PROGRESS IN BIOLOGICAL INQUIRIES, 926 o2/ 
O. E. Sette, assisted by R. A. Nesbit and R. A. Goffin. The program 
contemplates the simultaneous collection of biological and _statis- 
tical data and their analysis to provide an understanding of the life 
history of the species and the fluctuations of the fishery. During 
the 1926 season an observer was stationed at the principal mackerel 
receiving ports for the purpose of interviewing mackerel fishermen 
as fish were landed and securing data on the locality, dates, size of 
catch, and fishing effort involved, as well as taking measurements, 
scales, ete. of the mackerel landed. During the season over 1,200 
vessel skippers were interviewed, over 25,000 mackerel were measured, 
and about 3,500 scale samples were taken. Other data were collected 
at Woods Hole, Mass. 
Analyses of the 1925 and 1926 data on sizes and ages have pro- 
ceeded as rapidly as possible with the present limited personnel. 
Although they are yet tar from complete it is now fairly certain that 
the unusually large catches of 1925 and 1926 were composed largely 
of mackerel that originated in one spawning season, provisionally 
determined to be that of 1923. The preliminary age analysis of the 
stock of mackerel present during the past two years leads us to be- 
lieve, further, that the 1921 spawning season was more than normally 
suecessful; that the 1922 season was practically a failure; that 
the 1923 season was extraordinarily successful; and the 1924 season 
was probably average in production. This at once gives the clue to 
one cause of fluctuations in the mackerely fishery—that is, unequal 
increments in various years. It is believed that continued observa- 
tions of this sort eventually will permit the forecasting of immediate 
future success or failure of the mackerel fishery. 
The steamer Gannet was detailed to mackerel investigations for 
about five weeks during the spawning season in Massachusetts Bay, 
and was engaged in making tow-net hauls and taking oceanographic 
data. An incomplete analysis of the plankton collected showed that 
an abundance of mackerel eggs and larvee was present during and 
immediately after the spawning season. ‘This is significant, inasmuch 
as very few mackerel eggs and no larve had been found previously 
in the Gulf of Maine. It had been thought heretofore that the Gulf 
of St. Lawrence; where large quantities of mackerel eggs and larvee 
had been taken by the Princess and Acadia in the Canadian fisheries 
expedition of 1914-15, and again on the Cheticamp expedition of 
1917, was the only important spawning ground for American 
mackerel. The 1926 cruise in Massachusetts Bay demonstrated the 
presence of comparable quantities of eggs and larve in this locality, 
thus extending our knowledge of the mackerel spawning grounds. 
It is possible that more extensive work of this nature may indicate 
even greater ranges for important breeding places of the mackerel. 
Tagging operations in 1926 were very limited, only 599 fish being 
tagged off the coast of Delaware in April. Two of these fish were 
recaptured, one of them on the date of tagging at virtually the place 
of release. The other was retaken in August off Cape Cod. Twelve 
fish tagged in 1925 were reported recaptured during 1926. It will 
be recalled that all of the mackerel tagged in 1925 were released 
along the coast of New England, and the recaptures during the same 
season indicated a general spread of mackerel from the points of 
release. The recaptures in the next year (1926) occurred from Fire 
