Experiments were conducted in opaque floating plastic containers
with a removable lid, with the lid just above the lake surface. The
containers measured 35 × 28 × 15 cm deep and were divided in half
with a fine-mesh vertical stainless steel screen so that two sculpins
could be tested simultaneously within each container. Fresh lake
water could enter through the containers by 5 × 10 cm rectangular
openings covered with fine screen at each end of the container. Each
of 12 containers was tethered to separate posts in 1.5 m of water.
Weighted black ABS pipes were provided for shelter