Suchergebnisse

Abstract
The global contamination with persistent organic pollutants (POPs), or compounds with similar characteristics, is well known. Still there are data gaps for POP concentrations from many areas in the world. The aim of the present study is to assess several legacies POPs and also hexabromocyclododecane (HBCDD) and methoxylated polybrominated diphenyl ethers (MeO-PBDEs) in shellfish from three locations in the Yellow Sea and East China Sea. The sources of the contaminants are discussed. Pooled samples were treated by liquid-liquid extraction and acid and column cleanup prior to analysis by gas chromatogram equipped with electron capture detector (GC-ECD) and gas chromatography-mass spectrometry (GC-MS). The by far most abundant environmental contaminant originates from dichlorodiphenyltrichloroethane (DDT), independent of species analyzed or sampling site. The results indicate ongoing or at least recent discharges of DDT. The second highest concentrations were reported for HBCDD (21–40 ng/g fat) in the shellfish, independent of sampling sites. The two natural products, 6-MeO-BDE-47 and 2′-MeO-BDE-68, were also present in the shellfish (1.3–22 and 1–14 ng/g fat, respectively). The polychlorinated biphenyl (PCB) congener CB-153 (0.8–6.5 ng/g fat), hexachlorobenzene (HCB) (1.1–3.6 ng/g fat), and β-hexachlorocyclohexane (β-HCH) (2.3–4.9 ng/g fat) were all higher than the concentrations of other HCH isomers, β-endosulfan, PBDE congeners, and mirex. Apart from the DDTs and HBCDDs, it is evident that the pollution of shellfish was similar to, or lower than, the contamination of shellfish in other parts of the world.

The China-ROK boundary disputes in the Yellow Sea and the associated fishing conflict are often neglected in the rich body of literature on China's maritime disputes. This article examines the question of why and how China has persistently pursued a de-escalatory posture in the Yellow Sea in the past decade despite having considerably hardened its posture in the East and South China Seas. I argue that the high stakes China has in its bilateral ties with South Korea create strong incentives for Beijing to deescalate maritime controversies whereas the absence of broad-based hawkish pressure at home creates a permissive domestic political climate for Beijing to pursue de-escalation. This paper also evaluates conditions that may facilitate a hardening Chinese position. (J Contemp China / GIGA)

While comparatively few amphibian species have been described on the North East Asian mainland in the last decades, several species have been the subject of taxonomical debates in relation to the Yellow sea. Here, we sampledDryophytessp. treefrogs from the Republic of Korea, the Democratic People's Republic of Korea and the People's Republic of China to clarify the status of this clade around the Yellow sea and determine the impact of sea level change on treefrogs' phylogenetic relationships. Based on genetics, call properties, adult morphology, tadpole morphology and niche modelling, we determined the segregated status species ofD.suweonensisandD.immaculatus. We then proceeded to describe a new treefrog species,D.flaviventrissp. nov., from the central lowlands of the Republic of Korea. The new species is geographically segregated fromD.suweonensisby the Chilgap mountain range and known to occur only in the area of Buyeo, Nonsan and Iksan in the Republic of Korea. While the Yellow sea is the principal element to the current isolation of the three clades, the paleorivers of the Yellow sea basin are likely to have been the major factor for the divergences within this clade. We recommend conducting rapid conservation assessments as these species are present on very narrow and declining ranges. ; Conservation Research grant from The Biodiversity Foundation; National Research Foundation of KoreaNational Research Foundation of Korea [2017R1A2B2003579]; National Institute of Biological Resources (NIBR) - Ministry of Environment (MOE) of the Republic of Korea [NIBR201803101] ; This work was supported by a Conservation Research grant from The Biodiversity Foundation to AB, a research grant from the National Research Foundation of Korea (2017R1A2B2003579) to YJ, and by a grant from the National Institute of Biological Resources (NIBR), funded by the Ministry of Environment (MOE) of the Republic of Korea (NIBR201803101) to MSM and TK.

Abstract. This study examined the occurrence of meteotsunamis in
the eastern Yellow Sea and the conceptual framework of a monitoring/warning
system. Using 1 min intervals of mean-sea-level pressure and sea-level
observations from 89 meteorological stations and 16 tide gauges between 2010
and 2019, a total of 42 pressure-forced meteotsunami events were classified.
Most meteotsunamis (71 %) displayed a distinct seasonal pattern occurring
from March to June, and intense meteotsunamis typically occurred at harbor
tide gauges. The occurrence characteristics of the meteotsunamis were
examined to improve the meteotsunami monitoring/warning system. Air pressure
disturbances with speeds of 11–26 m s−1 and NNW–SW directions were conducive to meteotsunami generation. Most meteotsunamis (88 %), as well as strong
meteotsunamis with a wave height exceeding 40 cm (19 %), had dominant
period bands of less than 30 min, containing the resonant periods of harbors
in the eastern Yellow Sea. Thus, the eastern Yellow Sea is a harbor-meteotsunami-dominated environment, characterized by frequent meteotsunami
occurrences and local amplification in multiple harbors. This study can
provide practical guidance on operation periods, potential hot spots, and
risk levels to monitoring/warning system operators in the eastern Yellow
Sea.