PROGRESS IN BIOLOGICAL INQUIRIES, 1926 615 
salmon. <A few years ago there was an unprecedented catch of young salmon 
(“smolts”) in traps and pounds along a section of the Maine coast. The 
following year there was an abundance of “ grilse”; later larger salmon were 
numerous; but last year (1926) the salmon catch was very small. For years 
the salmon catch on the coast of Maine has fluctuated, but until comparatively 
recent years s.lmon were taken only rarely in the outer Casco Bay region. 
For many years the United States Fish Commission propagated the Penob- 
scot salmon, and the Bureau of Fisheries has continued the operations to some 
extent. It seems to me that it would be worth while if the periodical appear- 
ances of salmon could be traced positively to the operations at Craigs Brook. 
Tagging adult salmon might be supplemented by marking some of the output 
of the hatchery. 
Referring to my major subject: The smelt is a small species best known as 
a marine fish, which, like the salmon, ascends fresh-water streams (principally 
brooks) to spawn. As it appears in the market, it usually ranges from 5 to 7 
inches in length, sometimes larger, sometimes smaller. Certain lakes contain 
“landlocked” varieties of smelt. My studies pertain to both the salt-water 
and fresh-water forms. 
At one time the fishery for smelt was quite an important industry on the 
eoast of New England and to some extent as far south as New Jersey ; but 
it has greatly declined. It is a shore fishery still of some importance in Maine, 
and in value per pound the fish ranks with some of the commercially more 
important food fishes. 
One of the objects of my work has been, by study of the biological and 
physical conditions affecting the supply, to endeavor to find some facts upon 
which regulatory measures designed to check the decline and possibly to im- 
prove the fishery might be based. While for many years the smelt fishery of 
Maine has declined gradually, that of New Brunswick, in the meantime, has 
undergone a remarkable growth, a great part of the products of which are 
shipped to the United States. Nearly 40 years ago the inspector of fisheries 
of that Province sounded an alarm concerning an imminent destruction of the 
fishery unless steps were taken to prevent it. Later regulatory laws were 
enacted, protecting the smelt in the breeding season and restricting the com- 
mercial fishery to two and one-half months in the winter. 
In Maine there has never been any protection of the smelt while spawning 
in fresh water and they were caught at that time in great quantities, but not 
as a commercial fishery. Men and boys, from near and far, still visit the 
brooks and take all they can get almost every night during the breeding season. 
However, there is a close season for the commercial fishery during certain 
months in the year. 
Maine has two independent commissions, one of which is the Inland Fish and 
Game Commission and the other the Sea and Shore Fisheries Commission, and 
each has its own laws and regulations. The general smelt law pertaining to 
the sea and shore fisheries prohibits the capture of smelts in tide water between 
the 31st of March and the 30th of September, inclusive. The Inland Fish and 
Game Commission’s law allows the fish to be caught in fresh water, above tide 
water, for an indefinite period after April 1. 
Before outlining the problem pertaining to the fresh-water smelt, first I 
will briefly describe some features of my work on the marine smelt, because of 
its bearing upon the situation just described and because it is the latest to 
engage my attention, although it simply supplements what I have done from 
time to time in years past. 
In the last three years I have collected samples of the runs of smelts in 
the brooks during the breeding season of about a month in each year. My 
procedure was to visit the brook nightly, for the smelts run only after dark, 
on the ebb tide, beginning si on after high tide. 
The size of the samples secured depended much upon the muMnee of other 
fishers on the bank, which might be anywhere from 1 to 20 or more. The more 
smelters there were, the fewer ffSh would be caught by each. As high tide 
occurs about an hour later each night, of course my visits were succeedingly 
later. The following day the fish were measured and marked according to 
sex and scales were taken from each or from representative sizes for subsequent 
study. Three length measurements were taken—total length, length to fork 
of tail, and length to end of scales at base of tail—so that if any puzzling situa- 
tion arose the use of one or the other dimension might remove the difficulty. 
Inasmuch as the other dimensions, particularly that of the total length, are 
subject to more or less unavoidable variation, the most exact measurement is 
