion study for a period of 12 months. Not surprisingly, the study revealed that fouling patterns differed between ports possibly as a result of dissimilar hydrographic conditions. However, there were also underlying similarities that reflected a regional uniformity in the composition of fouling communities. At the same time, the alien Caribbean bivalve Mytilopsis sallei was detected in Manila Bay (Philippines), Songkhla Port (Thailand) and Singapore. This is a first simultaneous biofouling survey involving scientists and government stakeholders from India and ASEAN nations of Brunei Darussalam, Indonesia, Lao PDR, Malaysia, Myanmar, Singapore, Thailand, Philippines and Vietnam.

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.

An immersion experiment was conducted in the Manila South Harbor to document the development of sessile biofouling communities. Test panels were submerged below the sea surface in April 2012 for short-(one and three months) and long-term (one year) exposures in seawater, then fouling types and occurrences were scored based on digital images of panel surfaces. The short-term immersed panels were found with significant cover of soft fouling (undet.), slime, and the invasive Balanus (=Amphibalanus) amphitrite. These also filled the long-term immersed panels, although some fell off due to mortality from crude oil smothering. Perna viridis, native but also invasive, successfully established and then dominated the fouling cover by the 12 th month (April 2013). Oysters, bryozoans (Watersipora sp.), colonial tunicates, polychaetes (Hydroides sp.), and green algae contributed minor to fouling cover. These fouling communities in the Manila South Harbor consisted of organisms that were cosmopolitan in port waters of SE Asia. A similar study must be carried out in other major ports of the country and then compared.