FISHERY BULLETIN: VOL. 70. NO. 3 



Figure 3. — Block areas grouped in zones (C-K), selected to outline the more important coastal fishing areas. 



4. Whales, porpoises, and sharks were re- 

 corded as numbers of individuals observed. 



5. When the flight track entered any portion 

 of a block area, the block area was credited for 

 the purpose of determining observation efl!"ort 

 as having a "block area flight." 



RESULTS 



During survey flights, 20 species of fish were 

 observed and identified. A number of other 

 marine species (mammals, invertebrates) were 

 observed and all are listed in Table 1. 



DISTRIBUTION OF FLIGHT 

 OBSERVATION EFFORT 



A total of 17,593 flight hours were logged by 

 spotter pilots during the survey period. The 

 number of block area flights from September 



1962 through the end of 1969 totaled 57,628 with 

 37,186 block areas surveyed during the day and 

 20,442 at night. Distribution of day and night 

 block area flights by year and by zone is shown 

 in Table 2. 



NOCTURNAL AND DIURNAL VARIATION 



IN NUMBER OF SIGHTINGS 



AND TONNAGE 



To determine criteria concerning the frequen- 

 cy of observation during the day and night for 

 each of the species more commonly observed, the 

 ratios in numbers of sightings and tonnages ob- 

 served were calculated for the period September 

 1962 through December 1966. Information on 

 the diurnal and nocturnal frequencies and mag- 

 nitude of occurrence for each species is of im- 

 portance in evaluating which observation (day 



1010 



