Metadata
Metadata
(Accession Number: ERDP-2015-03)
Title
Compilation of Japanese fisheries statistics for the Japanese eel, Anguilla japonica, since 1894: a historical dataset for stock assessment
Authors
Hiroshi Hakoyama1*, Hiroka Fujimori1, Chiaki Okamoto1, Sakie Kodama1
1 Fisheries Research Agency, 1088 Komaki, Ueda, Nagano 386-0031, Japan
* Corresponding author: Hiroshi Hakoyama
E-mail: hako@affrc.go.jp
Abstract
Fishery sustainability and the extinction risk of the Japanese eel, Anguilla japonica, are of global concern. The landings of the Japanese eel in Japan comprise a large part of the landings in East Asia. This study provides a compiled dataset of the annual fisheries statistics of the Japanese eel in Japan for stock assessment. The Japanese government has been recording Japanese eel statistics annually since 1984 in five series of annual reports by conducting systematic questionnaire surveys of fisheries managers and associations; however, most of these data are stored in analog format. The key variables in the dataset include the harvest weight of eels, the harvest weight and number of seeds for aquaculture, the number of eels stocked, and the number of management entities engaged in the eel fishery. The levels of spatial aggregation of the variables include the site (river and lake), prefecture, inland and coastal waters, and total in Japan. We also incorporated location data (latitude and longitude) of the site and prefecture into the dataset. Eel harvest includes primarily yellow eels (late juvenile stage) and silver eels (mature stage). Seed harvest in inland waters includes glass eels (intermediate stage between leptocephalus and elver) and elvers (early juvenile stage). Seed harvest from coastal waters comprises glass eels. This dataset provides information to assess long-term trends in the Japanese eel population.
Keywords
fishery statistics time series, site-by-site statistics, eel harvest, seed harvest, eel stocking, fishery management entity, glass eel, elver, yellow eel, silver eel
Introduction
The decrease of the annual harvest of Japanese eel, Anguilla japonica, in the last 50 years are of increasing global concern related to sustainable fisheries and the extinction risk of Japanese eel (e.g., Tatsukawa 2003; MOE 2013, 2015; Jacoby and Gollock 2014; Joint Statement 2014): On February 1, 2013, the Ministry of the Environment of Japan (MOE) classified Japanese eel as Endengerd in the Fourth version of the Japanese Red List (MOE 2013, 2015). On June 12, 2014, the IUCN also classified Japanese eel as Endengerd in the IUCN Red List (IUCN 2014; Jacoby and Gollock 2014). On September 17, 2014, China, Japan, South Korea, and Chinese Taipei adopted, unofficially, a joint statement for the conservation and management of Japanese eel, in which they agreed to restrict the annual amounts of eel seeds for aquaculture (Joint Statement 2014).
In risk assessments by MOE (2013) and by Jacoby and Gollock (2014), fisheries statistics (time-series of eel harvests) provided important information related to the trends of eel population. In general, the trends in harvest statistics of fishes have been used as a proxy for assessing the abundance trends of fishes (e.g., IUCN 2015) as a precautionary approach against uncertainty (FAO 1985; Kriebel et al. 2001; Wiener 2001), although debate continued on the question of whether harvests reflect abundance of fish population (Pauly et al. 2013).
In spite of the importance of fisheries statistics of Japanese eel for the stock assessment, it has remained difficult to access detailed fisheries data that the Japanese government has recorded in five series of fisheries reports over the last century because most of the data were being stored in analog format on previous annual reports (But see Tanaka 2014. He extracted the total catch of eels in Japan from 1903 to 1943 and some data from prefectural statistics). As presented in this data paper, we converted the analog data into digital data. Then we compiled all the available official statistics of Japanese eel to provide more detailed and geographical information related to the harvest, stocking, and fishing efforts of Japanese eel in Japan.
Metadata
1. Title
Compilation of Japanese fisheries statistics for the Japanese eel, Anguilla japonica, since 1894: a historical dataset for stock assessment
2. Identifier
ERDP-2015-03
3. Contributors
A. Source data owner
The Ministry of Agriculture, Forestry and Fisheries of Japan
Address:
1–2–1, Kasumigaseki, Chiyoda-ku, Tokyo 100–8950, Japan
B. Dataset owners
Hiroshi Hakoyama
Fisheries Research Agency
Address:
1088 Komaki, Ueda, Nagano 386-0031, Japan
E-mail address: hako@affrc.go.jp
Hiroka Fujimori
Fisheries Research Agency
Address:
1088 Komaki, Ueda, Nagano 386-0031, Japan
E-mail address: fujimo@affrc.go.jp
Chiaki Okamoto
Fisheries Research Agency
Address:
1088 Komaki, Ueda, Nagano 386-0031, Japan
Sakie Kodama
Fisheries Research Agency
Address:
1088 Komaki, Ueda, Nagano 386-0031, Japan
E-mail address: skodama@affrc.go.jp
4. Geographic Coverage
A. Geographic description
Japan
B. Bounding coordinates
West: 122° 56′ 01″ E
East: 153° 59′ 11″ E
North: 45° 33′ 25″ N
South: 20° 25′ 31″ N
Geographic coordinate system is WGS84
5. Temporal coverage
A. Begin
1894
B. End
2015
6. Methods
A. Data compilation
We compiled available data on annual fisheries statistics of Japanese eel in Japan from five official reports of the Japanese government: (1) Statistical Report of the Department of Aquaculture and Commerce (SRDAC) from 1894 through 1923 (reference period, the same applies hereinafter), (2) Statistical Yearbook of Ministry of Agriculture and Forestry (SYMAF) from 1924 through 1976, (3) Annual Report of Catch Statistics on Fishery and Aquaculture (ARCSFA) from 1954 through 1962, (4) Annual Statistics on Fishery and Aquaculture Production (ASFAP) from 1963 through 2015, and (5) the Census of Fisheries (COF; quinquennial census) from 1968 through 2013. We also referred to "Suisan gyō ruinen tōkei, No. 3, todōfuken betu tōkei" (MAF and NTK 1978) and the errata of the ASFAP (MAFF 2015) for verification.
Key variables of the compiled dataset are (1) the annual harvest in weight of eels, (2) the harvest in weight (in number partially) of seeds for aquaculture, (3) the number of eels stocked, and (4) the number of fishery management entities (FMEs) engaged in eel fisheries.
A-1. Conversion of analog data into digital data
Data of the fisheries statistics of Japanese eel in 2002 or before are analog formats (hard copy or PDF without the text layer) except for some exceptions. Therefore, we converted the analog data into digital data by feeding the data into a computer. PDF (without the text layer) copies of the series of the SRDAC and SYMAF are available for download from the Book/Journal Cross Search of the MAFF (MAFF 2014).
A-2. Official digital data
Digital data of the fisheries statistics of Japanese eel in 2003 or after (ASFAP and COF) are available for download from the portal site of the ASFAP (MAFF 2015) and the portal site of official statistics of Japan (MIAC 2015). Exceptionally, long-term time-series of some statistics that include data earlier than 2003 are also available as digital data: harvests of eels throughout Japan from 1956 through 2012, harvests of seeds in inland and coastal waters from 1957 through 2012 (MAFF 2015), and numbers of inland FMEs that caught seeds from 1973 through 1998 (MIAC 2015).
A-3. Four aggregation levels of fisheries statistics
In the official reports, the fisheries statistics of Japanese eel have been recorded at the following four aggregation levels: site (river and lake), inland and coastal waters, prefecture, and the total in Japan.
The site includes major 220 rivers and 83 lakes in the ARCSFA and ASFAP, and 561 rivers and 80 lakes in the COF. We standardized some site names to be consistent among reports to the greatest extent possible.
Figure 1 presents the locations of respective prefectures of Japan. In certain periods of years, the official reports have not recorded the data aggregated at the prefectural and total levels, but have recorded the site-level data with the name of the prefecture that includes the site. In such cases, we calculated the prefectural and total aggregations by summing site data for each prefecture and by summing all site data (see Table 1–4 for details).
A-4. Geographic locations of sites and prefectures
Official reports do not provide the geographic location of the sites and prefectures. We measured the location using Google map (WGS84). We recorded respectively the longitude and latitude of the mouth of river (or the center of lake) and the prefecture capital as representative values of the site location and prefecture.
A-5. Conversion of the unit of statistics
The unit of weight in the official reports was the "kwan" (1 kwan = 0.00375 ton) from 1984 through 1957; it has been ton since 1958. We standardized the weight unit by converting the kwan into ton. We do not use the SI weight unit (kg) because the rounding increment of weight has been given basically in the unit of ton since 1958.
A-6. Conversion of missing and rounding symbols
Data of the official reports include missing values. The missing values are represented by three common symbols: "—" is no record, "x" is secret, and "⋯" is unknown or not available. We converted all of them to "NA". The other symbol "0" means "less than the unit amount": for example, the unknown value X of a "0" is within an interval 0＜X＜0.5 when the rounding method is the round-half-up and the rounding increment is 1. In another case, a "0" means 0＜X＜1 when the rounding method is the round-down with an increment of 1. Depending on the rounding method, we converted the "0" of the former and latter cases, respectively, to the representative values 0.25 and 0.5. See Table 5–15 for the rounding method in the official reports.
A-7. Harvest in weight of Japanese eel
Table 1 presents historical data related to the annual harvest in weight of Japanese eel. The harvests in weight of Japanese eel include eels at different life stages: glass eel, elver, yellow eel, and silver eel. Weights of yellow and silver eels are dominant in the data because the size of silver and yellow eels is significantly larger than that of elvers and glass eels (seeds). The annual harvests of yellow and silver eels are calculable by subtracting the annual harvest of seeds (next subsection, Table 2) from the annual harvest of eels (Table 1).
We investigated potential outliers in the annual prefectural harvest of Japanese eel by comparing the values with that in statistical reports published by prefectures. As a result, we corrected two clear outliers: The harvest of eels in Aichi prefecture in 1921 was corrected from 2652.51 ton to 796.26 ton (Aichi Prefecture 1925). The harvest of eels in Tokyo prefecture in 1905 was corrected from 1127.52 ton to 77.52 ton (Tokyo Prefecture 1906). We also corrected the corresponding total harvest of Japanese eel by the amount of correction.
| Report | Reference period (year) | Census interval (year) | Aggregation period | Available period of eel–harvest data by aggregation level (year) | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Total in Japan | Prefecture-by-prefecture | Inland water | Coastal water | |||||||||
| From | To | Initial date | Last date | Total | Prefecture-by-prefecture | Site-by-site (river and lake) | Total | Prefecture-by-prefecture | ||||
| SRDAC | 1894 | 1923 | 1 | Jan 1 | Dec 31 | 1894–19231, 2 | 1894–19231, 2 | NA | NA | NA | NA | NA |
| SYMAF | 1924 | 1953 | 1 | Jan 1 | Dec 313 | 1924–1943 | 1924–1943 | 1941–1942, 1949–1953 | 1941–1942, 1949–1953 | NA | 1941–19424 | 1941–19424 |
| ARCSFA | 1954 | 1962 | 1 | Jan 1 | Dec 31 | NA | NA | 1954–1962 | 1954–1962 | 1954–1956 | NA | NA |
| ASFAP | 1963 | 20155, 6 | 1 | Jan 1 | Dec 31 | NA | NA | 1963–20157 | 1963–20157, 8 | 1965–2015 | NA | NA |
1In the SRDAC from 1905 through 1921, aquaculture production was included in the harvest of eels in Tochigi, Gunma, Saitama, Yamanashi, Nagano, Gifu, and Nara prefectures (MAF and NTK 1978, p.569, p.575, p.581, p.587, p.593, p.599, and p.617). We corrected them in our dataset by subtracting the aquaculture production from the harvest of eels.
2The total harvest of eels in Japan does not include the harvest in Kanagawa prefecture in 1922, and does not include harvests in Hokkaidō prefecture from 1894 through 1904.
3Aggregation period of the SYMAF differs by year: Jan 1 through Dec 31 in 1924–1940; Feb 1 through the following Jan 31 in 1941–1943; Mar 1 through the following Feb 28 in 1949–1953.
4In the SYMAF, both the total and inland harvests of eels were recorded only in 1941 and 1942. We calculated the harvests of eels in coastal waters in 1941 and 1942 by subtracting the inland harvest from the total harvest.
5Since 2006, the harvest of eels has not included harvests by recreational fishery activities.
6The eel harvests do not include the harvests in Okinawa prefecture from 1949 through 1973.
7Japanese government did not survey the harvests of minor rivers in 1965–1967 or in 1969–1972; the government imputed the missing values by the values surveyed respectively in 1964 and 1968 (ASFAP 1974, p 9). The Japanese government also did not survey the harvests of minor rivers from 1973 through 1993 except the surveys of the COF conducted once every five years (1973, 1978, 1983, 1988, and 1993). The government imputed the missing values by the adjusted values based on the once-every-five-years surveys (ASFAP 1975–1995).
8From 1965 through 1967 and from 1969 through 1974, the harvest of eels by prefecture was not recorded in the ASFAP. We calculated them by summing available data by site (river and lake) for each prefecture. Particularly the harvest of a few large rivers crossing prefectures has been recorded separately by prefecture from 1965 through 2015, but that was not recorded separately by prefecture (recorded in total) in 1965, 1966, 1967, and 1969. For calculations, we assumed the ratio of the harvests by prefecture in the large rivers in 1965, 1966, 1967, and 1969 are proportional to that in 1970.
A-8. Harvest of seeds for aquaculture
Table 2 presents historical data related to the seed harvest of Japanese eel. The harvest of seeds includes glass eels and elvers. The harvest of seeds in coastal waters comprises glass eels. However, the harvest of seeds in inland waters includes glass eels and elvers. Since 1957, the harvest of seeds has been measured by weight. Exceptionally, the harvest of seeds was measured by the number of seeds in the early short period of the survey from 1941 through 1946.
| Report | Reference period (year) | Census interval (year) | Aggregation period | Available period of seed–harvest data by aggregation level (year) | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Total in Japan | Prefecture-by-prefecture | Inland water | Coastal water | |||||||||
| From | To | Initial date | Last date | Total | Prefecture-by-prefecture | Site-by-site | Total | Prefecture-by-prefecture | ||||
| SYMAF | 1941 | 1946 | 1 | Last Aug 1 | Jul 31 | 1941–1946 | 1941–1946 | NA | NA | NA | NA | NA |
| ARCSFA | 1957 | 1962 | 1 | Jan 1 | Dec 31 | 1957–1962 | 1957–1962 | 1957–1962 | 1957–1962 | NA | 1957–1962 | 1957–1962 |
| ASFAP | 1963 | 2015 | 1 | Jan 1 | Dec 31 | 1963–20152 | 1963–20152 | 1963–1964, 1968–20152 | 1963–1964, 1968–20152, 3 | 1963–1964, 1968–2015 | 1963–2015 | 1963–20154 |
1From 1949 through 1973, the harvest of seeds does not include the harvest in Okinawa prefecture.
2The Japanese government did not survey minor rivers in 1965–1967, in 1969–1972, and in 1976, but respectively imputed the values of 1964, 1968, and 1975 (ASFAP 1976, p 9).
3From 1969 through 1980, the harvest of seeds by prefecture was not recorded in the ASFAP. We calculated them by summing available data by site (river and lake) for each prefecture.
4From 1984 through 1994, the seed harvest by prefecture was recorded as statistics divided by the sea region in the ASFAP. We summed up them for each prefecture.
A-9. Eel stocking
Table 3 presents a summary of historical data on the number of eels stocked in inland waters of Japan. No eel stocking in coastal waters.
| Report | Reference period (year) | Census interval (year) | Aggregation period | Available period of eel–stocking data by aggregation level (year) | ||||
|---|---|---|---|---|---|---|---|---|
| From | To | Initial date | Last date | Total in Japan | Prefecture-by-prefecture | Site-by-site | ||
| SYMAF | 1921 | 1946 | 1 | Jan 1 | Dec 311 | 1921–1946 | 1930–1946 | NA |
| ARCSFA | 1957 | 1962 | 1 | Jan 1 | Dec 31 | 1957–1962 | 1957–1962 | NA |
| ASFAP | 1963 | 1969 | 1 | Jan 1 | Dec 31 | 1963–19692 | 1957–19653 | 1966–1969 |
| COF | 1973 | 2013 | 5 | Nov 1 | Oct 31 | 1973, 1988, 1993, 1998, 2003 | 1973, 1988, 1993, 1998, 2003 | 1988, 1993, 1998, 2003 |
1The aggregation period of the SYMAF differs by year: Jan 1 to Dec 31 in 1921–1940; prior Aug 1 to Jul 1 in 1941–1946.
2From 1966 through 1969, the total number of eels stocked was not recorded in the ASFAP. We calculated them by summing all available data by site (river and lake) in the ASFAP.
3The number of eels stocked by prefecture in 1963 was not recorded in the ASFAP. We used the data from the SYMAF (1963).
A-10. Fishery management entity (FME)
Table 4 presents a summary of data related to the number of the lake FMEs that caught or mainly targeted yellow or silver eels, and the inland FMEs that caught glass/elver eels (seeds). No data are available for the river or coastal FMEs.
| Report | Reference period (year) | Census interval (year) | Aggregation period | Available period of FME data by aggregation level (year) | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Number of lake FMEs that caught yellow/silver eels | Number of lake FMEs that mainly targeted yellow/silver eels | Number of the inland FMEs that caught glass/elver eels (seeds) | |||||||||||
| From | To | Initial date | Last date | Total | Prefecture-by-prefecture1 | Lake-by-lake | Total | Prefecture-by-prefecture1 | Lake-by-lake | Total | Prefecture-by-prefecture | ||
| COF | 1968 | 2008 | 5 | Nov. 1 | Oct. 31 | 1978, 1983, 1988, 1993, 1998, 2003, 2008 | 1983, 1988, 1993, 1998, 2003, 2008 | 1983, 1988, 1993, 1998, 2003, 2008 | 1978, 1983, 1988, 1993, 1998, 2003, 2008 | 1968, 1973, 1978, 1983, 1988, 1993, 1998, 2003, 2008 | 1968, 1973, 1978, 1983, 1988, 1993, 1998, 2003, 2008 | 1973, 1983, 1988, 1993, 1998 | 1973, 1983, 1988, 1993, 1998 |
1The Census of Fisheries recorded the FME data by lake, but the data were not recorded by prefecture. Therefore, we calculated the FME data by prefecture by summing the available lake data for each prefecture.
7. Data Status
Latest update: October 2018
8. Accessibility
A. License and usage rights
1) Acceptable use. Use of the data set will be restricted to academic, research, educational, government, biodiversity conservation, or other non-profit professional purposes. 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 data set. As the metadata and the data set may be updated, the date the data was retrieved should also be included in the citation. 3) Collaboration. Data users are strongly encouraged to consider consultation, collaboration, and/or co-authorship with the authors.
B. Contact persons
See 3. B.
C. Storage location
9. Data Structure
A. Dataset files
The dataset is recorded in ten separate files (Table 5). Table 5 presents the names of each file, descriptions of data in each file, and links to information related to variables in each file (Table 6–16).
|
Data file name |
Description |
Information on variables in the file |
|---|---|---|
|
Harvest_by_water_and_in_total_Japan.csv |
The annual harvests of Japanese eel (total and seed harvests) in inland and coastal waters, and throughout Japan. |
|
|
Harvest_by_prefecture.csv |
Annual harvests of Japanese eel by prefecture. The data file includes the total annual harvests of eels in the prefecture, the annual harvests of eels in the inland water within the prefecture, and the annual harvests of seeds in inland and coastal waters within the prefecture. |
|
|
Harvest_by_river.csv |
Annual harvests of Japanese eel (total and seed harvests) from rivers. |
|
|
Harvest_by_lake.csv |
Annual harvests of Japanese eel (total and seed harvests) from lakes. |
|
|
Seed_harvest_by_prefecture_1941-1946.csv |
Annual numbers of seed harvests by prefecture during 1941–1946. |
|
|
Eel_stocking_in_total_Japan.csv |
Annual amounts of eels stocked throughout Japan. |
|
|
Eel_stocking_by_prefecture.csv |
Annual amounts of eels stocked by prefecture. |
|
|
Eel_stocking_by_site.csv |
Annual amounts of eels stocked by site (river and lake). |
|
|
FME_by_prefecture.csv |
Number of FMEs by prefecture and year. The data file includes the number of FMEs that caught eels in lakes within the prefecture, the number of the FMEs that mainly targeted eels in lakes within the prefecture, and the number of the FMEs that caught seeds in inland waters within the prefecture. |
|
|
FME_by_lake.csv |
Number of FMEs by lake and year. The data file includes the number of FMEs that caught eels in the lake and the number of FMEs that mainly targeted eels in the lake. |
B. Format type
The data are in CSV text files with LF line-endings.
The name of each variable is listed in the first row (header row) of the CSV file.
C. Variable information
|
Variable name |
Variable definition |
Unit |
Storage type |
Rounding increment |
Rounding method |
|---|---|---|---|---|---|
|
Year |
Fishing year |
year |
Integer |
NA |
NA |
|
From |
Beginning of the fishing year. mm-dd |
day |
Character |
NA |
NA |
|
To |
End of the fishing year. mm-dd |
day |
Character |
NA |
NA |
|
Total_eel_harvest |
Annual harvest of eels throughout Japan, including glass eel, elver, yellow eel, and silver eel |
ton |
Real number |
0.00375 |
Round half up in 1984–1953 and 1965–2015; Round down in 1954–1964 |
|
Inland_eel_harvest |
Annual harvest of eels in the inland water of Japan, including glass eel, elver, yellow eel, and silver eel |
ton |
Real number |
0.375 in 1949–1957; 0.1 in 1958; 1 in 1959–2015 |
Round half up in 1984–1953 and 1965–2015; Round down in 1954–1964 |
|
Inland_seed_harvest |
Annual harvest of seeds in inland waters of Japan |
ton |
Real number |
0.375 in 1957; 0.1 in 1958; 0.001 in 1974; 1 in 1959–1973 and 1975–2015 |
Round half up in 1984–1953 and 1965–2015; Round down in 1954–1964 |
|
Coastal_seed_harvest |
Annual harvest of seeds in coastal waters of Japan |
ton |
Real number |
0.375 in 1957; 0.001 in 1958–1960; 1 in 1961–2015 |
Round half up in 1984–1953 and 1965–2015; Round down in 1954–1964 |
|
Data_source |
Data source of the dataset. |
NA |
Character |
NA |
NA |
|
Variable name |
Variable definition |
Unit |
Storage type |
Rounding increment |
Rounding method |
|---|---|---|---|---|---|
|
Year |
Year |
NA |
Integer |
NA |
NA |
|
From |
Beginning of the fishing year. mm-dd |
day |
Character |
NA |
NA |
|
To |
End of the fishing year. mm-dd |
day |
Character |
NA |
NA |
|
Prefecture |
Prefecture name |
NA |
Character |
NA |
NA |
|
Pref_Code |
Prefecture code. Numerical part of the ISO 3166-2 code |
NA |
Integer |
NA |
NA |
|
Lat |
Latitude of the prefecture capital |
Decimal degrees (WGS84) |
Real number |
10-7 |
Round half up |
|
Long |
Longitude of the prefecture capital |
Decimal degrees (WGS84) |
Real number |
10-7 |
Round half up |
|
Total_eel_harvest |
Total annual harvest of eels in the prefecture, including glass eel, elver, yellow eel, and silver eel
|
ton |
Real number |
0.00375 |
Round half up in 1984–1953 and 1965–2015; Round down in 1954–1964 |
|
Inland_eel_harvest |
Annual harvest of eels in the inland water within the prefecture, including glass eel, elver, yellow eel, and silver eel |
ton |
Real number |
0.375 in 1949–1957; 0.1 in 1958; 1 in 1959–2015 |
Round half up in 1984–1953 and 1965–2015; Round down in 1954–1964 |
|
Inland_seed_harvest |
Annual harvest of seeds in inland waters within the prefecture |
ton |
Real number |
0.375 in 1957; 0.1 in 1958; 0.001 in 1974; 1 in 1959–1973 and 1975–2015 |
Round half up in 1984–1953 and 1965–2015; Round down in 1954–1964 |
|
Coastal_seed_harvest |
Annual harvest of seeds in coastal waters within the prefecture |
ton |
Real number |
0.375 in 1957; 0.001 in 1958–1960; 1 in 1961–2015 |
Round half up in 1984–1953 and 1965–2015; Round down in 1954–1964 |
|
Data_source |
Data source of the dataset. |
NA |
Character |
NA |
NA |
|
Variable name |
Variable definition |
Unit |
Storage type |
Rounding increment |
Rounding method |
|---|---|---|---|---|---|
|
Year |
Fishing year |
NA |
Integer |
NA |
NA |
|
From |
Beginning of the fishing year. mm-dd |
day |
Character |
NA |
NA |
|
To |
End of the fishing year. mm-dd |
day |
Character |
NA |
NA |
|
River |
River name |
NA |
Character |
NA |
NA |
|
Lat |
Latitude of the river |
Decimal degrees (WGS84) |
Real number |
10-7 |
Round half up |
|
Long |
Longitude of the river |
Decimal degrees (WGS84) |
Real number |
10-7 |
Round half up |
|
Prefecture |
Name of prefecture that includes the river. Alternatively, the name of the prefecture with the largest of harvests in the river crossing prefectures |
NA |
Character |
NA |
NA |
|
Pref_Code |
Prefecture code. Numerical part of the ISO 3166-2 code |
NA |
Integer |
NA |
NA |
|
Eel_harvest |
Annual harvest of eels in the river, including glass eel, elver, yellow eel, and silver eel |
ton |
Real number |
0.375 in 1954–1956; 1 in 1965–2015 |
Round down in 1954–1956; Round half up in 1965–2015; |
|
Seed_harvest |
Annual harvest of seeds in the river |
ton |
Real number |
1 |
Round half up |
|
Data_source |
NA |
Character |
NA |
NA |
|
|
Note |
Names of prefectures engaged in eel fisheries in the river are denoted as prefecture:prefecture:...:prefecture. (e.g., "Tokyo:Saitama:Chiba" for Tokyo, Saitama, and Chiba). |
NA |
Character |
NA |
NA |
1 Prefecture at the mouth of the river for large rivers that cross prefectures.
|
Variable name |
Variable definition |
Unit |
Storage type |
Rounding increment |
Rounding method |
|---|---|---|---|---|---|
|
Year |
Fishing year |
NA |
Integer |
NA |
NA |
|
From |
Beginning of the fishing year. mm-dd |
day |
Character |
NA |
NA |
|
To |
End of the fishing year. mm-dd |
day |
Character |
NA |
NA |
|
Lake |
Lake name |
NA |
Character |
NA |
NA |
|
Lat |
Latitude of the lake |
Decimal degrees (WGS84) |
Real number |
10-7 |
Round half up |
|
Long |
Longitude of the lake |
Decimal degrees (WGS84) |
Real number |
10-7 |
Round half up |
|
Prefecture |
Name of prefecture that includes the lake. Alternatively, the name of the prefecture with the largest of harvests in the lake crossing prefectures |
NA |
Character |
NA |
NA |
|
Pref_Code |
Prefecture code. Numerical part of the ISO 3166-2 code |
NA |
Integer |
NA |
NA |
|
Eel_harvest |
Annual harvest of eels in the lake, including glass eel, elver, yellow eel, and silver eel |
ton |
Real number |
0.375 in 1954–1956; 1 in 1965–2015 |
Round down in 1954–1956; Round half up in 1965–2015; |
|
Seed_harvest |
Annual harvest of seeds in the lake |
ton |
Real number |
1 |
Round half up |
|
Data_source |
NA |
Character |
NA |
NA |
|
|
Note |
Names of prefectures that engaged in eel fisheries in the lake are denoted as prefecture:prefecture:...:prefecture. (e.g., "Tokyo:Saitama:Chiba" for Tokyo, Saitama, and Chiba). |
NA |
Character |
NA |
NA |
|
Variable name |
Variable definition |
Unit |
Storage type |
Rounding increment |
Rounding method |
|---|---|---|---|---|---|
|
Year |
Fishing year |
NA |
Integer |
NA |
NA |
|
From |
Beginning of the fishing year. mm-dd |
day |
Character |
NA |
NA |
|
To |
End of the fishing year. mm-dd |
day |
Character |
NA |
NA |
|
Prefecture |
Prefecture name |
NA |
Character |
NA |
NA |
|
Pref_Code |
Prefecture code. The numerical part of the ISO 3166-2 code |
NA |
Integer |
NA |
NA |
|
Lat |
Latitude of the prefecture capital |
Decimal degrees (WGS84) |
Real number |
10-7 |
Round half up |
|
Long |
Longitude of the prefecture capital |
Decimal degrees (WGS84) |
Real number |
10-7 |
Round half up |
|
Seed_harvest |
Annual harvest of seeds in the prefecture |
Number in thousand |
Integer |
1 |
Round half up |
|
Data_source |
Data source of the dataset. |
NA |
Character |
NA |
NA |
|
Variable name |
Variable definition |
Unit |
Storage type |
Rounding increment |
Rounding method |
|---|---|---|---|---|---|
|
Year |
Fishing year |
year |
Integer |
NA |
NA |
|
From |
Beginning of the fishing year. mm-dd |
day |
Character |
NA |
NA |
|
To |
End of the fishing year. mm-dd |
day |
Character |
NA |
NA |
|
Total_eel_stocked |
Total annual number of eels stocked in inland waters of Japan |
Number in thousand |
Integer |
1 |
Round half up in 1921–1946 and 1965–2015; Round down in 1957–1964 |
|
Data_source |
Data source of the dataset. |
NA |
Character |
NA |
NA |
|
Note |
Potential outlier is denoted as "Outlier". |
NA |
Character |
NA |
NA |
|
Variable name |
Variable definition |
Unit |
Storage type |
Rounding increment |
Rounding method |
|---|---|---|---|---|---|
|
Year |
Year |
NA |
Integer |
NA |
NA |
|
From |
Beginning of the fishing year. mm-dd |
day |
Character |
NA |
NA |
|
To |
End of the fishing year. mm-dd |
day |
Character |
NA |
NA |
|
Prefecture |
Prefecture name |
NA |
Character |
NA |
NA |
|
Pref_Code |
Prefecture code. Numerical part of the ISO 3166-2 code |
NA |
Integer |
NA |
NA |
|
Lat |
Latitude of the prefecture capital |
Decimal degrees (WGS84) |
Real number |
10-7 |
Round half up |
|
Long |
Longitude of the prefecture capital |
Decimal degrees (WGS84) |
Real number |
10-7 |
Round half up |
|
Eel_stocked |
Annual number of eels stocked in inland waters within the prefecture
|
Number in thousand |
Integer |
1 |
Round half up in 1930–1946 and 1965–2013; Round down in 1957–1964 |
|
Data_source |
Data source of the dataset. |
NA |
Character |
NA |
NA |
|
Note |
Potential outlier is denoted as "Outlier". |
NA |
Character |
NA |
NA |
|
Variable name |
Variable definition |
Unit |
Storage type |
Rounding increment |
Rounding method |
|---|---|---|---|---|---|
|
Year |
Fishing year |
NA |
Integer |
NA |
NA |
|
From |
Beginning of the fishing year. mm-dd |
day |
Character |
NA |
NA |
|
To |
End of the fishing year. mm-dd |
day |
Character |
NA |
NA |
|
Site |
Name of site (river and lake) |
NA |
Character |
NA |
NA |
|
Lat |
Latitude of the site |
Decimal degrees (WGS84) |
Real number |
10-7 |
Round half up |
|
Long |
Longitude of the site |
Decimal degrees (WGS84) |
Real number |
10-7 |
Round half up |
|
Prefecture |
Name of prefecture that includes the site. Alternatively, the name of the main prefecture stocked eels for the site crossing prefectures. |
NA |
Character |
NA |
NA |
|
Pref_Code |
Prefecture code. Numerical part of the ISO 3166-2 code |
NA |
Integer |
NA |
NA |
|
River_or_Lake |
River or lake |
NA |
Character |
NA |
NA |
|
Eel_stocked |
Annual number of eels stocked at the site |
Number in thousand |
Integer |
1 |
Round half up |
|
Data_source |
NA |
Character |
NA |
NA |
|
|
Note |
Names of prefectures that stocked eels in the site are denoted by prefecture:prefecture:...:prefecture. (e.g., "Tokyo:Saitama:Chiba" for Tokyo, Saitama, and Chiba). |
NA |
Character |
NA |
NA |
|
Variable name |
Variable definition |
Unit |
Storage type |
Rounding increment |
Rounding method |
|---|---|---|---|---|---|
|
Year |
Year |
NA |
Integer |
NA |
NA |
|
From |
Beginning of the fishing year. mm-dd |
day |
Character |
NA |
NA |
|
To |
End of the fishing year. mm-dd |
day |
Character |
NA |
NA |
|
Prefecture |
Prefecture name |
NA |
Character |
NA |
NA |
|
Pref_Code |
Prefecture code. Numerical part of the ISO 3166-2 code |
NA |
Integer |
NA |
NA |
|
Lat |
Latitude of the prefecture capital |
Decimal degrees (WGS84) |
Real number |
10-7 |
Round half up |
|
Long |
Longitude of the prefecture capital |
Decimal degrees (WGS84) |
Real number |
10-7 |
Round half up |
|
FME_caught_eel |
Number of the FMEs that caught yellow/silver eels in prefecture lakes
|
Number |
Integer |
NA |
NA |
|
FME_target_eel |
Number of the FMEs that mainly targeted yellow/silver eels in prefecture lakes
|
Number |
Integer |
NA |
NA |
|
FME_caught_seed |
Number of the FMEs that caught seeds in inland waters within the prefecture
|
Number |
Integer |
NA |
NA |
|
Data_source |
Data source of the dataset. |
NA |
Character |
NA |
NA |
|
Variable name |
Variable definition |
Unit |
Storage type |
Rounding increment |
Rounding method |
|---|---|---|---|---|---|
|
Year |
Fishing year |
NA |
Integer |
NA |
NA |
|
From |
Beginning of the fishing year. mm-dd |
day |
Character |
NA |
NA |
|
To |
End of the fishing year. mm-dd |
day |
Character |
NA |
NA |
|
Lake |
Lake name |
NA |
Character |
NA |
NA |
|
Lat |
Latitude of the lake |
Decimal degrees (WGS84) |
Real number |
10-7 |
Round half up |
|
Long |
Longitude of the lake |
Decimal degrees (WGS84) |
Real number |
10-7 |
Round half up |
|
Prefecture |
Name of prefecture that includes the lake. Alternatively, the name of the prefecture with the greatest number of FMEs for the lake crossing prefectures. |
NA |
Character |
NA |
NA |
|
Pref_Code |
Prefecture code. Numerical part of the ISO 3166-2 code |
NA |
Integer |
NA |
NA |
|
FME_caught_eel |
Number of the FMEs that caught yellow/silver eels in the lake |
Number |
Integer |
NA |
NA |
|
FME_target_eel |
Number of the FMEs that mainly targeted yellow/silver eels in the lake |
Number |
Integer |
NA |
NA |
|
Data_source |
Data source of the dataset. |
NA |
Character |
NA |
NA |
|
Note |
Names of prefectures that have FMEs in the lake are denoted as prefecture:prefecture:...:prefecture. (e.g., "Tokyo:Saitama:Chiba" for Tokyo, Saitama, and Chiba). |
NA |
Character |
NA |
NA |
10. Acknowledgments
This work was supported by grants from the Fisheries Research Agency, and the River Foundation (River Environment Fund, Grant Number 24–1215–017).
11. References
Aichi Prefecture (1925) Taisho 10 nen Aichi ken tōkei sho. Aichi Prefecture, Aichi (in Japanese)
Aoki S (2004) Drawing a colored map. http://aoki2.si.gunma-u.ac.jp/R/color-map2.html. Accessed 8 May 2015 (in Japanese)
Food and Agriculture Organization [FAO] (1995) Code of conduct for responsible fisheries. FAO, Rome
International Union for Conservation of Nature [IUCN] (2015) The IUCN Red List of Threatened Species. http://www.iucnredlist.org/. Accessed 8 May 2015
International Union for Conservation of Nature [IUCN] (2014) IUCN – IUCN Red List raises more red flags for threatened species. http://www.iucn.org/?14964/IUCN-Red-List-raises-more-red-flags-for-threatened-species. Accessed 8 May 2015
Jacoby D, Gollock M (2014) Anguilla japonica. The IUCN Red List of Threatened Species. Version 2015.1. http://www.iucnredlist.org/details/166184/0. Accessed 8 May 2015
Joint Statement (2014) Joint Statement of the Bureau of Fisheries of People’s Republic of China, the Fisheries Agency of Japan, the Ministry of Oceans and Fisheries of the Republic of Korea and the Fisheries Agency of Chinese Taipei on International Cooperation for Conservation and Management of Japanese Eel Stock and Other Relevant Eel Species. http://www.jfa.maff.go.jp/j/saibai/pdf/140917jointstatement.pdf. Accessed 8 May 2015
Kriebel D, Tickner J, Epstein P, Lemons J, Levins R, Loechler EL, Quinn M, Rudel R, Schettler T, Stoto M (2001) The precautionary principle in environmental science. Environ Health Perspect 109:871–876
Ministry of Agriculture and Commerce [MAC] (1896–1925) Statistical Report of the Department of Aquaculture and Commerce [SRDAC]. MAC, Tokyo (in Japanese)
Ministry of Agriculture and Forestry of Japan [MAF] (1926–1977) Statistical Yearbook of Ministry of Agriculture and Forestry [SYMAF]. MAF, Tokyo (in Japanese)
Ministry of Agriculture and Forestry of Japan [MAF] (1955–1963) Annual Report of Catch Statistics on Fishery and Aquaculture [ARCSFA]. MAF, Tokyo (in Japanese)
Ministry of Agriculture and Forestry of Japan [MAF], Nōrin Tōkei Kenkyūkai [NTK] (1978) Suisan gyō ruinen tōkei, No. 3, todōfuken betu tōkei, NTK, Tokyo (in Japanese)
Ministry of Agriculture, Forestry and Fisheries of Japan [MAFF] (2015) Ministry of Agriculture, Forestry and Fisheries / Kaimen gyogyō seisan tōkei chōsa. http://www.maff.go.jp/j/tokei/kouhyou/kaimen_gyosei/index.html. Accessed 8 May 2015 (in Japanese)
Ministry of Agriculture, Forestry and Fisheries of Japan [MAFF] (2014) Book/Journal Cross Search. http://www.library.maff.go.jp/opac/AllSchE.htm. Accessed 8 May 2015
Ministry of Agriculture, Forestry and Fisheries of Japan [MAFF] (1964–2015) Annual Statistics on Fishery and Aquaculture Production [ASFAP]. MAFF, Tokyo (in Japanese)
Ministry of Agriculture, Forestry and Fisheries of Japan [MAFF] (1971, 1975, 1980, 1985, 1990, 1995, 2000, 2005, 2010, 2015) The Census of Fisheries [COF]: Inland Fisheries. MAFF, Tokyo (in Japanese)
Ministry of Internal Affairs and Communications of Japan [MIAC] (2015) Portal Site of Official Statistics of Japan. http://www.e-stat.go.jp/SG1/estat/eStatTopPortalE.do. Accessed 8 May 2015
Ministry of the Environment of Japan [MOE] (2015) Red Data Book 2014. — Threatened Wildlife of Japan — Volume 4, Pisces—Brackish and Fresh Water Fishes, ME, Tokyo, pp 148–149 (in Japanese)
Ministry of the Environment of Japan [MOE] (2013) Press release: The Fourth version of the Japanese Red Lists on Pisces—Brackish and Fresh Water Fishes. http://www.env.go.jp/press/16264.html. Accessed 8 May 2015 (in Japanese)
Pauly D, Hilborn R, Branch TA. (2013) Does catch reflect abundance? Nature, 494:303–306, doi:10.1038/494303a
Tanaka K (2014) Stock assessment of Japanese eels using Japanese abundance indices. Fish Sci, 80:1129-1144
Tatsukawa K (2003) Eel resources in east Asia. In: Aida K, Tsukamoto K, Yamauchi K (ed) Eel Biology. Springer, Tokyo, pp 293–298
Tokyo Prefecture (1906) Meiji 38 nen Tokyo fu tōkei sho. Tokyo Prefecture, Tokyo (in Japanese)
Wiener JB (2001) Precaution in a multi-risk world. In: Paustenbach DD (ed) The Risk Assessment of Environmental and Human Health Hazards, John Wiley & Sons, New York, pp 1509–1531
Forgot your password?
