the seasonal variations of nitrite and nitrate 

 and the relation of nitrite to nitrate, phosphate, 

 density, and temperature at the surface and 

 depth. These relations in the Gulf of Maine 

 and other areas are discussed in detail. 

 Redfield and Keys (1938) presented results 

 on the occurrence of ammonia in various sec- 

 tions of the Gulf of Maine in September 1933 

 and May 1934. They showed that in the deeper 

 basin of the Gulf of Maine in May ammonia 

 occurred in maximal concentration in a defi- 

 nite stratum between 30 and 60 m., while in 

 September the concentration of ammonia was 

 uniform at all depths. In the strong tide ways 

 of the deep channels ammonia was distributed 

 uniformly with depth, and in the shallow water 

 over Georges Bank its occurrence showed no 

 regularity. The distribution of ammonia paral- 

 leled the distribution of organic phosphorous 

 compounds, nitrate, and zooplankton, indicating 

 that its distribution marked the location and 

 intensity of organic decomposition. 



Redfield (1948) estimated the seasonal varia- 

 tion in the magnitude of oxygen exchange 

 across the sea surface as it occurs in the 

 Gulf of Maine and evaluated the factors re- 

 sponsible for this exchange. He determined the 

 quantity of dissolved oxygen to a depth of 

 200 m. and inorganic phosphate to a depth 

 of 100 m. at stations in a 35-mile square 

 area in the western basin of the Gulf from 

 July 1933 through September 1934. He esti- 

 mated that about 30 x 10 4 cc. of oxygen per 

 m.2 leaves the surface of the Gulf of Maine 

 between the end of October and the latter 

 part of March and that a similar amount 

 enters during winter. Of the annual exchange 

 across the sea surface he attributed only two- 

 fifths to net production or consumption of 

 oxygen by organisms. The remainder pre- 

 sumably resulted from the effects of tem- 

 perature on the solubility of oxygen. In spring 

 the production of oxygen in photosynthesis 

 was sufficient to account for the entire sur- 

 face exchange; during summer the exchange 

 was attributable to decreasing solubility be- 

 cause of warming; in late fall and winter, 

 excess oxygen consumption and increasing 

 solubility caused the exchange. He estimated 

 the exchange coefficient of oxygen to be 13 x 

 106 cc. per m.2 per atmosphere per month 

 in winter and 2.8 x 10° in summer. These 

 seasonal differences were attributed to dif- 

 ferences in sea surface conditions. 



Several other studies of the oceanography of 

 the Gulf of Maine during the 1930's should 

 be noted. Enough new information on fishes 

 in the Gulf of Maine had accumulated during 

 this period to warrant the issuance of a sup- 

 plement to "Fishes of the Gulf of Maine" 

 (Bigelow and Welsh, 1925). Bigelow and 

 Schroeder (1936) published a supplement con- 

 taining data on the abundance, distribution, 

 breeding habits, and food habits of 88 species 



of cartilaginous and bony fishes and a revised 

 key to the skates and rays. 



Redfield, Smith, and Ketchum (1 937) deter- 

 mined the distribution of phosphorus present 

 as inorganic phosphorus, as dissolved organic 

 compounds, and as particulate matter for 

 specific depths at a standard station in the 

 western part of the Gulf of Maine during 

 May, August, and November, 1935 and Febru- 

 ary and May 1936. They reported on the cycle 

 of phosphorus throughout the year and on the 

 methods for analyzing quantitatively the fac- 

 tors producing seasonal changes in the dis- 

 tribution of such a compound. 



Ketchum and Keen (1953) studied the ex- 

 change of fresh and salt waters in the Bay of 

 Fundy and in Passamaquoddy Bay, based on 

 an analysis of salinity observations made 

 during the 1930's. They determined the dis- 

 tribution of river water within the Bay of 

 Fundy and in Passamaquoddy Bay and evaluated 

 the rate of transport of river water. They also 

 made empirical calculations of exchange ratios 

 and of total accumulation of river water. The 

 close agreement between the calculated and 

 observed accumulations of river water in- 

 dicated that such tidal- exchange calculations 

 would be useful in any area having vigorous 

 tidal mixing. 



In August 1936, researchers on the Atlantis 

 made 22 hauls with Norwegian shrimp trawls 

 over mud bottoms in deep water in the western 

 and northern parts of the Gulf to determine 

 the abundance of Pandalus borealis and as- 

 sociated fishes. Bigelow and Schroeder (1939) 

 reported on the faunal community of the water 

 just above these deep-mud bottoms. The most 

 significant faunal contrast noted was that 

 P. borealis had a well-marked center of 

 population in the deep bowl west of Jeffreys 

 Ledge where bottom currents are weak and 

 the supply of organic debris on the bottom 

 is relatively large. No regional contrast was 

 evident in the qualitative composition of the 

 fish fauna found over mud bottoms in different 

 parts of the Gulf. 



The Atlantis made 1 1 cruises from Sep- 

 tember 1939 to June 1941 during a study of 

 the productivity of George Bank by various 

 members of the staff of the Woods Hole 

 Oceanographic Institution. Stations covered 

 the region from the South Channel on the 

 southwest to the eastern tip of Georges Bank 

 and from the deep basin of the Gulf of Maine 

 on the northwest to the edge of the continental 

 shelf on the southeast. Standard hydrographic 

 observations for salinity and temperature 

 were made at every station, transparency 

 measurements were obtained during daylight 

 hours, and phytoplankton collections and spe- 

 cific chemical data were obtained at selected 

 stations. Zooplankton was collected at each 

 station by means of oblique hauls with plank- 

 ton samplers (Clarke and Bumpus, 1950) and 



