Northern Virginia Reservoirs Ranked for Largemouth Bass
District fisheries biologists sampled major reservoirs in northern Virginia in spring 2005-2009. The samples were conducted during daytime with boat electrofishing gear targeting largemouth bass and were conducted in a manner that allows several comparisons to be made concerning these fish populations. Since many anglers seek largemouth bass, and fish considered over 15 inches are considered "preferred" nationwide; the following summary contains information about bass over 15" (preferred size).
The term "RSD-P" (below) stands for "relative stock density of preferred fish" - which is the proportion of bass in a population over eight inches (stock size or "recruits") that are also at least 15". Thus, this index describes the size structure of the population… the higher the number - the larger the percentage of the population is composed of big fish. The index "CPE-P" stands for "catch per effort of preferred fish." This is a measure of how many bass over 15" are collected by biologists during a set unit of effort (in this case, 1-hour of electrofishing). Thus, the higher the number is, the more abundant big bass were during the sample.
Several factors can bias the data (e.g., weather conditions, fish behavior), but samples were conducted with efforts to minimize these biases. The following is a summary of these data with lakes ranked by CPE-P:
| Reservoir | Rank | Year | Size (AC) | County | CPE-P | RSD-P |
|---|---|---|---|---|---|---|
| Occoquan | 1 | 2007 | 2100 | Fairfax | 39 | 52 |
| Burke | 2 | 2006 | 218 | Fairfax | 38 | 55 |
| Mountain Run | 3 | 2005 | 75 | Culpeper | 37 | 21 |
| Motts | 4 | 2008 | 160 | Spotsylvania | 32 | 35 |
| Beaverdam Cr. | 5 | 2008 | 350 | Loudoun | 28 | 47 |
| Anna | 6 | 2009 | 9600 | Spotsylvania | 28 | 42 |
| Pelham | 7 | 2005 | 255 | Culpeper | 28 | 41 |
| Germantown | 8 | 2008 | 109 | Fauquier | 23 | 17 |
| Fairfax | 9 | 2008 | 28 | Fairfax | 22 | 31 |
| Brittle | 10 | 2006 | 77 | Fauquier | 21 | 26 |
| Abel | 11 | 2009 | 185 | Stafford | 14 | 20 |
| Orange | 12 | 2008 | 124 | Orange | 14 | 12 |
| Ni | 13 | 2007 | 411 | Spotsylvania | 13 | 30 |
| Breckinridge | 14 | 2006 | 47 | Stafford | 12 | 9 |
| Lunga | 15 | 2005 | 477 | Stafford | 11 | 13 |
| Hunting Run | 16 | 2009 | 420 | Spotsylvania | 8 | 8 |
| Curtis | 17 | 2009 | 91 | Stafford | 6 | 8 |
| Smith | 18 | 2007 | 250 | Stafford | 5 | 7 |
| Accotink | 19 | 2009 | 90 | Fairfax | 2 | 10 |
All of these lakes are considered "small impoundments" except Lakes Anna and Occoquan; and Lake Anna is, by far, the largest. Therefore, it is not entirely appropriate to compare them all "head-to-head", as catch rates at large reservoirs are usually lower than in small impoundments (which makes Anna's rise in the standings that much more impressive - most bass indices at Anna were at or near all-time record levels).
John Odenkirk, fisheries biologist, noted many of the best district lakes (for big bass per hour) were consistent producers year-after-year such as Burke and Occoquan. Hunting Run, a new reservoir with great potential continued a skid in the rankings due to a stockpile of sub-15" fish - anglers need to harvest sub slot (<16") fish to relieve this predator-heavy stunting. Threadfin shad stockings and a full pool water level (for the first time) should also help correct the bass population at Hunting Run. For more information, contact Fisheries Division in Fredericksburg (540-899-4169).