說明
Original provider: Wildlife Conservation Society Dataset credits: Wildlife Conservation Society Abstract: The Wildlife Conservation Society (WCS) has digitally captured the Townsend Whaling Charts that were published as a series of 4 charts with the article titled "The distribution of certain whales as shown by logbook records of American whale ships" by Charles Haskins Townsend in the journal Zoologica in 1935. The 4 charts show the locations of over 50,000 captures of 4 whale species; sperm whales (36,908), right whales (8,415), humpback whales (2,883) and bowhead whales (5,114). Capture locations were transcribed from North American (“Yankee”) pelagic whale vessel log books dating from 1761 to 1920 and plotted onto nautical charts in a Mercator projection by a cartographer. Each point plotted on the charts represents the location of a whaling ship on a day when one or more whales were taken and is symbolized by month of the year using a combination of color and open and closed circles. Townsend and his cartographer plotted vessel locations as accurately as possible according to log book records. When plotting locations on an earlier sperm whale chart published in 1931 the cartographer spaced points where locations were very dense, "extending areas slightly" for a number of whaling grounds. However, for charts in preparation at this time, Townsend states that "this difficulty is avoided by omitting some of the data, rather than extend the ground beyond actual whaling limits." We assumed that this statement refers to the 1935 charts but there is still some question as to whether the cartographer did in fact space locations and thus expand whaling grounds. Purpose: This dataset provides point features that represent the historical locations of right whale catches taken by North American pelagic whaling vessels between 1761 to 1920. Points were derived from 4 charts that were first scanned on a large format scanner at a resolution of 200 dpi. The charts were then georeferenced in the native projection of the charts, the Mercator projection, using GIS software (ESRI ArcView 3.2). Each vessel capture location plotted on the charts was then digitized as a point feature and attributed with the month of capture. One GIS file (ESRI shapefile) was then created for each whale species represented by the charts; sperm whale, right whale, humpback whale and bowhead whale. Digitizing errors include missed points, particularly from areas of dense chart locations, and incorrect assignment of month of capture because of difficulty distinguishing between chart colors. However to limit these errors multiple checks of digitized and chart locations were made and color enhancements of chart scans were used to ensure correct month assignments. Overall we are confident that at least 95% of catch locations have been digitized and that at least 95% of month attributes are correct. For full resolution digital copies of the Townsend charts please contact Gillian Woolmer (gwoolmer@wcs.org). Supplemental information: [2023-01-31] The year of the date was changed from 1913 to 1849, the midpoint of the time range of the data. WCS digitized the Townsend whaling charts in 2002 using ArcView 3.2 from ESRI. The information WCS has captured for each point location is the whale species (based on the chart) and the month, based on the chart point symbol. Exact dates and number of whales taken was not possible to determine. Right whale captures were separated into northern and southern right whale species, based on their geographic location. Since time, count, day, and year were not available, "00:00:00," 1, 1, and 1913 were used, respectively. Only month is available.
資料紀錄
此資源出現紀錄的資料已發佈為達爾文核心集檔案(DwC-A),其以一或多組資料表構成分享生物多樣性資料的標準格式。 核心資料表包含 34,059 筆紀錄。
此 IPT 存放資料以提供資料儲存庫服務。資料與資源的詮釋資料可由「下載」單元下載。「版本」表格列出此資源的其它公開版本,以便利追蹤其隨時間的變更。
版本
以下的表格只顯示可公開存取資源的已發布版本。
如何引用
研究者應依照以下指示引用此資源。:
Woolmer, G. 2013. Historical distribution of whales shown by logbook records 1785-1913. Data downloaded from OBIS-SEAMAP (http://seamap.env.duke.edu/dataset/885) on yyyy-mm-dd.
權利
研究者應尊重以下權利聲明。:
此資料的發布者及權利單位為 OBIS-SEAMAP。 This work is licensed under a Creative Commons Attribution (CC-BY 4.0) License.
GBIF 註冊
此資源已向GBIF註冊,並指定以下之GBIF UUID: 01d9d254-b18c-458e-b6e1-fc569edb7f09。 OBIS-SEAMAP 發佈此資源,並經由Ocean Biodiversity Information System同意向GBIF註冊成為資料發佈者。
關鍵字
Occurrence,Vessels,Sightings,whales,charts,sperm whale,humpback whale; Observation; Occurrence
外部資料
此資源尚有其他格式可用
OBIS-SEAMAP Dataset Page | https://seamap.env.duke.edu/dataset/885 UTF-8 Interactive map |
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FGDC Metadata | https://seamap.env.duke.edu/dataset/885/xml UTF-8 XML |
聯絡資訊
- 元數據提供者 ●
- 散布者
地理涵蓋範圍
world
界定座標範圍 | 緯度南界 經度西界 [-58.464, -180], 緯度北界 經度東界 [73.264, 180] |
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分類群涵蓋範圍
Scientific names are based on the Integrated Taxonomic Information System (ITIS).
Species | Balaena mysticetus (Bowhead), Megaptera novaeangliae (Humpback Whale), Eubalaena japonica (North Pacific Right Whale), Eubalaena australis (Southern Right Whale), Physeter macrocephalus (Sperm Whale) |
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時間涵蓋範圍
起始日期 / 結束日期 | 1913-01-01 / 1913-12-01 |
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計畫資料
無相關描述
計畫名稱 | Historical distribution of whales shown by logbook records 1785-1913 |
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經費來源 | NA |
參與計畫的人員:
- 擁有者
取樣方法
NA
研究範圍 | NA |
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方法步驟描述:
- NA
收藏資料
蒐藏名稱 | zd_885 |
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蒐藏編號 | zd_885 |
上層採集品識別碼 | OBIS-SEAMAP |
額外的詮釋資料
marine, harvested by iOBIS
目的 | This dataset provides point features that represent the historical locations of right whale catches taken by North American pelagic whaling vessels between 1761 to 1920. Points were derived from 4 charts that were first scanned on a large format scanner at a resolution of 200 dpi. The charts were then georeferenced in the native projection of the charts, the Mercator projection, using GIS software (ESRI ArcView 3.2). Each vessel capture location plotted on the charts was then digitized as a point feature and attributed with the month of capture. One GIS file (ESRI shapefile) was then created for each whale species represented by the charts; sperm whale, right whale, humpback whale and bowhead whale. Digitizing errors include missed points, particularly from areas of dense chart locations, and incorrect assignment of month of capture because of difficulty distinguishing between chart colors. However to limit these errors multiple checks of digitized and chart locations were made and color enhancements of chart scans were used to ensure correct month assignments. Overall we are confident that at least 95% of catch locations have been digitized and that at least 95% of month attributes are correct. For full resolution digital copies of the Townsend charts please contact Gillian Woolmer (gwoolmer@wcs.org). |
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替代的識別碼 | 01d9d254-b18c-458e-b6e1-fc569edb7f09 |
https://ipt.env.duke.edu/resource?r=zd_885 |