3 
85% VARIATION EXPLAINED 
c\l 
co 
X 
< 
-I 
-2 
CONIMICUT 
MOUTH 
EAST PASSAGE 
MOUTH 
WEST PASSAGE^ ^SOUTH-ROSE ISLAND 
PROVIDENCE * 
RIVER 
OHIO dutch ISLAND 
LEDGE, 
SOUTH- 
MOUTH 9 PATIENCEmt.HOPE 3) 
EAST GREENWICH $ BRIDGE// 
EAST-PRUDENCE / 
QUONSET* /V 
SOUTH-EAST PRUDENCE 
POINT 
merl TANKS 
-I 0 
AXIS 
1 I 
1 2 3 
Figure 24-8. A Discriminant Analysis of Data from the 9 MERL 
Microcosms and the 13 Bay Stations Using the Variables: 
Chlorophyll, Zooplankton, Ammonia, Nitrate Plus Nitrite, 
Phosphate and Silicate. 
NOTE: MERL data from August 17 to December 6, 1976. Bay data from 
1972-1973 survey. For detailed information on the analysis see Table 24-6. 
significantly different from microcosms 3, 5, 9, and microcosm 3 is 
significantly different from microcosm 9, but the bay stations “Dutch Island,” 
“Southeast Prudence,” “East Prudence” and “Mt. Hope Bridge,” are not 
significantly different from any of the microcosms (Table 24-6). Other mid-bay 
stations are different from some of the microcosms, but no more so than they 
are with regard to each other. 
These intercomparisons between the MERL microcosms and Narragansett 
Bay show that the MERL microcosms diverged surprisingly little from stations 
in the bay or from other microcosms, with regard to concentrations of 
nutrients, chlorophyll, zooplankton biomass and phytoplankton species 
composition during the replicability experiment. 
375 
