Port Clinton, Ohio is commonly referred to as the Walleye capital of the world and for the past few years, the Walleye fishing has exceeded expectations. Charter after charter brought in full multiple-person limits, often about 36 fish per boat per day. While this is beneficial for the economic industry around Lake Erie, the high numbers of walleye might be unintentionally causing an impact on another major sport fish, the Yellow Perch. Oftentimes, when Walleye are abundant the Yellow Perch populations are inversely related. For many Charter fishing captains, this year’s Yellow Perch season is by far one of the worst. The Charter captains have been discussing potential reasons for this issue, as their living is dependent upon the quality of fishing on Lake Erie. By looking at additional factors impacting the Yellow Perch in Lake Erie it can aid in the management of this irreplaceable recreational fishery.
Currently, the Ohio Division of Wildlife implemented the daily legal limit at 6 walleye per person of at least 15 inches and 30 perch per person with no size limit.1 It is hoped that the anglers throw back the smaller Yellow Perch to promote sustainable numbers for each spawning season. Stuart Ludsin, a professor of evolution, ecology and organismal biology at The Ohio State University, mentioned that only about 10 million 2-year-old Yellow Perch showed up in population survey catches compared to the approximately 75 million caught in the mid-1980s.2 Additionally, Ludsin stated in the Outdoor News interview that there are about 46 million to 106 million predators in the western basin of Lake Erie.2 In just 24 hours the predators can consume between 32 million and 189 million Yellow Perch larvae.2 The main predator is the White Perch as well as the Walleye and White Bass.
There has been a strong competition among White Perch and Yellow Perch with the population of the native Yellow Perch decreasing up to 79% after the introduction of the White Perch more than 50 years ago.3 The research study performed stomach content analysis and found that there were similar diets between the two species.3 There is competition of food resources among these two fish species due to their overlapping niche. Other invasive species such as the Round Goby have been negatively impacting age-0 Yellow Perch. Age-0 is a critical period for fish to have sufficient resources available to aid in their survival. During this stage Yellow Perch typically search for rock substrate to locate a main food source, benthic invertebrates.4 Benthic invertebrates are a type of small aquatic animal or insect larvae that includes dragonfly larvae, snails, and worms. However, after the population boom of the Round Goby, the age-0 Yellow Perch changed their habitat from rock to sand as well as their dietary preferences from benthic invertebrates to zooplankton.4 Additionally, this is coupled with invasive Zebra Mussels in Lake Erie consuming the zooplankton that the age-0 Yellow Perch were feeding on. All of the pressure from multiple invasive species can accumulate. Figure 3 shown below depicts a fish biomass (not true abundance) breakdown from the Lake Erie Western Basin. It is important to consider that nonnative species make up a significant portion of this chart.
The temperature of the water throughout the year significantly impacts the fish since they are ectotherms. When the summer season is longer it allows for more growing, but when examining the reproductive success after short winters, the results were not promising.5 After short winters the females spawning in warmer water temperatures produce smaller eggs that hatch at lower rates as well as produce smaller larvae than females do after long winters.5 Figure 4 shows the difference between shorter and longer winters regarding the spawning timespan. Based on the figure, during long winters there was a continuously increasing water temperature that occurred later in the year whereas the short winters had a steady higher temperature that occurs sooner. Yellow Perch thrive in cooler water temperatures. The water temperature limiting the number of successful eggs produced could impact the population in each sequential hatch year.
While there is no single, definite answer to the sub-par Yellow Perch fishing in Lake Erie this year, it has local anglers worried. It is even possible that the Yellow Perch simply aren’t in their usual location at this time of year or might not be as interested in consuming the tackle used when fishing. The Ohio Division of Wildlife uses scientific data to calculate the daily bag limit that is sustainable for the future of the Lake Erie fishing industry. Many variables play into having an ample fish population, so it will always be important to be aware of the fluctuating dynamics of this valuable ecosystem.
1.) Ohio Division of Wildlife. (2019). Ohio Fishing Regulations. Department of Natural Resources. Retrieved from http://wildlife.ohiodnr.gov/portals/wildlife/pdfs/fishing/2019-20%20Ohio%20Fishing%20Regs_WEB.pdf
2.) Meyerson, H. (2014). Increasing white perch affecting yellows. Outdoor News. Retrieved from https://www.outdoornews.com/2014/03/13/increasing-white-perch-affecting-eries-yellows/
3.) Guzzo M., Haffner D., Legler, N., Rush S. & Fisk A. (August 2013). Fifty years later: trophic ecology and niche overlap of a native and non-indigenous fish species in the western basin of Lake Erie. Biological Invasions. 15(8): 1695-1711.
4.) Houghton, C. (May 2015). Round Goby-Induced Changes in Young-of-Year Yellow Perch Diet and Habitat Selection. Thesis and Dissertations. 879: 1-94.
5.) Farmer T., Marchall E., Dabrowski K. & Ludsin S. (2015). Short winters threaten fish populations. Nature Communications. 6(7724): 1-10.