. Bulletin. Natural history; Natural history. July, 1966 Hansen: Stocking and Sport Fishing at Lake Glenuale 113. Fig. 3.—Weir for collecting fish that moved out of Lake Glendale during the draining operations 1946 and 1950. the screens were removed and were not replaced until the level of the lake had been dropped 7 feet. Fish did not begin coming through the drain valve until October 24, when the lake level had fallen 14 feet. The fish that came through the drain \aKe were counted, weighed, and then hauled to a nearby farm pond by a crew of five men. This part of the oper- ation required 5 d
. Bulletin. Natural history; Natural history. July, 1966 Hansen: Stocking and Sport Fishing at Lake Glenuale 113. Fig. 3.—Weir for collecting fish that moved out of Lake Glendale during the draining operations 1946 and 1950. the screens were removed and were not replaced until the level of the lake had been dropped 7 feet. Fish did not begin coming through the drain valve until October 24, when the lake level had fallen 14 feet. The fish that came through the drain \aKe were counted, weighed, and then hauled to a nearby farm pond by a crew of five men. This part of the oper- ation required 5 days, October 26-30. The fish were afterward used in re- stocking the lake. When as much water as possible had been drained from the lake basin, the larger part of the fish population of 2 inches and longer remained within the basin in a 1,300 foot stretch of the original stream channel (Fig. 4), while small numbers of fish remained in some very small isolated pools in other parts of the basin. The part of the channel where the fish were concen- trated was approximately 30 feet wide and had an a\'erage depth of about 2 feet. Many of the fish that remained in the channel might ha\'e gone out with the drain water if, in the late stages of draining, the water could have been let through the drain valve more rapidly and without interrup- tions. However, continuous rapid drain- ing was impracticable: (i) because the drain water might ha\'e topped the screens, which were partially clogged with leaves, and (ii) because fish would have come through the valve faster than they could ha\'e been proc- essed. Early in the afternoon of November 6, a heatment of 11 pounds of pow- dei-ed derris (5 per cent rotenone) was applied to the channel and the isolated pools; this was followed by a second heatment of the same waters with 15 pounds of derris on the afternoon of No\'cmber S. The volume of water treated was about 2 acre-feet. A hoop net that was placed in the channel and raised at irregul
Size: 1817px × 1375px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., booka, bookcentury1900, bookdecade1910, booksubjectnaturalhistory
