Endangered lake sturgeon in the East Fork White River: A brief statement.
Nov 11, 2016 — Lake sturgeon is a potamodromous migratory species. According to the USFWS field officer in Bloomington, it is "highly migratory, moving hundreds of miles along freshwater streams." (Scott Pruitt to FERC, 1/20/04) Given that Indiana's lake sturgeon sub-species, if you will, once inhabited the entire Ohio River drainage, its former migrations can only be imagined. "In fact, lake sturgeon may be capable of extremely long migrations (1,000-1,800 km) but are prevented by natural barriers and human alterations." (USDA, 2003).
Its former range in the East Fork White River included tributaries, and doubtless they preferred only particular tributaries with particular habitats. Lake sturgeon move between habitats for various reasons; spawning, their size/age, etc. The East Fork White River watershed is 5746 square miles. Williams Dam, in Lawrence County, blocks passage of most fish species (except Asian carp), particularly the lake sturgeon, to approximately 4889 square miles of drainage above it. If the EFWR's population of lake sturgeon - which the state has characterized as "small" or "rare" - inhabits the river only in Lawrence County downstream of Williams Dam, plus Martin County below that, then one might say its habitat is diminutive. That dams are a threat to lake sturgeon has been widely documented in reports, including very many by U.S. government agencies. The Indiana DNR notes in annual reports that Williams Dam blocks passage and migration of the lake sturgeon, without getting into much detail on how that effects spawning and populations. Which is, in any case, obvious. However it has been noted that lake sturgeon "would be expected to make spawning runs, which would be inhibited by the dam." (Hoffman, DNR, 2003)
Reconstruction of Williams Dam, versus the state's 2004 plan to remove it, will obviously mean that the survival of the lake sturgeon in the river will continue to be jeopardized. Simply maintaining the status quo will leave them susceptible to further decline due to environmental factors, disasters such as drought or chemical spill, and disease and parasites. Such events could extirpate them. Construction on and operation of the dam will have various negative impacts to the lake sturgeon and their habitat below the dam, although they may not be greatly negative, and are discussed in vast detail in the license docket documents. On the other hand, normal flows and river morphology are crucially important to the lake sturgeon, and Williams Dam negatively affects those aspects, to a great degree just below the dam, where lake sturgeon congregate, and for many miles beyond.
Construction of fish passage, and/or restocking efforts in the watershed above Williams Dam, would surely help to restore the East Fork's lake sturgeon population. However, entrainment in the dam's hydroelectric structure would very likely occur, resulting in the death of juvenile and adult lake sturgeon. A fishway for the sturgeon would have to be carefully designed for their specific use, as well as by other native species. There are currently plans to install barriers to mitigate entrainment, however it is not clear if the current designs would be effective for lake sturgeon.
Gary W. Moody, Director
Fishable Indiana Streams for Hoosiers, Inc. (FISH)
See also: http://link.springer.com/article/10.1007/s10592-007-9441-9