0-26 General Biological Observations. — 



Marine life in the oceans is important to tlie 

 conduct of naval operations and is of interest 

 to the oceanograpliic community in general; 

 therefore, the visual sightings of biological life 

 should be recorded by the oceanographic ob- 

 server. A suggested format for a biological ob- 

 servation sheet is given in figure 0-14. 



0-27 Deep Scattering Layer. — The presence 

 of the deep scattering layer (DSL) often can be 

 observed with echo-sounding equipment. AVhen 

 evidence of these biological phenomenon are 

 observed on the echogram, the echo sounder 

 should be adjusted to obtain a good signal at 

 the deep scattering layer depth, and the chart 

 should be annotated with appropriate informa- 

 tion to indicate DSL. Enter the observation 

 under remarks on the biological observation 

 sheet, indicating depth of DSL, depth of water, 

 date, time, position, and echogram roll number. 



Instruction for obtaining DSL data with the 

 AN/UQN-1 echo sounder follow : 



Step 1. At 0400 (local time) each day, turn 

 the recorder on, press the EVENT MARK, 

 and using a soft lead pencil, annotate the chart 

 paper with date, local time, latitude, and 

 loiigitude. 



Step 2. Switch the recorder to the 600-f athom 

 scale, and advance the GAIN control to the 

 point of blackening the paper; then, reduce the 

 GAIN until the contrast is suitable for record- 

 ing the scattering layer. Record the GAIN con- 

 trol setting on the chart paper. 



Step 3. At each hour, press the EVENT 

 MARK and annotate the local time, and at 

 least once during each watch, record tlie injec- 

 tion line temperature on the chart. In addition, 



mark significant course changes and points 

 wliere ship's track crosses a parallel or meridian 

 that is a multiple of 5°. Make necessary GAIN 

 control adjustments, from time to time, to im- 

 prove contrast. Alway annotate new GAIN 

 settings. 



Step 4. Secure the recorder at 2100 (local 

 time). 



Step 5. At the end of an exercise, annotate 

 the sounding records with the ship's name, fold 

 the chart in an accordian pleat, and forward 

 to Commander, Naval Oceanographic Office, 

 Washington, D.C. 20390. 



0-28 Seabird Observations. — The presence or 

 absence of pelagic seabirds in an ocean area 

 constitutes a seabird observation. A suggested 

 format for logging seabird observations is given 

 in figure 0-15. 



Seabird observations, if possible, should in- 

 clude species ( followed by P for positive identi- 

 fication, U for uncertain) ; size of bird (body, 

 wingspread) ; common name; age (adult, ju- 

 venile, immature) ; sex; color description of 

 plumage, bill, feet, and eye; sketches showing 

 plumage patterns, wing shape, shape of bill, 

 etc. ; and the approximate number of birds in a 

 flock. Figure 0-16 is a suggested format for a 

 field identification of seabirds. 



Binoculars, a camera with telephoto lens, and 

 ornithological publications such as W. B. Alex- 

 ander's "Birds of the Ocean" (1928, G. P. Put- 

 nam's Sons, New York, republished 1954), G. E. 

 Watson's "Seabirds of the Tropical Atlantic 

 Ocean" (1965, Smithsonian Institution, Wash- 

 ington, D.C), or R. T. Peterson's "A Field 

 Guide to the Birds" (1947, Houghton Mifflin, 

 Boston) will be helpful to the observer. 



0-14 



