April 20th Walleye - Point 5ish area

[Tanderson15]

Nice job and rewarded with a meal. I don't like crowds so I guess I'll have to wait until next wk with the tournament.

[kjackson]

Nice job and rewarded with a meal. I don't like crowds so I guess I'll have to wait until next wk with the tournament.

Or you can fish tomorrow as today is the last practice day...

[YAKFM]

Nice job Green!

[Notropis]

"The ones I have caught have been really skinny." It's not unusual for walleye to be a little thin after the spawn is over, especially the males. If you continue to see a lot of walleye in poor condition, you should let Jon Stein (AGFC Fisheries biologist) know about it. Condition factors in fish can be good clues as to how well the fish population is doing. Beaver Lake has a lot of predator fish and sometimes too much competition for forage can become a problem. I'm not saying it's a problem currently but it could be in the future. Hopefully the fish you are seeing are some lean post spawn males.

Nice stringer of fish, good day on the lake!

[J-Doc]

Based on what I've seen this winter.........

I think there is enough forage to go around.

But yes. I'm hoping it's just post spawn males myself.

[YAKFM]

Based on what I've seen this winter.........

I think there is enough forage to go around.

But yes. I'm hoping it's just post spawn males myself.

Shadalanche!

[J-Doc]

That shad school started at War Eagle Marina and went all the way back towards point 12 and was at least a par 4 or par 5 length so 400-500yds long. It may have kept going but I turned around to find the fish at the very beginning of it. There were gizards and whites mixed in with it I think. Pretty sure these are gizards. It's the biggest I've ever seen. And there have been some big ones this year.

[Notropis]

Yes, I've seen lots of schools of shad on the lake, a good sign of adequate forage. I noticed the images were in the winter (water temp 45), a typical time for shad to group up, looking for water that's a few degrees warmer. The threadfin shad in particular will do this since there tolerance of cold water is very weak and they can be stressed to the point dying when the water temps gets in the low 40's and below.

The availability of the shad as forage for the walleye may be an issue in the summer when the lake stratifies. Typically the upper 1/2 to 2/3 of the lake has little or no oxygen below the thermocline, causing the cool-water species (stripers and walleye) to migrate closer to the dam where adequate dissolved oxygen levels exist below the thermocline. The stripers in particular are forced to migrate and in some years there is a minor striped bass die off from a few of the straggler's that don't make the move to the lower lake in time. I remember one year when there was a minor die off ( a few hundred fish) of walleyes at the same time. I think the walleyes are a little more tolerant of warm water and can in some cases survive in the middle parts of the lake in the summer by staying just above or right at the thermocline but they are limited in their ability to chase shad in the warm waters above the thermocline.

So far, the walleye seem to be doing very well in the lake and have good growth rates. I've caught yearling walleye this spring that were already 12 inches long. I think there's a pretty good chance the "skinny" walleye are post spawn males but it's always a good idea to keep an eye on condition factors of fish species that are abundant and protected from harvest by length limits.

Sorry about the long-winded discussion, sometimes I get carried away talking about the lake!

[J-Doc]

Interesting perspective. Thanks for sharing! :-)

Didn't know stripers and walleye could have a die off due to water temps/oxygen. Interesting.

[Notropis]

It's an interesting phenomena related to the nutrient load (nitrogen, phosphorus, etc.) and water retention time (about 1.5 years) of Beaver Lake. Nutrients that enter the lake create algal and zooplankton blooms on the upper end (river arms and south half of the lake). As the water moves slowly down the lake, the nutrients are utilized by the phytoplankton and zooplankton until they are reduced to very low levels. That's why the lower lake, close to the dam has much clearer water (less algae).

The algae and plankton are great for growth and survival for larval fish and fish species that feed on plankton (ex. threadfin shad), which is why the upper end of the lake is more productive and has a greater biomass of fish than the lower half. The down-side to the heavy algal blooms comes during the summer, when the lake is stratified. As the algae and plankton dies and sinks, bacteria decompose them, using up the dissolved oxygen creating anoxic conditions below the thermocline.

Since there's a lot less of the algae and plankton on the lower end, close to the dam, the water below the thermocline has more dissolved oxygen, creating a thermal refuge for the stripers and walleye to survive the summer water temps. The minor die offs occur in late spring, early summer when some of the striped bass don't make the migration to the lower end of the lake in time and get trapped above the thermocline in the middle section of the lake.

The size of the thermal refuge is inversely related to the amount of inflow to the lake, the more inflow, the smaller the refuge. High water years bring the most nutrients creating anoxic conditions below the thermocline over a greater percentage of the lake.

If your interested in more information regarding this phenomena, do an internet search for Dr. Reed Green of the USGS. He did some great research on Beaver Lake on the thermal refuge and it's relation to water inflow of the lake.