DISTRIBUTION OF NUTRIENTS 



The deep water distributions of the inorganic phosphate and total 

 phosphorus show that the highest concentrations occur within the 

 central Labrador Sea basin away from the coastal shelves and extend 

 vertically throughout nearly the total extent of the water column. 

 Values of inorganic phosphate greater than 1.0 jugA/l are shown by 

 shading in figure 32. Some maximum values in excess of 1.1 jugA/l 

 can be noted at middepths near the western end of the section. 

 Values across the section begin at about 0.5 MgA/1 at the surface 

 and increase rapidly through the euphotic zone to the highest con- 

 centrations observed, starting at depths from 100 to 300 meters. 

 On the Labrador Shelf the concentrations are 0.1 to 0.2 fxgA/l higher 

 than for the same area near Greenland. A similar distribution is 

 seen in the total phosphorus concentrations reported in figure 33. 

 The highest concentrations obtained are 1.4 /xgA/l in the west and 

 1.3 MgA/1 in the east at depths of 500 to 800 meters. These maxima, 

 shown in figure 33 by the progressive shading of all concentrations 

 greater than 1.1 MgA/1, extend to depths near 2,000 meters. Surface 

 concentrations on the coastal shelves are reduced, with the lowest 

 values for the near-surface depths occurring near Greenland. 



From the difference between the total phosphorus and the inorganic 

 phosphate levels, the concentration of the total organic phosphorus 



GREENLAND 



INORGANIC 

 PHOSPHATE 



Figure 32. — Distribution of inorganic phosphate as PO4-P in MgA/1, along 

 section between South Wolf Island, Labrador, and Cape Farewell, Greenland, 

 from data collected 17-21 July 1963. 



64 



