Lake Of The Ozarks Crappie Management: Is It Time For A Change?

Lake of the Ozarks Crappie Management: Is it time for a change?

History of the Lake of the Ozarks crappie length limit

In 1989, a somewhat novel and controversial regulation was put into effect at Lake of the Ozarks; a 9-inch minimum length limit on crappie. Prior to that, complaints from anglers regarding the overall small average size of the crappie being caught led to a multi-year study to look at the dynamics of the crappie population.  The major conclusions of this study were;

Crappie averaged 7.0, 9.2, and 10.2 inches at ages 2, 3, and 4 respectively.

From 1980-89, the average length of harvested crappie was 8.3 inches which included a high percentage of age 2 and even 1 year old fish.

50% to 60% of the adult crappie population was being harvested annually.

In summary, high angler harvest of young crappie was preventing a quality fishery from developing.  By protecting these fast-growing young fish for an additional year or two, we have developed the quality crappie fishery that we all enjoy today.

9 inch vs. 10 inch minimum length limit

 I generally take the “If it’s not broke, don’t fix it” approach.  We already have a quality crappie fishery at Lake of the Ozarks as a result of the 9-inch minimum length limit.  The question is, do we want to try to enhance it further with a more restrictive length limit?

In recent years, the only complaint I’ve heard from anglers regarding the crappie fishery (other than those occasional spells when they just seem to vanish) is “Why didn’t you make the length limit 10 inches?”  At the time, 9 inches was selected based upon the growth rates of the fish and expected longevity.  Several of the southern reservoirs in the state produce faster growing crappie due to a longer growing season and/or the presence of threadfin shad.  As a result they have been managed under a 10-inch minimum length limit for several years.

Since 1989, we have come to realize that crappie can and do live to 6, 7 or even up to 9 years of age.   At age 3 and approximately 9+ inches, crappie are still relatively young and will likely have several years before mortality due to old age becomes a significant factor.  Also since that time, we have seen a decline in the density of white crappie in portions of Lake of the Ozarks.  There are likely a number of reasons for this, from an increase in angler harvest to a decline in nutrient input (primarily phosphorus).  However, along with this decrease in the number of crappie has come a slight increase in growth rates.

Points to consider:

•  Under a 10 inch minimum, angler harvest will decrease, especially in the first year of the regulation change until those fish that are 9.0 to 9.9 inches have time to grow above 10 inches.  The initial decrease in harvest could be as much as 50%. Ask yourself, “Am I willing to possibly harvest fewer crappie in exchange for the opportunity to catch larger crappie?”

•  On average, the filets of a 10-inch crappie weigh 44% more than those of a 9 inch crappie.  In other words, 10 or 11 10-inch crappie produce the same amount of “Fillets in the fryer” as 15 9-inch crappie.  At the present growth rates, this size increase takes about 1 year. 

•  As with any regulation change, there are some drawbacks.  Some of the fish that would have been harvested by anglers (those between 9 and 10 inches) will die from either natural causes or hooking mortality before they can be legally harvested under a 10-inch minimum length limit.  As a result, overall angler harvest under a 10-inch limit will decline compared to a 9-inch limit.  Although the daily limit will remain at 15 crappie per day, it may take anglers longer to catch a limit of legal fish which, depending on how you look at it, may not be a bad thing.

Delaying harvest by one year will give many crappie an additional chance to spawn.

From talking to many crappie anglers over the past few years, it appears that there may be widespread support for an increased length limit, but we need to know if the majority of anglers will support a change or if the present fishery is good enough?  I’d really like to hear your thoughts on the issue, pro or con.  Please feel free to contact me at greg.stoner@mdc.mo.gov or at (573) 346-2210 x235. 

Good Luck Fishing!

Greg Stoner

Fisheries Management Biologist – Lake of the Ozarks