Standard Station 



The water depth in the area of operation 

 was too great for anchoring, so the position 

 of 26°21.5'N and 76°46'W was held within the 

 limits of the navigational equipment aboard. 

 This station was located so that it was free of 

 the effects of the Gulf Stream . It was of 48 

 hours duration when conditions permitted. 

 Observations were similar to those taken for 

 regular and special stations except:. 



1 . BT lowerings were made to 900 feet 

 before and after each Nan sen 

 bottle cast. 



2 . Nansen bottle casts were lowered 

 two hours after completion of the 

 previous cast, and were made to a 

 depth of 700 meters with 12 bottles 

 spaced at standard depths . Samples 

 for oxygen and salinity determina- 

 tions were drawn for each cast and 

 treated as on regular stations. 

 Water samples for the other chem- 

 ical determinations were drawn on 

 four casts during the standard sta- 

 tion (these at dawn, mid-day, dusk, 

 and mid-night as nearly as possible). 



3 . Special plankton tows were made for 

 the Office of Naval Research for 

 deep scattering layer investigation 

 (four tows with half-meter silk nets 

 during the station timed to represent 

 the periods of dawn, mid-day, dusk, 

 and mid-night) . Towing depths were 

 surface, 100, and 200 meters . 



4. Hydrophone and special echo- 

 ranging observations were made 

 by the Office of Naval Research . 



5. Dip-netting was conducted continu- 

 ously. 



CHEMICAL METHODS AND PROCEDURES 

 General 

 Containers used for collection of samples 



1 . Total phosphorous and salinity - 

 4 oz . prescription bottles having 

 plastic screw caps with vinyl liners. 



2. Inorganic phosphate - 200 mm. 

 culture tubes with polyethylene 

 screw caps. 



3 . Carbohydrates and proteins - 

 125 mm . culture tubes with 

 plastic screw caps having poly- 

 ethylene inserts. 



4. Nitrate -nitrite - 60 mm. vials 

 with plastic screw caps having 

 polyethylene inserts. 



5 . Oxygen - standard 250 ml . oxygen 

 bottles. 



Initial preparation of containers 



Culture tubes and vials were aged in con- 

 centrated sulfuric acid for approximately one 

 week, thoroughly rinsed with tap water, fol- 

 lowed by three rinses with distilled water. 



Prescription and oxygen bottles were washed 

 with a detergent, rinsed with tap water, fol- 

 lowed by three rinses with distilled water. 



A small amount of thorium carbonate was 

 added to each total phosphorous sample bottle 

 at the shore laboratory (to prevent loss of 

 organic phosphorous by attachment to the 

 sides of the bottle). 



