12/04/2024
Talk about a boat-load of crappie! District fish biologists completed their annual trap net surveys on Crab Orchard Lake in Williamson County the week of November 11th. 2,863 crappie were caught in 12 nets over a two-night period. The fall 2024 catch rate of 119 fish/net night far exceeded the usual 40-50 crappie/net night, which also far exceeds the statewide average for crappie catch rates. This increase in catch rate is a result of a massive year-class of fish spawned in the spring of 2022 following a 4 foot draw-down in the summer through winter of 2021. We have been monitoring this year class over the last couple of years to ensure that the relatively high growth rate of crappie in Crab Orchard Lake is being maintained.
The average length of 2-year-old crappie in the fall (a common metric for population monitoring) is usually around 9.75" for White Crappie and 8.75" for Black Crappie, and the vast majority of the Crab Orchard Lake population usually is within the 8"-12" length range. These length metrics are well within the desirable ranges of assessment parameters, especially for a high-density population like Crab Orchard Lake.
We sub-sampled approximately equal numbers of Black, White, and Hybrid Crappie from the catch for age and growth analyses. This information will help us to monitor the effects of such a large number of fish coming through the system and make management decisions for the future based on these changes in the population. Structures used for aging fish will be analyzed in the next couple of weeks, management recommendations will be made, and biologist Luke Nelson will provide a presentation at the Marion Boat Show in early January 2025.
Luke would like to thank the SIUC chapter of American Fisheries Society for assistance in age structure collection and urges anglers on Crab Orchard to harvest as many crappie as they can use on the smaller side of desirable harvest length (7" to 10") to help maintain growth rates and numbers of larger fish for the future.
More information on Crab Orchard Lake can be found here: https://www.ifishillinois.org/profiles/waterbody.php?waternum=00235
