468 DEPARTMENT OF THE NAVAL SERVICE 



at Prince station 3 in the mouth of the Bay. There can be no doubt that the absence 

 of warm, brackish surface water in this part has prevented their development, the 

 Bay of Fundy being a distinctly unfavourable breeding place,, although quite suitable 

 for the adults, as large numbers of them were found. In the Bay of Islands fjord the 

 conditions appear to be ideal for both the old and the young, the icy bottom water 

 containing an abundance of the adults and the warm brackish surface water an 

 abundance of the young. There is therefore a sharp contrast between the conditions 

 in: (1) the Bay of Islands, (2) the lower part of the gulf, and (3) the Bay of 

 Fundy. In the first the conditions are suitable for both adults and young, in the 

 second suitable only for the young and in the third suitable only for the adults. 



The virtual absence of small individuals in the Bay of Fundy is important, as 

 indicating the lack of suitable conditions for the breeding of species that require 

 quite warm water of comparatively low salinity for at least the early stages of develop- 

 ment. Many fish of economic importance have eggs and young larvae at the surface 

 that would be affected by this. Further investigation of the Bay of Fundy is needed. 



The hauls lacking young Sagitta elegans were made in September. Prof. J. P. 

 ^VfcMurrich informs me that in a series of tow-nettings taken regularly in Passama- 

 quoddy bay from October, 1914, to May, 1915, only two small Sagittoe were obtained, 

 and these at the mouth of the St. Croix river on October 29, 1914. This is a spot 

 with strong tidal currents^ where forms brought in from without would appear, if 

 they did appear anywhere. The nets used were more suitable for talking younj^ 

 Sagittce than older ones, and yet ten large individuals from 23-5 to 32-5 mm. in length 

 were taken in a haul on January 1, 1915. 



The centre of abundance during the earlier cruises (May-June) is shown in 

 fig. 8. Stations at which more than 100 individuals were obtained in the deep vertical 

 haul occur in an area represented by the most closely placed lines. This area occupies 

 the Laurentian channel from the centre of the gulf outwards to slightly beyond the 

 mouth. Two tongues extend from it to the southwest. One just outside Cape Breton 

 island and the other just outside Banquereau. These may signify the directions in 

 which the currents are carrying the abundant schools. On the later cruises the centre 

 of abundance of the larger individuals is at the lower end of Nova Scotia (as shown 

 in fig. 10). This part of the region was not investigated on the first cruise, but it is 

 at least probable that the currents have during the intervening two months carried' 

 large numbers from the Laurentian channel down along the coast, and thus depopulated 

 the northern part of the area. This is all the more probable because the conditions 

 at the lower end of Nova Scotia do not appear to be as suitable for the large individuals 

 as those of the intermediate water in the Laiirentian channel. 



Another centre of abundance is seen among the banks north of Sable islaiid 

 at Acadia station 89 where 124 specimens were obtained in the vertical haul. Their 

 presence near the surface was demonstrated by the taking of sixty-one in the haul 

 from 55 metres to the surface, and by tlie large number ol>tained in the tow. This 

 zone apparently extended to station 90, where many were obtained in the tow, but 

 where no vertical haul was made. The neighbouring station (66) showed very few 

 large individuals, but at station 65 ofl" Cape Canso, fifty were obtained in the deepest 

 haul. The distribution suggests that the pressing-in of the boreal water over the 

 banks south of Sable island has tended to separate the zone of abundant ^S*. elegans 

 into two parts, one north of Sable island and the other at the lower end of Nova Scotia. 



At Acadia station 77 at the mouth of the Laurentian channel no vertical havl 

 was made, but since the deep-water form Eul-rohnia hamafa was obtained in the tow 

 haul and no S. eleqanst. it is practically certain that the. latter species was absent. This 

 is significant, indicating almost pure boreal water at that point between two stations 

 where coastal water was present. This boreal tongue extends into the Laurentian 

 channel on the north side. Farther up the channel it is covered with coastal water 

 (stations 85 and 9'^). 



