Lewis and 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?  Walleye/sauger hybrids can also spawn.  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 are in fact hybrids.

Lewis and Clark Lake Walleye/Sauger/Hybrid Regulations (For more information on Missouri River Regulations, see 2007 Fishing Handbook, pages 20-23)

*These regulations apply to waters of the Missouri River from Gavins Point Dam upstream to the SD-Nebraska border to the point where the river becomes entirely in SD.

• 4 fish daily/8 possession: Walleye/Sauger/Hybrid (in any combination)

• Minimum length 15 inches year-round

*Note: There is NO one fish over 20 inch regulation on the previously mentioned portion of the Missouri River due to its status as a border water with Nebraska.

Walleye

The young walleye produced during a year are referred to as that year’s year class of fish.  There are currently three large year classes of walleye in Lewsis and Clark Lake that were produced from 2001-2003.  The percentage of walleye longer than 15 inches has increased each year since 2000 due to growth of fish in these year classes.  This indicates that the number of fish above 15 inches available to anglers should be higher in 2007 than 2006.  Walleye production during 2004-2006 has been below average, therefore once the 2001-2003 year classes move through the population, numbers of fish above 15 inches will decline.

Lewis and Clark Lake walleye abundance near long-term average

 

 

Percentage of walleye sampled over 15 inches increased in 2006

 

 

Relative weight is an index used to describe if fish are in good condition.  Values well below 100 for an individual or size-group indicate problems may exist in food or feeding conditions.  Walleye relative weight values in 2006 were within the standard range of 80 to 85 for Lewis and Clark Lake. 

 

Walleye condition in 2006 was similar to 2005

 

Sauger

The number of sauger caught per gill net set has remained the same for the past three years.  The total number of sauger sampled in 2006 was higher than the number of walleye, indicating an extremely healthy population of sauger exists in Lewis and Clark Lake.  Sizes of sauger available to anglers for 2007 is excellent, with nearly 50% of sampled sauger above the 15 inch minimum.  Fish above 18 inches composed nearly 20% of the sampled sauger with fish up to 21 inches present!  As with walleye, sauger relative weights are within the standard range of 80 to 85.    

 

Points to Ponder

Reservoir ageing, more specifically sedimentation and delta formation, is an ongoing issue in Missouri River reservoirs.  As these systems age, the amount of sediment present increases, leading to decreased capacity for water storage and access issues for recreational use.  The Niobrara River Delta on Lewis and Clark Lake has been expanding and will continue to expand over time.  The full impact of this habitat on the fish communities present in Lewis and Clark Lake is yet unknown.  Research has shown that fish habitat use for certain species has changed over time as the habitats themselves have changed.  As this process continues to occur, fish locations will undoubtedly change as well.  Successful anglers on Lewis and Clark Lake now and in the future will have to adapt to the changing nature of the fishery.  Locations that held fish in previous years may be poor fish habitat today.  Willingness to adapt and explore new locations may increase an anglers ability to routinely catch fish on this ever-changing reservoir.