Spatial distribution, mass flux, and ecological risk of antibiotics in Taiwan and Luzon Straits: A case in the West Pacific Region.

Emerging pollutants are hazardous to the ecological environment and human health, and these issues have attracted increasing attention from scholars. In the current study, the Taiwan Strait is long and narrow, highly influenced by terrestrial domains, and frequently disturbed by human activities. Conversely, the Luzon Strait is an open sea far from the shore, and the impact of human activities on it is minimal. The description of antibiotics in two different types of seas revealed that contaminants were most commonly detected in both straits. In particular, the coasts of the Minjiang River, Jinjiang River, and Jiulong River were found to be pollution hotspots in the Taiwan Strait. The calculation of risk quotients revealed that antibiotics were more sensitive to algae. Furthermore, estimation of the risk quotients of the mixtures found that antibiotics in the environment do not pose a high risk to aquatic organisms at different trophic levels.

Microplastics Prevalence in Different Cetaceans Stranded along the Western Taiwan Strait.

Microplastics (MPs) pollution is of global concern, which poses serious threats to various marine organisms, including many threatened apex predators. In this study, MPs were investigated from nine cetaceans of four different species, comprising one common dolphin (Delphinus delphis), two pygmy sperm whales (Kogia breviceps), one ginkgo-toothed beaked whale (Mesoplodon ginkgodens), and five Indo-Pacific humpback dolphins (Sousa chinensis) stranded along the western coast of the Taiwan Strait from the East China Sea based on Fourier transform infrared (FTIR) spectroscopy analysis. Mean abundances of 778 identified MPs items were 86.44 ± 12.22 items individual-1 and 0.43 ± 0.19 items g-1 wet weight of intestine contents, which were found predominantly to be transparent, fiber-shaped polyethylene terephthalate (PET) items usually between 0.5 and 5 mm. The abundance of MPs was found at a slightly higher level and significantly correlated with intestine contents mass (p = 0.0004*). The MPs source was mainly likely from synthetic fibers-laden sewage discharged from intense textile industries. Our report represents the first study of MPs in pelagic and deep-diving cetaceans in China, which not only adds baseline data on MPs for cetaceans in Asian waters but also highlights the further risk assessment of MPs consumption in these threatened species.

Dataset on Cs-137 in waters surrounding Taiwan.

The Fukushima accident released short-lived Cs-134 and longer-lived Cs-137 to the ocean. The amount, although substantial, is much less than that produced during the atomic bomb tests 60 yrs ago. Cs-134 and Cs-137 are anthropogenic radionuclides and soluble in seawater; hence, the radioactivity can be used as a tracer for special events or currents. Samples of Cs-134 and Cs-137 in seawater were collected around Taiwan, including the Kuroshio, the northern South China Sea, the Taiwan Strait, and the southern East China Sea from 2018 to 2021. The average surface Cs-137 activity was 1.18±0.25 Bq m - 3, and the activities of Cs-134 samples were all under the detection limit. Complete data are archived, including sampling date, location, water depth, temperature, salinity, and Cs-137 activity; the total sample amount is 577.

Seasonal distribution patterns of Scomberomorus commerson in the Taiwan Strait in relation to oceanographic conditions: An ensemble modeling approach.

The decline in the stock of the narrow-barred Spanish mackerel in the Taiwan Strait has sparked interest in conservation efforts. To optimize conservation and restoration efforts, it is crucial to understand their habitat preference in response to changing environments. In this study, ensemble modeling was used to investigate the seasonal distribution patterns of Spanish mackerel. Winter was identified as the most productive season, followed by fall; productivity was the lowest in summer. Five single-algorithm models were developed, and on the basis of their performance, four were selected for inclusion in an ensemble species distribution model. The spatial distribution of Spanish mackerel was primarily along the latitudinal range 23°-25°N in spring and summer. However, in fall and winter, the geographical range increased toward the southern region. The findings of this study will contribute to the understanding of this specific species and the approach used in this study may be applicable to other fisheries stocks also.

Fishery-based adaption to climate change: the case of migratory species flathead grey mullet (Mugil cephalus L.) in Taiwan Strait, Northwestern Pacific.

The flathead gray mullet (Mugil cephalus L.) is a cosmopolitan fish that lives in warm and temperate zones over 42°N-42°S. It is a key fish species for industrial fishing off coastal Taiwan. Gray mullets enter the coastal waters of the southeastern Taiwan Strait (22°N-25°N) to spawn in winter and feed in the coastal and tidal waters of China (25°N-30°N). From 1986 to 2010, the annual catch of gray mullet decreased substantially and remained low. Although the Pacific Decadal Oscillation and El Niño-Southern Oscillation are recognized to affect gray mullet migration, the increase in sea surface temperature may be the main cause of the aforementioned decrease. We explored how weather changes affect fishing conditions and patterns at the gray mullet fishing grounds in Taiwan's coastal areas. Because of the decrease in gray mullet catches, the most common method for catching gray mullet in Taiwan's coastal areas between 1990 and 2010 was the use of drift or trawl nets instead of two-boat purse-seiner fleets. Since 2012, purse-seiner fleets have become the most common method for catching gray mullet. This trend indicates that the local fishing industry is adapting to changing environmental conditions.

Phylogeography of the Fiddler Crab Tubuca arcuata (Crustacea: Brachyura: Ocypodidae) in East Asia and Northern Vietnam.

The fiddler crab Tubuca arcuata (Crustacea: Ocypodidae: Gelasiminae) is widely distributed across East Asia and northern Vietnam. Particularly, this species inhabits estuarine mangroves and mudflats of the East Asian continent, as well as the main islands of Japan and the Ryukyus. By comparing sequences of the mitochondrial 16S, cytochrome oxidase subunit I (COI), and control region genes, two main clades of this species were elucidated. The northern (N) clade was mostly restricted to the region north of the Taiwan Strait, whereas the wide (W) clade could be found throughout the entire range inhabited by this species. Based on the distribution of the ancestral haplotypes of COI and the divergence time of the two clades, our findings suggest that the land bridge barrier present in the Taiwan Strait during glaciations might have played an important role in their cladogenesis, approximately 0.93 million years ago. Here, we propose that the distribution of the ancestral haplotype of the W clade in the Ryukyus and the main islands of Japan was determined by the Paleo-Kuroshio Current, whereas the modern distribution pattern is shaped by the modern Kuroshio Current and other warm currents during the crab reproduction season in the summer.

The geochemical and environmental characteristics of trace metals in surface sediments of the river estuarine mouths around the Taiwan Island and the Taiwan Strait.

The trace metals species in surface sediments of the Taiwanese river estuarine mouths and the Taiwan Strait were examined by sequential extraction method. Based on the metal species present in sediments, trace metals can be divided into three groups: (1) Co, Cr, Fe, Ni and Zn; (2) Cu and Hg; and (3) Mn and Pb. The total concentrations of trace metals in the first two groups are dominated by the residual fraction. While, Cu and Hg their organic species also contributes a significant percentage and reduces the residual fraction portion. Lead and Mn are dominated by the labile fraction. The total metal concentrations in the analyzed sediments seem to be influenced by Fe oxides, TOC and grain size. The metals contamination status assessed by three environmental indices suggests that the analyzed sediments are minor contaminated by trace metals, with a few exceptions of Cu and Hg at some stations.

Occurrence, Distribution, and Risk of Organophosphate Flame Retardants in Sediments from Jiulong River Estuary and Adjacent Western Taiwan Strait, China.

Organophosphate ester flame retardants (OPFRs) are widely prevalent in the environment and are of significant concern because of their potential toxicity to human health and wildlife. In this study, the concentration, frequency, spatial distribution, potential sources, and ecological risks of OPFRs in sediments from the Jiulong River estuary and the adjacent western Taiwan Strait were investigated. Concentrations of four of the five studied OPFRs were between

Distribution and Transformation of Mercury in Subtropical Wild-Caught Seafood from the Southern Taiwan Strait.

Wild-caught seafood contains significant amounts of mercury. Investigating the mercury accumulation levels in wild-caught seafood and analyzing its migration and transformation are of great value for assessing the health risks of mercury intake and for the tracking of mercury sources. We determined the concentrations and stable mercury isotopic compositions (δ202Hg, Δ199Hg, Δ200Hg, and Δ201Hg) of 104 muscle samples collected from 38 species of seafood typically harvested from the Taiwan Shallow Fishing Ground (TSFG), Southern Taiwan Strait. Overall, the concentrations of total mercury (THg) and methylmercury (MeHg) ranged from 11 to 479 ng/g (dry weight, dw) and 10 to 363 ng/g (dw), respectively, and were below the threshold value established by the USEPA and the Chinese government. Demersal and near-benthic species accumulated more mercury than pelagic or mesopelagic species. The characteristics of mercury isotopes in wild-caught marine species differed in terms of vertical and horizontal distribution. Considering the known peripheral land sources of mercury (Δ199Hg ≈ 0), the mercury in seafood from the TSFG (Δ199Hg > 0) did not originate from anthropogenic emissions. The ratio of Δ199Hg and Δ201Hg (1.18 ± 0.03) suggested that the photoreduction of Hg (II) and the photo-degradation of MeHg equally contributed to mass-independent fractionation. Based on the values of Δ199Hg/δ202Hg (1.18 ± 0.03), about 67% of the mercury in seawater had undergone microbial demethylation prior to methylation and entering the seafood. Additionally, the vertical distribution of Δ200Hg in seafood from different water depths implies that mercury input was in part caused by atmospheric deposition. Our results provide detailed information on the sources of mercury and its transfer in the food web in offshore fishing grounds.

Co-occurrence and potential ecological risk of parent and oxygenated polycyclic aromatic hydrocarbons in coastal sediments of the Taiwan Strait.

Thirty-two surface sediment samples, collected from the Taiwan Strait (TWS), were investigated for the occurrence, composition profile, and spatial distribution of polycyclic aromatic hydrocarbons (PAHs) and oxygenated PAHs (OPAHs). PAHs were ubiquity in the TWS with a total concentration (∑PAHs, excluding naphthalene due to its high volatility) ranging from 17.8-213 ng g-1. Benzo[b] fluoranthene, fluoranthene, phenanthrene, and pyrene were the predominant PAHs. Also, eight OPAHs were detected, having a cumulative concentration range (∑OPAHs) of 10.5-118 ng g-1, predominated by anthraquinone and 6H-Benzo[c,d]Pyren-6-one. Higher concentrations of ∑PAHs and ∑OPAHs were detected at sampling sites adjacent to the mainland and in the northwest part of the TWS. The results suggested important continental input, and particle sedimentation under the specific hydrodynamic conditions of the region. Based on the measured concentrations and sediment quality guidelines, PAHs had a limited ecological impact on the area.

Microplastics in seawater and two sides of the Taiwan Strait: Reflection of the social-economic development.

Microplastic abundance, distribution and source characteristics were investigated for the surface seawaters from the Taiwan Strait as well as those of sediments along its west and east coasts. The microplastic abundances were in the range of 28-208 (mean 90) and 10-246 (mean 69) items/kg (d.w.) along the west and east coasts respectively. The higher microplastic abundance on the west coast might be related to the different local economic development, population, land-use and other human activities. Combined with microplastic pollution and socio-economic development, regression analysis results showed that urbanization level is negatively correlated with foams while positively correlated with fibers. This study, as the first report of microplastics in the Taiwan Strait, suggested further research on microplastics cross-strait transportation and the relationship with economic developments.

Parent and alkylated polycyclic aromatic hydrocarbons in surface sediments of mangrove wetlands across Taiwan Strait, China: Characteristics, sources and ecological risk assessment.

The characteristics, distributions and sources of parent polycyclic aromatic hydrocarbons (PAHs) and alkyl-PAHs (A-PAHs) as well as their ecological risk were explored in six mangrove wetlands across the Taiwan Strait, China. A-PAHs fingerprinting information, combined with PAHs diagnostic ratios and a positive matrix factorization model, were used to identify the sources of PAHs in the mangrove wetland surface sediment samples. The results showed that the total concentration of the 36 PAHs in the sediment samples varied from 186.2 to 2469.2 ng⸱g-1. Furthermore, the total concentration of PAHs would be underestimated about 37.1%-80.6% when only the concentrations of 16 priority PAHs were examined in the sediment samples. Coal combustion (32.7%) and petroleum combustion (24.6%) were identified as important contributing sources in the Yunxiao, Fugong, and Quanzhou mangrove wetlands, whereas the main source was mainly petroleum combustion (49.1%) in the Guandu, Zhuwei and Waziwei mangrove wetlands. In addition, the guidelines for assessing the ecological risk of individual A-PAHs need to be developed due to lack of criteria for most individual A-PAHs.

Assessment of heavy metal contamination in surface sediments in the western Taiwan Strait.

The concentrations of the heavy metals Cu, Pb, Zn, As, Cr, Co, and Ni of a total of 187 surface sediment samples collected from the western Taiwan Strait were analyzed. The distribution characteristics and degree of contamination of these elements were investigated. The mean concentrations of Cu, Pb, Zn, As, Cr, Co, and Ni in the surface sediments of the study area were 10.2 mg/kg, 18.3 mg/kg, 51.7 mg/kg, 7.5 mg/kg, 38.7 mg/kg, 8.0 mg/kg, and 16.5 mg/kg, respectively. The heavy metals in the study area were mainly from natural sources. The regional pollution load index (PLIzone) was 0.64, indicating that there was no contamination, and an area with a relatively high PLIzone was found in the northern part of the study area. Furthermore, the impacts of the rapid development of Fujian's marine economy on the marine environment in the past decade should be further compared and analyzed.

Occurrence and distribution of organophosphorus flame retardants/plasticizers in coastal sediments from the Taiwan Strait in China.

Concentrations and spatial distributions of organophosphate esters (OPEs) in marine sediment samples in the western Taiwan Strait were investigated and analyzed for the first time. The total OPE concentration (∑OPE) in sediments was in the range of 5263-34,232 pg/g (dry weight), with an average value of 12,796 pg/g. Generally, there was a higher abundance of non-halogenated OPEs than halogenated OPEs and aryl OPEs, with tributyl phosphate, tris (2-ethylhexyl) phosphate, and tri-(1-chloro-2-propyl) phosphate being the main components. The ∑OPE concentrations in the western coastal and northern sampling sites were relatively high. The results indicated that OPEs in the study region originated mainly from terrestrial river inputs and local emission sources, as well as exogenous influxes by ocean currents.

Occurrence and distribution of pharmaceutical compounds in the Danshuei River Estuary and the Northern Taiwan Strait.

Ten pharmaceutically active compounds (PhACs) were determined in northern Taiwan estuarine waters and Taiwan Strait (TS) seawater. The ecological risk of these PhACs was assessed using risk quotient (RQ), which is the ratio of the measured maximum concentration to the predicted no-effect concentration. Six PhACs were detected within the estuarine waters. Caffeine concentration (130-718 ng l-1) was the highest among the analyzed PhACs. The distribution of PhACs in the Danshuei River Estuary generally exhibited addition behavior, except that caffeine showed conservative behavior. Carbamazepine, gemfibrozil, caffeine, and ketoprofen were detected in TS seawaters. Their concentrations follow the sequence: gemfibrozil > ketoprofen > caffeine > carbamazepine. The caffeine concentrations in TS seawaters were 2-3 orders of magnitude lower than those in Danshuei estuarine waters. With few exceptions for caffeine, erythromycin, and sulfadiazine posing low risk in some estuarine waters, most of the RQ values were <0.01, suggesting no adverse effects on aquatic organisms.

Vertical distribution of perfluoroalkyl substances in water columns around the Japan sea and the Mediterranean Sea.

Perfluoroalkyl substances (PFASs) have become an important class of global environmental contaminants, yet their vertical profile in the marine water column is still less understood, especially for the semi-closed seas. In this study, the contamination level and spatial distribution of 8 PFASs were investigated in both surface and vertical water samples from two semi-closed seas, the Japan Sea and the Mediterranean Sea. Similar levels and compositions of PFASs were found between these two seas. The vertical profile of PFASs in the Mediterranean Sea was variable while that was relatively steady in the Japan Sea, probably due to their different pollution sources. The accumulation rate of PFASs from the East China Sea to the Japan Sea was calculated, for which perfluorooctanesulfonic acid and perfluorooctanoic acid were found to have high accumulation potency in both surface and deep water; most of the investigated PFASs were accumulated in the deep water due to the long residence time while they were more likely to escape to the Pacific Ocean in the surface water. This work aimed (i) to study the distribution of PFASs in both surface and vertical water samples in two semi-closed seas, namely the Japan Sea and for the first time the Mediterranean Sea, (ii) to assess the temporal trend in the Japan Sea, and (iii) to firstly investigate the potential transport of PFASs from the East China Sea and Taiwan Strait in order to estimate the inventory of PFASs in whole water mass in the Japan Sea.

Distribution and isotopic composition of sedimentary black carbon in a subtropical estuarine-coastal region of the western Taiwan Strait: Implications for tracing anthropogenic inputs.

Estuarine and coastal margins are strongly influenced by anthropogenic inputs. To trace anthropogenic inputs to the subtropical Jiulong River Estuary (JRE) and the adjacent western Taiwan Strait (WTS), black carbon (BC) and its stable carbon isotope composition (δ13СBC) in surface sediments were investigated as an indicator of human activities. The concentrations of sedimentary BC were measured by an emerging method of thermal/optical reflectance with wet-chemical treatment (BCTOR, including char and soot), and the conventional method of chemothermal oxidation (BCCTO, related to the soot fraction) was also used to determine BCCTO concentrations and δ13СBC compositions. In the JRE and adjacent WTS, the concentrations of BCTOR (0.77 to 3.79 mg g-1) were higher than those of BCCTO (0.55 to 2.46 mg g-1), and both were similar to the moderate ranges obtained in other coastal sediments around the world. The small offsets between δ13СTOC and δ13СBC and the relatively low char/soot ratios revealed that fossil fuel combustion-derived contributions were likely more significant compared with inputs from biomass burning. The decreasing BC concentrations and increasing δ13СBC values with increasing distance from the JRE towards the adjacent WTS, indicates the decline of land-based anthropogenic inputs through fluvial transport. Furthermore, the differences in BC/TOC and char/soot values between the southern and northern WTS, indicated an effective preferential dispersal of the fluvial BC to the southern coast. The estimation for mass inventories of sedimentary BC in the coastal WTS showed that direct riverine discharge from the JRE was nearly equivalent to atmospheric deposition, and both of them contributed half of the sedimentary BC sink. To balance the sedimentary BC budget in the coastal WTS, long-range alongshore sediment transport driven by the Fujian-Zhejiang coastal current containing Yangtze River derived materials (indirect riverine discharge) could be another significant input pathway to contribute sedimentary BC.

Species composition and toxicity of the genus Pseudo-nitzschia in Taiwan Strait, including P. chiniana sp. nov. and P. qiana sp. nov.

In a field survey in the Taiwan Strait during April 2016, the species composition and the domoic acid production of the diatom genus Pseudo-nitzschia were investigated. A total of 80 strains of Pseudo-nitzschia were established, and species identification was determined based on a combination of morphological and molecular data. Fourteen taxa were recognized, i.e., P. americana, P. brasiliana, P. calliantha, P. cuspidata, P. galaxiae, P. lundholmiae, P. multiseries, P. multistriata, P. pseudodelicatissima, P. pungens var. aveirensis, P. pungenus var. pungens and P. sabit, as well as two novel species P. chiniana C.X. Huang & Yang Li and P. qiana C.X. Huang & Yang Li. Morphologically, P. chiniana is characterized by striae comprising one or two rows of poroids, and valve ends that are normally dominated by two rows of poroids within each stria. Whereas P. qiana is unique by having a narrow valve width (1.3-1.5 µm) and sharply pointed valve ends. Both taxa constitute their own monophyletic lineage in the phylogenetic analyses inferred from LSU and ITS2 rDNA, and are well differentiated from other Pseudo-nitzschia species. Pseudo-nitzschia chiniana forms a group with P. abrensis and P. batesiana in LSU and ITS trees, whereas P. qiana is sister to P. lineola. When comparing ITS2 secondary structure, five CBCs and seven HCBCs are recognized between P. chiniana and P. abrensis, and four CBCs and ten HCBCs between P. chiniana and P. batesiana. Two CBCs and eight HCBCs are found between P. qiana with P. lineola. The ability of the strains to produce domoic acid was assessed, including a potential toxin induction by the presence of brine shrimps. Results revealed production of domoic acid in six strains belonging to three species. Without presence of brine shrimps, cellular DA (pDA) was detected in four P. multiseries strains (1.6 ± 0.3, 26.6 ± 2.7, 68.3 ± 4.2 and 56.9 ± 4.7 fg cell-1, separately), one strain of P. pseudodelicatissima (0.8 ± 0.2 fg cell-1) and one strain of P. lundholmiae (2.5 ± 0.4 fg cell-1). In the presence of brine shrimps, pDA contents increased significantly (p < 0.05) in P. lundholmiae (strain MC4218) and P. multiseries (strain MC4177), from 2.5 ± 0.4 to 8.9 ± 0.7 and 1.6 ± 0.3 to 37.2 ± 2.5 fg cell-1 respectively.

Aerosol light absorption in a coastal city in Southeast China: Temporal variations and implications for brown carbon.

Light-absorbing carbonaceous aerosols including black carbon (BC) and brown carbon (BrC) play significant roles in atmospheric radiative properties. One-year measurements of aerosol light absorption at multi-wavelength were continuously conducted in Xiamen, southeast of China in 2014 to determine the light absorption properties including absorption coefficients (σabs) and absorption Ångström exponent (AAE) in the coastal city. Light absorptions of BC and BrC with their contributions to total light absorption were further quantified. Mean σabs at 370 nm and 880 nm were 56.6 ±â€¯34.3 and 16.5 ±â€¯11.2 Mm-1, respectively. σabs presented a double-peaks diurnal pattern with the maximum in the morning and the minimum in the afternoon. σabs was low in warm seasons and high in cold seasons. AAE ranged from 0.26 to 2.58 with the annual mean of 1.46, implying that both fossil fuel combustion and biomass burning influenced aerosol optical properties. σabs of BrC at 370 nm was 24.0 ±â€¯5.7 Mm-1, contributing 42% to the total absorption. The highest AAE (1.52 ±â€¯0.02) and largest BrC contributions (47% ±â€¯4%) in winter suggested the significant influence of biomass burning on aerosol light absorption. Long-distance air masses passing through North China Plain and the Yangtze River Delta led to high AAE and BrC contributions. High AAE value of 1.46 in July indicated that long-range transport of the air pollutants from intense biomass burning in Southeast Asia would affect aerosol light absorption in Southeast China. The study will improve the understanding of light absorption properties of aerosols and the optical impacts of BrC in China.

Source apportionment and source-to-sink transport of major and trace elements in coastal sediments: Combining positive matrix factorization and sediment trend analysis.

Major and trace elemental concentrations in coastal marine sediments were incorporated into positive matrix factorization (PMF) to identify potential sources and source contributions. Transport pathways of fine-grained sediments and sediment-bound elements were inferred from sediment trend analysis (STA). The spatial distribution patterns of 21 elements (Co, Cu, Ni, Sr, Zn, V, Ba, Sc, Ga, Pb, Cr, Zr, SiO2, Al2O3, Fe2O3, MgO, CaO, K2O, MnO, TiO2, and P2O5) coupled with sediment grain sizes were investigated. The natural and anthropogenic sources of the elements were distinguished by their medium enrichment factors (EFs). Seven sources were recognized by PMF: weathering products, anthropologic emissions, sand, older sediment, biogenic carbonates, products of siliceous organisms, and mine exploitation. Some land-derived elements, including weathering products, anthropogenic-related elements, and mining-related elements, had a significant positive correlation with sediment silt, clay, and organic carbon contents. The spatial patterns of the land-derived elements' concentrations and source contributions were consistent with the sediment transport pathways inferred from the STA. This result revealed that the delivery of the land-derived elements was determined by marine current flows and the associated sediment transport processes. Conversely, elements originating from marine sources, such as sand and older sediment, and from the biological activities of calcareous and siliceous organisms showed little response to sediment transport and deposition processes. Our study links the outputs of statistically oriented approaches (e.g., PMF) to a process-based understanding of elemental transport in marine environments.