Irvl 



No. 2. — Explorations in the Gulf of Maine, July and August, 1912, 



by the U. S. Fisheries Schooner Grampus. Oceanography and 



Notes on the Plankton. 



By Henry B. Bigelow. 



CONTENTS. 



PAGE. 



The cruise 32 



Equipment and methods ......... 35 



Oceanography 42 



Surface temperature 43 



Temperature sections ......... 48 



Temperature at 25 fathoms 54 



Bottom temperatures 55 



Temperature profiles . . . . . . . . 56 



Seasonal changes in Massachusetts Bay 58 



Salinity , 62 



Surface salinity .......... 62 



Salinity at intermediate depths ....... 64 



Salinity at 25 fathoms . . . . . .• . . 68 



Salinity at 50 fathoms ........ 70 



Bottom salinity .......... 70 



Salinity profiles 71 



Density ............ 76 



Color ' 81 



Transparency ........... 82 



Circulation in the Gulf of Maine 83 



Tidal currents .... , .... 83 



Surface and bottom currents ....... 85 



Circulation as shown by temperature and salinity .... 87 



Comparison with previous records of temperature and salinity . . 92 



General considerations ......... 95 



Preliminary notes on the macroplankton ...... 98 



List of fishes 107 



Larval and postlarval stages ....... 107 



Adult stages . . . . . . . . . . Ill 



List of copepods .......... 115 



Distribution of the more important plankton species . . . .117 



Calanus finmarchicus .117 



Euchaeta norvegica 118 



Anamalocera pattersoni 118 



