• Journal of the korean society of oceanography
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• 제39권1호
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• pp.14-19
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• 2004

Difference of Dissolved Inorganic Phosphorus (DIP), Dissolved Inorganic Nitrogen (DIN) and Dissolved Silicate (DSi) budgets in the Bohai Sea between 1982 and 1992 related the decrease of the Yellow River discharge is discussed on the basis of observed data. The estuarine circulation in the Bohai Sea had been weakened from 1982 to 1992 due to the decrease of the Yellow River discharge and the average residence time of fresh water had become longer. DIN concentration increased but DIP and DSi concentrations decreased from 1982 to 1992 in the Bohai Sea. Primary production was regulated mainly by water temperature and DIN concentration in 1982 but it was regulated mainly by DIP concentration in 1992. Primary production was larger than decomposition plus bottom release and nitrogen fixation was larger than denitrification in 1982. However, decomposition plus bottom release was larger than primary production and denitrification was larger than nitrogen fixation in 1992 in the Bohai Sea.

• Ocean Science Journal
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• 제42권4호
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• pp.199-209
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• 2007

Empirical band-ratio algorithms and artificial neural network techniques to retrieve sea surface chlorophyll concentrations were evaluated in the Bohai Sea of China by using an extensive field observation data set. Bohai Sea represents an example of optically complex case II waters with high concentrations of colored dissolved organic mattei (CDOM). The data set includes coincident measurements of radiometric quantities and chlorophyll a concentration (Chl), which were taken on 8 cruises between 2003 and 2005, The data covers a range of variability in Chl in surface waters from 0.3 to 6.5 mg $m^{-3}$. The comparison results showed that these empirical algorithms developed for case I and case II waters can not be applied directly to the Bohai Sea of china, because of significant biases. For example, the mean normalized bias (MNB) for OC4V4 product was 1.85 and the root mean square (RMS) error is 2.26.

• 한국환경보건학회:학술대회논문집
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• 한국환경보건학회 2001년도 Proceedings of the 3rd Annual Meeting of Yellow Sea Environment
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• pp.6-10
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• 2001

Distribution characteristics, variation patterns and affecting factors of hetorotrophic bacteria were studied from April to May 1999 in Bohai Sea by standard Acridine Orange epifluorescence microscopy (AO method). The biomass in surface waters showed a small day-night variation, varying from 0.13-2.51$\mu\textrm{m}$$.$dm$\^$-3/ with an average of 0.84 $\mu\textrm{m}$$.$dm$\^$-3/. The biomass in bottom waters showed, however, a large variation, changing from 0.15-4.18 $\mu\textrm{m}$$.$dm$\^$-3/ with an average of 1.36 $\mu\textrm{m}$$.$dm$\^$-3/. The peak values were obtained at 5 and 11 am. The bottom water biomass showed a significant correlation with particulate organic carbon (r=0.639, p<0.05). Heterotrophic bacteria showed high biomass in nearshore waters and low values in offshore areas with a high biomass zone around Yellow Sea river mouth, which was consistent with the distribution of nutrients. The vertical distribution of heterotrophic bacteria showed biomass in bottom waters was higher than in surface water. The biomass of heterotrophic bacteria in Bohai Sea was similar with that in other marine waters.

• 한국환경보건학회:학술대회논문집
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• 한국환경보건학회 2001년도 Proceedings of the 3rd Annual Meeting of Yellow Sea Environment
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• pp.19-29
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• 2001

Nutrients are key environmental factors in marine ecosystem. They limit algal growth when at low concentrations and cause algal bloom when at high contents. They also control the growth and succession of many other biota including bacteria and zooplankton, either directly or indirectly. Nutrient contents therefore affect both the structure and functions of marine ecosystem. To study the contents and distribution of nutrients in Chinese Bohai Sea, two cruise surveys were undertaken in August 2000 (summer) and January 2001 (winter), respectively. A total of 595 water samples were collected from 91 sites. After collection the samples were transported to the laboratory and five nutrients, i.e., nitrate, nitrite, ammonia, phosphate and silicate, were analyzed. The results showed that tile average concentration of total inorganic nitrogen (TIN) in Bohai Sea in winter (6.5293.717 ${\mu}$mol$.$l$\^$-1/) was significantly higher than that in summer (3.717 ${\mu}$mol$.$l$\^$-1/). The phosphorus concentration in winter (0.660 ${\mu}$mol$.$l$\^$-1/) was also significantly higher than that in summer (0.329 ${\mu}$mol$.$l$\^$-1/). Mean silicate concentration in winter (7.858 ${\mu}$mol$.$l$\^$-1/) was not significantly different from that in summer (7.200 ${\mu}$mol$.$l$\^$-1/). Nutrients also varied considerable among different areas within Bohai Sea. TIN concentration in Laizhou Bay (4.444 ${\mu}$mol$.$l$\^$-1/), for example, was significantly higher than those in Bohai Bay (2.270 ${\mu}$mol$.$l$\^$-1/) and Bohai Straight (2.431 ${\mu}$mol$.$l$\^$-1/), which probably reflects tile discharge of large amounts of nitrogen into Laizhou Bay via Yellow River. The nutrients also showed vertical distribution pattern. In summer, nutrients in bottom layer were generally higher than those in surface and medium layers. In winter, however. nutrients in different layers were not significantly different Compared with historic data, TIN contents increased continuously since early 1980s, phosphorus arid silicone contents, nevertheless, fell down to some degree. Based on atomic ratios of different nutrients, nitrogen is still the main limiting factor for algal growth in Bohai Sea.

• Journal of the korean society of oceanography
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• 제37권3호
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• pp.125-133
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• 2002

Water and salt budgets in the Yellow Sea and Bohai are analyzed based on the historical data and CTD data collected recently using box models. The amounts of volume transport and of water exchange across the boundary between the Yellow and East China Seas are estimated to be 2,330-2,840 $\textrm{km}^3$/yr and 109-133 $\textrm{km}^3$/yr, respectively, from the one-layer box model. Corresponding water residence time is 5-6 years. In the Bohai, water residence time is twice as long as that in the Yellow Sea, suggesting that the Yellow Sea and Bohai cannot be considered as a single system in the view of water and salt budgets. The results indicate that water and salt budgets in the Yellow Sea depend almost only on the water exchange between the Yellow and East China Seas. The computation with the coupled two-layer model shows that water residence time is slightly decreased to 4-5 years for the Yellow Sea. In order to reduce uncertainties for the budgeting results the amount of the discharge from the Changjiang that enters into the Yellow Sea, the vertical advection and vertical mixing fluxes across the layer interface have to be quantified. The decreasing trend of the annual Yellow River outflow is likely to result that water residence time is much longer than the current state, especially for the Bohai. The completion of the Three Gorges dam on the Changjiang may be change the water and salt budgets in the Yellow Sea. It is expected that cutting back the discharge from the Changjiang by 10% through the dam would increase water residence time by about 10%.

• Parasites, Hosts and Diseases
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• 제35권1호
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• pp.19-24
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• 1997

The infection status of anisakid larvae was examined in 290 marine fish of 25 species and in 108 cephalopods of 3 species purchased in Bayuquan region, Yingko city nearby the coast of the Bohai Sea from may to August 1992. A total of 7,327 laivae were collected from 156 fish of 19 species and 8 squids of one species. The 3rd-stage larvae of Anisokis simplex were collected from 121 fish (63..4%) of 15 species (N : 191) and from 8 squids (14.8%) of one species (N : %4), and they were total, 5,992 (81.8%). Out of remaining 1,335 larvae, 154 (2.1%) were classified as Rvnnqscnris type B from 23 fish of 4 species, 1,013 (13.8%) as avnnosccris type C from 79 fish of 13 species, 164 (2.2%) as Hvsterothylacium China type V from 20 fish of 4 species, 3 (0.04%) as Raphinoscnris from 3 fish of 2 species and one was Pseunotewonovc necipiens larva. Key words: Bohai Sea, Anisokinae, larvae , Anisckis, HvsterothWLacium, Thwnnascaris, Raphinqscaris , Pseudoterranova.

• Journal of Species Research
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• 제13권2호
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• pp.147-158
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• 2024

Four species of the free-living nematodes were collected from marine sediments in the sublittoral zone in the East Sea, Korea and were identified, described, and illustrated. Paranticoma tricerviseta Zhang, 2005, originally described from the Bohai Sea, China, is recorded for the first time in the East Sea, Korea; only in body length and thickness (1902-2282 ㎛ compared to 2472-3300 ㎛, 50-62 ㎛ compared to 57-82 ㎛, respectively). Specimens of Parodontophora marina Zhang, 1991, from East Sea, Korea largely agrees with the original description of Zhang (1991) of nematodes from the Bohai Sea, except for differences in body length and thickness (1190-1345 ㎛ compared to 1235-1408 ㎛, 40-44 ㎛ compared to 42-72 ㎛). Terschellingia longicaudata de Man, 1907 is reported for the first time in Korea, but was previously considered a cosmopolitan species of nematodes with a widespread distribution from the North Sea, Belgium to the Exclusive Economic Zone of New Zealand; it differs from the original description in body thickness(30-38 ㎛ vs. 40-62 ㎛). Vasostoma brevispicula Huang & Wu, 2011, originally described from the subtidal muddy sediment in the Yellow Sea, China, is newly reported in Korea; apart from a few minor morphological differences, body length and thickness (2009-2425 ㎛ vs. 2119-2906 ㎛, 41-48 ㎛ vs. 37-58 ㎛). The present study on unrecorded species improves our understanding of nematode species diversity in Korean waters.

• 한국환경독성학회:학술대회논문집
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• 한국환경독성학회 2004년도 Sharing Experience of Human and Ecological Risk Assessment and Management in Asia/Pacific Region
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• pp.63-64
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• 2004

• 한국전자통신학회논문지
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• 제11권3호
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• pp.325-330
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• 2016

해수면은 19세기 말부터 상승 추세에 있으며, 20세기 이후 상승률이 더욱 가속화되고 있다. 해수면 높이는 지역적인 차이가 크기 때문에 한반도 주변 해역을 대상으로 해수면 변동에 관하여 알아보고자 하였다. 사용된 자료는 해상도 $1/4^{\circ}$의 Topex/Poseidon, Jason-1, Jason-2 위성의 고도계 자료를 이용하였다. 1993년부터 2013년까지 21년간 월별 평균 해수면 아노말리는 1~4월은 음의 값을 보였으며, 5~10월까지 양의 값을 보였다. 중국 보하이만은 대륙성 기후의 영향을 받아 해수면 변동이 큰 것으로 나타났다. 21년 자료를 평균한 결과 중국 보하이만은 대륙성 기후 영향을 받는 것이 두드러지게 나타났으며, 쿠로시오 해류 및 와동류 영향을 받아 해수면 변동이 나타나는 것을 알 수 있었다.

• 산업진흥연구
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• 제8권4호
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• pp.267-276
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• 2023

본 연구는 2015~2021년 중국 환 발해만지역의 5개 성 및 도시의 관광 투입 및 생산 데이터를 기반으로 DEA-BCC와 DEA-Malmquist 지수를 사용하여 지역의 관광 효율성을 분석하고 지역경제 효율성에 기여하고 종합적인 효율성에 영향을 미치는 요인을 찾는다. 연구 결과에 따르면 이 지역의 종합 관광 효율성은 최고 수준인 88.9%에 도달했지만 여전히 일정한 발전 여지가 있으며 일반적으로 상하파동 모멘텀을 나타낸다. 관광의 전요소생산성은 전체적으로 'u'자 변동형 증가 상태이며 성장은 주로 기술 진보 변화의 기여에 기인하며 코로나19의 영향으로 2019~2020년 중국 환 발해만 지역의 전요소생산성은 거의 50% 감소하여 그러나 2021년 중국 정부의 각종 부양책 발표로 관광 효율성이 코로나19 이전 80%로 빠르게 회복되었다. 중국 환 발해만 관광업이 지역 경제에 미치는 영향의 결과로 볼 때 하북성은 특히 북경-천진-하북성 공동 개발 전략의 결과인 지역 경제에 상당한 기여를 했다. 위의 연구 결과를 바탕으로 지역 관광의 효율성을 높이고 지역 조화로운 발전을 촉진하기 위해 공급 구조를 최적화하고 혁신에 대한 투자를 늘리며 내부 협력을 강화하는 세가지 측면에서 제안을 제시한다.