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

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generally agree with the findings of the present study.
Whenever the effect of depth is statistically removed from the
abundance of Pontoporeia, the average density appears to be highest at
the most western inshore stations in the northern basin of the lake.
Ayers et al. (1958) have shown that areas on the western margin of the
lake, in the vicinity of stations E-6 and D-6, are periodically subjected
to upwelling and currents sweeping down from Green Bay. The increased
productivity attributable to upwelling plus the added nutrients carried
south from the Green Bay region could make the western protions of the
lake more productive than would normally be expected, The inshore
regions of the eastern portions of the lake, in proximity to the C, D,
and E transects, are subjected to upwelling caused by short-lived NE
winds and the normal outflow current which is enriched by local runoff
and nutrients sweeping north from the southern basin. The amphipod
density also appears to be higher within these regionso
Station B-8, located approximately 2 miles from Waukegan, Wiso.
station A- 6 situated 9 miles from Chicago, and A- I located 2 miles from
Benton Harbor, Micho, are found within the regions of the southern lake
basin that have been classified as grossly polluted by the Federal Water
Pollution Control Administration (1968). Although it is currently fashionsable to regard areas in the lake with low Pontoporeia densities as areas
of gross pollution, it must be pointed out that the sediment types in these
regions are quite: variable, ranging from fine beach sands to glacial tills,