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•Microalgal bioassay with multiple endpoints was applied to the effect-directed analysis.•Great microalgal toxicity was induced in polar fractions of sediment extracts.•Cell viability ...was a more sensitive endpoint compared to growth inhibition.•Nitrophenols were newly identified as microalgal toxicants in sediments.•Newly identified toxicants did not fully explain the induced toxicities of microalgae.
Microalgal toxicants in sediments from an industrialized area (Ulsan Bay) in South Korea were identified using effect-directed analysis (EDA) with full-scan screening analysis (FSA) and microalgal bioassays with multiple endpoints. The growth rate and cell viability of three microalgae (Isochrysis galbana, Dunaliella tertiolecta, and Phaeodactylum tricornutum) were strongly inhibited following exposure to raw organic extracts of sediments from Site D5 (Woehang River). The polar fraction separated using a silica gel column significantly inhibited growth rate, esterase activity, cell membrane intensity, and chlorophyll a autofluorescence. In comparison, non- and mid-polar fractions induced non-toxic or esterase inhibition. Target toxicants, such as polycyclic aromatic hydrocarbons, styrene oligomers, and alkylphenols, were detected at low concentrations (450, 79, and 98 ng g−1 dw, respectively) in the sediment of D5, indicating the presence of unmonitored toxicants. FSA was performed for the polar fraction using LC-QTOFMS, and 31 candidates of toxicants were selected. Toxicological confirmation was conducted for 7 candidates for which standards are available. Out of these, 2-nitrophenol, 3-nitrophenol, and 4-nitrophenol showed significant microalgal toxicity; however, these compounds did not fully explain the induced toxicity. Overall, combining EDA and FSA with multiple endpoint bioassays demonstrated the benefits of characterizing the microalgal toxicants in the environments.
Perfluoroalkyl substances (PFASs) are known to be persistent and toxic, and can be accumulated and trophic magnified in the environments. PFASs are widely distributed, and their coastal input poses a ...threat to the health of aquatic organisms and local residents. In present study, 17 PFASs including one emerging polyether substitute in water, sediment, and organisms were investigated from the South China Sea. Perfluorobutanoic acid (PFBA) was predominant in water, of which concentration ranged from ND to 10.26 ng/L, with a mean of 5.21 ng/L. Similar to sediment and organisms, PFBA was the substance with the highest concentration detected among PFASs. This result seemingly indicated that use of short-chain PFASs as substitutes for long-chain PFASs in recent years. Trophic magnification factors (TMFs) of PFASs were estimated in the marine food web. TMFs > 1 was observed only in perfluorooctane sulfonic acid (PFOS), indicating a biomagnification potential of PFOS in the given ecosystem. The estimated daily intake (EDI) of PFOS and PFOA were most prevalent in mollusk, whereas the EDI of PFBA was greater in fish and shrimp. The hazard ratio (HR) reported for seven dominant PFASs were lower than 1, which suggests that PFASs via seafood consumption would not cause significant health risk to local residents.
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•Perfluoroalkyl substances (PFASs) were extensively investigated in South China Sea.•PFBA prevailed in environments and biota due to increased recent use of short-chains.•Long-chain (PFOS, PFNA and PFDA) significantly bioaccumulated in the aquatic food web.•PFOS trophic transfer mechanisms were evidenced by use of stable isotope technology.•PFASs showed low exposure risks via consumption to local residents in Southern China.
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•Successfully identified the interface between the BE and the total environment by network analysis.•A direct link between the BE and the total environment increasingly invoked, yet ...interactions remain vague.•Three key-links found between the BE and total environment; sustainability, resources, and development.•Core topics for the BE included growth, spatial planning, environmental management and sustainability.•Identified research clusters showed key knowledge domains and future agenda with the needs of the BE.
The term ‘Blue Economy (BE)’ is increasingly popular in modern environmental research. The concept seeks to explore ocean-based development opportunities with environmental stewardship and protection. Yet different scholars and actors adopt this term often in conflicting ways without attempting to explore the relevance and the link between the blue economy and the broader environment viz., total environment. The potential opportunities to resolve the conflicts require a better understanding of the impacts and/or interactions of the BE on the total environment. This paper aims to map the interface between the two for a better understanding of the total environment and implications for the BE. Using a systematic literature review, this study finds that the field of the blue economy in association with the total environment is very new and emerging in the literature, and the link between the BE and the total environment is increasingly being invoked, yet clarity on the link or interactions remain vague. By analysing the co-occurrence of selected keywords and networks, we present six clusters (three for general relationship, and the other three for specific dimensions of total environment). In a general relationship between the BE and the total environment, clusters of environmental sustainability, marine resource, and economic development are identified to link directly to the BE. In specific dimensions of the total environment, clusters of growth and sustainable development, spatial planning and environmental management, and environmental sustainability and the BE are presented. The analysis outcomes show that specific areas from the total environment (growth, spatial planning, environmental management, and environmental sustainability) are directly linked to the BE where a call for a wider range of studies in the future is identified.
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► Waterborne concentrations of PFCs reflected land use and local activities. ► Concentrations of PFCs in soils and sediments were less than those in biota. ► Composition of PFCs cross ...target aquatic organisms reflected species-specific accumulation. ► Field-based BCFs for PFCs significantly varied among species and compounds. ► Compound- and organ-specific bioconcentration of PFCs in fishes was observed.
As part of an ongoing study of the status and trends of contaminants in the Yellow Sea, during May of 2009, the concentrations of perfluorinated compounds (PFCs) were determined in water (n=15), sediment (n=12), soil (n=13), and biota (n=74) from estuarine and coastal areas along the west coast of Korea. Of the 12PFCs monitored, PFOS and PFOA were the most frequently detected compounds in water. Greater concentrations of PFCs were found in waters from the inner regions of sea dikes in three artificial lakes, Shihwa, Asan, and Sapgyo, than outer regions. Concentrations were also comparable in two estuarine areas, which indicated that most PFCs in coastal areas originated from industrial and local regions and river water flowing through estuaries. Concentrations of PFCs in soils and sediments were generally less than limits of quantification and were generally less than those measured in biota. Compound-specific bioaccumulation of PFBS and PFOS had the greatest BCF values in crab, while in fish it was PFOS and PFDA, and in gastropods and bivalves it was PFHxS. Distributions of BCFs for PFOS in body-parts of crab showed the greatest values in soft tissues followed by shells and then legs. Distribution among tissues and organs of fishes was more variable than those observed for crab. When compared to a similar study conducted by our group in 2008, concentrations of PFCs in water samples were significantly less in 2009. However, there was little change in bioconcentration from sediments into benthic organisms. Finally, we conducted the assessment of potential adverse effects for PFCs on aquatic life by use of current and previous reported data.
Trace metal dynamics have not been studied with respect to growth increments in octocorals. It is particularly unknown whether ontogenetic compartmentalization of trace metal accumulation is ...species-specific. We studied here for the first time the intracolonial distribution and concentrations of 18 trace metals in the octocorals Subergorgia suberosa, Echinogorgia complexa and E. reticulata that were retrieved from the northern coast of Taiwan. Levels of trace metals were considerably elevated in corals collected at these particular coral habitats as a result of diverse anthropogenic inputs. There was a significant difference in the concentration of metals among octocorals except for Sn. Both species of Echinogorgia contained significantly higher concentrations of Cu, Zn and Al than Subergorgia suberosa. We used for the first time exponential growth curves that describe an age-specific relationship of octocoral trace metal concentrations of Cu, Zn, Cd, Cr and Pb where the distance from the grip point was reflecting younger age as linear regressions. The larger colony (C7) had a lower accumulation rate constant than the smaller one (C6) for Cu, Zn, Cd, Cr and Pb, while other trace metals showed an opposite trend. The Cu concentration declined exponentially from the grip point, whereas the concentrations of Zn, Cd, Cr and Pb increased exponentially. In S. suberosa and E. reticulata, Zn occurred primarily in coenosarc tissues and Zn concentrations increased with distance from the grip point in both skeletal and coenosarc tissues. Metals which appeared at high concentrations (e.g. Ca, Zn and Fe) generally tended to accumulate in the outer coenosarc tissues, while metals with low concentrations (e.g. V) tended to accumulate in the soft tissues of the inner skeleton.
Chitosan/diatomite composite (CH/D) was synthesized at potential multifunctional adsorbent of enhanced uptake capacities for different species of organic water pollutants. The synthetic CH/D ...composite was characterized and applied in batch adsorption studies for pefloxacin (PF) as pharmaceutical residual and chlorpyrifos (CF) as pesticide residual from water. The CH/D composite is of enhanced uptake capacities for both PF (310.7 mg/g) and CF (392.2 mg/g) as compared to diatomite and chitosan and single components. The PF and CF uptake reactions follow the Langmuir model as an equilibrium model which demonstrates their adsorption in monolayer and homogenous form. The PF uptake process is of Pseudo-First order kinetic while the CF uptake process is of Pseudo-Second order kinetics. The Gaussian energies (6.74 KJ/mol (PF) and 7.76 KJ/mol (CF)) and thermodynamic parameters suggest PF and CF adsorption reactions of physical, feasible, exothermic, and spontaneous properties. The CH/D composite exhibits strong selectivity for PF and CF molecules in the existence of PO
4
3−
, SO
4
2−
, and NO
3
−
anions and considerable selectivity for them in the coexistence of Zn
2+
, Cd
2+
, and Pb
2+
metal cations. The CH/D composite is of remarkable recyclability and reused in the removal of PF and CF for five cycles with removal percentages higher than 86% and 89%, respectively.
In this study, we identified major aryl hydrocarbon receptor (AhR) agonists in the sediments from Yeongil Bay (n = 6) using effect-directed analysis. Using the H4IIE-luc bioassays, great AhR-mediated ...potencies were found in aromatic fractions (F2) of sediment organic extracts from silica gel column chromatography and sub-fractions (F2.6–F2.8) from reverse phase-HPLC. Full-scan mass spectrometric analysis using GC-QTOFMS was conducted to identify novel AhR agonists in highly potent fractions, such as F2.6–F2.8 of S1 (Gumu Creek). Selection criteria for AhR-active compounds consisted of three steps, including matching factor of NIST library (≥70), aromatic structures, and the number of aromatic rings (≥4). Fifty-nine compounds were selected as tentative AhR agonist candidates, with the AhR-mediated activity being assessed for six compounds for which standard materials were available commercially. Of these compounds, 20-methylcholanthrene, 7-methylbenzaanthracene, 10-methylbenzapyrene, and 7,12-dimethylbenzaanthracene exhibited significant AhR-mediated potency. Relative potency values of these compounds were determined relative to benzoapyrene to be 3.2, 1.4, 1.2, and 0.2, respectively. EPA positive matrix factorization modeling indicated that the sedimentary AhR-active aromatic compounds primarily originated from coal combustion and vehicle emissions. Potency balance analysis indicated that four novel AhR agonists explained 0.007% to 1.7% of bioassay-derived AhR-mediated potencies in samples.
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•Novel AhR agonists were identified in industrial sediments using EDA combined with FSA.•7,12DbA, 10MbA, 7MbA, and 20MC had significant AhR-mediated potencies.•Relative potency values of novel AhR agonists compared to benzoapyrene were obtained.•Novel AhR agonists explained from 0.007 to 1.7% of total induced AhR potencies.
•Ascidian abundance and diversity greatly varied in space in an Antarctic fjord.•We found ‘distance to glacier’ is a key factor for the observed shift.•The shift was mostly related to sediment ...properties altered by glacial retreat.•Physical disturbance accompanying retreat is likely shaping ascidian assemblages.•Such shift reflects a long-term succession, giving an insight into future change.
We report strong evidence for the utility of ascidian communities as sentinel organisms for monitoring nearshore Antarctic marine ecosystem response to climate-induced warming and glacial melting. Ascidians are one of the most common Antarctic epibenthic megafauna, but information on their distribution and the determinants is still scarce. In this study we investigated spatial patterns of ascidians in Marian Cove (MC), a rapidly deglaciating fjord in the West Antarctic Peninsula, one of the most rapidly warming regions on earth. We also analyzed key drivers structuring the communities and assessed their relevance to glacial retreat and following processes. The first applied ROV survey in MC discovered that ascidians were the most diverse (14 out of 64 taxa) taxa with the greatest abundance (~264 inds·m−2). Ascidian abundance and diversity greatly varied in space, by distance from glacier and/or depths, explaining ~64% of total megafaunal variations. Notably, in deep seabed (50–90 m) they shifted distinctly from early colonization communities near glacier (0.2 km to glacier) with predominance of two opportunistic species, Molgula pedunculata and Cnemidocarpa verrucosa, to mature communities at the most remote site (3.5 km). A set of analyses revealed that such shifts were related mostly to changes in sediment properties that develop in association with glacial retreat and consequent processes. Sediment composition, grain size and sorting collectively explained outward increasing physical stability apparently with decreased influence of glacial retreat, supporting ascidian community maturing at the deep and distant site. BIOENV analysis indicated that “distance” to glacier is one key factor influencing ascidian community structure in the deep seabed. Overall, the results of the analyses strongly indicated that physical disturbances (mainly sedimentation and ice scouring) accompanying glacial retreat are an important force shaping ascidian assemblages in the cove, and that these forces are altered by the distance from the glacier and water depth. Notably, in this fjord, the period of sea bed deglaciation was roughly proportional to the distance to glacier over the last six decades. This suggested that the ascidian shift identified in this study reflects a long-term successional process associated with glacial retreat in the past in MC, which in turn warrants to project future changes in this glacial fjord and possibly other similar environments.
The effect of sediment pollution on benthos was investigated in the vicinity of a large sewage treatment outflow at Incheon North Harbor, Korea. Animal size, vertical distribution and standard ...community parameters were analyzed along a 3 km transect line (n = 7). Univariate parameters showed a general trend of increasing species diversity with increasing distance from the pollution source. Multi-dimensional scaling analysis led to the clear separation of 3 locational groups, supporting gradient-dependent faunal composition. The innermost location was dominated by small sub-surface dwellers while the outer locations by large mid to deep burrowers. Looking for the size-frequency distribution, most abundance species (Heteromastus filiformis) showed the presence of larger size animals with increasing proximity to the pollution source. Meanwhile, species-specific vertical distributions, regardless of the pollution gradient, indicated that such shifts were due to species replacement resulting from a higher tolerance to pollutants over some species.
► Hypotheses on benthic responses to sediment pollution were tested. ► Decrease of species diversity with the proximity to the pollution source. ► Shift of vertical distribution along the transect line attributes to species replacement. ► Larger-size species occurred distant from the pollution source. ► Larger individuals of Heteromastus filiformis occurred closer to the pollution source.
Community and population level response to the polluted environment of the harbor reflected an integration effect, together with biological interactions.
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