512 



BULLETIN OF THE BUREAU OF FISHERIES 



Pngd 



Salinity 701 



General summary 701 



Detailed account of salinity 703 



February and March 703 



Surface 703 



Vertical distribution 705 



40 meters 708 



100 meters' 710 



150 meters and deeper 712 



Profiles 714 



Limits of water more saline than 34 



per miUe 720 



Bottom 720 



Annual variations in salinity in 



March -' 722 



Vernal freshening 723 



Vertical distribution of salinity in 



April 728 



Salinity below the surface in April 733 



Annual variations in the salinity of the 



bottom water in April 740 



May 741 



Surface 741 



Below the surface 746 



June 754 



July and August 763 



Surface 763 



Annual variations in surface salinity 



in summer 771 



Vertical distribution 772 



General distribution of salinity below 



the surface 781 



Autumn and early winter 799 



Midwinter 804 



Summaries of salinity for representa- 

 tive localities 808 



Bay of Fundy 808 



Massachusetts Bay region 810 



Offing of the Merrimack River 813 



Near Mount Desert Island 813 



German Bank 814 



Western side of the basin 814 



Annual survey of salinity on the bot- 

 tom.-- — 815 



Alkalinity 819 



Visual transparency 822 



Color -- 823 



Sources from which the Gulf of Maine re- 

 ceives its waters 824 



Superficial stratum 825 



Nova Scotian current 825 



Tropic water 836 



Coastal water from the west 837 



River water 837 



Rainfall and evaporation 840 



Page 

 Sources from which the Gulf of Maine re- 

 ceives its waters — Continued. 



Deep stratum 842 



Slope water 842 



Abyssal upwellings 852 



Recapitulation 854 



Circulation in the Gulf of Maine 855 



Tidal currents 855 



Dominant or nontidal drift 857 



Measurements of currents 857 



Summary ^ 866 



Experiments with drift bottles 867 



Bay of Fundy 868 



Gulf of Maine . 871 



Drift-bottle record 871 



General discussion of the recoveries. 879 



Southwestern series 879 



Recoveries from Cape Ann and 



Massachusetts Bay lines 887 



Drifts of bottles set out north of 

 Cape Ann and off Cape Eliza- 

 beth 895 



Line off Mount Desert, August, 



1923 902 



Bottles put out off western Nova 



Scotia — — — 908 



Drifts of bottles entering the gulf 



from the eastward 908 



Circulation of superficial stratum, as 



indicated by saUnity 910 



Circulation of the superficial stratum, 



as indicated by temperature 918 



Circulation in the deep strata, as indi- 

 cated by temperature and salinity. 921 

 Circulation as indicated by the plank- 

 ton 923 



Vertical stability, as affecting the cir- 

 culation of the gulf 924 



Dynamic evidences of circulation 930 



Construction of dynamic charts 930 



Dynamic contours and gradient cur- 

 rents 936 



February and March 936 



April 942 



May 944 



June 948 



July and August 953 



Autumn and winter 962 



Wind currents 962 



Horizontal tidal oscillations as deflected 



by the earth's rotation ■ — 970 



Summary of the horizontal, nontidal 



circulation of the Gulf of Maine.- 972 

 Tables of temperature, salinity, and den- 

 sity 976 



Standards of accuracy 976 



Bibliography 1015 



