Polycyclic Aromatic Hydrocarbons (PAHs) in Road Dust Collected from Myanmar, Japan, Taiwan, and Vietnam.

In this study, we determined the concentrations of polycyclic aromatic hydrocarbons (PAHs) in road dust from Myanmar, Japan, Taiwan, and Vietnam. PAHs were detected in urban and rural areas of Myanmar at mean concentrations of 630 ng/g dry weight and 200 ng/g dry weight, respectively. PAHs were also detected in road dust from Vietnam (mean 1700 ng/g) and Taiwan (2400 ng/g). PAH diagnostic ratios suggested that fossil fuel vehicular exhaust and biomass combustion are major sources of PAHs in road dust in Myanmar. Road dust samples from Japan, Taiwan, and Vietnam had similar PAH diagnostic ratios, implying that PAH sources are similar. We assessed the human health risks posed by PAHs in road dust using carcinogenic equivalents (CEQs) and incremental lifetime cancer risk (ILCR). Mean CEQs were decreased in the order Taiwan (173 ng/g) > Vietnam (162 ng/g for Hanoi) > Myanmar (42 and 31 ng/g for Yangon and Pathein, respectively) > Japan (30 ng/g for Kumamoto). Benz[a]pyrene, fluoranthene, and benzo[b]fluoranthene, the predominant PAHs, contributed > 70% of total CEQs. High ILCR values were found for Taiwan (5.9 × 10-4 and 9.9 × 10-4 for children and adults, respectively) and Vietnam (6.5 × 10-4 and 9.2 × 10-4 for children and adults, respectively, in Hanoi), indicating that PAHs in road dust pose cancer risks to the inhabitants of Taiwan and Hanoi. To our knowledge, this is the first report to identify PAH pollution in the environment and to evaluate the human health risks of these PAHs in Myanmar.

Meiofaunal communities in a tropical seagrass bed and adjacent unvegetated sediments with note on sufficient sample size for determining local diversity indices.

BACKGROUND: Seagrass beds are highly diverse and productive marine habitats for many associated organisms in nearshore coastal waters. The differences in abundance, diversity, and community structure of benthic invertebrates between seagrass beds and adjacent unvegetated sediments have been stated, whereas most studies are primarily focused on macrofauna or based on a comparatively long distance, i.e., more than 10 m. The present study is designed to test if the community structures of meiofauna, especially the free-living nematodes, differ between seagrass beds and adjacent unvegetated sediments on a meter scale. RESULTS: There are 21 meiofaunal taxa and 63 nematode genera that have been identified from a tropical seagrass bedof Thalassia hemprichii inLudao, Taiwan. Although the compositions of higher meiofaunal taxa are undistinguished, according to correspondence analysis, the assemblages of nematode genera differ substantially between the seagrass bed and unvegetated sediments. Regarding the nematodes, approximately 50% of genera are restricted to the seagrass bed whereas 6% are restricted to unvegetated sediments, which indicate both habitats possessing distinct infaunas. The number of replicates for reasonable estimation of the local diversity index is calculated by the randomization technique. For local seagrass beds, only a single core is sufficient for reliably estimating meiofaunal diversity, but at least three cores or a sample size of 300 individuals is needed for the nematode community. CONCLUSIONS: Nematode assemblages provide more particular differences between seagrass and unvegetated habitats than meiofaunal communities on small spatial scales. Both seagrass beds and adjacent unvegetated sediments harbor specific meiofaunal communities, and hence, the conservation strategy for seagrass should also consider the peripheral bare area of seagrass beds.

A Dataset of Deep-Sea Fishes Surveyed by Research Vessels in the Waters around Taiwan.

The study of deep-sea fish fauna is hampered by a lack of data due to the difficulty and high cost incurred in its surveys and collections. Taiwan is situated along the edge of the Eurasia fig, at the junction of three Large Marine Ecosystems or Ecoregions of the East China Sea, South China Sea and the Philippines. As nearly two-thirds of its surrounding marine ecosystems are deep-sea environments, Taiwan is expected to hold a rich diversity of deep-sea fish. However, in the past, no research vessels were employed to collect fish data on site. Only specimens, caught by bottom trawl fishing in the waters hundreds of meters deep and missing precise locality information, were collected from Dasi and Donggang fishing harbors. Began in 2001, with the support of National Science Council, research vessels were made available to take on the task of systematically collecting deep-sea fish specimens and occurrence records in the waters surrounding Taiwan. By the end of 2006, a total of 3,653 specimens, belonging to 26 orders, 88 families, 198 genera and 366 species, were collected in addition to data such as sampling site geographical coordinates and water depth, and fish body length and weight. The information, all accessible from the "Database of Taiwan's Deep-Sea Fauna and Its Distribution (http://deepsea.biodiv.tw/)" as part of the "Fish Database of Taiwan," can benefit the study of temporal and spatial changes in distribution and abundance of fish fauna in the context of global deep-sea biodiversity.

A dataset from bottom trawl survey around Taiwan.

Bottom trawl fishery is one of the most important coastal fisheries in Taiwan both in production and economic values. However, its annual production started to decline due to overfishing since the 1980s. Its bycatch problem also damages the fishery resource seriously. Thus, the government banned the bottom fishery within 3 nautical miles along the shoreline in 1989. To evaluate the effectiveness of this policy, a four year survey was conducted from 2000-2003, in the waters around Taiwan and Penghu (Pescadore) Islands, one region each year respectively. All fish specimens collected from trawling were brought back to lab for identification, individual number count and body weight measurement. These raw data have been integrated and established in Taiwan Fish Database (http://fishdb.sinica.edu.tw). They have also been published through TaiBIF (http://taibif.tw), FishBase and GBIF (website see below). This dataset contains 631 fish species and 3,529 records, making it the most complete demersal fish fauna and their temporal and spatial distributional data on the soft marine habitat in Taiwan.

Trace elements and stable isotope ratios (delta(13)C and delta(15)N) in fish from deep-waters of the Sulu Sea and the Celebes Sea.

Trace elements (TEs) and stable isotope ratios (delta(15)N and delta(13)C) were analyzed in fish from deep-water of the Sulu Sea, the Celebes Sea and the Philippine Sea. Concentrations of V and Pb in pelagic fish from the Sulu Sea were higher than those from the Celebes Sea, whereas the opposite trend was observed for delta(13)C. High concentrations of Zn, Cu and Ag were found in non-migrant fish in deep-water, while Rb level was high in fish which migrate up to the epipelagic zone, probably resulting from differences in background levels of these TEs in each water environment or function of adaptation to deep-water by migrant and non-migrant species. Arsenic level in the Sulu Sea fish was positively correlated with delta(15)N, indicating biomagnification of arsenic. To our knowledge, this is the first study on relationship between diel vertical migration and TE accumulation in deep-water fish.