Investigating the levels, spatial distribution, and trophic transfer patterns of short-chain chlorinated paraffins in the Southern Bohai Sea, China.

The marine environment of the southern Bohai Sea is severely polluted by short-chain chlorinated paraffins (SCCPs). To improve understanding of how SCCPs occur and of how they migrate, are transformed, and transferred in this area, we collected seawater, sediment, and organism samples, and determined the SCCP contents using a new approach based on high-resolution mass spectrometry. The ΣSCCP concentrations in the seawater, sediment, and organism samples ranged from 57.5 to 1150.4 ng/L, 167.7-1105.9 ng/g (dry weight), and 11.4-583.0 ng/g (wet weight), respectively. Simulation of the spatial distribution of SCCPs using Kriging interpolation showed that SCCPs were markedly influenced by land-based pollution. Substantial quantities of SCCPs were transported to the marine environment via surface runoff from rivers that passed through areas of major SCCP production. Once discharged from such rivers into the Bohai Sea, these SCCPs were further dispersed under the influence of ocean currents. Furthermore, the logarithmic bioaccumulation factor that varied from 2.12 to 3.20 and the trophic magnification factor that reached 5.60 (r2 = 0.750, p < 0.01) suggest that organisms have the ability to accumulate and biomagnify SCCPs through the food chain, which could potentially present risks to both marine ecosystems and human health.

Metabolomic Alterations in the Digestive System of the Mantis Shrimp Oratosquilla oratoria Following Short-Term Exposure to Cadmium.

Mantis shrimp Oratosquilla oratoria is an economically critical aquatic species along the coast of China but strongly accumulates marine pollutant cadmium (Cd) in its digestive system. It is necessary to characterize the toxicity of Cd in the digestive system of mantis shrimp. The metabolic process is an essential target of Cd toxicity response. In this work, we used ultra-performance liquid chromatography coupled with time-of-flight mass spectrometry (UPLC-TOF-MS) for untargeted metabolomics to characterize the metabolic changes in the digestive system of O. oratoria, exposed to 0.05 mg/L for 96 h. The aim of this study was to further investigate the effect of O. oratoria on Cd response to toxicity and develop biomarkers. Metabolomics analysis showed the alteration of metabolism in the digestive system of mantis shrimp under Cd stress. A total of 91 metabolites were differentially expressed and their main functions were classified into amino acids, phospholipids, and fatty acid esters. The enrichment results of differential metabolite functional pathways showed that biological processes such as amino acid metabolism, transmembrane transport, energy metabolism, and signal transduction are significantly affected. Based on the above results, the Cd-induced oxidative stress and energy metabolism disorders were characterized by the differential expression of amino acids and ADP in mantis shrimp, while the interference of transmembrane transport and signal transduction was due to the differential expression of phospholipids. Overall, this work initially discussed the toxicological response of Cd stress to O. oratoria from the metabolic level and provided new insights into the mechanism.

Environmental status and early warning value of the pollutant Semicarbazide in Jincheng and Sishili Bays, Shandong Peninsula, China.

A verified method for measuring Semicarbazide (SEM) in seawater, sediments, and shellfish was developed based on ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). A total of 30 stations were radially distributed in Jincheng and Sishili Bays in the Bohai and Yellow Seas, and 1025 monitoring data were collected in 41 voyages, 615 seawater samples, 320 sediment samples and 90 shellfish samples. The concentration ranged from 0.011µg/L to 0.093µg/L and 0 to 0.75µg/kg in seawater and shellfish respectively, but SEM in sediment was all below the limit of detection. Temporal and spatial distribution of SEM was investigated using multivariate analysis to estimate the degree of SEM pollution. Based on the SEM concentration in the three sample types, together with our previous findings, early warning values were deduced for SEM in seawater, and the developed method overcame shortcomings with existing technologies. The results may be helpful to draft national baseline values for SEM in seawater and sediments, and provide a scientific basis for assessing the impacts of SEM on marine ecology and human health.