Cost and relative effectiveness of Lake Sturgeon passage systems in the US and Canada

Abstract

Sturgeons throughout their circumpolar range comprise one of the most imperiled group of fishes due to their unique life history characteristics, overharvest and habitat changes and loss. Lake Sturgeon, a potamodromous Acipenseridae species, despite showing recent significant signs of recovery in the US and Canada, continue to be impacted in systems throughout its range in part because of dams on rivers in which critical sturgeon spawning and nursery habitat is not available in sufficient quantity and/or quality to maintain adequate long-term recruitment in the population due to fragmentation. There are a small number of fish passage structures and methodologies specifically designed and implemented for Lake Sturgeon in North America, but there has been no general evaluation of their installation and operation costs nor their relative effectiveness. Data were collected on seven different fish passage systems representing the range of options currently being utilized for Lake Sturgeon passage within the species’ North American range. Costs per meter of head were $206 060 for nature-like by-pass channel fishways, $305 579 for an upstream projecting pool-weir fishway, $1.1 million for a vertical slot fishway, and $1.6 million for a fish elevator. A capture and transfer operation cost an estimated $11 284 to transfer an average of 110 adult Lake Sturgeon annually. Projected costs per sturgeon passed after 40 years of operation were estimated at $12/fish for the upstream projecting pool-weir fishway, $85/fish for the nature-like by-pass channel fishways, $132 for capture and transfer, $1659 for the vertical slot fishway, and $1680 for the fish elevator. Before Lake Sturgeon passage is pursued, it is important to first determine whether passage would be necessary for restoring, maintaining, or sustaining a LS population and its genetic integrity within the system (above and below the dam); followed then, if passage is warranted, by determining what type of passage methodology might be the most effective, and the most effectively and practically funded, operated, and maintained at the dam in question.