Historic ANARE ship-based wildlife observations from 1947 to 1982.
The quality of the data are varied as they have originate from multiple sources and have been combined into one database. No implicit quality levels have been set. Only observations where the identification of the animal appears certain have been entered. There are however many observations that are...
| Other Authors: | , |
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| Format: | Dataset |
| Language: | unknown |
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Australian Ocean Data Network
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| Online Access: | https://researchdata.ands.org.au/historic-anare-ship-1947-1982/685065 https://data.aad.gov.au/metadata/records/DB_Historic_WoV https://data.aad.gov.au/eds/3328/download http://data.aad.gov.au/aadc/metadata/citation.cfm?entry_id=DB_Historic_WoV |
| Summary: | The quality of the data are varied as they have originate from multiple sources and have been combined into one database. No implicit quality levels have been set. Only observations where the identification of the animal appears certain have been entered. There are however many observations that are recorded against generic species types such as Shearwater sp. or Prion sp. Position data varies. The observers from the first voyages typically logged positions at ship's local noon. The later voyages, from 1975 onwards, improved the position accuracy by recording positions during each hourly observation. For observations without a directly recorded position, the inferred position has been derived from interpolation from the adjacent recorded positions. Most ships in the open ocean travel in fairly consistent directions, especially in fair weather. The error's from such interpolations is at most likely to be less than 60 km for those interpolations done from 24 hour data gaps and substantially less for voyages where there is an hourly log of positions. The vast majority of the observations have been recorded using local ship time with an unknown correction to UTC. On ANARE voyages, as the ship travels over longitude, local ship clocks are migrated forward or back one hour during night time when it is most convenient for day-based activities. This also coincidentally occurs when there are few observations attempted due to low light or darkness. The only exception is the short period around summer solstice. Assuming the estimate of UTC from the ship clock based on longitude of the observation is at most one hour in error and that ships travel at most 12 knots, then a position error based on this timing issue will be less than 20 km (12 nautical miles). It is most likely that this error is nearer 30 minutes of longitude with an associated spatial error in longitude of less than 10km. Given the size of the surveyed region (longitude 40 east to 170 east, distance at 60 deg south of approx 7,000 km), then derived positional errors are small compared to the scale of the region or associated oceanographic features such as polar fronts. A few observations are associated with land features (e.g. Macquarie Island) and their position errors are substantially smaller than the mid-ocean observations. Ship-based observations of birds, seals and whales from the original 'ANARE Bird Log' books have been recovered into a single repository of sightings and associated abiotic information. ANARE (Australian National Antarctic Research Expeditions) is the historic acronym for these voyages. A few voyages have been included that were not part of ANARE but have Australian observers or volunteer observers. Voyages start from the 1947/48 austral season up to 1982/83 with an average of 3 voyages per season. There are a few voyages where there is no data. It is not known if either no bird observations were undertaken during this period or that the bird logs exist if observations were undertaken. Current counts are birds, seals and whales Observing platforms include the following ships - Wyatt Earp, Tottan, River Fitzroy, Norsel, Kista Dan, Thala Dan, Magga Dan, Nella Dan, Lady Franklin and Nanok S and a single voyage from the private yacht Solo. The quality and quantity of abiotic data associated with observations such as air temperature, sea ice cover etc vary immensely from voyage to voyage. Where possible this data has been entered. This dataset contains very little information on estimates of survey effort and cannot be used to derive useful presence/absence spatial coverages of species during this period. It is purely sighting data only. |
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