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Kynard, B. (1998). Twenty-two years of passing shortnose sturgeon in fish lifts on the Connecticut River: what has been learned? Pages 255-266 in M. Jungwirth, S. Schmutz and S. Weiss, eds. Fish Migration and Fish Bypasses, Fishing News Books, Vienna (Austria).

The shortnose sturgeon Acipenser brevirostrum population in the Connecticut River has been physically separated into upstream and lower river groups by Holyoke Dam at river km 140 since 1849. Some lower river pre-spawning adults annually migrate to the dam, enter fish lifts and are passed upriver. I examined the passage pattern of 97 migrants lifted from 1975 to 1996. The annual number of fish passed was 0-16 (mean = 4.4, SE = 0.86, mode and median = 4 ind/yr). There was no trend in annual abundance during the 22 year period. Most fish (N = 67) were lifted individually during a day. Adults were passed each month that the lift operated (April-October). Fish were lifted at water temperatures of 10 to 27 °C, with 86% lifted between 12 and 23 °C. River discharge may affect when fish migrate upstream, or enter the lift, or both, e.g. 60 of 71 dates that fish passed were within 23 days (mean -8.5 days, 95% CI = 6.9-10.2 days) following a river discharge > 600 m³/s. Most fish entered during decreasing discharge of 200-450 m³/s (mean = 312 m³/s). Fish were passed by the spillway lift where water depth at the entrance is more shallow than at the tailrace lift entrance. Shortnose sturgeon passage can be enhanced by improving the approach route to the spillway lift, lifting migrants during late May-October when fish are in good physiological condition, increasing lift frequency and attraction flow during summer and fall, and increasing efforts to pass fish within 10 days following natural discharge that exceeds 600 m³/s.