Upper Midwest Environmental Sciences Center

Figure 3a: Estimated power to detect temporal trends in bluegill catch-per-unit effort (CPUE) in Pool 4 in all sampled strata (backwater, main channel border, wing dam, side channel strata) under half the current sampling intensity (approx n = 41). Trends assumed exponential. CPUE represents mean catch per 15 minutes effort. Estimates based on design-based, across-episode annual means. Note that halving the current sampling intensity for day electrofishing in Pool 4, without adjusting relative sampling intensities across strata, may lead to inadequate sample sizes for some strata.
Estimating power to detect temporal trends in LTRM metrics

 

legendFigure 3a: Estimated power to detect temporal trends in bluegill (Lepomis macrochirus) catch-per-unit effort (CPUE) in Pool 4 in all sampled strata (backwater, main channel border, wing dam, side channel strata) under half the present sampling intensity (n ≈ 41). Trends assumed exponential. The CPUE represents mean catch per 15-min effort. Estimates based on design-based, across-episode annual means. Note that halving the present sampling intensity for day electrofishing in Pool 4, without adjusting relative sampling intensities across strata, may lead to inadequate sample sizes for some strata.

larger scale

Figure 3a

Disclaimer: This information is provided to help better inform ongoing LTRM partner discussions. The power plots are generated from small sample sizes; all plots should be treated as approximate.

Contact: Questions or comments may be directed to Brian Gray, LTRM statistician, Upper Midwest Environmental Sciences Center, La Crosse, Wisconsin, at brgray@usgs.gov.

Page Last Modified: April 17, 2018