Pacemaker Fishing Forum

NORTHERN VIRGINIA RESERVOIRS RANKED FOR LARGEMOUTH BASS

District fisheries biologists sampled major reservoirs in northern Virginia in spring 2005-2008.  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
Pelham               6    2005    255              Culpeper        28        41
Germantown    7   2008   109                    Fauquier        23            17
Fairfax                 8     2008     28                   Fairfax            22            31
Anna               9    2008    9600             Spotsylvania        21          36
Brittle                10    2006    77                  Fauquier            21         26
Abel                11    2005    185                  Stafford           20        24
Curtis                 12     2005    91                   Stafford           17        18
Hunting Run    13   2008    420          Spotsylvania       14        19
Orange             14    2008    124            Orange              14        12
Ni                 15       2007       411               Spotsylvania        13        30
Breckinridge    16     2006    47         Stafford              12        9
Lunga               17    2005    477          Stafford               11        13
Smith              18    2007    250          Stafford               5        7


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 Occoquan’s first place even more impressive). 
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 Motts, but a few “sleepers” emerged after the 2007 sampling season.  Of special note, Beaverdam Creek and Germantown made major moves up and offer anglers a change of scene and a chance of catching a trophy.  Hunting Run, a new reservoir, has great potential, but anglers need to harvest sub slot (<16”) fish to relieve stockpiling.  For more information, contact Fisheries Division in Fredericksburg (540-899-4169).

Charlie NHBA