| General Information: |
| Title: | Phytoplankton species abundance in Tokyo Bay (Japan) from 1998 to 2019 |
| Identifier: | ERDP-2021-03.1.1 |
| Abstract: |
Tokyo Bay is a semi-enclosed coastal system located in the center of Japan. Eutrophication has progressed since 1950, resulting in red tides and blue tides appearing frequently. This data paper reports the abundance of phytoplankton species sampled monthly from April 1998 to March 2019 at 17 stations in Tokyo Bay. Monitoring has been carried out by Chiba Prefectural Government. Phytoplankters were enumerated by microscopy as numbers of cells or colonies. The abundance of each species was expressed as cells per milliliter of sea water. The total cell density ranged from 102 to 106 cells·ml−1. The dominant taxa were diatoms, such as Chaetoceros spp., Skeletonema spp., and Thalassiosira spp. in most of the months. The dominant diatom species reached concentrations of 106 cells·ml−1. Microflagellates or Cryptomonadaceae were also abundant, especially in winter, reaching 106 cells·ml−1. These data can be used to appreciate how anthropogenic disturbances such as eutrophication and global warming affect the density and community composition of phytoplankton. The detailed Metadata for this abstract published in the Data Paper section of the journal is available in MetaCat in JaLTER at http://db.cger.nies.go.jp/JaLTER/metacat/metacat/ERDP-2021- 03.1/jalter-en.
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| Keywords: |
- eutrophication
- red tide
- diatom
- long-term monitoring
- phytoplankton dataset
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Involved Parties
| Data Set Owners: |
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Organization: | Chiba Prefectural Environmental Research Center |
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| Data Set Contacts: |
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Individual: | Maiko Kagami |
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Organization: | Faculty of Environment and Information Sciences, Yokohama National University |
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Address: |
| Faculty of Environment and Information Sciences, Yokohama National University, |
| Kanagawa Japan |
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Phone:
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Email Address:
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| Associated Parties: |
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Individual: | Takashi Nakada |
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Address: |
| Faculty of Environment and Information Sciences, Yokohama National University, |
| Kanagawa Japan |
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Individual: | Toshiya Katano |
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Organization: | Graduate School of Marine Science and Technology, Tokyo University of Marine Science and Technology |
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Address: |
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Individual: | Keigo Hashimoto |
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Organization: | Graduate School of Marine Science and Technology, Tokyo University of Marine Science and Technology |
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Address: |
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Individual: | Maiko Kagami |
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Address: |
| Faculty of Environment and Information Sciences, Yokohama National University, |
| Kanagawa Japan |
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Data Set Characteristics
| Geographic Region: |
| Geographic Description: | Tokyobay1 |
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Bounding Coordinates:
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| West: | 139.89777777 degrees
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| East: | 139.89777777 degrees
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| North: | 35.61055555 degrees
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| South: | 35.61055555 degrees
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Mimimum Altitude: | -9.0 meter |
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Maximum Altitude: | -7.0 meter |
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| Geographic Region: |
| Geographic Description: | Tokyobay3 |
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Bounding Coordinates:
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| West: | 139.99027777 degrees
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| East: | 139.99027777 degrees
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| North: | 35.64583333 degrees
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| South: | 35.64583333 degrees
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Mimimum Altitude: | -7.0 meter |
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Maximum Altitude: | -5.0 meter |
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| Geographic Region: |
| Geographic Description: | Tokyobay4 |
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Bounding Coordinates:
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| West: | 139.96722222 degrees
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| East: | 139.96722222 degrees
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| North: | 35.60722222 degrees
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| South: | 35.60722222 degrees
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Mimimum Altitude: | -12.0 meter |
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Maximum Altitude: | -11.0 meter |
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| Geographic Region: |
| Geographic Description: | Tokyobay5 |
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Bounding Coordinates:
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| West: | 140.06111111 degrees
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| East: | 140.06111111 degrees
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| North: | 35.60527777 degrees
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| South: | 35.60527777 degrees
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Mimimum Altitude: | -9.0 meter |
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Maximum Altitude: | -8.0 meter |
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| Geographic Region: |
| Geographic Description: | Tokyobay7 |
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Bounding Coordinates:
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| West: | 140.07611111 degrees
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| East: | 140.07611111 degrees
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| North: | 35.56444444 degrees
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| South: | 35.56444444 degrees
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Mimimum Altitude: | -10.0 meter |
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Maximum Altitude: | -9.0 meter |
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| Geographic Region: |
| Geographic Description: | Tokyobay8 |
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Bounding Coordinates:
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| West: | 139.91 degrees
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| East: | 139.91 degrees
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| North: | 35.55055555 degrees
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| South: | 35.55055555 degrees
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Mimimum Altitude: | -19.0 meter |
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Maximum Altitude: | -18.0 meter |
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| Geographic Region: |
| Geographic Description: | Tokyobay9 |
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Bounding Coordinates:
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| West: | 140.02 degrees
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| East: | 140.02 degrees
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| North: | 35.53694444 degrees
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| South: | 35.53694444 degrees
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Mimimum Altitude: | -17.0 meter |
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Maximum Altitude: | -15.0 meter |
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| Geographic Region: |
| Geographic Description: | Tokyobay13 |
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Bounding Coordinates:
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| West: | 139.91055555 degrees
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| East: | 139.91055555 degrees
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| North: | 35.48388888 degrees
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| South: | 35.48388888 degrees
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Mimimum Altitude: | -20.0 meter |
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Maximum Altitude: | -20.0 meter |
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| Geographic Region: |
| Geographic Description: | Tokyobay15 |
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Bounding Coordinates:
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| West: | 139.86305555 degrees
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| East: | 139.86305555 degrees
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| North: | 35.40194444 degrees
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| South: | 35.40194444 degrees
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Mimimum Altitude: | -14.0 meter |
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Maximum Altitude: | -13.0 meter |
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| Geographic Region: |
| Geographic Description: | Tokyobay20 |
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Bounding Coordinates:
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| West: | 139.83388888 degrees
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| East: | 139.83388888 degrees
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| North: | 35.24 degrees
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| South: | 35.24 degrees
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Mimimum Altitude: | -11.0 meter |
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Maximum Altitude: | -9.0 meter |
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| Geographic Region: |
| Geographic Description: | Tokyobay21 |
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Bounding Coordinates:
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| West: | 139.82333333 degrees
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| East: | 139.82333333 degrees
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| North: | 35.13583333 degrees
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| South: | 35.13583333 degrees
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Mimimum Altitude: | -25.0 meter |
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Maximum Altitude: | -22.0 meter |
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| Geographic Region: |
| Geographic Description: | Tokyobay22 |
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Bounding Coordinates:
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| West: | 139.82805555 degrees
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| East: | 139.82805555 degrees
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| North: | 35.08888888 degrees
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| South: | 35.08888888 degrees
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Mimimum Altitude: | -18.0 meter |
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Maximum Altitude: | -16.0 meter |
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| Geographic Region: |
| Geographic Description: | Tokyobay23 |
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Bounding Coordinates:
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| West: | 139.8025 degrees
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| East: | 139.8025 degrees
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| North: | 35.05249999 degrees
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| South: | 35.05249999 degrees
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Mimimum Altitude: | -32.0 meter |
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Maximum Altitude: | -25.0 meter |
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| Geographic Region: |
| Geographic Description: | Tokyobay25 |
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Bounding Coordinates:
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| West: | 139.84694444 degrees
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| East: | 139.84694444 degrees
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| North: | 34.995 degrees
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| South: | 34.995 degrees
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Mimimum Altitude: | -14.0 meter |
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Maximum Altitude: | -12.0 meter |
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| Geographic Region: |
| Geographic Description: | Tokyobay27 |
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Bounding Coordinates:
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| West: | 139.80111111 degrees
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| East: | 139.80111111 degrees
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| North: | 34.99638888 degrees
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| South: | 34.99638888 degrees
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Mimimum Altitude: | -64.0 meter |
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Maximum Altitude: | -61.0 meter |
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| Geographic Region: |
| Geographic Description: | Tokyobay28 |
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Bounding Coordinates:
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| West: | 139.76055555 degrees
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| East: | 139.76055555 degrees
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| North: | 35.05055555 degrees
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| South: | 35.05055555 degrees
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Sampling, Processing and Quality Control Methods
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Step by Step Procedures
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| Step 1: |
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Description:
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Study sites
Tokyo Bay is a hydrographically semi-closed temperate coastal system located in central Japan. The inner bay is approximately 922 km2 with an average depth of 19 m. It deepens in the southern part and connects with the Pacific Ocean through the Uraga Strait (Figure 1). Monitoring has been conducted at 9 sites (Station T1–T15) in inner Tokyo Bay, 8 sites (Station T20–T28) in outer Tokyo Bay. At the central station of inner Tokyo Bay, Station T4, total cell density ranged from 101 to 105 cells·ml−1 (Figure 2). The water quality monitoring program has been conducted by Chiba Prefectural Government (http://www.pref.chiba.lg.jp/suiho/kasentou/koukyouyousui/index.html: Note that the webpage is in Japanese).
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| Step 2: |
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Description:
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Sampling, sample preservation, and counting methods
Water samples were taken monthly with a bucket at a depth of 0.5 m. The sample (2 L) was immediately fixed with either 10 mL of Lugol’s solution (0.5% in final concentration) or 40 mL of 50% glutaraldehyde (1% in final concentration). The samples were concentrated by sedimentation, and number of cells or units (colonies) of each phytoplankton taxon was counted using counting chambers (e.g. MATSUNAMI plankton chamber [MPC-200]) under the microscope (Olympus or Nikon) with the magnitude of 100, 200 and 400.
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| Step 3: |
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Description:
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Taxonomy and systematics
The textbook used for the identification was Chihara and Murano (1997). Some taxa were counted based on units (colonies per mL). Original name recorded in Chiba Prefecture database were checked and reclassified, if necessary, according to the most recent classifications based on AlgaeBase (https://www.algaebase.org/; accessed on 14 March 2021). Some taxa have been revised after their records, and some species cannot be identified according to the current classification. For example, some Ceratium species have been transferred to Tripos, and unidentified species recorded as “Ceratium sp.” may represent either Ceratium or Tripos species. In such case, traditional name is shown with “(s.l.)” (sensu lato; e.g. “Ceratium (s.l.) sp.”), and possibly current genus (genera) are listed in the Note in TaxonList.csv.
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| Step 4: |
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Description:
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Data verification procedures
The data were manually digitized and checked for typographical errors by the investigators.
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Data Set Usage Rights
| 1) Acceptable use. The dataset should not be used for illegal purposes or to violate the rights of others. The usage of the dataset will be restricted to academic, research, educational, government, or other, not for profit professional purposes. The dataset is licensed under a Creative Commons Attribution 4.0 (CC-BY 4.0).
2) Citation. Data users should properly cite this data paper in any publications or in the metadata of any derived data products that were produced using the dataset. As the metadata and the data set can be updated at any time, the update date should be shown in the bibliography.
3) Acknowledgement. To support this long-term monitoring activity, data users should provide acknowledgements in any publications to whose content the data set contributed as follows: “Data for XXX was provided by the Chiba Prefectural Environmental Research Center”.
4) Notification. Data users should notify the Dataset Contact when any study or publication based on or derived from the data set is distributed. Inform the Dataset Contact with two reprints or a PDF file of any publications resulting from the usage of the dataset.
5) Collaboration. Data users are strongly encouraged to consider consultation, collaboration, and/or coauthorship with the data owners.
6) Disclaimer. In no event shall the authors, data owners, or the Chiba Prefectural Environmental Research Center be liable for a loss of profits or for any indirect or incidental damages arising from the use or interpretation of the data. |
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