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Population Size and Status of the Razorback Sucker in the Green River Basin, Utah and Colorado
Author(s) -
Lanigan Steven H.,
Tyus Harold M.
Publication year - 1989
Publication title -
north american journal of fisheries management
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.587
H-Index - 72
eISSN - 1548-8675
pISSN - 0275-5947
DOI - 10.1577/1548-8675(1989)009<0068:psasot>2.3.co;2
Subject(s) - sucker , canyon , fishery , population , habitat , drainage basin , ecology , environmental science , geography , biology , zoology , cartography , demography , sociology
The status of the razorback sucker Xyrauchen texanus in the Green River, Utah, was evaluated with capture–recapture data collected from 1980 to 1988. The razorback sucker population in the upper Green River (river kilometers 282–555) was estimated at 948 fish (95% confidence interval, 758–1,138), based on a total of 410 fish captured (68 recaptured). Razorback suckers in the lower Green River (km 0–211) were extremely rare; their numbers were too small (13 fish captured, 1 recaptured) to allow a reliable population estimate. Gray and lower Desolation canyons separated the upper and lower Green River razorback sucker populations. These canyons and a low diversion dam appeared to be barriers to fish movement. The absence of the razorback sucker in Gray and lower Desolation canyons (km 211–282) suggested a lack of suitable habitat. The Green River supports the largest known population of razorback suckers among the species' native riverine habitats. However, low population density and recruitment, as well as habitat alteration, mandate increased research and management efforts to save this population.