Fisheries Management: Resetting Fisheries

AS SEEN IN Pond Boss Magazine, Written by David Beasley, Fisheries Biologist and Director of Fisheries 

It may be a surprise, but it was only a few decades ago that private land owners began pursuing the art of trophy bass management. Until the late 1900’s, ponds were primarily viewed as a source for food or water for livestock. Over the last 35 years, landowners began wanting more out of their ponds, and as a result, management strategies have gradually developed through trial and error. Thanks to pioneers of this industry, and lessons learned the hard way, current management strategies have progressed and increased the odds of successfully establishing a trophy fishery. One of the most important lessons learned over the years is that either new ponds or fisheries that have been reset (started over) have a much higher probability of producing trophy caliber fish than trying to manage an existing, older fishery. This process of building a fishery from ground zero provides pond owners much greater control over the outcome. As more and more pond owners across the country are pursuing their dreams of growing trophy-caliber bass, the concept of resetting waterbodies is trending. Although resetting ponds has become a valuable fishery management strategy, many people find themselves with some level of uncertainty when it comes to proper resetting techniques. As a result, it is common for people to fail in their attempt to reset their fishery. The worst part surrounding an unsuccessful reset is it often takes a year or two before the trouble is realized, and at that point, the landowner has too much invested to restart the process correctly.

One fundamental concept of the reset process is to understand why resetting is such a successful management strategy. If successful, you eradicate existing fish, and then are able to develop a thriving forage base as well as limit the number of predators initially stocked into the system. The process of allowing the forage base to establish properly sets the fishery up for success for several years. During restocking, it is typical to stock small, young forage fish since they cost less. This process of stocking small forage will expose a big risk of failure if any predatory fish species survive the reset process. If a fish population is properly eradicated, success is higher. If not, and even a few predator fish survive, success is fleeting. If you fail to successfully reset the pond, it is likely that instead of a thriving forage base, the low number of predators that were not eradicated will clean up all of the small forage fish you stock, leaving you with a fishery that falls short of your goals. The first step to a successful reset is having the correct mindset. Since a clean start is critical to the success of the fishery, and since you are rarely in a position to reset a fishery, it is important to take it seriously. Far too often, people say convincingly that they know that no fish are alive in the remnants of a waterbody. Without draining, it is difficult to know zero fish are alive. Rather than making the assumption nothing is present, the correct action is to properly apply the appropriate rate of rotenone, a widely used restricted-use natural fish toxin, to ensure the waterbody is void of fish. Consider following up, several weeks after rotenone application, by sampling the lake, looking for survivors. Depending the size of the lake, it is wise to have someone electrofish, or at the least, pull a short seine around different areas of the perimeter, looking for remaining fish. Existing waterbodies that are being reset, but are not being drained, are typically at a much higher risk of failing to achieve a 100 percent reset. This is because many variables come into play that increase the chance of failure, such as small coves where fish can escape, or maybe deep water where it’s difficult to apply the rotenone. To ensure success, one of the first steps is to obtain a good understanding of the waterbody’s water volume. This process requires mapping the waterbody using sonar or collecting manual points and plotting them on a map. Once you know how many acre-feet of water are present, you can then properly estimate how many gallons of rotenone would be needed to complete the application. Rotenone can be an expensive product, so, to save money, it typically makes sense to draw the water level down as much as reasonably possible, except in drought-prone areas. An additional benefit to drawing down the water level is the improved chance that fish cannot find a spring or pocket of fresh water and survive the treatment.