An inter-site study of biofouling recruitment on static immersion panels in major ports of South East Asia and India

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

Dugong (Dugong dugon) and seagrass in Thailand: present status and future challenges

December 13-14, 2006, Siam City Hotel, Bangkok, ThailandDugong and seagrass research in Thailand has been principally conducted by Phuket Marine Biological Center (PMBC), Department of Marine and Coastal Resources (DMCR). The first stranded dugong was reported in 1979. The interview surveys with villagers and aerial surveys for dugong population were started in 1993 and 1997, respectively. Several research topics were documented on dugong, both the biological and chemical aspects, and including the management plan. Seagrass surveys had been originally conducted in 1988 particularly in the Andaman sea coast and seagrass surveys in the Gulf of Thailand have been recently performed. Seagrass data-based information of PMBC was officially available in 2004. Although, the diversity of only 12 seagrass species have been reported in Thai waters, the seagrass beds have been shown to play an important role as the nursery ground of economically important species. We have reviewed the recent status and future research of dugong and seagrass in Thailand according to the follo ing items: population, genetic divergence and threats; dugong behavior, feeding habit and acoustic survey; heavy metal and organotin compounds concentration; status of seagrass; marine organisms in seagrass beds; future challenges; and conservation and management

Nematode Diversity at Thachin River Mouth, Samut Sakhon, Thailand

Nematode communities were investigated in January and June 2008 at the western Thachin River mouth, Samut Sakhon, Thailand. The sampling site is comprised of two different habitats, i.e. mangrove forest characterized by Avicennia marina and mudflat adjacent to the mangrove forest. Mean densities of the nematode ranged from 110 - 995 ind.10 cm-2 while taxonomic classification showed 32 and 50 genera in the mudflat and mangrove forest, respectively. The high diversity indices of nematode assemblages were recorded in both habitats with values ranged between 0.49 - 2.32 in mudflat and 2.02 - 2.92 in mangrove. The predominant genera were Terschellingia sp. Daptonema sp. Sabatieria sp. and Hopperia sp. Two distinct groups of nematode communities between the two habitats were detected by multidimensional scaling, analyses of similarity percentages. The number of species and density were significantly different in the two different habitats (p < 0.05). The mangrove forest provided wide variety of microhabitat and physically stable environment while the mudflat area was exposed to water turbulence and prone to anthropogenic activities. The environmental differences of the two communities may have resulted in higher diversity and density of nematodes in the mangrove forest

Stomach contents of dugongs (Dugong dugon) from Trang Province, Thailand

March 5-6, 2009, Bangkok, ThailandSix stomachs of stranded dugongs, collected in Trang Province, Thailand during January 1997- January 1999, were inspected. Based on physio/morphological characters of leaves and epidermal cells, seagrass fragments were identified down to species under stereo - and compound-microscopes. Nine species of six genera of seagrasses were found in dugong stomachs, 4-6 species each and their biomass was determined in terms of dry weight. The percentage dry weight of each species found in the stomach contents was as follows: Halodule spp. 0.84-44.99%, Halophila ovalis 3.11-29.60%, Thalassia hemprichii 3.50-28.69%, Cymodocea spp. 5.06-42.52%, Syringodium isoetifolium 0.42- 22.39%, and Enhalus acoroides 31.76-41.39%. The biomass of Halophila decipiens was not determined because of its scarcity. Four dugongs fed mainly on the dominant species (H. ovalis, E. acoroides, Cymodocea. serrulata, and Halodule pinifolia) available in the catch areas whereas the another two dugongs may have selected their target seagrasses from the existing species. Rhizome appeared to be the importance part of dugong dietary. Remarkably, the dominant available seagrass species in the catch areas contributed to be the most heavily utilized genera of the dugongs in Trang waters

Food preference studies and ingestion rate measurements of the mangrove amphipod Parhyale hawaiensis (Dana)

Large populations, up to 7000 individuals. m-*, of the amphipod Parhyale hawaienir (Dana), not previously reported for Australia, were found in a mangrove forest near Cape Ferguson, northern Australia. The amphipod inhabits accumulations of decomposing Rhizophora stylosa Griff. detritus in the upper littoral zone. Laboratory studies, using measurements of faecal production as an index of feeding rate, showed that the amphipod could consume large quantities of decomposing R. stylosa leaves, with maximum faecal production in the order of 1700 mg.g amphipod-1.day-1 (dry weights), depending on favourable salinity and food source conditions. Feeding rates were not significantly different over the salinity range 15-35%, although significant decreases were noted at further extremes i.e. 10 and 40%,. Short-term (24 h) and long-term (8 wk) food preference and survival studies showed a highly significant increase in food preference with increasing degrees of leaf decomposition. Proximate chemical and physical analyses of different stages of decomposed leaf material showed strong, signilicant correlations between feeding (defaecation) rate and leaf nitrogen, starch (positive correlations), tannin, crude tibre and toughness (negative correlations). An estimated maximum rate of faecal production in the field of up to 10 g dry matter. rne2. day- ’ indicates that this amphipod may be an important component of the mangrove detritus-based food chain in the area studied