Ecology of the burrowing amphipod, Pontoporeia affinis, in Lake Michigan / by Wayne Paul Alley.

87

TABLE 7. The relationships that exist between Pontoporeia affinis and
the physical and biological environment as determined by correlation
analysis for the stations of the C, D, and E transects.
-- - --- - -..- -. - - - -

--

X1
X2
x3
X4
X5
X6
X7
X8
X9
x10
11
X12
X12

Variable
Wave height
Day of year
Depth
Depth squared
Surface temperature
Bottom temperature
Sediment type
Percent carbon in sediment
Distance from shore
Oligochaeta
Sphaeriidae
Chironomidae

20-50m. 038. 167
-. 125
146. 134. 181.049
-. 087
-, 146.258 -3203*.333**

L

< 105m. 019. 023. 617**
-. 614**. 013. 342"'"
-. 483**. 336**. 622*,.472 -'.6300",373'"";
It, la,t.
*k *JI; n

All
Depths.017
-.021
-.823**
-.748**.080.476**
-.610**
&61 o,,
673.**
-.618**.701**.82 9**.586**

_ __ _ _ __ __

* Significant at 5%
*,-, Significant at 1%

70 d.f.

136 d.f.

267 d.f.

sequential time intervals was examined by sampling the stations of the C
transect on two successive days, 9 and 10 August 1966 (Fig, 43). It was
felt that the density of Pontoporeia at these stations should not radically
change within a 24 hour period, and any significant deviation in amphipod
density between the two collecting dates would be the result of experi