Penghu Islands Research Articles

New record of Engyprosopon macrolepis (Regan, 1908) from Taiwan (Pleuronectiformes: Bothidae)

Specimens of the largescale dwarf flounder, Engyprosopon macrolepis (Regan, 1908) (Pleuronectiformes: Bothidae), were collected from the fishery landing of Chi-kan, Peng-hu Islands, western Taiwan. Although this species has been recorded from western Pacific Ocean including the Philippines and Japan, it has never been recorded from Taiwanese waters. Therefore, our specimens represent the first record for Taiwanese waters and fill a gap in the distribution of this species between the two countries. A detailed description of the specimens, including coloration of the fresh condition is provided and compared to the data of specimens collected in other regions. With the addition of E. macrolepis, a total of 11 species of Engyprosopon are recorded from Taiwanese waters, and we suggest that more species are expected to occur off Taiwan.

Pulsed sounds caused by internal oxygen transport during photosynthesis in the seagrass Halophila ovalis.

Oxygen bubbles that leak from seagrass blades during photosynthesis have been hypothesized to cause cavitation sounds in aquatic plants. Here we investigate low-amplitude sounds with regular pulse rates produced during photosynthesis in seagrass beds of Halophila ovalis (Qitou Bay, Penghu islands and Cigu Lagoon, Taiwan). Sound pulses appear in the morning when illumination exceeds 10,000 Lux, peak at midday and decrease in midafternoon on a sunny day. Frequencies peak between 1 to 4 kHz, durations range between ca. 1.8 to 4.8 ms, and sound pressure level 1 cm from the bed is 105.4 ± 0.5 dB re 1 μPa (1100 h on a cloudy day). Sounds attenuate rapidly with distance, disappearing beyond 15 cm. Blocking sunlight or administering herbicide stops ongoing sounds. Gas bubbles are not typically seen during sound production ruling out cavitation, and external force (scissor cutting or plant pressed against the substrate) applied to the patch, leaves, petioles, or rhizomes generally increases pulse rate. We suggest sound emission is caused by internal oxygen transport through pores in diaphragms (a whistle mechanism) at the leaf base and nodes of the rhizome.

Thermal histories reveal spatiotemporal distribution and population overlapping of Sepioteuthis lessoniana

Abstract Thermal histories describe ambient temperature experienced by cephalopod species from birth to death, reflecting their habitats and distributions. Thermal histories were reconstructed by analyzing ontogenetic oxygen isotopes (δ18O values) in statoliths of adult Sepioteuthis lessoniana collected from northeastern and southwestern Taiwan between 2017 and 2019. The probabilities of occurrence associated with thermal histories in the two populations were modeled using a spatial interpolation approach, ordinary kriging method. The northeastern population exhibited larger ontogenetic variations in experienced temperature (ranging from 9.1 to 10.4°C) than did the southwestern population (ranging from 4.3°C to 6.8°C). The two geographical populations exhibited distinct ontogenetic movement patterns and distribution. The southwestern population demonstrated wide dispersal influenced by seasonal wind directions and tended to remain in 20°C isotherm areas around the Penghu Islands for maturing and spawning. At the seasonal cohort level, the northeastern population exhibited a southward shift during the 2-year study period as a result of the El Niño event. The distribution of the two geographical populations overlapped in the adult stage primarily in the northern Taiwan Strait, supporting an assumption of population connection in Taiwan. This study revealed the thermal histories of S. lessoniana, providing insights into the field observation of distribution patterns and the progress in relating population dynamics to environmental variability, which are essential for the sustainable management of squid fisheries.

Boulder transport and wave height of a seventeenth-century South China Sea tsunami on Penghu Islands, Taiwan

Abstract. The South China Sea faces widespread tsunami risks from diverse sources, including trench megathrusts, intraplate earthquakes, and landslides. However, historical and geological records to constrain worse-case simulations are scarce. The cliff-top basalt boulders on the Penghu Islands in the Taiwan Strait provide wave estimates from incipient motion formulas and stratigraphic links to the probable sources. Calibrating for ancient local sea levels and a 100-year surge indicates that storm waves in the shallow interisland bathymetry only enable boulder sliding–rolling below the 2.5 m high cliff. A minimum tsunami wave height of ∼ 3.2 m is necessary for cliff-top overflow to exceed boulder height and terminal rolling before deposition. Coeval gravels in two other outcrops also record the time and extent of tsunami deposition with beach-derived bioclasts, stranded pumices, a sharp base, matrix support, poor sorting, and elevations surpassing the 100-year surge. These gravels mark local minimum wave run-ups, reaching 2.4–4.0 m above sea level. The radiocarbon age of the studied boulder, between 1575 and 1706, suggests a probable tie to the disastrous 1661 earthquake in southwest Taiwan and the megathrust source in the northern Manila Trench.

Monitoring and management of abandoned, lost and discarded fishing gear (ALDFG) in Penghu Islands, Taiwan

This study investigated the conditions of abandoned, lost, discarded fishing gear (ALDFG) in natural and artificial reef zones and removed it afterward in Penghu Islands. Various feasible suggestions for improving ALDFG management were proposed for the county government to manage and reduce the generation of ALDFG in the future and maintain the marine ecosystem. This study divided the ocean areas of Penghu into five sub-areas for carrying out research and surveys. 165 boat trips of ALDFG investigation and removal were conducted from July 2018 to October 2019. The results show the ALDFG in natural reef areas is mostly large-mesh gillnets (26 %). The rest are single-layer bottom gillnets (21 %) and multi-layer bottom gillnets (20 %). In line with the recent efforts of the Penghu County Government to address ALDFG, it is recommended that the participation of citizen scientists and the promotion of ocean education can be utilized for fishery co-management in Penghu.

Ameliorating effects of crude fucoidan extracts from Sargassum spp. obtained from Penghu Islands, Taiwan

Ameliorating effects of crude fucoidan extracts from Sargassum spp. obtained from Penghu Islands, Taiwan

Evaluation of green transit networks for tourism on Penghu Island

Selecting modes of green transit for a transportation network can be challenging. In this study, individual and multiperson tourist travel itineraries for various green transit networks on Penghu Island in Taiwan were developed and optimized to minimize energy consumption, travel time, and construction costs; case studies involving various itineraries were conducted and compared. The green transit networks could enable low-carbon and ecofriendly tourism around Penghu Island. The individual itineraries were produced by identifying an optimal travel route for visiting various destinations in a predetermined order by using the available green transit and on foot. Itineraries for electric scooters alone were first developed, and these itineraries were compared with those for green transit networks comprising various combinations of electric buses, electric scooters, and shared bicycles. The itineraries were optimized using the genetic algorithm and artificial bee colony algorithm to minimize energy consumption, travel time, or construction costs. The network comprising electric scooters and shared bikes had the lowest energy consumption, and that comprising electric scooters and buses had the shortest travel time and the lowest construction costs.

University-driven coastal partnerships to address ghost gear pollution: A case study in Penghu Islands of Taiwan

Ghost gear has become a significant environmental and economic challenge affecting oceans worldwide. Preventing and eliminating ghost gear is essential for achieving sustainable development goals (SDGs), and partnerships between universities and multi-stakeholders are considered feasible solutions. This case study illuminates the implementation of the Partnerships for Ghost Gear Cleanups & Education Project (PGGCEP) conducted by the National Kaohsiung University of Science and Technology (NKUST) in the Penghu Islands of Taiwan, which involves engagement with local stakeholders to prevent and remediate ghost gear in Penghu seas, providing insights into coastal partnerships building to promote ocean sustainability. The conceptual schemes of PGGCEP include education projects, marine citizenship practices, and awareness campaigns. The outcomes of PGGCEP were analyzed under the framework of SDGs. The results showed that PGGCEP not only successfully supported SDG 14 life below water through the achievement of SDG17 partnerships for the goals, and it also contributed to other SDGs, including SDG 4 quality education, SDG 5 gender equality, SDG 8 decent work and economic growth, and SDG 10 reduced inequalities. Future directions for PGGCEP were subsequently provided to refine the project. Based on the findings, this study proposed a framework of university-driven coastal partnerships to address ghost gear pollution. This 4-phase framework highlights the pivotal role played by universities as facilitators of collaborative efforts that involve a broad spectrum of stakeholders for enhancing ocean sustainability.

Comparison of the Late Miocene Sediments and Early Quaternary Red Paleosols in the Penghu Islands, Taiwan and Zhangpu, Fujian

This study aims to compare the clay mineralogy and whole-soil major chemistry of elements in late Miocene soil sediments and early Quaternary red paleosols in the Penghu Islands, (Pescadores), Taiwan, and Zhangpu Volcanic Park, Fujian. There were the late Miocene Chu Wan (CWI and CWII), Shiao Men Yu (SMY) and two intergrade red soils, Chu Wan (CW(irs)) and Shiao Men Yu (SMY(irs)), with three distinctive zones of different dominating kaolins in the profiles of the Penghu Islands. A Tong Wei (TW) paleosol of early Quaternary basaltic eruptions in the Penghu Islands was collected. The Anzei (AZ), Si Yu (HY) and Chianmei (CM) paleosols were sampled from the Penghu Islands and Yulinshi (YLS) paleosols near the Zhangpu Volcanic Park for this study. The CW and SMY paleosols erupted in the late Miocene, and the other paleosols erupted on the Penghu Islands. These paleosols were fractionated into clay fractions and subjected to soil physical and chemical analyses. Kaolin minerals were dominant in the CW(irs) and SMY(irs) paleosols. The top layer (layer one) in the CW(irs) was 7 Å-halloysite, and order/disordered kaolinites were present in layers two and three. The CW(irs) and SMY(irs) hexagonal-like, platy kaolinites (0.1–0.2 µm in diameter), spheroidal and hollow 7 Å-halloysite (layer 1) was determined with transmission electron microscopic (TEM) investigations. The early Quaternary red soil of TW consisted of kaolinite, illite, vermiculite and smectite clay assemblages. Late Miocene paleosols were classified as fine, kaolinite, hyperthermic and Typic Rhodic Paleudults, and the early Quaternary red paleosols were classified as fine, mixed, hyperthermic and Typic Rodistalf, respectively. Late Miocene paleosols contained more clays, lower SiO2/Al2O3 and higher chemical index of weathering (CIW) than early Quaternary paleosols. The kaolin, illite, smectite and vermiculite mineralogy, physical and chemical properties of paleosols and landscapes in the Zhangpu YLS, Fujian, were similar to those of late Miocene sediments and early Quaternary red paleosols in the Penghu Islands.

Mechanism and inhibitory effects of cactus (Opuntia dillenii) extract on melanocytes and its potential application for whitening cosmetics

Penghu cactus (Opuntia dillenii [Ker.] Haw) is a cactus plant that commonly grows in Penghu Island, Taiwan, Republic of China (ROC). However, still lack of scientific study on the Opuntia dillenii [Ker.] Haw extract on skin-whitening-associated tyrosinase activity and melanin production. The activities of its extract in melanogenesis were investigated in this article. In this experiment, we used an extract from the Penghu cactus (Opuntia dillenii [Ker.] Haw) to study its tyrosinase inhibition, anti-melanin generation, UV-protection effects and wound healing capacity in B16-F10 melanocytes. Without reducing cell growth greatly or causing cell death, 20 g/L cactus extract effectively inhibited the melanin production of B16-F10 cells, and melanogenesis was induced by 3-isobutyl-1-methylxanthine. The cactus extract could also promote cell proliferation. Cactus extract treatment decreased the mRNA expression of insulin-like growth factor 1 (IGF-1) and vascular endothelial growth factor (VEGF) and increased that of transforming growth factor β (TGF-β). Thus, it could reduce cell melanin production and promote cell growth but by also reducing IGF-1 and VEGF mRNA expression, may reduce wound scarring and prevent tumor proliferation and swelling. Increasing TGF-β mRNA expression can help increase collagen to remove wrinkles and help in wound healing. Skin patch test results agreed with in vitro results with B16-F10 melanoma cells. The cactus extract significantly inhibited tyrosinase activity and reduced melanin production, showing a whitening effect on skin tests. Cactus may be a good natural candidate for inhibiting melanin production and promoting cell proliferation.

Analysis of genetic diversity in two different shell colors of the giant triton snail (Charonia tritonis) based on mitochondrial COI sequences

The giant triton snail (Charonia tritonis) is widely distributed in tropical coral reefs in the Indo-West Pacific. Its distribution areas in China include the Penghu Islands, Hengchun Peninsula, and Xisha Islands. In this study, we use Multivariate Analysis of Variance (MANOVA) to compare the live weight and shell length between different shell colors of C. tritonis. In addition, we conducted sequence analysis of the mitochondrial cytochrome oxidase (COI) gene to assess the affinity of C. tritonis with two different shell colors based on the sample we obtained. Then, we constructed phylogenetic trees using the maximum likelihood (ML) and Bayesian Inference methods, and constructed haplotype network diagrams. In addition, we performed Tajima’s D and Fu’s neutrality tests. The results show that The Partial mitochondrial COI sequences of 28 C. tritonis were all 603 base pairs in length, and seven haplotypes were detected from the samples, besides, the gene flow was calculated to be 11.78, the genetic differentiation coefficient was 0.02078. Our results indicated that the population size of C. tritonis remained relatively stable. Besides, the genetic and size differentiation between the two different shell colors was small, and individuals of C. tritonis with different shell colors belong to the same genetic clade. In fact, the two morphotypes could not be distinguished by both genetic and morphometric data. The mitochondrial COI gene fragments of the two different shell colors were sequenced and analyzed to accumulate information about the population genetics of C. tritonis and to provide a scientific basis for the conservation of its species resources.The giant triton snail (Charonia tritonis) is widely distributed in tropical coral reefs in the Indo-West Pacific. Its distribution areas in China include the Penghu Islands, Hengchun Peninsula, and Xisha Islands. In this study, we use Multivariate Analysis of Variance (MANOVA) to compare the live weight and shell length between different shell colors of C. tritonis. In addition, we conducted sequence analysis of the mitochondrial cytochrome oxidase (COI) gene to assess the affinity of C. tritonis with two different shell colors based on the sample we obtained. Then, we constructed phylogenetic trees using the maximum likelihood (ML) and Bayesian Inference methods, and constructed haplotype network diagrams. In addition, we performed Tajima’s D and Fu’s neutrality tests. The results show that The Partial mitochondrial COI sequences of 28 C. tritonis were all 603 base pairs in length, and seven haplotypes were detected from the samples, besides, the gene flow was calculated to be 11.78, the genetic differentiation coefficient was 0.02078. Our results indicated that the population size of C. tritonis remained relatively stable. Besides, the genetic and size differentiation between the two different shell colors was small, and individuals of C. tritonis with different shell colors belong to the same genetic clade. In fact, the two morphotypes could not be distinguished by both genetic and morphometric data. The mitochondrial COI gene fragments of the two different shell colors were sequenced and analyzed to accumulate information about the population genetics of C. tritonis and to provide a scientific basis for the conservation of its species resources.

The Sino-Japanese Peace Treaty and the Chinese residents in Japan—Legal status problem under the 1952 regime

ABSTRACT The Sino – Japanese Peace Treaty signed in April 1952 not only set the basic framework for diplomatic relations between China, Japan, and Taiwan until 1972, but was also significant in substantially determining the legal status of Chinese residents in Japan during the same period. Subsequently, this paper analyzes both the legislative process in Japan leading up to the Sino – Japanese Peace Treaty and the process of diplomatic negotiations between Japan and China and identifies the following points. In the process of legislating the Immigration Control Ordinance, the Japanese government, while recognizing that Chinese mainlanders in Japan were Chinese nationals, considered them to be outside the legal jurisdiction of the Republic of China (R.O.C.) government, and while recognizing the jurisdiction of the R.O.C. government over Formosans in Japan to a certain extent, interpreted “the ultimate nationality of Taiwanese people has not been determined” from the standpoint that the legal status of Taiwan was undetermined. The R.O.C. government was forced to accept the Japanese government’s treatment regarding the legal status of Chinese residents in Japan because it was unable to have its sovereignty over Taiwan and the Penghu Islands clearly stated in the articles of the Sino – Japanese Peace Treaty out of consideration for the United States, which acted as an intermediary in the negotiations of the treaty.

Multigene Phylogenies of the Estuarine Sesarmid Parasesarma bidens Species Complex (Decapoda: Brachyura: Sesarmidae), with Description of Three New Species.

S Parasesarma bidens (De Haan, 1835) is a common intertidal sesarmid crab that inhabits the estuarine and mangrove regions of East Asia, as well as Vietnam and the Philippines. Previous studies have suggested that P. bidens is a species complex composed of several species. Our findings indicated that the P. bidens species complex is monophyletic with six clades, as shown by reconstructed phylogenies based on mitochondrial 16S rDNA and cytochrome c oxidase subunit I, as well as nuclear 28S rDNA. Specimens of each clade exhibited different characters, including the morphology of the cheliped, anterior carapace, male gonopod 1, and female vulvae, as well as the coloration. Three species in this complex have been previously described: P. bidens (De Haan, 1835), P. cricotum (Rahayu & Davie, 2002), and P. sanguimanus Li, Shih & Ng, 2019. Here, we describe three additional species: P. continentale n. sp., P. insulare n. sp., and P. chiahsiang n. sp. Biogeographically, the range of P. bidens includes the southern margin of Korea, the main islands of Japan, and the Ryukyus, with a comparatively northern distribution. P. continentale is widely distributed from the continental coasts of southeastern and southern China (including northern Hainan Island) to southern Vietnam and is occasionally found in Penghu, Taiwan. Parasesarma insulare is an insular species distributed from Taiwan main island, the central Philippines, to northern Borneo. Finally, P. chiahsiang is mainly limited to the Penghu Islands (Pescadores) but is also sometimes found in Taiwan main island and the offshore Gueishan Island.

Research on the Key Success Factors for the Transformation of the Traditional Fishery to Recreational Fishery in Taiwan’s Outlying Islands

Outlying islands are affected by the environment and economy, and fishery resources are the first to experience these impacts. Therefore, it is necessary to actively and effectively transform traditional fisheries in outlying islands. This is the case in Penghu County (Penghu Islands), located on the outlying islands of Taiwan. The transformation to recreational fishery can increase the additional income of traditional fisheries during the fishing moratorium through the development of recreational fishery boats by fishermen. Recreational fishery means the fishery using fishing vessels for recreational purposes or for passengers to harvest aquatic organisms on the reef or to engage in sightseeing on the islets. Therefore, this study will explore the key factors for the successful route planning of fishermen who switch to recreational fishery boats to assist the fishermen in successfully transitioning and enabling recreational fishery to flourish. In the research, using the method of the Analytic Hierarchy Process (AHP) expert questionnaire, it was found that the key factors affecting the route planning of recreational fishery boats are “boat conditions”, “berthing conditions”, “operating environment”, and “sightseeing potential”. After the expert questionnaire, a weight comparison of each level was performed, and it was found that “operating environment” was the most important factor, followed by “tourism potential”. However, the key factors of the “natural environment” and “cultural environment” are more important under the influence of the “operating environment”. Under the influence of “tourism potential”, “attractiveness” is a key factor, as is the “accessibility” factor. In this study, the four main fishing ports in Penghu County were also used for empirical discussion. The study results showed that Magong Fishing Port was the first choice for transformation, followed by Chikan Fishing Port. The results of this study can be used as a reference for fishermen and officials in developing a subsidy scheme for fishing boat operation, and they can be used as a reference for transforming traditional fisheries in outlying islands into recreational fishing to develop recreational fishery boats and leisure tourism industries. This research can help fishermen to attach importance to the development of recreational fishing activities and promote the stable growth of the fishery industry environment.

Exploring tourists' purchase intention of food-related souvenirs

This study aims to understand the association between food souvenirs and a destination. Most related studies focused on locally consumed food while this study aims at food that can act as a souvenir. Food image plays an important role in shaping destination brand and perceived tourist value, which consequently contributes to purchase intention for food souvenirs. In short, the study examines how local food consumption improves perceived tourist value, which eventually contributes to tourists' intention to purchase food-related souvenirs. 355 tourists who purchased brown sugar steamed cake while visiting Penghu Island in Taiwan were surveyed. The study performed structural equation modeling to test the mediating effects of destination brand and perceived tourist value on souvenir food image prompting purchase intention for food souvenirs. The findings indicate that food souvenirs image contributes more strongly through perceived tourist value than through destination brand.

Groundwater potential mapping based on long time series remote sensing data in Penghu Islands, China

AbstractIslands are special bodies of land surrounded by seawater. Many islands are facing water shortages as the demand for groundwater increases, thus, highlighting the importance and urgency of the assessment, planning, and management of island groundwater resources. To facilitate the same, the groundwater potential of the Penghu Islands in China was assessed for the first time using remote sensing (RS), geographic information system (GIS), and the analytic hierarchy process (AHP). Long‐term series remote sensing studies were also conducted to monitor the dynamic change in groundwater potential and to identify groundwater potential areas. In this study, the geological environment factors were normalized, and their weight was allocated based on the AHP of RS and GIS. The groundwater potential assessment (GPA) index, established using the weighted comprehensive algorithm, was used to analyse groundwater potential and demarcate groundwater potential zones. Finally, the trend in the spatio‐temporal variation of groundwater potential was analysed using long‐term series remote sensing data. The results from 2015 to 2021 showed that the Penghu Islands can be divided into five groundwater potential zones of different grades, such as 6.3%–8.1% of grade I, 22.2%–24.2% of grade II, 23%–24.4% of grade III, 19.6%–21% of grade IV, and 25.1%–25.5% of grade V. The results of the GPA were verified by comparing them with the abundance of water‐content rock formation in hydrogeologic maps, which yielded correlation coefficients of 78.3%–88.9%. Overall, the groundwater potential zones of different grades in the study area tended to be stable all year‐round, including the zones of grades I and II. The results of this study highlighted the reliability of predicting groundwater potential based on long‐term series remote sensing data and its usability to local personnel in appropriate groundwater resource planning and management.

Gymnothorax poikilospilus, a new moray eel (Teleostei: Anguilliformes: Muraenidae) from Penghu Islands, western Taiwan

Gymnothorax poikilospilus sp. nov. is described based on two specimens collected from Penghu Islands, western Taiwan. It is a medium-sized brown moray that body covered with several rows of inconspicuous large dark brown patches on the back of body and dorsal fin. It has slightly elongated and arched jaws similar to the common characteristic of the genus Enchelycore Kaup, but the dentition supports it belongs to typical morays of the genus Gymnothorax Bloch. The new species can be distinguished from other similar Indo-Pacific brown morays by the combination of dentition, vertebral formula, and morphometric measurements. Molecular analyses based on 612 bp of mitochondrial COI gene also support it as a distinct species.

Evaluation of low energy consumption control for seawater desalination on Penghu Island

In fact, current water supplies due to natural constraints or lack of infrastructure (or both) cannot be provided in a sustainable manner for all increasing and competing uses (e.g. residential, industrial, agricultural). While promoting Penghu's low-carbon islands, in a water-scarce environment, it is the motivation of this research to take into account the development of water resources and lower energy consumption costs. The seawater desalination plant water production technology is improved, the cost of water production is reduced. This research uses a genetic algorithm (GA) to optimize the recovery rate to solve the minimum Specific energy consumption (SEC) value, and then, according to the required water production, the optimal flow rate of raw seawater of the high-pressure pump is obtained, so as to minimize the energy consumption of the reverse osmosis (RO) system. The energy recovery device has a great effect on reducing the energy consumption of the RO system, and it can be seen from the results that the higher efficiency does greatly reduce the energy consumption of the SEC and water production under the different energy recovery device efficiency. Calculated using genetic algorithms, and the SEC is 3.275 and the recovery rate is 45.1%, and the water production energy consumption is 2.35 kWh/m3. Scheme B changed the efficiency of the energy recovery unit to 97.22%, resulting in a SEC of 1.819 and a recovery rate of 25.3%, and a water production energy consumption of 1.31 kWh/m3. Finally, challenges and research gaps are also proposed.

Factors underlying urinary arsenic levels in a population residing close to a coastal heavy-industrial area in southern Taiwan

The public in the southwestern Taiwan’s Kaohsiung City expressed concern over risk of arsenic (As) to people living in six of that city’s townships nearby a coastal area with heavy industry. To investigate, we first analyzed urinary total As levels in 539 subjects administered Taiwan’s Nutrition and Health Survey, a nationwide survey of nutritional status 2005-2008 (NAHSIT 2005-8). We found the top three highest median urinary total As levels in residents from Penghu island (136.93 µg/L, n = 24), the upper northern region of Taiwan (78.54 µg/L, n = 69), and the southwestern region of Taiwan (71.87 µg/L, n = 36). We then measured total urinary As levels in 1,801 and 1,927 voluntary residents of the above-mentioned six townships in 2016 and 2018, respectively, and compared with those with people residing in the top three highest total As levels of NAHSIT 2005-8. Median urinary As levels were 84.6 µg/L in 2016 and 72.5 µg/L in 2018, similar to those in southwestern region of Taiwan, but far below those in Penghu island (p <0.05). Finally, in 2020, we interviewed 116 healthy and voluntary residents from the same six townships and collected one-spot urine samples to analyze total inorganic-related As (TiAs), a summation of As3+, As5+, monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA). Median urinary TiAs in participants consuming seafood two days before urine sampling (n=15) was 24.0 µg/L, significantly higher than those not consuming seafood then (median: 20.5 µg/L, n=101, p=0.029). The results remained significant after adjusting for other covariates (p = 0.028). These findings suggest that seafood consumption is probably the main source of urinary total As and TiAs in people residing close to that coastal heavy industrial area of southern Taiwan. A future intervention study (dietary control) could be conducted to re-confirm our findings.

Chemical significance of atmospheric mercury at fishing port compared to urban and suburb in an offshore island

This study explored the chemical significance, spatiotemporal variation, and source origins of atmospheric speciated mercury (ASM) at three contexts (urban, suburb, and fishing port) at the Penghu Islands in the Taiwan Strait. Continuous monitoring of 5-min total gaseous mercury (TGM) was used to determine its hourly, daily, and seasonal concentrations. Manual sampling of 12-h gaseous oxidixed mercury (GOM) and particulate bound mercury (PBM) was used to resolve their diurnal and seasonal variation. ASM further correlated with meteorological parameters and criteria air pollutants. Backward trajectories coped with regional fire maps to identify the potential sources of atmospheric mercury. The yearly mean TGM concentration was about 2.9 times higher than the background level (1.4 ng/m3) of Northern Hemisphere. The highest and lowest seasonal TGM concentration appeared in spring and summer, respectively. Asian continental outflows (ACOs) containing mercury-laden contaminants (MLCs) in spring, while polluted air masses were blown from southern Taiwan where heavily industrial complex had in summer, causing the second highest ASM level. In fall, MLCs emitted from the coastal industrial and urban areas were blown from the Korea Peninsula by Asian Northeastern Monsoons (ANMs). In terms of gas-particle partition, TGM was superior to PBM. Moreover, the highest TGM concentration was observed at the fishing port site, and followed by the suburb and urban sites. High TGM concentration peaks were regularly observed at the fishing port site due to the exhausts of fishing boats.