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

16

Short-Term Study Area
The macrobenthic fauna of the short-term study area was collected
from two 15 x 15 ft areas of the lake bottom, designated study areas 1
and 2. These areas were sampled in detail by divers utilizing a hand
coring device patterned after that described by Fager et al. (1966)
(Fig. 7). The steel coring tube was 7 inches in length, had an inside
2
diameter of 2. 05 inches, and sampled a surface area of 0. 022 ft. The
butt-end of the corer was fitted with an adaptor made of rubber hose,
machined so that a wide mouth pint mason jar could be inserted over it.
The 15 x 15 ft "sampling frame" used by R. F. Anderson, constructed of steel pipe and supported by 4 legs 3 ft. long, defined the
boundaries of the study area. A grid network consisting of plastic line
with attached number tags was arranged on top of the frame to position
sample transects and to space the samples. The frame also provided
support for the divers, permitting sampling with a minimum disturbance to the bottom sediment and organisms.
The frame was assembled on the beach with flotation tubes attached
to each corner. It was then towed to the study area, lowered to the
bottom, and positioned by the divers. Two divers working together
were able to take samples rapidly. A wide mouth mason jar was
attached to the coring tube which was then inserted two inches into the
1 A study of fish predation on the macrobenthos of Lake
Michigan. Paper presented at the 11th Conference on Great Lakes
Research, Milwaukee, Wis., 1968.