Cetacean Sightings Survey and Southern Ocean Cetacean Program - data collected from the BROKE-West voyage of the Aurora Australis, 2006
Data were entered real-time as and when observations were made, with time (GMT) and Lat/Long drawn directly from ship data. These data have not been validated. Observation on V3 commenced as the Aurora Australis departed Fremantle and concluded on the approach to Hobart. The SOCEP research objective...
| Summary: | Data were entered real-time as and when observations were made, with time (GMT) and Lat/Long drawn directly from ship data. These data have not been validated. Observation on V3 commenced as the Aurora Australis departed Fremantle and concluded on the approach to Hobart. The SOCEP research objective is to detect and document cetacean sightings and relevant environmental and other information throughout the voyage. The BROKE-West multidisciplinary voyage provides an opportunity to correlate sightings data with oceanographic and biology research conducted by other programs. Search effort is conducted over a broad range of weather conditions. The majority of Antarctic species are medium to large whales, with cues that can be detected in relatively high Beaufort sea states up to and including Beaufort Sea State 7. Observers search for whales while ever light, weather and sea conditions are suitable unless the vessel is stopped (e.g. CTD stations) or traveling slowly (e.g. trawling). Data are recorded using a laptop computer-based sighting program (Wincruz for Logger v3) that automatically logs under-way data from the ship's system including GPS position, ship course and speed, wind direction and speed, and also downloads time and date when required (F1 key). Data Collection In the preferred and highest level of (Full Effort) two observers are positioned on the port (Port) and starboard (Starboard) sides of the flying bridge (wheelhouse roof). The search area is an arc 180 degrees ahead to abeam of the vessel, primarily with the naked eye and augmented by the use of Fujinon 7x50 binoculars. A third observer (Tracker) is also stationed on the flying bridge. This person's role is to positively identify species, numbers and behaviour, particularly in the case of distant sightings, with the aid of Fujinon 25 x 150 binoculars (BigEyes). This team member also captures digital video footage of cetacean sightings when appropriate. The fourth rostered team member, the Central Logger (CL) is located on the bridge and communicates with those on the flying bridge via hand-held radio transceiver. The role of the CL is to record all relevant data on the Logger laptop computer. When in sea ice, a fifth member of the team ('Duplicate Identifier') is rostered to collect sea ice digital still images and video, and enter ice data in the SeaIce page in Logger. The CL monitors the effort activity and progressively updates as necessary general information such as search effort, observers, weather, sea conditions. Search effort is dropped a lower level of effort (CAS Effort), if visibility is determined to be too poor for Full Effort due to some combination of adverse weather conditions that precluded detection of most species (i.e. strong winds, fog, and large swell, confused swell, high sea state). If conditions become too poor to survey, or if the ship is traveling slowly or stopped, the effort is terminated (Off Effort). At such times the CL is generally rostered to remain on the bridge to ensure that passing whales do not go unreported, and to alert the rest of the team when the ship begins transiting at speed again or if visibility improves. Sightings When observers report whale sightings the CL enters the time, angle and distance from vessel, species identification, number of animals, sighting cue, behaviour and presence of ice and ancillary data. Cetaceans are identified to the lowest taxonomic level possible. Positive species identification is made only when there is certainty. Best, high and low estimates of group size are recorded for each sighting, and where more than one observer made an estimate, the final record is arrived at by consensus. Photographic records of cetaceans (and other wildlife and habitat) are collected opportunistically using digital cameras. Other Wildlife Seal and penguin species are logged while in sea ice, and opportunistically elsewhere. Flying birds within 100 metres of the ship are logged half-hourly, and large flocks are logged when observed. Other Event Occurrences such as the sighting or marine debris are logged as they are observed. Sea Ice Data Sea ice observations are recorded in Logger every 10 minutes while in transit in sea ice unless the ship is stopped or transiting slowly. Sea ice data are based on observations within a 1km 90 degree radius of the ship on the port side. A buoy of known diameter is suspended just above the waterline in front of the bridge to assist with estimates of ice and snow thickness. Sea ice still digital images are taken every 10 minutes while in transit in sea ice (unless transiting slowly), coinciding with SeaIce data recording in Logger. Sea Ice continuous video is taken for ten minutes each half-hour, showing the bow and horizon. The images and video assist in post cruise validation of sea ice thickness and assessment of the 1km radius for sea ice data collection. Sea ice habitat images are also captured when/where minke whales are sighted. Acronyms % Species 1 Percentage of group made up by Species 1 % Species 2 Percentage of group made up by Species 2 % Species 3 Percentage of group made up by Species 3 Bearing Bearing of sighting, in degrees, relative to the ship Beaufort Sea state assessment using Beaufort Scale (1-12) Berg Count No of icebergs 180 degrees ahead Best school size Best estimate of the number in group Casual observations (CAS) Lower level of Effort e.g. fewer observers Duplicate Identifier Person gathering/entering ice observations/images Dynamics Changes to the pod's composition. Effort Status Classification of level of observation effort End Time Time sighting observation ended Est distance Estimated distance from ship in nm. Floe Size Descriptive of size/nature of ice flows Full effort Highest level of observation effort Glare strength Classification of glare as it effects visibility Habitat Bathymetry Determined by reference to ship's chart High school size Highest estimate of the number in group Ice Conc Concentration of ice, in tenths Ice Thick Ice thickness in cm Ice Type Descriptive nature of ice Image File Identification number allocated to image taken at time of data entry In or Near Ice Ice conditions where wildlife was sighted Initial cue What first drew the observer's attention to the sighting. Left Glare Left extremity of glare Low school size Lowest estimate of the number in group Method Whether sighting was made using naked eye, 7x50 binoculars or 25x150 (Big-eye) binoculars Minke Vis Estimate of the distance at which a minke whale blow could be seen in prevailing conditions Notes For Recorder's additional information and comments Observer Person reporting the sighting Open Water Overall ice/water situation Port Observer monitoring the ocean on the port side Primary Ice Obs. Observations of thickest ice type Reaction The animal's reaction to the ship Recorder Person entering data into Logger Right Glare Right extremity of glare Secondary Ice Obs. Observations of second-thickest ice type Sightability Assessment of overall viewing conditions Sighting No Progressive numbering of whale sightings by Logger (default) Snow Thick Snow thickness in cm Snow Type Descriptive of snow on ice Species 1 When multiple species are being reported, with the species in greatest number listed first Starboard Observer monitoring the ocean on the starboard side Swell Code Descriptive of ocean swell Swell Direction Compass direction from which swell moving. Swim direction Animal's swim direction in degrees relative to the ship's heading Tertiary Ice Obs Observations of third-thickest ice type Topog Descriptive of ice topography e.g. ridging Total Ice Conc Ice concentration in tenths Tracker Observer using BigEyes binoculars to identify species, and assisting other observers generally Weather Code Weather conditions effecting visibility An excel spreadsheet containing a full list of terms used in the observation logs is available for download from the URL given below. This work was completed as part of ASAC projects 2253, 2655 and 2679 (ASAC_2253, ASAC_2655, ASAC_2679). |
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