34 



THE MIGRATION AND CONSERVATION OF SALMON 



and produces at this point a reversing falls, 

 the fresh vv^ater falling out only when the 

 water of the bay is below half -ride level. 

 The discharge, although intermittent, is so 

 great that there is a continuing zone of 

 river influence from the harbor mouth 

 southwestward along the coast for about 

 50 miles to the Passamaquoddy region, 

 where it is dissipated in the strong tidal 

 mixing of the archipelago there. 



This peculiar physical background is as- 

 sociated with a definitely limited sea move- 

 ment of the salmon. The salmon, when 

 near the end of their first summer in the 

 sea and around a pound in weight, are 

 taken quite regularly, sometimes in very 

 considerable quantities, in the herring or 

 ''sardine" weirs from just outside St. John 

 harbor to the island of Grand Manan just 

 outside the zone of river influence. These 

 facts indicate that, although the smolts 

 descend the river for as much as 175 miles, 

 and pass through 70 miles of estuary, they 

 are when half-way to becoming grilse from 

 three to perhaps 50 miles from the mouth 

 of the estuary and definitely related to the 

 zone of river influence. In this zone there 

 is an abundance of food, consisting of pe- 

 lagic Crustacea of various kinds and small 

 fishes. We may reasonably conclude that 

 these small salmon are like the herring in 

 being liable to capture in the weirs only 

 when roaming about, that is when not feed- 

 ing, and when the temperature is not too 

 low (Huntsman, 1933). At any rate, the 

 time of the year when they are taken is 

 around September, when growth (and pre- 

 sumably feeding) slackens and the tem- 

 perature is highest. 



In the following year, as grilse, they are 

 taken in the weirs (the drift-nets are of 

 too large a mesh) from St. John harbor to 

 Grand Manan. They are taken principally 

 at St. John, where they are nearly all males, 

 appear as early as June, and increase in 

 numbers during the summer. A fair num- 

 ber enter the estuary, ascend the river and 

 spawn in the fall. About November, quite 

 a number of others, practically all females 

 about 9 lb. in weight and immature, begin 

 to enter the estuary, and the run continues 

 till stopped by the cold in early January. 



These remain in the deeper parts of the 

 estuary toward its inner end, and ascend 

 the river in the spring, starting about the 

 middle of May. At this same time the main 

 mass of the salmon out in the bay in the 

 zone of the river influence start to move, 

 first near St. John. They are about 11 lb. 

 in average weight and principally females, 

 and they enter the estuary and ascend the 

 river. They are feeding on the local shrimp 

 (Euphausiids) and small herring, increase 

 in weight with the season, become most 

 numerous toward the end of June or early 

 in July, and as maturing salmon are taken 

 with drift-nets of suitable mesh in St. John 

 harbor and throughout the zone of river in- 

 fluence in the bay and only rarely outside 

 this. 



Tagging experiments being made this 

 year are already showing that these salmon 

 do not leave the zone of influence of the 

 river, but move to and fro in it, going from 

 the harbor outwards towards the extremity 

 of the zone as well as inwards to the mouth 

 of the estuary. There is not the steady 

 movement riverward that theorists have led 

 us to expect. 



When these salmon, after being spawned 

 in the autumn are liberated just outside 

 the harbor, they enter the estuary, so far as 

 can be judged by recaptures. They occur 

 as kelts the next spring, as clean fish during 

 that summer, and as clean fish in the sum- 

 mer following, from the harbor through the 

 estuary and up the river. Very few are 

 found in the bay, and only in the second 

 year; likewise they are found far up the 

 river only in the second year. In their phe- 

 nomenal inward distribution these large 

 fish exhibit a marked contrast with the 

 small salmon or post-smolts found only in 

 the bay and toward the outer end of the 

 zone of river influence. 



The Miramichi Salmon 



The Miramichi salmon (Fig. 2) liberated 

 as kelts in the Northwest Miramichi estu- 

 ary (not outside the estuary as were the St. 

 John kelts), show a distribution as kelts 

 the next spring similar to the St. John fish, 

 from some distance up the river down 

 through the estuary to its mouth. As clean 



