DOCSLIB.ORG

Foraminiferal Faunal Trends and Assemblages of the Bohai Sea, Huanghai Sea and East China Sea

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Foraminiferal Faunal Trends and Assemblages of the Bohai Sea, Huanghai Sea and East China Sea BULLETIN OF MARINE SCIENCE. 47(1:): 192-212. 1990 FORAMINIFERAL FAUNAL TRENDS AND ASSEMBLAGES OF THE BOHAI SEA, HUANGHAI SEA AND EAST CHINA SEA Shouyi Zheng ABSTRACT Qualitative and quantitative studies of Recent foraminifera of the Bohai, Huanghai, and East China Seas gave distributional data on: faunal composition; dominant indicator species (including species occurring in high to low numbers); species diversity; faunal dominance; absolute abundance; percentage composition of agglutinated, porcelaneous and hyaline tests; planktonic/benthonic (P/B) foraminiferal ratio; and others. Correlation offaunal trends with known environmental parameters such as salinity, temperature, prevailing current and water mass systems, substrate, CaCO, content of sediment, and more allowed establishment of foraminiferal assemblages useful for ecological and paleoecological interpretations. Based on marked changes in frequency composition among dominant benthic species, six benthonic assemblages were recognized in the Bohai Sea, three in the northern Huanghai Sea, five in the southern Huanghai Sea, and nine in the East China Sea. In addition, four planktonic assemblages characterized the East China Sea and southern Huanghai Sea. The small size, great abundance and wide distribution of their preservable tests in Recent and fossil sediments, together with their usefulness as environmental indicators, has resulted in more comprehensive study of foraminifera than most other marine protozoa. Their sensitivity to environmental changes is reflected in various specific and non-specific distributional trends. The cumulative occurrence of their preservable tests on the sea floor mirrors not only small-scale temporal and spatial features, but also long-term average environmental and taphonomic processes. PHYSIOGRAPHY AND HYDROGRAPHY OF THE AREA STUDIED The three seas under study for their foraminiferal trends cover a range of 15 degrees of latitude (Fig. 1). Each sea has its distinctive set of physical and hydrological characteristics which control the distribution of the foraminifera. The East China Sea, averaging 370 m in depth, ranges from a few meters to 2,719 m. It is largely influenced by the warm, saline Kuroshio Current and its branches, the Taiwan Warm Current, the Tsushima Warm Current, and the Huanghai Warm Current (Fig. I). It has an average surface water temperature of 28°C in summer and II-21°C in winter. The average surface salinity is 300/00at the Changjiang River mouth and 34.50/00in the main Kuroshio area in the southeastern part of the sea. The southern Huanghai Sea ranges in depth from a few meters to 103 m, averaging 46 m. The average surface and bottom temperatures are 25-27°C in summer, and 5-lQoC in winter, with salinities of 31-340/00.It is influenced by the cold Huanghai Sea Coastal Current and the Huanghai Sea Cold Water Mass. The northern Huanghai Sea ranges in depth from a few meters to 70 m. Average surface to bottom winter temperatures are 0-5°C; summer temperatures are 25-27°C. Salinity averages 31- 320/00. The Bohai Sea ranges in depth from a few meters to 70 m, averaging 18 m. Three bays surround its central basin. Its yearly average salinity is 300/00.The average surface temperature is 22-28OC, largely influenced by its surrounding continental climate. According to Backus' (1986) map of world biogeographic regions, the East China Sea falls into the northern subtropical region, the southern Huanghai Sea into the northern subtropical to northern temperate regions, and the northern Huanghai Sea and Bohai Sea into the northern temperate bio- geographic region. Previous works wholly or partly touching on the foraminifera of these seas include those of Jacot (1952); Bezrukov et aI. (1958); Polski (1959); Waller and Polski (1959); Cheng and Cheng (1960, 1962, 1963); Zheng, Zheng and Fu (1979); Stschedrina and Lukina (1984); Wang et a1.(1984); Zheng (1988). 192 ZHENG: FORAMINIFERAL TRENDS OF CHINA SEAS 193 Figure 1. Distribution of current systems (after Guan, 1983), Huanghai Sea Cold Water Mass (after He et aI., 1959), Changjiang Diluted Water (after Le, 1980). MATERIALS AND METHODS Study materials were foraminiferal tests from more than 500 surface sediment grab samples collected over a 30-year period from longitudes 118°00-120"00'E and latitudes 26°28'-41°00'N. Collection depths ranged from a few meters to over 2,000 m (Fig. 2). The samples represent great environmental variability; they were collected from semi-enclosed bays, river mouths, vast expanses of continental shelf, and bathyal depths. A unit weight of 50 g of dried sediment was used for quantitative analysis. The samples were washed on a 150 Ilm-opening screen. Foraminifera were floated with carbon tetrachloride (sp. gr. 1.59). Floated concentrates were weighed by torsion balance to obtain total weights per 50 g of sediment. Specimen 194 BULLIETIN OF MARINE SCIENCE, VOL. 47, NO. I, 1990 N Hebel Sh8ndong o Jjongsu JOU .JUU IhoJlang 2U· o ruJ'.n 26° lIU· 120· 122· Figure 2. Location of samples .and Traverses I-III. Isobaths based on the depths of stations where samples were collected. ZHENG: FORAMINIFERAL TRENDS OF CHINA SEAS 195 count for rich concentrates were either of an aliquot or a portion sufficient to demonstrate dominant species and great decline in addition of minor species. The uncounted portion was weighed to obtain the counted portion's weight for calculating total test number per 50 g. The residue was examined for unftoated tests; these were also counted and included in the total test numbers. Benthonic and plank- tonic foraminifera were counted and analyzed separately. Faunal analysis included the determination of specific faunal trends such as taxonomic composition, areal and depth distribution of dominant species (e.g., those species relatively abundant within their samples but ranging in absolute abundance from high to low). It also included determination of non- specific faunal trends such as distribution of absolute abundance, species diversity using the simple diversity index S (Gibson and Buzas, 1973), the Shannon-Wiener index H(S) (Gibson and Buzas, 1973), the faunal variability index V (Walton, 1964), the Buzas-Gibson equitability index D (Buzas and Gibson, 1969), the faunal dominance index D (Walton, 1964), the proportion of shell types (agglutinated, porcelaneous, and hyaline tests), and the ratio of planktonic to benthonic (P/B) foraminif- era (Tipsword et aI., 1966). The five most abundant species in a sample were given decreasing dom- inance ranks of 5,4,3, 2, and I, respectively. Adding the ranks for all occurrences of rank 5-1 species gives the species' total dominance rating for the area where it is dominant (Zheng and Fu, 1988). Thus, species which are dominant (and have environmental significance) are considered, no matter whether their absolute abundances are high, intermediate or low (Table I). ANALYSIS OF DISTRIBUTION Parameters Considered for Benthonic Foraminifera Taxonomic Composition. - A sudden appearance, disappearance or a radical change in abundance of an abundant organism along a transect is usually indicative of a change in environmental conditions (presence of a boundary, Backus, 1986). In this study, results show that ranking changes among the 10 most abundant species define broad geographic differences in environmental regimes. While different regions have dominant species common to each other, each region has its own characteristic taxonomic composition (Tables 1, 2). A north to south transect at longitude 123°30'E, extending from 39°23'N in the northern Huanghai Sea to 26°30' in the East China Sea (Fig. 2), clearly shows increasing change in taxonomic composition with latitude (Table 2). Changes in taxonomic composition across physically generated environmental gradients are clearly evident in a southern transect (Fig. 3) at latitude 27°N, covering longitudes 121-127°E, cutting across the shelf to a depth of 1,300 m. The most marked change occurs at Stn. £196 in the bathyal region where the five most abundant species (Cribrostomoides crassimargo (Norman), Cyclammina pusilla Brady, Tro- chammina globigeriniformis (Parker and Jones), Cribrostomoides subglobosa (G. O. Sars), and Globocassidulina subglobosa (Brady)) differ entirely from those of the preceding station El94 on the slope (Heterolepa cushmani (Ujiie and Kusu- kawa), Spirorutilis fistulosa (Brady), Cribrobigenerina textularioidea (Goes), Len- ticulina calcar (Linne), and Fontbotia wuellerstorfi (Schwager)). Dominant and Indicator Species. - Distributional patterns of many benthonic foraminifera are controlled by and/or correlated positively with the variables that characterize different water masses and which may fluctuate in space and time (Van Morkhoven et aI., 1986). Species, however, have upper depth limits con- strained by biology that may make them useful as depth zone indicators. For example, Rotalinoides gaimardii (d'Orbigny) is the most abundant species in almost all middle to outer shelf samples in the East China Sea. Its relative abun- dance decreases northward, and in the shallower water of the northwestern Huang- hai Sea and the Bohai Sea it is not within the five most dominant species (Table 3). Thus it appears characteristic of middle to outer shelf conditions (though other variables associated with more northerly and inshore locations may playa role). Arenoparrella asiatica (Polski), on the other hand, is very abundant in shallow, nearshore areas (<50 m depth) throughout the area of investigation and may rank 196 BULLETIN OF MARINE SCIENCE,
Load more

Recommended publications
  • Regional Climatology East Asian Seas: an Introduction
    NOAA Atlas NESDIS 79 doi:10.7289/V5D21VM9 REGIONAL CLIMATOLOGY OF THE EAST ASIAN SEAS: AN INTRODUCTION National Centers for Environmental Information Silver Spring, Maryland December 2015 U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Environmental Satellite, Data, and Information Service National Centers for Environmental Information Additional copies of this publication, as well as information about National Centers for Environmental Information (formerly the National Oceanographic Data Center) data holdings and services, are available upon request directly from the National Centers for Environmental Information. National Centers for Environmental Information User Services Team NOAA/NESDIS/NCEI SSMC III, 4th floor 1315 East-West Highway Silver Spring, MD 20910-3282 Telephone: (301) 713-3277 E-mail: [email protected] NCEI Oceans Home Page: http://www.ncei.noaa.gov/ This document should be cited as: Johnson, D.R., Boyer, T.P., 2015: Regional Climatology of the East Asian Seas: An Introduction. NOAA Atlas NESDIS 79, Silver Spring, MD, 37 pp. doi:10.7289/V5D21VM9. This document is available at http://data.nodc.noaa.gov/woa/REGCLIM/EAS/DOC/nesdis79-doi107289V5D21VM9.pdf. Editor: Dan Seidov, National Centers for Environmental Information Technical Editor: Alexey Mishonov, National Centers for Environmental Information NOAA Atlas NESDIS 79 doi:10.7289/V5D21VM9 REGIONAL CLIMATOLOGY OF THE EAST ASIAN SEAS: AN INTRODUCTION Daphne R. Johnson and Tim P. Boyer National Centers for Environmental Information Silver Spring, Maryland December 2015 U.S. DEPARTMENT OF COMMERCE Penny Pritzker, Secretary National Oceanic and Atmospheric Administration Kathryn Sullivan Under Secretary of Commerce for Oceans and Atmosphere and NOAA Administrator National Environmental Satellite, Data, and Information Service Stephen Volz, Assistant Administrator This page intentionally left blank Table of Contents ABSTRACT ......................................................................................................................................
    [Show full text]
  • China and the Law of the Sea: an Update
    IV China and the Law of the Sea: An Update Guifang Xue* Introduction his article examines the practice of the People's Republic of China with re­ Tspect to the 1982 United Nations Convention on the Law of the Sea {1982 LOS Convention),l Two principal areas will be assessed: China's efforts to accom­ modate the challenges of the Convention to its ocean domain as a coastal State and its major maritime legislation to implement the Convention regime. The analysis begins with a brief introduction of China's maritime features and a review of its basic stance toward the Convention. This is followed by a discussion of the major challenges China encountered while establishing its ocean domain based on the Convention regime. China's efforts in implementing the 1982 LOS Convention through national legislation are examined to assess the consistency of that statu­ tory framework with Convention requirements. Finally, conclusions are drawn from China's law of the sea practice. It is shown that China, fo r its part, has been accelerating domestic procedures with a view to enabling it to comply with Con­ vention requi rements. However, China's maritime practice has not been wholly consistent with Convention provisions. At the same time, China's oceans policy adjustments indicate a move away from its previous position as solely a coastal .. Direaor and Professor, Institute for the Law of the $ea, Ocean University of China . The views expressed herein are solely those of the author and do not necessarily reflect those of the government of the People's Republic of China Part of this article is built on the author's previous work entitled China and International Fisheries Law and Policy, published by Martinus NijhoffPublishers in 2005.
    [Show full text]
  • Bohai-Sea-Sustainable-Development
    BOHAI SEA SUSTAINABLE DEVELOPMENT S TRATEGY BOHAI SEA SUSTAINABLE DEVELOPMENT STRATEGY STATE OCEANIC ADMINISTRATION 1 BOHAI SEA SUSTAINABLE DEVELOPMENT S TRATEGY BOHAI SEA SUSTAINABLE DEVELOPMENT STRATEGY STATE OCEANIC ADMINISTRATION 1 BOHAI SEA SUSTAINABLE DEVELOPMENT S TRATEGY 2 BOHAI SEA SUSTAINABLE DEVELOPMENT S TRATEGY TABLE OF CONTENTS List of Acronyms and Abbreviations . iv List of Tables . v List of Figures . v Preface . vi x Acknowledgements . vii xx Foreword . 1 1 Overview of Bohai Sea . 9 The Value of Bohai Sea . 15 15 Threats and Impacts . 25 25 Our Response . 33 33 Principles and Basis of the Strategy . .41 41 The Strategies . .47 47 Communicate . 49 49 Preserve . 53 53 Protect . 57 57 Sustain . 63 63 Develop . 66 66 Executing the Strategy . 75 75 References . 79 79 iii3 BOHAI SEA SUSTAINABLE DEVELOPMENT S TRATEGY LIST OF A CRONYMS AND A BBREVIATIONS BSAP – Blue Sea Action Plan BSCMP – Bohai Sea Comprehensive Management Program BSEMP – Bohai Sea Environmental Management Project BS-SDS – Bohai Sea – Sustainable Development Strategy CNOOC – China National Offshore Oil Corp. CPUE – catch per unit of effort GDP – Gross Domestic Product GIS – Geographic Information System GPS – Global Positioning System ICM – Integrated Coastal Management MOA – Ministry of Agriculture MOCT – Ministry of Communication and Transportation PEMSEA – GEF/UNDP/IMO Regional Programme on Partnerships in Environmental Management for the Seas of East Asia RS – Remote sensing SEPA – State Environmental Protection Administration SOA – State Oceanic Administration iv4 BOHAI SEA SUSTAINABLE DEVELOPMENT S TRATEGY LIST OF TABLES Table 1. Population Growth in the Bohai Sea Region (Millions) . 11 Table 2. Population Density of the Bohai Sea Region and Its Coastal Areas .
    [Show full text]
  • Characteristics of the Bohai Sea Oil Spill and Its Impact on the Bohai Sea Ecosystem
    Article SPECIAL TOPIC: Change of Biodiversity Patterns in Coastal Zone July 2013 Vol.58 No.19: 22762281 doi: 10.1007/s11434-012-5355-0 SPECIAL TOPICS: Characteristics of the Bohai Sea oil spill and its impact on the Bohai Sea ecosystem GUO Jie1,2,3*, LIU Xin1,2,3 & XIE Qiang4,5 1 Key Laboratory of Coastal Zone Environmental Processes, Chinese Academy of Sciences, Yantai 264003, China; 2 Shandong Provincial Key Laboratory of Coastal Zone Environmental Processes, Yantai 264003, China; 3 Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003, China; 4 State Key Laboratory of Tropical Oceanography, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; 5 Sanya Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya 572000, China Received April 26, 2012; accepted June 11, 2012; published online July 16, 2012 In this paper, ENVISAT ASAR data and the Estuary, Coastal and Ocean Model was used to analyze and compare characteristics of the Bohai Sea oil spill. The oil slicks have spread from the point of the oil spill to the east and north-western Bohai Sea. We make a comparison between the changes caused by the oil spill on the chlorophyll concentration and the sea surface temperature using MODIS data, which can be used to analyze the effect of the oil spill on the Bohai Sea ecosystem. We found that the Bohai Sea oil spill caused abnormal chlorophyll concentration distributions and red tide nearby area of oil spill. ENVISAT ASAR, MODIS, oil spill, chlorophyll, sea surface temperature Citation: Guo J, Liu X, Xie Q.
    [Show full text]
  • Low Ph and Carbonate Saturation State of Aragonite in China Seas: Variations and Controls
    Low pH and carbonate saturation state of aragonite in China Seas: variations and controls Juying Wang, Weidong Zhai, Nan Zhen, Jingli Mu, Xuemei Xu and other contributors National Marine Environmental Monitoring Center, SOA, CHINA June 17, 2013 OUTLINE • Background of OA • Coastal acidification and case studies in China; • Chinese activities at national scale; Ocean Acidification: Global Warming’s Twin The burning of fossil fuels result in increased CO 2 in the atmosphere being taken up by the ocean resulting in it becoming more acidic. Source: Laffoley et.al. 2010. Ocean Acidification: Questions Answered. Oceans are acidifying fast Changes in oceanic pH over the last 25 million years Source after Turley et al. in Avoiding Dangerous Climate Change (2006). pH Time (millions of years before present) Source: Laffoley et.al. 2010. Ocean Acidification: Questions Answered. Changes in surface oceanic pCO2 (in matm) and pH from time series stations Source: IPCC, 2007 Ocean Acidification Impacts Stein, 2009 Decrease in pH 0.1 over the last two centuries 30% increase in acidity; decrease in carbonate ion of about 16% These changes in pH and carbonate chemistry may have serious impacts on open ocean and coastal marine ecosystems. Hall-Spencer, Nature, June 18, 2008 What we know about the ocean chemistry of …saturation state 2− − CO2 + CO3 + H2O ⇔ 2HCO3 Stein, 2009; Feely 2009 Saturation State []2+ []2− Ω Ca CO 3 phase = Aragonite * Ksp ,phase 2+ + 2−→ Ca CO3 CaCO3(s) Ω >1= precipitation Ω = = calcium carbonate calcium 1 equilibrium calcium carbonate calcium Ω < = carbonate 1 dissolution Calcite marine calcifying organisms may require much higher Ω for optimal growth Saturation State []2+ []2− Ω Ca CO 3 phase = * Ksp ,phase Natural processes that could accelerate the ocean acidification of coastal waters Local Oceanography: coastal upwelling Metabolism Processes Regional Environ.
    [Show full text]
  • Yellow Sea East China Sea
    Yellow Sea East China Sea [59] 86587_p059_078.indd 59 1/19/05 9:18:41 PM highlights ■ The Yellow Sea / East China Sea show strong infl uence of various human activities such as fi shing, mariculture, waste discharge, dumping, and habitat destruction. ■ There is strong evidence of a gradual long-term increase in the sea surface temperature since the early 1900s. ■ Given the variety of forcing factors, complicated changes in the ecosystem are anticipated. ■ Rapid change and large fl uctuations in species composition and abundance in the major fi shery have occurred. Ocean and Climate Changes [60] 86587_p059_078.indd 60 1/19/05 9:18:48 PM background The Yellow Sea and East China Sea are epi-continental seas bounded by the Korean Peninsula, mainland China, Taiwan, and the Japanese islands of Ryukyu and Kyushu. The shelf region shallower than 200m occupies more The coasts of the Yellow Sea have diverse habitats due than 70% of the entire Yellow Sea and the East China Sea. to jagged coastlines and the many islands scattered The Yellow Sea is a shallow basin with a mean depth around the shallow sea. Intertidal fl at is the most of 44 m. Its area is about 404,000 km2 if the Bohai signifi cant coastal habitat. The tidal fl at in the Yellow Sea in the north is excluded. A trough with a maximum Sea consists of several different types such as mudfl at depth of 103 m lies in the center. Water exchange is with salt marsh, sand fl at with gravel beach, sand dune slow and residence time is estimated to be 5-6 years.37 or eelgrass bed, and mixed fl at.
    [Show full text]
  • Changing States of the Yellow Sea Large Marine Ecosystem: Anthropogenic Forcing and Climate Impacts
    Changing States of the Yellow Sea Large Marine Ecosystem: Anthropogenic Forcing and Climate Impacts Qisheng Tang Yellow Sea Fisheries Research Institute Qingdao, China The Yellow Sea Large Marine Ecosystem is a semi-enclosed shelf sea with distinctive bathymetry, hydrography, productivity, and trophically dependent populations. Shallow but rich in nutrients and resources, the Yellow Sea LME has productive and varied coastal, offshore, and transboundary fisheries. Over the past several decades, the resource populations in the Yellow Sea have changed greatly. Many valuable resources are threatened by unsustainable exploitation and by natural perturbations. To promote sustainable exploitation of the sea and implement effective management strategies is an important and urgent task. The purpose of this chapter is to describe the Yellow Sea LME, emphasizing the changing states of productivity and biomass yields in the ecosystem and their causes, affected by both anthropogenic forcing and climate impacts. Suggestions for adaptation actions for ecosystem-based management in the LME are discussed in the final section. The Setting The Yellow Sea LME is located between continental North China and the Korean Peninsula. It is separated from the West Pacific Ocean by the East China Sea in the south, and is linked with the Bohai Sea, an arm of the Yellow Sea in the north. It covers an area of about 400,000 km2, with a mean depth of 44m. Most of the Sea is shallower than 80m. The central part of the sea, traditionally called the Yellow Sea Basin, ranges in depth from 70m to a maximum of 140m. The general circulation of the Yellow Sea LME is a basin-wide cyclonic gyre comprised of the Yellow Sea Coastal Current and the Yellow Sea Warm Current.
    [Show full text]
  • Identification and Hydrocarbon Expulsion History Simulation of the Effective Source Rocks in the Dongying Formation, Paleogene, Bohai Sea Area, Eastern China
    Revista Mexicana de CienciasHydrocarbon Geológicas, expulsion, v. 30, núm. Dongying 2, 2013, Formation,p. 355-370 Bohai Sea area, eastern China 355 Identification and hydrocarbon expulsion history simulation of the effective source rocks in the Dongying Formation, Paleogene, Bohai Sea area, eastern China Fujie Jiang1,2,*, Xiongqi Pang1,2, Jigang Guo1,2, Xinhuai Zhou3, Xiaohui Zhou4, Dandan Liu3, and Pengwei Wang1,2 1State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum, Beijing 102249, China. 2Basin and Reservoir Research Center, China University of Petroleum, Beijing 102249, China. 3Tianjin Branch of CNOOC China Limited, Tianjin 300452, China. 4Sinopec Geophysical Research Institute, Nanjing in Jiangsu Province 210014, China. * [email protected] ABSTRACT This paper discusses a new method for identification and simulation of the hydrocarbon expulsion history of Effective Source Rocks (ESR) in the Dongying Formation (E3d), Bohai sea area, Bohai Bay basin, eastern China. This new method enables us to reliably identify the distribution and quantitatively determine the hydrocarbon expulsion history of ESR in petroliferous basins. ESR are the material basis for hydrocarbon accumulation, having important implications for oil and gas exploration prospects. The Bohai Bay basin is one of the most petroliferous basins in China, with nearly one third of the total oil production of the country. However, insufficient research on the ESR in the Dongying Formation (E3d), Bohai sea area, Bohai Bay basin obstructs further exploration. In this paper, ESR of E3d are identified with the new “two-stage and three-step” method, and their planar distribution is predicted by combining well data with sedimentary facies, and structure distribution.
    [Show full text]
  • World Bank Document
    Updated Project Information Document (PID) Report No: AB454 Public Disclosure Authorized Project Name CHINA - Hai Basin Integrated Water and Environment Management Project Region East Asia and Pacific Region Sector General water, sanitation and flood protection sector (50%); Irrigation and drainage (50%) Theme Water resource management (P); Enviromnental policies and institutions (P); Pollution management and environmental health (P) Project P075035 Borrower(s) PEOPLE'S REPUBLIC OF CHINA Implementing Agency(ies) MOF, MWR, SEPA, BEIJING & TIANJIN MUNICIPALITIES & HEBEI PRO Ministry of Water Resources State Environmental Protection Agency Municipalities of Beijing and Tianjin Province of Hebei Address: Ministry of Water Resources, Baiguang Road, Beijing, China Public Disclosure Authorized Contact Person: Mr. Liu Bin - MWR and Ms. Li Pei -SEPA Tel: (8610) 6320-2127 - MWR; (8610) 6615-3366 - SEPA Fax: (8610) 6320-2027 - MWR; (8610) 6615-1932 - SEPA Email: [email protected] Environment Category C (Not Required) Date PID Prepared November 7, 2003 Auth Appr/Negs Date September 10, 2003 Bank Approval Date April 15, 2004 1. Country and Sector Background The Bohai Sea, located in the northwest corner of the Yellow Sea, is one of the world's ecologically imnportant, and stressed, bodies of water. The fishery resources are important to China, Japan, and North and South Korea. More than 40 rivers discharge into the Bohai Sea, of which the Yellow (Huang), Hai, and Liao rivers are the most significant. From an ecological perspective, the Bohai Sea is a large, shallow Public Disclosure Authorized embayment of the Yellow Sea. The Yellow Sea, in turn, is a shallow continental sea of the northwest Pacific Ocean.
    [Show full text]
  • Introduction Key Features of New Region Mask Example: Beaufort
    A new regional mask for Arctic sea ice trends and climatologies Walter N. Meier and J. Scott Stewart [email protected] New 2021 Arctic region mask History of old region masks Introduction Sea of Overall, Arctic sea ice is declining and Antarctic sea ice has a Bohai Japan Sea Original NASA Goddard mask near-zero trend over the past 40+ years. However, there are Pacific Ocean China • Derived in mid-1980s by 1987 distinct regional variations in these trends. Regional masks were researchers at NASA Goddard developed to investigate these trends, but the masks were created • Modified in mid-1990s in a non-rigorous fashion for defined grids at low spatial resolution; Sea of • Derived on 25 km polar and there are inconsistencies in masks, even within products at Okhotsk stereographic grid NSIDC. Here we present an improved, more accurate regional • Based on accepted general 1995 mask based on accepted standards. definitions, but boundaries are not exact Bering • No coastal sea regions within Key features of new region mask Sea Siberia Arctic Ocean • Based off of International Hydrographic Office (IHO) • Combined Kara/Barents Sea Laptev region definitions of seas – modified for use with sea ice, e.g.: East Siberian Sea Sea • Parkinson et al., JGR, 1999 • Beaufort Sea northern border at 76° N latitude, at southwest coast of Chukchi Sea St. Patrick Island Kara Alaska Sea Russia • Beaufort Sea northern border extends west at constant latitude Beaufort Central instead of diagonally across to Point Barrow as in IHO definition Sea Arctic Barents Modified
    [Show full text]
  • The Age of Yellow River Water in the Bohai
    JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 117, C11006, doi:10.1029/2012JC008263, 2012 The age of Yellow River water in the Bohai Sea Zhe Liu,1 Haiyan Wang,1,2 Xinyu Guo,2 Qiang Wang,3 and Huiwang Gao1 Received 6 June 2012; revised 10 September 2012; accepted 21 September 2012; published 8 November 2012. [1] To quantitatively understand the transport timescales of dissolved material discharged from large rivers into a semienclosed sea, the age of Yellow River water in the Bohai Sea was calculated with the constituent-oriented age and residence time theory (CART) and particle-tracking method. Yellow River water has a mean age of 3.0 years for the entire Bohai Sea. The spatial variation of the water age is significant: 1.2 years near the Yellow River estuary but 3.9 years in the Liaodong Bay. However, the temporal variation in water age is insignificant. The water particles released at the river mouth need only several days to reach the estuary area. The great water age (1.2 years) near the Yellow River estuary is caused by the presence of old water particles that initially left this area but returned to this area again. Without the reentry of Yellow River water from the Yellow Sea to the Bohai Sea, the mean age of Yellow River water in the entire Bohai Sea decreases to 1.2 years. Calculations without tidal forcing give a reduction in water age by more than 50%, suggesting that tidal forcing plays the most dominant role in controlling the age of Yellow River water in the Bohai Sea.
    [Show full text]
  • NEMO-Bohai 1.0: a High-Resolution Ocean and Sea Ice Modelling System for the Bohai Sea, China
    https://doi.org/10.5194/gmd-2021-100 Preprint. Discussion started: 16 June 2021 c Author(s) 2021. CC BY 4.0 License. NEMO-Bohai 1.0: a high-resolution ocean and sea ice modelling system for the Bohai Sea, China Yu Yan1,2,3, Wei Gu2, Andrea M. U. Gierisch4, Yingjun Xu2, Petteri Uotila3 1School of Ocean Sciences, China University of Geosciences, Beijing 100083, China 5 2Academy of Disaster Reduction and Emergency Management, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China 3Institute for Atmospheric and Earth System Research (INAR), Faculty of Science, University of Helsinki, 00014 Helsinki, Finland 4Danish Meteorological Institute, DK-2100 Copenhagen, Denmark 10 Correspondence to: Yu Yan ([email protected]) and Petteri Uotila ([email protected]) Abstract. Severe ice condition in the Bohai Sea could cause serious harm to maritime traffic, offshore oil exploitation, aquaculture, and other economic activities in the surrounding regions. In addition to providing sea ice forecasts for disaster prevention and risk mitigation, sea ice numerical models could help explain the sea ice variability within the context of climate change in marine ecosystems, such as 15 that of spotted seals, which are the only ice-dependent sea animal that breeds in Chinese waters. Here, we developed NEMO-Bohai, an ocean-ice coupled model based on the Nucleus for European Modelling of the Ocean (NEMO) model version 4.0 and Sea Ice modelling Integrated Initiative (SI3) (NEMO4.0- SI3) for the Bohai Sea. This study will present the scientific design and technical choices of the parameterizations for the NEMO-Bohai model.
    [Show full text]