Lewis & Clark Lake walleye, sauger and hybrids

Did you know that the spawning seasons of walleye and sauger naturally overlap and they sometimes spawn together, forming hybrids known as saugeye? Saugeye can also spawn with one another, or with pure walleye or sauger. Of all four Missouri River reservoirs in South Dakota, Lewis and Clark Lake has the highest percentage of walleye/sauger hybrids. This means many of the fish caught by anglers in Lewis and Clark Lake that look like pure walleye or sauger could be hybrids.

Lewis and Clark Lake Walleye/Sauger/Hybrid Regulations (For more information on Missouri River Regulations, see 2013 Fishing Handbook, pages 16-18)

These regulations apply to waters of the Missouri River from Gavins Point Dam upstream to Fort Randall Dam.

• 4 fish daily/8 possession: Walleye/Sauger/Hybrid (in any combination)
• Minimum length 15 inches year-round *
• High-grading or culling of walleye/sauger/saugeye is prohibited.

*There is NO minimum length restriction in July and August and only 1 fish in the daily limit may be 20” or longer from the South Dakota/Nebraska border upstream to Fort Randall Dam

Walleye

Walleye abundance is monitored through an annual September population survey. The average number of walleye per gill net is compared with the data from previous years to detect changes in abundance. The overall trend in Lewis and Clark Lake has been a slow increase in abundance over the last 20 years, with the highest abundance occurring in 2008. Since 2008, walleye relative abundance has decreased each year through 2011 due to poor production in 2009 - 2011. Sampling for age-0 walleye (the 2012 year-class) was conducted using seines, gill nets and nighttime electrofishing. Results indicated moderate production in 2012; however most of those fish will not be available for harvest until 2015. The majority of the harvestable population currently is from the strong 2007 - 2008 year classes with a few fish from the 2009 and older year classes. The 2007-2008 fish provided much of the angling opportunity in the summer of 2012 and will continue to account for the bulk of the harvest in 2013.

Relative weight is an index used to describe fish condition. High values indicate that the fish are plump and healthy, while low numbers can indicate an imbalance between walleye and its prey. Walleye relative weight values in Missouri River reservoirs are generally between 80 and 90 and only approach 100 when prey species are overly abundant. Walleye relative weights observed in 2012 were near the long term average for Lewis and Clark Lake indicating adequate prey resources were available in 2012. Relative weights in 2013 will be dependent on prey abundance that year.

Points to Ponder
Anglers will likely see reduced catch rates of walleye and sauger in 2013. This is due to poor reproduction in recent years. A moderate year class was produced in 2012, and should provide for increases in catch rates in the future. For catch rates to increase to levels seen in 2008, moderate to strong reproduction needs to occur in upcoming years.

Lewis and Clark walleye tend to have stronger year classes produced during drought years. If the current drought continues into 2013, the chances of another moderate to strong year class increases.

Currently, 75% of the walleye population is above the 15 inch minimum and will provide anglers opportunity to harvest fish despite the lower overall abundance.