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Abstract: Four cruises were conducted in the Yellow Sea from 2007 to 2009. Through conductivity-temperature-depth (CTD) observation, we obtained data on the water depth, bottom water temperature and salinity of the Yellow Sea from 154 stations. We used a 0.1-m2 modified Grey-O’Hara box corer to collect the sediment samples, and obtained the median grain size of sediments, together with the horizontal and vertical distribution of sediment water content, organic matter, chlorophyll a and pheophytin a. The dataset of benthic environmental parameters aids in better understanding the long-term changes of the benthic environment and ecosystem in the Yellow Sea.
Keywords: Yellow Sea; CTD observation; benthic environment
|English title||A dataset of benthic environmental parameters in the Yellow Sea (2007 – 2009)|
|Corresponding author||Xu Kuidong (email@example.com)|
|Data authors||Meng Zhaocui, Dai Renhai, Li Yuhang, Zhang Guangtao, Xu Kuidong|
|Time range||2007 – 2009|
|Geographical scope||Yellow Sea (31.25°– 39.40°N, 119.50° – 125.01°E)|
|Data format||*.xls||Data volume||204 KB|
|Data service system||<http://www.sciencedb.cn/dataSet/handle/554>|
|Sources of funding||Science and Technology Infrastructure Program of China (No. 2013FY111100-03) and National Natural Science Foundation of China (No. 41306153, No. 41476144)|
|Dataset composition||The dataset consists of the following four files: benthic environment information of the Yellow Sea collected from 48 stations in summer 2007.xls, with a data volume of about 51 KB; benthic environment information of the Yellow Sea collected from 33 stations in summer 2008.xls, with a data volume of about 48 KB; benthic environment information of the Yellow Sea collected from 38 stations in spring 2009.xls, with a data volume of about 50 KB; benthic environment information of the Yellow Sea collected from 35 stations in winter 2009.xls, with a data volume of about 51 KB.|
The Yellow Sea is a semi-enclosed marginal sea of the Pacific Ocean located between China and the Korean Peninsula. The sea has an average water depth of 44 m, with a deeper trough of 50 m – 80 m in the center. Its hydrographic phenomena include the Yellow Sea Cold Water Mass, the Yellow Sea Warm Current and the Yellow Sea Coastal Current, providing grounds for spawning, feeding and breeding fish, shellfish, shrimps and crabs.
Water depth, temperature and salinity are the basics of marine hydrological observation. To date, various studies have addressed the hydrographic and chemical features of the Yellow Sea.1 Studies of the Yellow Sea environmental features during 1976 –2000 along the 36°N transect revealed a climb in water temperature, salinity, dissolved inorganic nitrogen, and nitrogen-phosphorus ratio, accompanied by a decline in dissolved oxygen, phosphorus and silicon.2 Being an important source and sink of biogenic element, marine sediments locate at the intersection of hydrosphere, biosphere and lithosphere, playing an important role in the biogeochemical cycle. The sediment grain size directly reflects the characteristics of marine sedimentation. The content of organic matter and its changes are important parameters with which to measure marine geochemical processes, marine carbon cycles, marine environment changes and global changes. The concentrations of chlorophyll a (Chl a) reflect the standing stock of photoautotrophy in the benthic environment and the primary productivity in the sea. Studies have been conducted on respective environmental parameters in the Yellow Sea,3 but no summary data are available so far on the environmental parameters, nor are datasets of CTD observation or sediment environmental factors in the Yellow Sea. Marine sedimentary environment has a significant impact on the community structure, diversity and distribution of benthos. Hydrological and sediment environmental parameters in the Yellow Sea are important for understanding the dynamic changes of marine benthic environment and ecosystem, exploiting marine benthic resources, predicting marine environmental changes, and assessing environmental impact, fishery negotiation, marine pollution compensation, and so on.
To investigate the hydrographic and sediment environmental parameters in the Yellow Sea, four surveys were conducted during 2007 – 2009 along the transects at 38.75°N, 38.50°N, 38°N, 37°N, 36°N, 35°N, 34°N, 33°N, and 32°N (Figure 1). During the survey cruises, we also collected hydrographic, ecological, chemical and geologic samples. The measured data aid in better understanding the effects of global climate change and human activity on the benthic ecosystem in the Yellow Sea.
2.1 Data collection
The hydrological data and sediment samples were collected from 154 stations in the Yellow Sea (31°15'–38°50'N, 120°57'–124°30'E) during four surveys. They were conducted, respectively, at 38 stations during 17 May and 26 June 2009 by the "Kexue 1" research vessel, at 48 stations during 15 and 28 June 2007, at 33 stations during 20 and 31 July 2008, and at 35 stations during 21 November and 23 December 2009 by the "Kexue 3" research vessel. The stations were set at every single or half latitude at an internal of half longitude, and they were denoted by latitude interval codes from zero to ten.
The sediment samples were collected using a 0.1 m2 modified Grey-O'Hara box corer and at least three replicates were randomly grabbed at each station. The upper 0 – 8 cm sediments were sampled using 30 ml syringes (23 mm i.d.): one syringe core sample was obtained from each of the three replicates grabbed at each station, while an additional fourth syringe was taken from any of the three replicates. Each of the four cores was sliced into 0 – 2 cm, 2 – 5 cm and 5 – 8 cm depth layers. Corresponding layers of the four cores were pooled and immediately stored at –20 °C in the dark for subsequent measurement of sediment grain size, and the content of water, organic matter, chlorophyll a (Chl a) and phaeophytin a (Ph a). At each station, water temperature, depth, and salinity were profiled by casting a SeaBird CTD system (Conductance Temperature Depth).4
2.2 Analysis method
Analysis methods for each environmental factor are listed in Table 1. The content of organic matter was determined by multiplying the organic carbon concentrations by the factor 1.724, and the concentrations were measured either by a titration method (for samples collected in 2007 and 2008) or by an elemental analyzer (Elementar Vario Macro Cube, for samples collected in 2009).5 A 0.001 g analytical balance was used to measure their weight.
|Environmental factors||Sampling||Analysis methods/Instrument|
|Grain size||Upper 0 – 2 cm sediment layer||Laser Diffraction Particle Size Analyzer (Cilas 940L)|
|Chlorophyll a||0 – 2 cm, 2 – 5 cm and 5 – 8 cm sediment layers||Turner Designs (Model II) fluorometer|
|Phaeophytin a||0 – 2 cm, 2 – 5 cm and 5 – 8 cm sediment layers||Turner Designs (Model II) fluorometer|
|Organic matter||Upper 0 – 2 cm sediment layer||Organic carbon concentrations were determined by a titration method or an elemental analyzer; organic matter contents were determined by multiplying the organic carbon concentration by the factor 1.724.|
|Water content||0 – 2 cm, 2 – 5 cm and 5 – 8 cm sediment layers||Calculating weight loss by drying the sediment at 60° for 72 h|
2.3 Data arrangement
This dataset contains information on sediment grain size, water content, organic matter content, and Chl a and Ph a concentrations, supplemented by information on corresponding station, longitude, latitude, depth and date.
The dataset of environmental parameters in the Yellow Sea during 2007 - 2009 was stored in .xls format. Each subset contains 23 data items, including survey project, survey institution, sea area, vessel name, station name, longitude, latitude, date sampled, size of box corer, water depth, bottom water temperature, bottom water salinity, water content in 0 - 2 cm sediment layer, water content in 2 - 5 cm sediment layer, water content in 5 - 8 cm sediment layer, Chl a concentration in 0 - 2 cm sediment layer, Chl a concentration in 2 - 5 cm sediment layer, Chl a concentration in 5 - 8 cm sediment layer, Ph a concentration in 0 - 2 cm sediment layer, Ph a concentration in 2 - 5 cm sediment layer, Ph a concentration in 5 - 8 cm sediment layer, organic matter content, and median grain size. Table 2 shows the name, description, unit and so on of the parameters included in the dataset.
|1||Survey project||Name of the survey project||-||The survey of Yellow Sea Cold Water Mass in 2007|
|2||Survey institution||Institution taking part in the survey||-||Institute of Oceanology, Chinese Academy of Sciences|
|3||Sea area||The sea area surveyed||-||Yellow Sea|
|4||Vessel name||Name of the research vessel||-||Kexue 3|
|5||Station name||Name of the station position surveyed||-||1099|
|6||Longitude||Longitude of the station surveyed||°E||121.17|
|7||Latitude||Latitude of the station surveyed||°N||35.00|
|8||Date sampled||Date of the sampling performed||-||2007-07-20|
|9||Size of box corer||Size of the box corer||m2||0.1|
|10||Water depth||Water depth at the station surveyed||M||29.50|
|11||Bottom water temperature||Bottom water temperature at the station surveyed||°C||28.30|
|12||Bottom water salinity||Bottom water salinity at the station surveyed||-||31.25|
|13||Water content in 0 - 2 cm sediment layer||Water content in 0 - 2 cm sediment layer||%||0.53|
|14||Water content in 2 - 5 cm sediment layer||Water content in 2 - 5 cm sediment layer||%||0.44|
|15||Water content in 5 - 8 cm sediment layer||Water content in 5 - 8 cm sediment layer||%||0.46|
|16||Chl a concentration in 0 - 2 cm sediment layer||Chl a concentration in 0 - 2 cm sediment layer||μg/g||1.13|
|17||Chl a concentration in 2 - 5 cm sediment layer,||Chl a concentration in 2 - 5 cm sediment layer||μg/g||0.62|
|18||Chl a concentration in 5 - 8 cm sediment layer,||Chl a concentration in 5 - 8 cm sediment layer||μg/g||0.34|
|19||Ph a concentration in 0 - 2 cm sediment layer||Ph a concentration in 0 - 2 cm sediment layer||μg/g||6.97|
|20||Ph a concentration in 2 - 5 cm sediment layer||Ph a concentration in 2 - 5 cm sediment layer||μg/g||3.62|
|21||Ph a concentration in 5 - 8 cm sediment layer||Ph a concentration in 5 - 8 cm sediment layer||μg/g||2.04|
|22||Organic matter content||Organic matter content at the station surveyed||%||0.26|
|23||Median grain size||Median grain size at the station surveyed||m||30.25|
To guarantee the quality of the data sources, more than 8 cm sediments were sampled from undisturbed box corer at each station. Four core samples were randomly taken from the box corer at least 2 cm distant from its edge.
Observed raw data were then subject to further quality control and laboratory analysis. For this, we performed raw data check, data entry check and data edit. Raw data check involved checking file format, standardized field naming, field dimension, data integrity, and so on. Data entry check was mainly to correct and eliminate abnormal data. At least two replicates were measured for each sediment environmental factor. A third sample was tested and a mean value of the three was adopted in case of large deviation between the test results of the two replicates (i.e., a ±10% deviation in the Chl a and Ph a concentrations, an over 1% deviation in the water content, or a deviation of the organic carbon value from standard linear ranges of the instrument). Abnormal data were validated against raw records including investigation report, station list, survey map, sampling record, laboratory analysis record, and so on. The abnormal data were identified when any of the following occurs: (1) the sample was disturbed slightly when the sea was in a worse condition according to the sampling record, and the test results differed substantially from corresponding historical data. (2) there was a huge deviation among test results of the replicates. Data processing involved data integration, collation, conversion and format unification. After paper material was digitized, we checked again to ensure no data omission, no mistake and no duplication. After abnormal data elimination, data quality control and evaluation, data of 154 stations were included in the dataset.
Resulting from four cruises during three years, the data of environmental parameters in the Yellow Sea during 2007 2009 provide fundamental data for us to study the change of marine benthic environments and ecological systems, and to exploit and utilize the marine benthos. Files are stored in .xls format, which enables users to easily browse and use the data by Microsoft Excel. On the basis of this dataset, we can map the distribution of the environmental factors. Figure 2 shows the distribution of water depth and Chl a concentration in the sediment based on the June 2007 cruise.
We thank all the members on the "Kexue 1" and "Kexue 3" research vessels of the Chinese Academy of Sciences.
Wang B, Wang G, Zheng C et al. Distributional features of bioactive elements in seawater in the Southern Yellow Sea in winter. Journal of Oceanography for Huanghai & Bohai Seas 17(1999): 40 – 45.
Lin C, Ning X, Su J et al. Environmental changes and the responses of the ecosystems of the Yellow Sea during 1976 – 2000. Journal of Marine Systems 55(2005): 223 – 234.
Wang W, Li A, Xu F et al. Distribution of surface sediments and sedimentary environment in the North Yellow Sea. Oceanologia et Limnologia Sinica 40(2009): 525 – 531.
General Administration of Quality Supervision, Inspection and Quarantine of China. Specification for Oceanographic Survey Part 2: Marine Hydrographic Observation (GB/T 12763.2-2007). Beijing: China Standard Press, 2007.
General Administration of Quality Supervision, Inspection and Quarantine of China. The Specification for Marine Monitoring Part 5: Sediment Analysis (GB 17378.5-2007). Beijing: China Standard Press, 2007.
1. Meng Z, Dai R, Li Y et al. A dataset of benthic environmental parameters in the Yellow Sea (2007 – 2009). Science Data Bank. DOI: 10.11922/sciencedb.554
How to cite this article
Meng Z, Dai R, Li Y et al. A dataset of benthic environmental parameters in the Yellow Sea (2007 – 2009). China Scientific Data 3(2018). DOI: 10.11922/csdata.2018.0002.zh