value of 20 jugA/1 is found here. Another region 

 of high silicates is found on the western side of the 

 section, where a value of 18 /tgA/1 is attained. 

 From 400 to 500 meters a band of lower silicate con- 

 centration (less than 10 ngA/\) stretches across 

 the section. Silicate values rise once more to the 

 bottom, however, and the concentration reaches 

 15 /ngA/1 at 600 meters in the center of the basin. 



The final figure presents the longitudinal varia- 

 tion in silicate distribution (fig. 47), adding the 

 data from deep stations in Baffin Bay to that al- 

 ready presented. An intermediate silicate maxi- 

 mum greater than 10 jugA/1 exists throughout the 

 area. Values near the bottom show only a small 

 increase until the deep water of Baffin Bay is 

 reached, where silicate levels increase uniformly 

 with depth to values of more than 40 jugA/1. Still 

 higher values are found along the steep slope of the 

 deep basin, but with a very irregular pattern. It 

 should be noted that silicate levels near the surface 

 in Baffin Bay are not quite as great as to the north. 

 The very pronounced increase in deep water com- 

 mences at about 600 meters. 



Discussion 



The most northern stations in the present survey 

 have nutrient characteristics most nearly similar 

 to the Arctic Ocean. Silicate results from Station 

 Bravo on Ice Island T3 are given by Kusunoki 

 (1960) and Muguruma (1961) in which the waters 

 of the Arctic Ocean are slightly richer at 100 

 meters than in the Kane Basin. Similarly, a 

 higher value for total phosphorus is reported by 

 Farlow (1958) at Ice Island Alpha (82° N., 105° 

 W.), though deep water concentrations are in 

 agreement with our data. The pronounced halo- 

 cline in Arctic Intermediate Water may provide 

 an effective barrier to upward mixing of nutrients 

 in the North Polar Sea, causing these increases in 

 the maximum concentrations while also acting to 

 keep down surface productivity. 



From the southern end of Kane Basin south- 

 ward, the nutrient conditions are most nearly like 

 Baffin Bay, suggesting that water from the Kane 

 Basin area flows into Baffin Bay and adds to the 

 deep water there. Bailey (1956) has shown from 

 temperature-salinity data that deep Baffin Bay 

 water (below 1,250 m) originates in the Arctic 

 Ocean at a depth of 250 m ; and Timofeyev (1963) 

 lias calculated from observations of Collin (1960) 

 that 12 percent of the total Arctic Ocean outflow 



occurs through the Canadian Archipelago. The 

 Kane Basin is intermediate in this circulation. 

 The nutrients entering Baffin Bay are restricted 

 by the sill depth of Davis Strait and hence tend to 

 accumulate in the deep water (Corwin and Mc- 

 Gill, 1963). 



The difference of the total phosphorus concen- 

 tration and the value of inorganic phosphate rep- 

 resents an estimate of the amount of organic phos- 

 phorus present. A statistical evaluation of this 

 parameter is given in table I, where the number 

 of available values (n), the mean organic phos- 

 phorus in ^gA/l(x), the variance (s 2 ), standard 

 deviation (s), and the standard error of estimate 

 (sV n ) are presented. The very high mean 

 amounts of organic phosphorus obtained may be 

 compared with the results of a similar determina- 

 tion on the standard U.S. Coast Guard Ice Patrol 

 section in the Labrador Sea, where a level of 0.1513 

 ixgA/l is found in summer 1963 for the 0- to 1,000- 

 meter depth increment (McGill and Corwin, 1964, 

 in press). For the total of all data below 1,000 

 meters, a value of 0.1172 ftgA/1 was obtained. The 

 organic phosphorus is most probably a part of local 

 circulation only and not exchanged over broad 

 horizontal limits, the material being regenerated 

 at depth in the region of its surface accumulation. 



The observed nutrient quantities can be con- 

 verted to ratios of the rate of change (by atoms) 

 through a least squares regression. The general 

 average for these ratios of change in Atlantic 

 Ocean waters has been determined by Richards 

 (1957) as 



ASi:AN:AP = 16:16:l. 



Proportions of this general magnitude are observed 

 in most of the area here analysed, although there 

 is a distinct decline in the relative nitrogen level 

 for the most northern region (Kane Basin, Sec- 

 tion A). The general average from the mean 

 values of the respective sections is given in table 

 II: 



ASi : AN : AP = 19.64 : 16.63 : 1. 



The relative proportions show a tendency to in- 

 crease southward, with highest results appearing as 

 Baffin Bay is reached. The three deep stations in 

 Baffin Bay are subdivided into a surface segment 

 (0-500 m) and a deep water segment (below 

 500 m), since there is a considerable accumulation 

 of silicate near the bottom and determinations of 

 the silicate to phosphorus ratio for the total water 

 column would give an anomalous high value. 



41 



