can be determined. The distribution of organic phosphorus is shown 

 in figure 34, which indicates that the eastern half of the basin has a 

 higher level throughout the water column than the western half. 

 The middepth maximum near station 8744 coincides with the pre- 

 viously noted high inorganic and total phosphorus levels in this 

 area. Limited high concentrations near the surface in the western 

 shelf and slope region of the basin are presumably related to the pres- 

 ence of the Labrador Current in this area. An organic phosphorus 

 value of more than 0.1 MgA/1 extends across the bottom of the basin. 

 A statistical analysis of the observed concentrations of organic 

 phosphorus for 1962 and 1963 is presented in the following section. 



The distribution of silicate-silicon, as shown in figure 35, has a 

 basic similarity with the phosphorus distribution. Values greater 

 than 9 MgA/1 occur in the same areas and depths as the phosphorus 

 maxima. At the western side of the basin, two separate high silicate 

 concentrations in deep water are shown in shading, separated by an 

 area of lower concentration. This pattern is closely similar to the 

 deep water phosphorus distribution which also shows two separate 

 areas of high concentration near the Labrador slope. There is a 

 high silicate concentration near the Greenland slope, but the values 

 are slightly lower than those found in the western area. The central 

 portion of the deep water shows a concentration as low as 3 MgA/1. 



The same general pattern of high and low concentrations is observed 

 in figure 36 which presents the nitrate-nitrogen distribution. The 

 high concentrations of more than 15 yug'A/l occur along the eastern 

 and western margins of the deep Labrador basin. On the western 

 side, two separate areas of high concentration in the deep water are 

 seen in the same position as the high silicate and phosphate deep water 

 values. The central area of the Labrador basin shows low nitrate 

 concentrations throughout the water column. Values on the coastal 

 shelves are also reduced and, as with the other properties, the eastern 

 slope and shelf is lower in concentration than the western region. 

 A significant amount of nitrite-nitrogen, with values greater than 0.1 

 MgA/1, was found only in the surface region, to a depth of about 200 

 meters. The coastal region near Labrador and just off the shelf 

 showed the highest nitrite values of 0.3 MgA/l, and a few values of 

 0.2 MgA/1 were found near Greenland, both at about 100 meters. 

 It has been suggested by Vaccaro and Ryther (1960) that the nitrite 

 maximum is correlated with a large phytoplankton standing crop. 



DISCUSSION 



The results from the 1963 postseason cruise of the Ice Patrol show 

 a general consistency and agreement between the various parameters. 

 High nutrient levels at 300-800 meters are confined to two areas on 

 the eastern and western fringes of the central basin. It has been 

 noted by Steeman-Nielsen (1958) and Hansen (1959) that the areas 



67 



