TVA biologist John Justice points out how a largemouth bass recently ate a Threadfin Shad, whose tail is barely visible within its mouth, while participating in an annual sport fish survey on the Chickamauga Reservoir near Harrison Bay's Wolftever boat ramp Tuesday morning, March 19, 2013 in Hamilton County, Tenn. (AP Photo/Chattanooga Times Free Press, Dan Henry) THE DAILY CITIZEN OUT; NOOGA.COM OUT; CLEVELAND DAILY BANNER OUT; LOCAL INTERNET OUT

TVA biologist John Justice points out how a largemouth bass recently ate a Threadfin Shad, whose tail is barely visible within its mouth, while participating in an annual sport fish survey on the Chickamauga Reservoir near Harrison Bay’s Wolftever boat ramp Tuesday morning, March 19, 2013 in Hamilton County, Tenn. (AP Photo/Chattanooga Times Free Press, Dan Henry) THE DAILY CITIZEN OUT; NOOGA.COM OUT; CLEVELAND DAILY BANNER OUT; LOCAL INTERNET OUT

Fish on! For the first time in almost 20 years the state Fish and Boat Commission has found the smallmouth bass population to be doing very well in the Susquehanna River just in time for the fishing season to begin.

Commission biologist Geoff Smith presented his research on the causes of the population decline that struck the smallmouth bass in the early 2000’s until recently.

In a public event recently held by the Susquehanna chapter of Trout Unlimited, Smith’s research showed a promising sign of the growing number of bass and where the best places are to have a shot at catching them.

Once a booming population with numbers above 200 fish in the Susquehanna, Smith has researched and recorded his findings as to what happened to cause a massive decline in 2005. There were less than 50 and nearing a total population loss in the Pennsylvania river system at that time. Smith came away with four main causes for the decline and a speculation that may have caused such a wide spread disease among the population.

Dating back to September of 2004, Smith believes Hurricane Ivan could have been the beginning of what brought in the diseases.

Although that cause couldn’t be prove, what could was all four diseases. “These diseases targeted younger fish and had higher fatality rates during normal stream flow and higher temperatures,” Smith said. These diseases coincided with the perfect conditions for the spawning period– no young fish to spawn with smaller spawns.

The first disease Smith and the commission encountered was an Endocrine Disruption. Young male fish Smith caught showed signs of female egg cells in the male reproductive system. The mix of male and female reproduction systems did not cause the fish to become asexual, but to become infertile and fail to reproduce, lowering the possibility of improve population numbers.

Another disease Smith encountered was a Myxozoan Parasite. Believed to have a correlation with agriculture around the Susquehanna River, the parasite infested itself in a part of the smallmouth bass body and appeared as a white ring. As the parasite grew, it restricted the infection part of the body and when the parasite left, it would dismember the part it attached to.

Smith and the commission also encountered two viruses that impacted the population. The largemouth bass virus (LMBV) and a cold-water virus.

Known to not have an impact on smallmouth bass, the largemouth bass virus may have mutated with the increase in temperatures in recent years, when water temperatures rose to above 73 degrees, it allowed the mutation to occur and affect the smallmouth population.

The cold-water virus was a late addition to Smith’s encounters as he found bass developing unusual black spots. With some added research, Smith was able to determine when the water temperature drops and maintains a low temperature through the winter and spring months the virus increased the melanin production similar to sunbathing for humans. Although it seemed harmless, the virus caused the bass to change colors and often turned black.

With over 15 years of data collected and monitoring of the smallmouth bass species, Smith noted a resurgence in the population beginning in 2018 and now with two full spawning periods, the population is continually getting back to normal levels as Smith projects the population is back above the 200 mark, just in time for the season to begin.

There’s a (cat)ch

Although increasing populations of smallmouth bass is a good thing, increased numbers are not inherently a positive sign.

Flathead catfish were found to be growing at an exponential rate in the Susquehanna River since being first introduced accidentally in 2002.

Although a blast to catch, they are an invasive species from the Chesapeake Bay area. These catfish are primary predators to anything swimming in the warmer sections of the Susquehanna.

Flatheads were found to hang around the river dams, feeding primarily on red breast sun fish. While smallmouth bass are not one the flathead catfish menu, the warmer spring weather may cause the catfish to invade more of the waterways, Smith said the cathfish were not found in the West Branch and Lycoming Creek yet, they may be on the way.

Muskie stocking

What started in 2019, the commission found it was more beneficial to the Muskellunge species to be stocked in the spring, rather that the winter as in the past.

Smith and the commission found the muskie population had higher survival rates and catches were larger when the fish were farmed during the winter months and released in the spring.

While the cost to hold more over the winter drives up the cost to farm, Smith and the commission believes with the right funding its can continue to stock muskie in the spring for a better fishing season.