106 Lake Maxinkuckee, Physical and Biological Survey 



In all, 128 hauls were made at the principal stations. Not all 

 of them are included in the following tables, however, as some 

 hauls were made at depths not regularly included in each set of 

 observations. Their omission does not affect the conclusions in 

 any way. The tables show the quantity of plankton in cubic centi- 

 meters under each square meter of surface and to the depth indi- 

 cated, exclusive of a correction for the coefficient of the net. That 

 is, they show the total quantity taken in each haul multiplied by 



91 9 /l<XMXK 



^l-AiTTsJ- 



In the results given for Station I, those for the first, second, and 

 fourth weeks are averages of three to five sets of observations 

 per week but only one set was made the third week. At Station 

 II, only one series of hauls was made each week. At Station III, 

 no hauls were made the first week and only one set each during the 

 second and third weeks. The result for the fourth week is the 

 average of ten sets of hauls. 



STATION I 



STATION II 



STATION III 



Decrease: The above tables show that there was a pronounced 

 decrease in the quantity of plankton during the four weeks. This 

 was due to the decline of the phytoplankton. The maximum de- 

 crease, 46 per cent., was found in the 0-1 meter stratum where 

 the phytoplankton was most abundant. The hauls from greater 

 depths showed a minimum decrease of 36 per cent. Most of the 

 Crustacea were found below one meter and a slight increase of 

 them partially compensated for the decrease of phytoplankton. 



