472 
BULLETIN OP THE BUREAU OF FISHERIES 
Analyses of nitrogen (as Nf) in sea sediments from the Gulf of Maine and vicinity, performed by the 
chemical laboratory, United States Geological Survey 
Station 
Locality 
Depth in 
meters 
Per cent 
N a 
10288 
Latitude 48° 28', longitude 67° 30'_ 
227 
0.09 
10291. 
64 
.12 
10292 
Latitude 43° 19', longitude 64° 59' 
157 
.11 
10294 
Latitude 42° 30', longitude 64° 27' 
176 
.06 
10295. 
Latitude 42° 22', longitude 64° 16'_ _ 
500+ 
.24 
10301 
Latitude 44° 31', longitude 67° 24'_ _ _ 
73 
.01 
10513 
Latitude 43° 47', longitude 69° 08' 
80 
.13 
10518. 
194 
.24 
10522 
157 
.32 
10523 
219 
.32 
10525. 
110 
.20 
10526 
44 
.19 
10530. 
Latitude 43° 38', longitude 69° 46'__ 
77 
. 12 
10534 
137 
. 17 
10540 
185 
.19 
10541.. 
Latitude 42° 00', longitude 68° 20'. _ 
201 
.27 
10548 
Latitude 43° 30', longitude 68° 38'. _ 
122 
.19 
10550 
Latitude 43° 13', longitude 68° 30' 
198 
.19 
10551 
192 
.07 
10552 
Latitude 43° 18', longitude 67° 11' 
201 
.11 
10553 
186 
. 19 
10556 
218 
.05 
10575. _ 
117 
.13 
10577. _ 
110 
. 16 
10595. 
Latitude 43° 58'|longitude 68° 16' ... 
101 
.13 
10608.. 
Latitude 41° 58', longitude 69° 40' 
174 
.13 
10617 
Latitude 42° 04', longitude 69° 57' 
64 
.09 
10623 
24 
.17 
20064. 
320 
. 19 
Owing to technically unsatisfactory preservation of the specimens, these deter- 
minations can be regarded only as approximations of the amounts of nitrogen actually 
present in the muds ; but recognizing this possible source of error, the average is about 
0.16 per cent of nitrogen (as N 2 ), for the whole series (otherwise expressed, about 3.2 
pounds per ton of mud or sand). 
As long as this store of nitrogenous detritus remains mingled with the mineral 
deposits that cover the sea floor, it remains unavailable for the use of the planktonic 
vegetation, though it supports many mud-eating animals that live on the bottom. 
It must be constantly going into solution, however, as the breaking down by decom- 
position proceeds, a process hastened in regions of strong tides where vertical currents 
keep much of this flocculent material in suspension, as is proved by the considerable 
amounts of fine organic debris often taken in the tow nets. Its availability for the 
support of diatoms and of the other planktonic plants thus depends largely on the 
state of circulation of the water, a question discussed below (p. 479). 
The gradual impoverishment of the animal plankton, which takes place from 
autumn on, with the dying of the large medusae, copepods, and other groups, has been 
commented on (pp. 47, 88). Its natural result is to cause a more rapid accumulation of 
animal debris during the cold half of the year than in summer. Generally the death 
rate among the animals living on bottom along the littoral zone is also higher in winter 
than in summer. Everyone who frequents the shores of the gulf knows that this is 
true of the algae, vast quantities of rockweed and kelp being torn adrift from the rocks 
by the autumnal gales and piled up along the beaches, where they are soon ground up 
