NUTRIENT DISTRIBUTION IN THE LABRADOR SEA AND 

 BAFFIN BAY ' 



By Nathaniel Corwin and David A. McGill 

 Woods Hole Oceanosraphic Institution 

 Woods Hole, Massachusetts 



The chemical characteristics of the Labrador Sea have not been as 

 thoroughly studied as more southern regions of the North Atlantic 

 Ocean. The general circulation pattern has been determined from 

 observations of temperature and salinity, but other parameters 

 are not widely available from early surveys, except for such limited 

 data as that obtained by the Godthaab expedition of 1928 (Hagen, 

 1931, 1936). The present paper gives the results of determinations 

 of several nutrient elements in sea water samples obtained in July 1962 

 during the annual postseason cruise of the International Ice Patrol. 

 The authors gratefully acknowledge the assistance of the U.S. Coast 

 Guard Oceanographic Unit of the Ice Patrol. 



METHODS 



Plax bottles (8 ounce) were filled with sea water collected on stations 

 of the USCGC Evergreen and were then stored in deep-freeze lockers 

 until the return of the ship to Woods Hole, where the analyses were 

 conducted. Inorganic phosphate and total phosphorus determinations 

 were made for all samples. Nitrate- and nitrite-nitrogen and silicate 

 were also measured. The techniques employed are summarized as 

 follows: 



Inorganic phosphate was determined by the ammonium molybdate 

 method as described by Wooster and Rakestraw (1951). Stannous 

 chloride was used as the reducing agent and measurements were made 

 colorimetrically using a model DU spectrophotometer with a 10-cm 

 light path at 700 m/x- 



Total phosphorus was analysed by the method described b}" Harvey 

 (1948) as modified by Ketchum, Corwin, and Keen (1955). Following 

 digestion in a steam autoclave for 5 hours at a pressure of 38 pounds 

 per square inch, samples were determined colormetricaUy for the 

 molybdate complex reduced by stannous chloride as in the inorganic 

 phosphate method. 



1 This work has been supported in part by the Office of Naval Research under contract Nonr-2196(00) . 

 Contribution No. 1370 from the Woods Hole Oceanographic Institution. 



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