OYSTER PROPAGATION IN P.E.I. 73 
SESSIONAL PAPER No. 38a 
Shipyard river. Seventy degrees was recorded for Shipyard basin, Darnley basin, 
Narrows, Bideford river, Shemody creek, Grand river, March water, Curtain Island 
jlats, ete. This figure was recorded more often than anv other, but 68° F., stands next 
in frequency, being recorded not only for the deeper and lower parts of the bay, as at 
the inlet, March water, head of Grand River cove, ete., but also from upper Grand 
river and Bideford river, after the cold winds and nights of the latter half of the 
month. There were eight instances of 66 to 67 degrees in March water and Grand 
river, after cold weather. August 28 the water at Ram Island shoals was 62 degrees. 
At the head of Shipyard river, where the water was quite fresh, it was 60 degrees on 
the 25th. ; 
At best, the length of the season when the water in Richmond bay is warm 
enough for oyster propagation, is short, and when the warm weather of spring is 
delayed, as was the case in 1915, the spawning is shoved into August, and the spatting 
comes so late that the spat secure only slight growth before winter temperatures begin. 
The late spat of 1914 thus attained only a small size during the second summer of its 
existence. We found spat in August from Ram island, searcely larger than one’s 
little fingernail, that must have set the preceding fall. 
A question arises here, to what extent may the oncoming cold of autumn interfere 
with the spatting of the late broods of fry which were the principal ones this year? 
In more southern waters we frequently get a set of spat in September, and even 
in October, and these have some chance to grow before winter. But there is quite 
likely a temperature limit, to spatting itself, which it is important to determine. 
The shallowness of a large part of Richmond bay, favouring rapid heating of the 
water, is also favourable to its quick cooling. If, therefore, the largest brood of fry 
should be prevented from setting, there is an additional obstacle to the rapid 
regeneration of oyster beds in Canadian waters. This also has favoured rapid 
depletion. 
SUMMARY OF DENSITY OBSERVATIONS. 
A great deal too much emphasis has been laid on the question of the saltness 
or density of the water in which oysters may be expected to flourish. Doubtless, 
the admixture, more or less periodically, of fresh water with the salt water, at the 
mouths of rivers, has a beneficial effect, but the range of salinity in which oysters 
will grow is so great that the careful observation of one or two points difference in 
reading on the scale of the salinometer, is of little practical, or possibly even scientific, 
value. 
While salinity depends on distance from inlet, distance up rivers, the stage of 
tide, on wind strength and direction, and on rainfall, the variations and range of the 
readings of our salinometer were remarkably small. We found, in fact, almost the 
same readings as obtained at our New Jersey, Edge Cove, station. The highest record 
was 1021 found in Darnley basin, at half flood (August 6), in the Narrows at low, 
off Low point at half flood, in the channel of March water, both top and bottom, 
at high tide August 9 and 17, in Central bay, north of Bunbury, and in Ram Island 
shoals at high. ; 
A reading of 1020 was most frequent,-as in Shipyard basin, August 5, in Malpeque 
harbour at low, off Lennox island, and in the Narrows, off the mouth of Plat river, 
in Shemody creek (August 7 and 13), off Tilton creek, and in the Upper bay, both 
at low (August 7) and high (August 24), in Oyster creek at half tide, at Grand River 
ferry on high, on Curtain Island shoals, and the mouth of Bideford river at high, 
and in March water at low (August 20 and 27). 
Twenty observations gave 1019 and 1019-5 most frequently in the rivers or at the 
mouths of creeks. In Grand river, 1017, 1018 and 1018-5 were found not far distant 
from the bridge. This record was also given in Barbara Weit, Oyster creek, and 
Shipyard river. A reading of 1015-5 was observed well up Shemody creek at low 
