PROGRESS IN BIOLOGICAL INQUIRIES, 1938 13 
with an internal anchor tag designed by Dr. Rounsefell. Tagging 
was done near Mt. Desert Island from a small line trawler. It is 
planned to continue the work next year on a sufficiently large scale 
to provide significant conclusions concerning the intermigration. be- 
tween the population of Maine shore haddock and that on the off- 
shore banks. 
Principal requirements of the investigation—The most urgent 
matters now facing the investigation are the completion of the study 
of variations in haddock abundance and total catch, analysis of the 
age and size composition of the commercial catch to show the effect 
of year-class strength on the fishery, study of the differences in 
growth rate between different year classes and fishing grounds, and 
the determination of the extent of intermigration between the various 
grounds. The first is now well on the way toward completion, but, 
although considerable progress has been made on the others, the work 
has been greatly handicapped by the lack of vessel facilities for col- 
lecting basic data on the offshore fishing grounds. The generous 
cooperation of the Woods Hole Oceanographic Institute in providing 
the occasional use of the Aflantis at nominal cost to the Government 
has been of great. help, but to no considerable degree has this served 
to displace the need for a vessel built and equipped for otter trawling 
and hydrographic duties and regularly assigned to fisheries work. 
Such a vessel is particularly needed for a systematic sampling of 
the young fish population at least twice a year to evaluate the distri- 
bution and abundance of each year class before it reaches commercial 
size; determine its mortality rate from natural causes and from the 
commercial fishery; and study the growth rate of the young fish. 
A vessel is urgently needed to carry on further work on offshore 
tagging. Adequate experiments should provide data of great value 
concerning haddock migrations, growth rates, and mortality rates. 
Preliminary attempts to carry on the work from commercial vessels 
have proved to be a complete failure (except from small line trawlers 
along the Maine coast), presumably because of the high mortality 
of the fish resulting from the effects of the commercial gear. It does 
not appear that these difficulties can be overcome without the use of 
a research vessel to develop and use special methods for catching 
and handling the fish. 
MACKEREL 
The 1938 mackerel season began late in March, and, because of 
growing emphasis on winter activity following the 1937 failure, was 
still in progress at the end of the year. Total vessel Jandings for the 
season will be approximately 29,000,000 pounds, about double the 
1937 catch. Prices dropped back to the 1936 level, close to 24% cents 
a pound, at principal New England ports. In general, fishermen 
fared better than in 1937. 
Throughout its history the mackerel catch has been characterized 
by extreme fluctuations in yield. The mackerel investigation was 
undertaken to study the causes of these fluctuations, with a view to 
devising means of predicting the relative abundance of mackerel in 
advance of the season. 
To provide a basis for understanding changes in abundance, catch 
statistics have been assembled covering the fishery from its mncep- 
tion—about 1804. These figures reveal a period of high catch level, 
162186—39 
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