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Libby, D. A. (1981). Difference in sex ratios of the anadromous alewife, Alosa pseudoharengus, between the top and bottom of a fishway at Damariscotta Lake, Maine. Fishery Bulletin. 79:207-211.

The Damariscotta River alewife, Alosa pseudoharengus , fishery has been monitored every year since 1971 for abundance of fish, length and weight frequencies, age distribution, and sex ratios. From 1977 through 1979, sampling plans were also devised to estimate numbers, size, and sex composition of ripe alewives escaping the fishery and entering the lake to spawn. While sampling the 1977 escapement run it became evident that a greater number of males than females were entering the lake to spawn. This male dominance was not unusual as it was reported in other alewife runs as well. What prompted this investigation was the fact that while the escapement runs had significantly more males than females, the samples from the commercial catch revealed a consistent sex ratio of 1:1. The explanation for the change in the sex ratio from the tidal area to the lake appears to be an effect of the fishway. The greatest disproportionate ratio of male to female alewives occurred at the first part of the escapement run when the largest fish were in the fishway. It seemed that the construction of the fishway was selective against the largest or heaviest fish which were the females at that time. As the size of females tended to decrease, the male to female ratio became more equal.