A student holds a small-mesh vertical gill net that will be deployed under the ice in Stanley Lake, Idaho (USA) to sample kokanee salmon and other fish in the water column. The bottom of the net (not shown) is weighted and stretches the bottom of the net taught. The PVC plastic tube at the top is filled with foam, and thus keeps the net vertical in the water column. To deploy the net a slit is cut in the ice with a chain saw.