Archive image from page 126 of Discovery reports (1934) Discovery reports discoveryreports09inst Year: 1934 DISTRIBUTION OF ANTARCTIC MACROPLANKTON 115 The main plankton survey has usually been carried out near the middle of the season, and in those years in which further hauls have been made later in the summer there has been evidence of a reduction in the amount of plankton towards the autumn, at any rate on the north side of the island. Fig. 30. Distribution of plankton quantities around South Georgia, 1930-1, Sts. WS 565-75. The following list includes all the N 100 B samples taken in
Archive image from page 126 of Discovery reports (1934) Discovery reports discoveryreports09inst Year: 1934 DISTRIBUTION OF ANTARCTIC MACROPLANKTON 115 The main plankton survey has usually been carried out near the middle of the season, and in those years in which further hauls have been made later in the summer there has been evidence of a reduction in the amount of plankton towards the autumn, at any rate on the north side of the island. Fig. 30. Distribution of plankton quantities around South Georgia, 1930-1, Sts. WS 565-75. The following list includes all the N 100 B samples taken in the immediate vicinity of South Georgia during the period 1927-31, and shows the average number of organ- isms per haul for each group of stations. Average number Number of organisms Date 1927-8 Feb .-March April 1928-9 October November Dec-Jan. April 1929-30 October Jan-Feb. May 1930- November March Station WS 144-93 WS 196 WS 257-96 WS311 WS313 WS 321-72 WS 417-26 WS464 3°°-58 393 475-525 WS 565-75 Position South Georgia survey South-west side of South Georgia South Georgia survey South-east of South Georgia South-east of South Georgia South Georgia survey South side of South Georgia North side of South Georgia South Georgia survey North side of South Georgia South Georgia survey North side of South Georgia of hauls per haul 44 1 *3 2,361 35 1 468 326 1 51 10 1 2,146 54 1 19,224 (Reduced numbers) 47 7 2,062 In Fig. 31 all four seasons are taken together and the average number of organisms per haul for each group of stations is plotted according to the month or mean date at which the stations were taken. As would be expected the plankton is much richer in the summer than in the winter, but the regularity of the curve is broken by the low figure for the 1928-9 survey (December-January). It is difficult to account for this, but the patchiness of the plankton may be seen from Figs. 24, 26 and 27, and might well result in irregularities in
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