The flight crew consisted of a pilot, data recorder, and two observers. Observers 

 were positioned on each side of the rear of the aircraft, while the pilot and recorder 

 manned the front seats. The data recorder also served as flight leader and was 

 responsible for flight details. Observer position was switched after 222 km of transect 

 flight. The following DWRC personnel participated as observers and/or recorders during 

 the Pilot Study: John Caffin, Thomas H. Fritts, Larry Hobbs, Wayne Hoffman, A. Blair 

 Irvine, and Robert P. Reynolds. Barbara Dorf and David Schmidly of Texas A & M 

 University also participated as observer/recorders. The observer/recorder seating 

 arrangement described was best for our purposes but should be adapted to the 

 configuration of the plane. 



Data Collection 



While on transect, observers searched continuously. Upon making an observation, 

 the observer relayed the information to the data recorder. The data recorded at each 

 encounter included local time, distance from transect line (radial and perpendicular 

 angles of observation using degrees marked on the wing struts and clinometers), species 

 identification (to the lowest taxon possible), position of sighting (latitude and longitude 

 from Loran C navigation system), group size, direction of movement, activity, and human 

 activities. Flight characteristics and environmental data were recorded at the start of 

 each flight and when changes occurred during the flight. Sea surface temperatures were 

 measured with a radiometer and recorded. Data were recorded with both handwritten 

 and verbal notes (cassette recorders). An example aerial survey observation sheet is 

 shown in Figure 3. Data were reviewed and verified by the flight crew following each 

 day's flight and subsequently transferred to computer compatible format for analysis. 

 Figure 4 summarizes data flow for the field surveys. 



Generally, whenever mammals or turtles were sighted, the aircraft diverted to the 

 sighting and circled for closer inspection. This was not practical for birds because of 

 their mobility. 



In addition to marine mammals, birds, and turtles, sightings were recorded for 

 fish, sharks, sargassum, oil, debris, oil platforms, and boats. 



When possible, vertical and oblique photographs were taken of observations and 

 indexed to actual time and date of observation. 



Environmental Parameters 



Two important variables that potentially influence the distributions of animals in 

 oceanic waters are water depth and distance from shore. These variables are correlated 

 but obvious differences do occur within the subunits surveyed during the present study. 

 Therefore, an attempt was made to separate the effect of depth and distance. Visual 

 representations of bathymetric variation have been constructed on the same scales as 

 maps. Diagrammatic representations of shoreline configurations were also compared to 

 the distributional patterns observed. 



Surface water temperatures were measured using a Barnes PRT-5 radiometer 

 onboard the aircraft at the time of the individual observations. These data are 

 remarkably uniform. Analyses of surface water temperatures are presented in the 

 results. 



