Bay water. Section H is clearly much different 

 from the other sections, being north of the still at 

 Davis Strait. The increase of nutrient concentra- 

 tions in deep water below the sill depth is indicated 

 by phosphate values of greater than 1.20 /igA/1. 



Total phosphorus distribution is consistent with 

 the pattern just described for the inorganic phos- 

 phate. Values average 0.10 to 0.20 /u.gA/1 greater 

 than inorganic readings, especially near the sur- 

 face and in the areas near shore or over the con- 

 tinental shelf. Section D again suggests an inflow 

 to Hudson Strait with lower total phosphorus 

 values on the northern side and an outflow from 

 Ungava Bay on the southern side having higher 

 values. The high nutrient level at 50 meters in 

 Section G persists. In Baffin Bay (section H) the 

 pattern is extremely complex : The water below sill 

 depth shows a total phosphorus concentration over 

 1.30 /igA/1 and near stations 9499 and 9500, on the 

 landward end of the profile, total phosphorus 

 values greater than 1.50 ju.gA/1 are found. As in 

 the other sections, the variations in near-surface 

 values found here between individual stations is 

 presumably due to phosphorus in biological 

 combination. 



The organic phosphorus is derived as the dif- 

 ference of the observations on total and inorganic 

 concentrations. These values are also reported 

 with the data tables which accompany this volume. 

 Values of organic phosphorus greater than 0.20 

 jtigA/1 occur at the surface in section A, B, and 

 C and again at G and H. The continental self 

 in A, B, and C has organic phosphorus values from 

 0.10 to 0.20 ugA/l while lower tend to be found 

 in the deeper water offshore along the continental 

 slope. Similarly low values are found in section 

 F although at "section G the organic phosphorus 

 level increases again. These data are perhaps best 

 handled statistically, as in the following section. 



The nitrate-nitrogen distribution in all sections 

 is well stratified. Zero surface values increase 

 to 5.0 jugA/l at 50-75 meters and values of 10 

 n*gA/l occur by about 200 meters. The offshore 

 deep waters on the continental slope in sections 

 A, B, and C show a continued increase in nitrate 

 concentration to values greater than 15 /xgA/l. 

 Similar high values are found below 300 metei-s 

 in sections F and I and at station 9485 in section 

 G. Relatively low nitrate concentrations are 

 found in the Hudson Strait and Ungava areas. 



Nitrite-nitrogen distribution are reported sepa- 

 rately from the values for nitrate concentration. 



The nitrite concentrations are also shown in figures 

 1 and 2. In the stations in the Baffin Bay area, 

 section H, the high nitrite values are found close 

 to the surface. In the other sections, the only 

 statistically significant values are grouped near 

 100 meters, with the highest values in all cases oc- 

 curring on the seaward end of the profile, especially 

 in the southern end of the Labrador Sea (fig. 2). 

 Low nitrite concentrations with a very indefinite 

 pattern of distribution, found in the section for 

 Hudson Strait and Ungava Bay (sections D and 

 D', fig. 2), contrast with the strongly emphasized 

 peak concentrations for the Labrador Sea. 



The silicate-silicon distribution also shows con- 

 siderable horizontal stratification from values less 

 than 5 /^gA/l at the surface to concentrations of 

 about 10 figA/l at 100 meters. Higher values oc- 

 cur in deep offshore water of section A, B, and C. 

 The silicate level on the continental self in section 

 C is slightly reduced, which may relate to the low 

 values (less than 10 /xgA/l) foimd also in section 

 D at the entrance of Hudson Strait. The Ungava 

 Bay area (section D'), on the other hand, shows 

 silicates greater than 10 /*gA/l below 100 meters. 

 Stratification is well marked in sections F and G, 

 though the high nutrient level in section G recurs 

 in the silicate concentrations at about 100 meters 

 on stations 9479-9482. High silicates, up to values 

 greater than 30 /igA/1, are found in the deep water 

 of section I. Such values are characteristic of 

 Baffin Bay at the depth below the sill (McGill and 

 Corwin,1962). 



DISCUSSION 



Analytical results for the various nutrient de- 

 terminations from the coastal sections near Labra- 

 dor and Baffin Island are in good agreement with 

 each other. The nutrient concentrations show a 

 general increase witli depth. A simple regression 

 analysis gives ratios by atoms for the relative 

 changes in nutrient concentration in each section, 

 as reported in table I, which also gives the 95 per- 

 cent confidence intervals as determined in Simpson 

 (1960). The AN : AP ratio is in general agree- 

 ment with the value of 16 : 1 which is widely 

 accepted despite the variations in some regions 

 which are discussed by Armstrong (1965). Sec- 

 ' jn D', in Ungava Bay, is the only area of this 

 survey with a marked change from this value. A 

 considerable reduction is found in Ungava Bay — 

 the value obtained is equivalent to winter values 



36 



