Daily Counts of White Sturgeon Passing Through Fishways Reveal Interesting Details about Dams, Fishways, White Sturgeon, and Passage in the Columbia River Basin

Summaries of the timing of counts and estimated lengths of white sturgeon passing dams reveal interesting information. Mean lengths and peak of timing of white sturgeon counted in fishways suggests that upstream passage is not related to a spawning migration. Differences in white sturgeon lengths and differences in timing of counts between fishways at individual dams suggest that physical or hydraulic conditions influencing approach, attraction, entry, and ultimately passage differ among sites.  In turn, these findings suggest that further study could provide information on ways to improve upstream passage of white sturgeon.

Nine mainstem dams on the Columbia River and four on the Snake River were constructed with fishways and counting stations. Ironically, white sturgeon, a species native to the Columbia Basin and once thought to be anadromous, were not mandated to be counted until 2006 despite knowledge of their presence in fishways. However, due to their charismatic appearance and relative scarcity in fishways, many fish counters voluntarily enumerated them and often estimated their size and noted direction of movement within fishways. Daily passage of white sturgeon from 1998 through present are now available in digital format and summaries of that data are presented here.