locations. Hough (1942) described the charac- 

 teristics and distribution of sediments in 

 Cape Cod Bay and compared them with the 

 sediments in other bays. 



In 1933 and 1934, WHOI made a detailed 

 oceanographic survey of the offshore waters 

 of the Gulf of Maine to obtain a more precise 

 seasonal picture of its hydrography and biology 

 than was available from Bigelow's observa- 

 tions. The Atlantis made 13 cruises in 15 

 months (July 1933 to September 1934) and 

 occupied 684 hydrographic stations. A standard 

 vertical haul (from bottom- to surface) with a 

 Heligoland larva net was made at each station. 

 Redfield (1941) gave the dates of these cruises 

 and the numbers of the stations occupied. The 

 Bulletin Hydrographique (1934, 1 935) published 

 the routine hydrographic and chemical data. 

 Supplementary cruises were made in May and 

 August 1936 to confirm certain observations 

 made during the primary survey. 



A description of published reports concern- 

 ing the distribution, abundance, and ecology 

 of the phytoplankton and zooplankton collected 

 during these cruises follows. Lillick (1938) 

 published a preliminary report on the phyto- 

 plankton in which the species composition and 

 abundance (cells per liter) at 1, 10, 30, 50, 

 and 80 m. at each station are presented in 

 tabular form showing that the phytoplankton 

 of the Gulf of Maine follows the cycle typical 

 of boreal waters. The frequency and continuity 

 of the cruises during this survey enabled 

 Redfield (1939) to follow the history of a rather 

 definite population of the pteropod Limacina 

 retroversa during the greater part of the 

 year as it drifted across the Gulf of Maine; 

 he noted its rate of drift and spread, mortality, 

 growth, reproduction, and replacement by 

 another population of the same species. This 

 evidence demonstrated that the population of 

 Limacina was not endemic, as Bigelow thought, 

 but owed its origin to invasions of young in- 

 dividuals from offshore waters to the east of 

 the Gulf of Maine. The discontinuous character 

 of the invasions accounted for the irregularity 

 in occurrence of this species. Hsiao (1939) 

 described in detail the reproductive history and 

 sequence of the sexual phases of Limacina 

 retroversa in relation to size. His study 

 indicates that the change in sexual constitu- 

 tion of the populations with time resulted from 

 a reversal of sex predominance of the in- 

 dividuals. 



The collections made in 1933 and 1934 

 provided the basis for a general survey of 

 the numerical distribution of phytoplankton 

 and planktonic protozoa and species composi- 

 tion of plankton flora of the Gulf of Maine 

 from season to season. In the first part of 

 this report, Bigelow, Lillick, and Sears (1940) 

 described the seasonal and regional abundance 

 of plant cells and planktonic protozoa and the 

 relation of the planktonic cycle to nutrients, 

 light, temperature, vertical circulation, and 



grazing. They based the numerical distribution 

 of plant cells (number per 0.1 m.2 of sea 

 surface) on water bottle samples at 1, 10, 30, 

 50, and 80 m. and vertical net haul samples. 

 In the second part of this report, Lillick ( 1 940) 

 presented data on the species composition of 

 the phytoplankton. These data corroborate the 

 joint evidence of earlier years that in the 

 Gulf of Maine the major fluctuations in the 

 total number of planktonic plant cells, both 

 regionally and seasonally, resulted chiefly 

 from fluctuations in the abundance of diatoms. 

 The phytoplankton cycle paralleled that of 

 other boreal waters in time sequence, differ- 

 ing only in the association of species con- 

 cerned. 



Redfield and Beale (1940) presented data 

 concerning the distribution and numerical 

 abundance of chaetognaths taken during the 

 1933-34 Atlantis cruises. Their data dem- 

 onstrate that deep currents carry Eukrohnia 

 hamata , Sagitta maxima , and S. lyra into the 

 Gulf of Maine (they do not breed there), that 

 S. serrodentata is a terminal immigrant from 

 the superficial waters of the Atlantic, and that 

 S. elegans is the only chaetognath truly endemic 

 to the region. The permanence of this stock 

 is correlated with the stability of hydrographic 

 conditions in various regions (notably Georges 

 Bank). The character of the chaetognath dis- 

 tribution is independent of the physical charac- 

 teristics and nutritive conditions of the water 

 and can be accounted for in terms of the bio- 

 logical characteristics of the species and the 

 movement of the water stratum within which 

 the species are found. 



In the final paper published on the plankton 

 collected during the Atlantis Gulf of Maine 

 cruises, Redfield ( 1 941 ) described the seasonal 

 and geographical fluctuations in abundance of 

 the calanoid community (total zooplankton 

 minus Salpa , ctenophores, and medusae). He 

 based the abundance figures on determinations 

 of the dry volume of the vertical tow-net 

 catches by the method of filtration and dis- 

 placement. He demonstrated that the center 

 of abundance is closely associated with the 

 surface circulation and that the principal 

 factor influencing population density was the 

 inflow of relatively barren coastal water from 

 the Nova Scotia coast in winter. He concluded 

 that the Gulf of Maine is the region of produc- 

 tion of the calanoid community and supplies 

 immigrants to the south, but receives no 

 appreciable recruitment from regions to the 

 eastward. 



Three papers describe the chemistry of the 

 Gulf of Maine waters based on the 1933-34 

 Atlantis cruises. Rakestraw's paper (1936) 

 on the occurrence of nitrite includes data 

 collected in other areas as well as in the 

 Gulf of Maine. He grouped stations in the 

 Gulf of Maine into seven locations, one on 

 Georges Bank and the other six in the deep 

 water to the north. He presented data showing 



