Author: Ontario Ministry of Natural Resources. 2009. The lake sturgeon in Ontario. Fish and Wildlife Branch. Peterborough, Ontario. 48 p. + appendices.
The construction of dams, many for hydroelectric power generation, restrict access to spawning, nursery and feeding habitats thereby fragmenting their natural habitat (Figure 12). Hydroelectric development was identified as the greatest problem for
lake sturgeon rehabilitation at 12 of 21 historic Lake Superior spawning sites (Ebener 2007). The blockage of migration routes has been attributed as the cause for decline and a factor preventing recovery of lake sturgeon in many situations (Harkness and Dymond 1961, Haxton and Findlay 2008, Mohr and McClain 2001, Swainson 2001).
Hydroelectric power generation can have strong negative effects on sturgeon spawning downstream. Sturgeon recruitment is believed to be related to the volume of spring water flows. The artificial alteration of water levels and flows disrupts the natural
environmental cues associated with movements, spawning and downstream drift of larval fish. Constant flows allow large fish migratory access and triggers reproduction resulting in less time spent on the spawning grounds (Auer 1996b).
On the Kaministiquia River, Friday and Chase (2005) reported that adult sturgeon did not move to the spawning area at the base of Kakabeka Falls until flows reached 23 m3 sec-1. Water level fluctuations below dams can leave eggs susceptible to dessication (Brousseau and Goodchild 1989, Evans et al. 1993, Rosenberg et al. 1997). In some cases, sturgeon can become entrained and
stranded in pools downstream of hydroelectric facilities (Seyler 1996).