XIV EEPORT OF COMMISSIONER OF FISH AND FISHERIES. 



at the northern end of the island, where there are no alewives, and 

 where herring appear to be the principal food, although the variation in 

 the abundance of these in different seasons appears to have an impor- 

 tant bearing upon the number of hake and cod. 



If these conclusions be correct — and I am quite satisfied of their 

 general validity — we have, for the efforts made to establish fish-ways in 

 the rivers of Maine, New Hampshire, and Massachusetts, a much more 

 weighty reason than that of merely enabling a few salmon to enter the 

 streams in order to permit their capture while on their way. 



Whatever may be the importance of increasing the supply of salmon, 

 it is trifling compared with the restoration of our exhausted cod-fisheries; 

 and should these be brought back to their original condition, we shall 

 find, within a short time, an increase of wealth on our shores, the amount 

 of which it would be difl&cult to calculate. Not only would the general 

 prosperty of the adjacent States be enhanced, but in the increased num. 

 ber of vessels built, in the larger number of men induced to devote them- 

 selves to maritime pursuits, and in the general stimulus to everything 

 connected with the business of the sea-faring profession, we should be 

 recovering, in a great measure, from that loss which has been the source 

 of so much lamentation to political economists and well-wishers of the 

 country. 



As the observations in regard to the marine animals and plants of 

 the Bay of Fundy will not be complete without referring to and includ- 

 ing those found on the remaining shores of Maine, I defer, for the pres- 

 ent, any report upon them such as has been made for Wood's Hole. It 

 is iDropOsed to devote the summer of 1873 to researches in Casco Bay and 

 the adjacent waters, and also, with the aid of the United States Ooast- 

 Survey steamer Bache, to examining the waters between the Maine 

 coast and Cape Cod; and it will be more satisfactory to i^resent the 

 results of the two years' work in one account. 



7. — mVESTiaATIONS IN 1871 AND 1872 ON THE GREAT LAKES. 



The act of Congress specially directed that investigations should be 

 conducted on the great lakes, of the same kind as those ordered for the 

 coasts of the United States ; and, under this provision, Mr. James W. 

 Milner was appointed assistant commissioner, with instructions to col- 

 lect as reliable data as possible on the following points : the evidences 

 of decrease in the numbers of the food-fishes ; and, this fact established, 

 to ascertain its causes, and what practicable methods may be applied 

 for their restoration. It was determined to confine the inquiry for the first 

 season to one lake, and to give it a thorough examination. Lake 

 Michigan, having the longest line of shore within the United States and 

 the largest number of fisheries, was selected as the region for the inves. 

 tigation. 



Instructions were also given him to make full collections of all forms 

 of life found in the waters, and to take as full notes as possible on the 



