562 



U. S. BUREAU OF FISHERIES 



The prevalence of this phenomenon in the sea fisheries makes it 

 important to examine the conditions that may be responsible for 

 the survival of year classes. To this (^ncl our investigations on fishes 

 proper have been accompanied by studies of oceanographic condi- 

 tions in so far as the limited means at our disposal would permit. 

 Results of such studies can not be forthcoming in a short time. They 

 involve continuous observations over a series of enough years to estab- 

 lish a norm from which departures may be measured and correlated 

 with changes in abundance as measured by the yield of the com- 

 mercial fisheries in subsequent years. For this reason progress 

 during the current year must be measured by the degree to which 

 it lays the foundation for future advancement, as well as by th,e 

 immediate results obtained. 



Most of the oceanographic work was done during the repeated 

 visits of the Albatross II to the mackerel -spawning areas which 

 cover an expanse of offshore waters extending from North Carolina 

 to Massachusetts, usually including the full width of the continental 

 shelf. The accompanying chart indicates the distribution of sta- 

 tions, while the kinds of observations made during the cruises are 

 listed in Table 1. 



Table 1. — Summary of offshore oceanographical ivork done in conjunction with 

 cod, mackerel, and shore-fish investigations, 1930 



Date 



Feb. 5-13. 



Apr. 3-11 



Apr. 23-May 1 



May 12-23 



June 6-14 



June 17-18 



June 23-July 1. 



July 7-8 



July 10-14 



July 16-18 



Aug. 1-Sept. 9. 



Sept. 15-17 



Oct. 17-23 



Station 

 numbers ' 



20652-20678 

 20679-20715 



20716-20760 



20761-20791 



20792-20795 



20796-20831 



20832-20835 



20836-20853 



20854-20858 



20859-20869 



20870-20874 



20875, 20876 



General locality 



No Mans Land, Mass., to Bodie 

 Island Light, N. C. 

 Do 



Cape Cod Bay, Mass., to Bodie 



Island Light, N. C. 

 Cape Cod Bay, Mass., to Cape 



Henry, Va. 

 Cape Cod Bay, Mass., to Cape 



May, N. J. 

 Cape Cod Bay, Mass., and offing 



of Cape Cod. 

 Cape Cod Bay, Mass., to Cape 



May. N.J. 

 Cape Cod Bay, Mass., and offlng 



of Cape Cod. 

 Nantucket Shoals to Barnegat, 



N.J. 

 Cape Cod Bay, Mass., and oflSng 



of Cape Cod. 

 Miscellaneous cod tagging trips 



in Gulf of Maine. 

 Cape Cod Bay, Mass., and offing 



of Cape Cod. 

 Offing of Cape Cod, Mass 



Total. 



Tem- 

 perature 



and 

 salinity 

 observa- 

 tions 



- o! 



Collections made 



'='•3 ii 



o-ja p. 2^ 



o g 5"" 

 S3 



20 



' Albatross series. 



2 2 series of hauls, 1 in daylight and 1 at night, were taken at each station. Each .series consisted of hori- 

 zontal tows at 5 or more levels. 



