Crappie "Cycle"

One of our fisheries biologists mentioned that crappie had a 7 year cycle. Can that be explained in more detail? For instance: Is this cycle universal? By that I mean, is the cycle the same everywhere, or does each lake have it's own cycle? Are all crappies in a lake on the same cycle, or is the cycle for whites different than the blacks?

If there are differences between lakes, is it known which lakes are at the better part of the cycle, and exactly how does the cycle progress? Does harvest have any effect on the cycle, and can we as fishermen/women, do anything to improve recruitment during the lows of the cycle?

Is the cycle tied to some other cycle, such as shad?

I know there are a lot of questions here.....so if I only get answers to some, I will understand. If there is any report or study that I could access, please point me in the right direction.

Thanks!

Great questions Vic.

crappie populations will cycle, and usually an "up" cycle means there a bunch of desirable-sized fish to catch, and a "down" cycle is the opposite...as far as a 7 year cycle...that is new to me...however, like everything in nature, populations in nature will tend to cycle based on various environmental conditions....in crappie... an 'up' cycle will be 2-3 years after a good year class coupled with plentiful forage..some lakes are blessed with good recruitment every year, you dont really see too many "cycles" of good and bad fishing in those lakes...while other lakes will tend to have good year classes every so often..you tend to see more pronounced 'cycles' in good and poor fishing in those lakes

stole this excerpt from craig johnson on the Kansas thread....he explains crappie "cycles" very well in the last paragraph...his comments about kansas reservoirs hold true in MO:

White crappie were native to most northeastern Kansas rivers. Over the years, stockings by government agencies and private landowners have produced the statewide population of white crappie that we have now. Black crappie are NOT native to Kansas, but self sustaining populations have been created through introductory stockings.

Black and white crappie, although quite similar, prefer and thrive in different water clarities. Black crappie do well in clear, deep, and weedy waters while white crappie excel in shallow, turbid waters. Since both species have been so widely introduced throughout the state they are available in most drainages and frequently co-exist. Young fish of both species are almost entirely planktivorous (feed exclusively on small animals called zooplankton). Adult black crappie can have a diet composed almost entirely of invertebrates where white crappie have usually switched to a fish based diet by the time they have reached 8-inches in length. Availability of gizzard shad enhances growth of both of the crappie species in Kansas.

Both species, especially the white crappie, are quite prolific. This can be beneficial in larger impoundments but can be detrimental in smaller waters. Over population, which leads to stunting, of the crappie is common where predation pressure or other population limiting factors is lacking. Too much natural recruitment produces high densities of small, slow growing individuals which are of little interest to anglers. Untimely crappie introductions in to newly renovated waters by well intentioned anglers can have disastrous effects upon the new sportfishery as the crappie are capable of out numbering and out competing predator species that are needed for crappie control.

Since crappie are prolific and capable of producing self sustaining populations in Kansas waters it is not necessary to supplementally stock crappie on a routine basis. Usually an introduction of a few adults or in some cases fingerling stockings is all that is required to start the crappie population. Crappie are not very selective when it comes to spawning substrates and their spawning requirements are met in the majority of Kansas waters making any stocking beyond the initial introduction unnecessary. Although most Kansas waters will support crappie, not all Kansas waters are capable of supporting crappie populations that are acceptable to anglers and therefore not all Kansas waters should be stocked with crappie. Presence of crappie in some impoundments will hinder the development of a quality sportfishery resulting in mediocre fishing at best.

Growth rates of Kansas crappie are more influenced by population characteristics (density, length frequency distribution, recruitment success, mortality, etc.) and impoundment productivity (availability of plankton, density of forage fish such as gizzard shad, etc.) than genetics. Theoretically, any crappie in Kansas that has ideal growing conditions and the time to grow should reach larger sizes. Poor crappie populations are not a result of poor genetics and excellent crappie populations are not a result of superior genetics. Many desirable factors must occur simultaneously to produce quality crappie fishing year after year. Even in the best Kansas crappie fisheries the population will cycle between high and low years as missed year classes move through the population. These missed year classes create 'holes' in the population and in time will effect the sizes of crappie that anglers find most desirable, causing an up and down cycle of quality fishing. If two or more consecutive years of bad production or poor growth occur, the 'hole' in the population becomes larger and the quality of the fishery decreases and takes longer to recover. The genetics haven't changed during the up years and the down years, but other factors that effect crappie regularly change and determine strength of year classes and growth rates of the fish.

I think a lot of what's going on in the KS lakes is a function of angling pressure. There are so many big lakes in a short driving distance in KS that everyone just hits the "hot" lake that year. I used to get chewed on pretty good by some friends who would go to KS to the "flavor of the year" crappie lake and then expect me to provide similar fishing at Smithville every year. One Memorial Day I went with them to Hillsdale. It was having a decent year but one of the other nearby lake was really good. We fished all day, caught some decent fish and I endured the complaining all day. When we got back to the ramp and were cleaning fish, I asked them to count the cars in the parking lot. There were 6 and two of them were ours! When I asked them how many would be at Smithville they replied, "you'd never find a parking space". I think that's the difference in KS. Crappie populations have their ups and downs, but if I only had to provide good fishing every 5 to 7 years, and no one really fished the other 4 to 6 years, my job would be easy.

Thanks for the replies guys. Some of my reading says that a great recruitment year may lead to great fishing the third thru the fifth year, but will also lead to very poor recruitment for those years due to the high number of crappie available to feed on their own young. Maybe this is part of the cyle referred to. It also appears to me that the success of the shad population is nearly as important as the success of crappie recruitment.