Sighting data base

This dataset has Commerson’s dolphin <i>Cephalorhynchus c. commersonii</i> and Peale’s dolphin <i>Lagenorhynchus australis</i> sightings collected during eight scientific cruises on board of the vessels <i>R/V Puerto Deseado</i> and <i>Tango SB-15 </i>of Argentina<i> </i>during austral summer and fall months (November-April) between 2009 and 2015, along the Patagonian shelf .Cetacean sightings were recorded on a portable handheld computer with integrated GPS (Trimble Juno ST), using the free software CyberTracker (CyberTracker Software (Pty) Ltd Reg. no. 97/01908/07, http://www.cybertracker.co.za). Surveys were conducted daily during daylight hours (~ 12 hrs) at a mean vessel speed of 10 knots. During the surveys, two observers collected the data from both sides of the vessel, through naked eye scans supplemented by use of 7x50 binoculars<b> </b>with internal compass and reticle. A third observer assisted in the scans and recorded observations. Observers switched between the three positions at 2 hour intervals. Data recorded for each sighting included GPS position, date and time, sighting distance, sighting angle, species, group size and composition. Vessel speed, air temperature, wind speed and direction, Beaufort Sea State (BSS), cloud cover and visibility were recorded at the start of each day and updated whenever they changed.