Go Fish

How many fish in the sea?

Wildlife Biologist John Odenkirk

Virginia Department of Wildlife Resources biologist John Odenkirk has been counting Potomac River bass since Northern Snakeheads (NSH) invaded in 2004. While shocking and studying NSH, the River’s prized largemouth bass were a by-catch.

While the Potomac NSH population is down, likely due to predation by fish, birds and anglers, the largemouth bass fishery is in outstanding shape. Odenkirk says the only poor year class in the last six was the 2018 class, the wettest year in recorded history, showing a drop off in the 2019 surveys. Odenkirk says the good years are “… driving the gravy train.” The DWR conducts regular and consistent fishing surveys with electro shocking boats maneuvering where bass are located. These areas are the same and the length of the surveys are timed. Once stunned, bass float to the surface where they’re netted, measured, logged, and released. This process doesn’t harm fish. Samples are collected from 4 Virginia creeks, once in April and once in May. There are 3 runs in each of the four creeks with 2 survey periods. Data collected is calculated to give a statistical count of largemouth bass. Odenkirk says when trying to compare catch rate with relative abundance... more sample sizes the better.

Odenkirk only conducts spring surveys when bass are shallow and before submerged aquatic vegetation emerges interferes with access to bass with thick vegetation. This is different from other jurisdictions, running their own surveys. From this data they determine the relative abundance of bass, and this statistical number of bass is a surrogate for actual population.

DWR data is stratified by age. Generally, a fish under 8 inches a fingerling or juvenile. On average a one year old bass is 4-12 inches. Much of this is dependent on environmental influences, habitat, and forage, but also multiple spawns. Fortunately, bass spawn for nearly a month on the river, providing variations in a year class. For 2021 the catch rate of young bass was above average, based on 20 years of data. Data is important when considering regulations or restrictions. However, Odenkirk also shares this information with anglers along with a brief explanation as to what’s behind the numbers. Most anglers appreciate the information about trends and the outlook.

While some anglers and even an agency will, from time to time, paint a dismal picture of Potomac bass populations, Odenkirk says many issues would show up in surveys with a downturn in a year class population that is unique to one year class or through several year classes. It’s reasonable to assume that great year classes experience an annual decrease in numbers due to predation, disease, or old age. But Odenkirk is quick to point out that angler influence doesn’t show up in bass surveys as there is nearly 100% catch and release. Bass boats have better livewell systems and tournament anglers are better at preserving their fish. While tournament delayed mortality is somewhat likely, it hasn’t shown up significantly in surveys. Successful spawns are always dictated by habitat and environment, not angler influence. As noted by the lower 2018 spawn due to high muddy water, Odenkirk maintains recruitment is driven by environment like SAV abundance and no floods, drought, or extreme water flow.

After crunching numbers, Odenkirk says age structure suggests a good year class, with many older larger fish, is where it should be. A case in point is Lake Anna where about 12 years ago the size restriction was removed. Odenkirk says this also made it easier for anglers to understand regulations. No more confusion on the time of year or location or slot limits. The statewide limit is 5 bass. Slot limits allow fisheries managers to control the structure of fish populations. Odenkirk says with voluntary and widespread catch and release, there’s no need to ask anglers to help restructure fisheries in size and numbers.

Several years ago, the activist group, Concerned Bass Anglers of Virginia lobbied and raised money for stocking of F1 strain largemouth bass. While these fish do not reproduce this strain of larger Florida bass, they do add to the relative abundance and the original stock provides lunker size bass for anglers. The DWR is in its 2nd year of stocking in 5 reservoir fisheries. Stockings will be rotated and if successful, there will be 8-12 pound bass in these selected fisheries.

While DWR manages Virginia’s Potomac tributaries, there’s interaction with the Potomac River Fisheries Commission, Maryland Department of Natural Resources and DC Fisheries to avoid a patchwork of regulations. VA and MD reciprocate licenses; however, DC requires theirs. Working with MD and DC biologists, Odenkirk is hopeful they can continue to collaborate on fisheries data, and hopefully this means spring collections so they can all see the same data and come to the same conclusions.

Author Capt. Steve Chaconas is Potomac bass fishing guide. Potomac River reports: nationalbass.com. Book trips/ purchase gift certificates: info@ NationalBass.com.

Potomac River Bassing in July

Hit the mats. Grass beds are getting thicker now, and fish are in them. There are two solid techniques for getting them to come out.

Hollow bodied frogs are effective as they cover water. Gamma Torque braid in 50-60 pound test is a must! At least a 7 foot medium heavy to heavy rod and a fast casting-reel are required for effective hook sets and for winching fish out of thick grass. Also bend the hooks open just a bit for better hook ups. Cast over grass and twitch the frogs to entice bass to bust through the grass to eat them. Once the fish has the bait, do not count to ten! Set the hook straight up.

The other technique is a bit more tedious but very effective. Punching mats refers to a heavy tungsten weight, 1 ounce or more, pegged to a stout hook with a small plastic crawfish. These are pitched to either small openings or shaken to drop to the fish below the grass mats.

Either method produces big fish.