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A baseline study was undertaken on polycyclic aromatic hydrocarbons (PAHs) in phytoplankton. Plankton samples from six stations (duplicates) in Kaohsiung Harbor (KH), Taiwan along with a phytoplankton control sample afar from the harbor, were collected. We applied size-fractionation to isolate phytoplankton (55–120 μm), followed by sedimentation and centrifugation to remove abiogenic particulates. The phytoplankton was freeze-dried, extracted with acetone: n -hexane (1:1, v/v), and analyzed using GC–MS. ΣPAHs in phytoplankton ranged between 5204 and 28,903 ng/g dry weight (mean: 12,150 ng/g). The ΣPAHs in KH were >7 times than the control site (C1: 3972 ng/g). Cluster analysis showed spatial gradients (northern < southern KH). Accumulated PAHs in phytoplankton were from petrogenic (fishing ports and ships) and pyrogenic (river outflows), dominated by lower-ring PAHs, likely due to their higher bioavailability in the dissolved phase. We present a practical phytoplankton isolation technique for more accurate phytoplankton PAH concentrations with insights into their distribution and sources. [Display omitted] • First report on PAHs in size-fractionated marine harbor phytoplankton • Use of simple pre-treatment to isolate and study PAHs in phytoplankton • PAHs accumulated in phytoplankton are from pyrogenic and petrogenic sources. • Fishing ports and rivers are major PAH sources in phytoplankton from study area. [ABSTRACT FROM AUTHOR]

One of the most concerning emerging pollutants is microplastics (MPs), which can infiltrate soft tissues of organisms by ingestion, adhesion, and fusing and may even become embedded in biominerals. However, very little evidence is available about MPs in biominerals found in the wild. This study detected the abundance and characteristics of MPs in the shells of farmed oysters (Crassostrea angulata) off the coast of Taiwan and discussed the distribution, accumulation, and diversity in the oyster shells. The results showed that MPs were ubiquitous in oyster shells, with an average abundance of 0.70 ± 0.40 MPs/g. MPs abundance was significantly (p < 0.01) higher in small oyster shells (shell length < 6.5 cm, weight 5–10 g) and inorganic (CaCO 3) fraction (HCl digestion) than in large oyster shells (>6.5 cm, 10–25 g) and an organic fraction (H 2 O 2 digestion), respectively. However, there was no significant difference in MPs abundance between the top and bottom shells (p > 0.05). MPs with a size <2 mm accounted for 78.5 %, fibrous MPs for 93.7 %, and rayon for 89.5 %. The MPs diversity integrated index (MPDII) in oyster shells was low (0.27), and the small and fibrous MPs seemed more easily embedded in biominerals. The findings confirm the presence of MPs in oyster shells in coastal environments. In addition, oyster shells may contain higher amounts of MPs than soft tissues 4–5 times, which needs to be confirmed. Further revealing the distribution and accumulation of MPs in water/terrestrial biominerals will help to understand the fate of MPs in the environment. • Microplastics are found in the shells of coastal-farmed oysters. • Small size (<2 mm) and fibrous MPs are more likely to embed in oyster shells. • Rayon is the main polymer type, followed by PET, cellophane, and PP. • There is low diversity of MPs in oyster shells. [ABSTRACT FROM AUTHOR]

The accumulation of pollutants in the semi-enclosed waters of ports has long been a concern. This study assessed the pollution status, sources, and toxicity risks of 16 polycyclic aromatic hydrocarbons (PAHs) in surface sediments of 7 major ports in Taiwan. Total PAHs concentrations in sediments ranged between 8.4 and 572.5 ng/g dw, with an average of 112.4 ± 136.5 ng/g dw. The 3- and 4-ring PAHs (63 %) were the major constituents of PAHs in the sediments. Diagnostic ratios and positive matrix factorization analyses indicated that PAHs in sediments were mainly contributed by biomass combustion (45.0 %), coal combustion (31.5 %), and vehicle emissions and related fossil fuels (23.5 %). The results of ecological risk assessment showed a low–medium risk of PAHs in the sediments outside the port, whereas most of the sediments within the port presented a medium–high risk. An assessment of the possible human health risks indicated that PAHs were present at acceptable levels. [Display omitted] • Significant accumulation of PAHs in sediments of commercial ports in Taiwan. • Biomass and coal combustion are the main sources of PAHs in sediments. • Coal-fired power plants near ports are a source of PAHs in sediments. • TEQ of PAHs in the port sediments may pose moderate–high ecological risk. [ABSTRACT FROM AUTHOR]