Lake Frederick Biologist Report 2024
Department biologists and technicians sampled Lake Frederick two times during the month of May. Biologists use boat electrofishing gear to collect the fish and time their sampling effort. As a result biologists can track the number of fish per hour of electrofishing or catch per unit of effort (CPUE). The CPUE as well as other metrics like growth and mortality are then monitored annually to determine the overall health of the fish population. Four permanent sites are sampled annually or biannually. The sites are located along the dam, east arm, and west arm of the lake (Map 1). In total, 446 fish were collected during the two nights of sampling. Biologists continue to monitor the lake carefully after Blueback Herring and Gizzard Shad were accidentally or illegally introduced into the lake. Both species were discovered in the spring of 2021. It is assumed that both species were a result of “bait bucket” introductions. We would like to remind anglers to dispose of their bait properly at the end of each fishing trip, never release bait into the wild. Fortunately, the gizzard shad have not been able to reproduce so far. However, the blueback herring population has exploded. Anglers using sonar will easily spot bait balls within the main basin of the lake, often with a school of bass in tow. Biologists are worried about this recent introduction because it can decrease the numbers of sunfish within the reservoir. Bank fishing success can also be inhibited by the herring as the largemouth are drawn out to the middle of the lake into more pelagic habitats.
In other news, Gregory’s Lakeside Bait and Tackle reopened a new bait hut on the property. It features a much larger selection of bait and tackle within a brand new facility. Come check it out and rent a boat or kayak the next time you visit the lake. The fishing pier was also refurbished. VDWR continues to partner with Warren County to deliver 200 Christmas trees to the lake in January of each year. Local anglers and members from the community all pitched in to help construct fish reefs that were later deployed by VDWR staff members. Check in with the staff at the bait hut for specific information regarding the fish reef locations.
Largemouth Bass
The largemouth bass population is stable, but has changed over the past 3 years. A large majority of our 2024 sample consisted of fish measuring 8-15”, however the lake still produces a number of quality sized bass (Figure 1). 97% of the largemouth sampled are considered adults or stock sized fish (>8”), within that group 41% are considered quality sized largemouth >12”, 13% were >15” and 1% were >20”. When 40-60% of the adult sample is made up of quality bass the population is considered balanced. If you look at the historic catch rates in figure 2 you will notice the total catch rates over the past three years have been below the long-term average. This is largely a result of poor juvenile survival. Over the past 5 years only one sample yielded a juvenile catch rate above the long term average (Figure 3). 2024 yielded the worst juvenile catch rate since we began consistently sampling the lake. Blueback Herring compete directly with young sunfish and bass by consuming a large portion of plankton within the lake. We are concerned that this may be reducing juvenile bass survival. In the long term, this may not be a terrible result as small impoundments often become overpopulated by stunted bass. However, if juvenile bass survival becomes too low angler catch rates will drop. Lake Frederick has historically produced the best quality largemouth bass fishery in the Shenandoah Valley. Anglers have wrestled largemouth up to 10 pounds from the lake in recent years. Compared to bass from more southern latitudes, largemouth in Lake Frederick exhibit slow growth rates. It takes around 5-6 growing seasons for a bass to reach 15″ in Lake Frederick. The primary forage for largemouth bass are numerous small bluegill, redear and black crappie. The addition of pelagic species like Gizzard Shad and Blueback Herring adds yet another prey option for the opportunistic largemouth.
Figure 1: Number and lengths of largemouth bass collected from Lake Frederick in Spring 2024. Juvenile bass (less then 8 inches) are represented with red bars, while adult smallmouth bass are shown with blue bars.
Figure 2: Annual catch of largemouth bass from 2002 – 2024 in Lake Frederick, the red line represents the historic average catch rate.
Figure 3: Annual catch of juvenile bass <8” from 2001 – 2024 in Lake Frederick, the red line represents the historic average catch rate.
The clear water of Lake Frederick often makes it difficult to catch bass. Bass often become suspended in the submerged standing timber that surrounds much of the shoreline. Anglers need to fish different depths until they locate fish. Night fishing during the summer months can also be productive. Some of the largest bass are caught during the pre-spawn in the months of March and April.
Sunfish
Lake Frederick is home to a variety of sunfish species including Bluegill, Redear, and Green Sunfish. In 2024, a total of 138 sunfish were collected. Bluegill sunfish and redear sunfish were the most abundant sunfish collected and ranged from 2-10 inches in length. As predicted, the blueback herring have had a negative impact on the sunfish population. Overall numbers of sunfish have decreased dramatically over the past 5-6 years (Figure 4). Despite the reduction in overall numbers, the percentage of quality sunfish within the population are high. 27% of the bluegill captured were >6” and 61% of the redear exceeded that mark. If you are looking to catch a “citation” sized sunfish then head to Lake Frederick. It is the only lake in the valley that produces good numbers of large sunfish. Anglers have been successful using live bait such as crickets and red worms to catch these “whopper” panfish. The fishing pier is an excellent area for new anglers to hone their skills by catching some of these dinner plates with fins.
Figure 4: Annual catch of Bluegill and Redear Sunfish from 2001 – 2024 in Lake Frederick.
Crappie
We have not conducted any specific sampling targeting crappie in recent years, but the population appears to be healthy. Anglers report decent numbers of harvestable size (8-10″) crappie available, especially around the brush piles near the boat ramp. Anglers should focus on the breast of the dam and around the fishing pier in the spring when water temperatures reach the mid 50’s. Later in the year try targeting the fish habitat structures scattered throughout the lake. Live minnows and small jigs should be the best baits.
Channel Catfish
Channel catfish are stocked annually by the Department and Lake Frederick provides anglers with a great opportunity to catch a tasty meal. In the fall of 2024, 1,580 ten-inch channel cats were stocked into the lake. During our two nights of sampling we netted 17 cats ranging in size from 16-24 inches. Catfish anglers should use cut bait, nightcrawlers, or commercial catfish baits to entice them into biting.
Northern Pike
Northern Pike are stocked periodically to provide diversity to the fishery as well as a challenging trophy fish for anglers to target. A few Pike are caught each year typically in early spring or during the winter. Their sizes range 20-35”. In the spring 223 northern pike fingerlings were stocked into Lake Frederick.
Walleye
Historically Walleye were stocked annually in Lake Frederick. However, due to low fishing pressure and low population numbers stocking was discontinued. Regardless, anglers continue to catch a few walleye each year. It’s probably not worth specifically targeting these fish at the lake, but they are a nice surprise when you hook into one. Fantastic table fare.
Northern Snakehead
Fortunately, for the past few years, no snakehead have been collected by biologists or by anglers.
Anglers are required to report snakeheads kept but are not required to kill them if caught and immediately released. Snakeheads must be dead if in possession (contained in live well, cooler, etc.) However, the Department asks that all snakeheads be killed if possible. If an angler wishes to keep a legally caught northern snakehead, the fish must be killed to be in possession, and the angler must call the hotline or other DWR contact and report the angler’s last name, date of catch, location of catch, and size. Kill the fish by:
- removing the head,
- separating the gill arches from the body, or
- removing the internal organs and put it on ice as quickly as possible.
For More Information: https://dgifwebtest.gooutdoorsvirginia.com/fishing/snakehead/
Map 1: VDWR Sampling Site Locations