2007 Volume 1 Pages 53-63
The spawning area for largemouth bass was surveyed with the Side scan sonar in Lake Izunuma. Individual spawning spot for largemouth bass was not able to be distinguished in a sound image of the Side scan sonar alone. However, it was possible to estimate the influence of waves on the spawning area by identifying the ripple besides the division of the sediment and the structures. The range where the artificial spawning beds were installed and that was the main spawning area in Lake Izunuma was chiefly composed the sediment of sand only, and the influence of waves was weak. On the other hand, it was chiefly composed the sediment of sand and mud outside of the range where the artificial spawning beds were installed. It was guessed that the range composed of sand was under the influence of waves from the situation of a surrounding ripple. If it was 1m or more in depth, even in case of the turbid water, it was shown to be able to select the spawning area of largemouth bass and the smallmouth bass, and to become one of the effective methods to control the alien fishes.
