Thread: Ask the Biologist

Craig, thanks for the video on Fisheries Management. When was the video made? How is the water willow working out? Seems like that could be helpful in other Kansas reservoirs!
Is there a method of telling the age of a a walleye is? How long does a walleye live?
Thanks Charlie

Originally Posted by CharlieM

Craig, thanks for the video on Fisheries Management. When was the video made? How is the water willow working out? Seems like that could be helpful in other Kansas reservoirs!
Is there a method of telling the age of a a walleye is? How long does a walleye live?
Thanks Charlie

Charlie,

The Fisheries Management video was completed in 2002.

Water willow is doing well in some reservoirs and not so well in others. The efforts of Ron Marteney at El Dorado resulted in a lakewide population of water willow. Water levels have a large impact on the quality and quantity of water willow within reservoirs. I introduced water willow to Hillsdale around 2000 and when I left Hillsdale in 2003 to come to El Dorado the water willow was doing quite well. I've heard it has continued to do well in Hillsdale. However, water willow hasn't done so well in other reservoirs. Water willow was planted in Melvern, Clinton, and Perry reservoirs (and numerous other reservoirs around the state) and some of these plantings met with little success. Water willow is very drought tolerant and survives low water situations very well. It can be 'drowned out' though and high water for extended periods can be very hard on water willow, especially plants still in the process of establishing. Reservoirs that experience very wide water level fluctuations are not prime for establishing water willow. Stable water conditions are best for the water willow and also for the fish species that utilize the water willow.

Walleye can be aged by reading scales or otiliths. Fish biologists use these structures to conduct age and growth studies on walleye. In Kansas, walleye are capable of reaching 10+ years of age but most walleye are harvested at younger ages in the 2.5 to 5 year range.

Craig,

Thanks for the great info... We where talking today and one of things we where debating is the movement of crappie in a lake during the year. I know you guys have done some studies on this so thing might be an interesting article it's self. My guess is that some crappie travel a lot and some stay in about the same place all year. It is the great question sometime of where the crappie go at certain times of the year.

Questions we have asked:
How far away from where they spawn do the travel in their life?
During a single year do the travel long distrances?
If a part of the lake is heavily fished does it reduce the levels of crappie in that part of the lake or do the fish spread out more with the reduced compatition?
Do crappie travel up rivers to spawn as much as they do go to rocks to spawn?

Thanks in advance.

Nick

Originally Posted by Springhill Duckman

Craig,

Thanks for the great info... We where talking today and one of things we where debating is the movement of crappie in a lake during the year. I know you guys have done some studies on this so thing might be an interesting article it's self. My guess is that some crappie travel a lot and some stay in about the same place all year. It is the great question sometime of where the crappie go at certain times of the year.

Questions we have asked:
How far away from where they spawn do the travel in their life?
During a single year do the travel long distrances?
If a part of the lake is heavily fished does it reduce the levels of crappie in that part of the lake or do the fish spread out more with the reduced compatition?
Do crappie travel up rivers to spawn as much as they do go to rocks to spawn?

Thanks in advance.

Nick

Nick,

You ask some VERY good questions!! Fish movements are always tough to nail down because they can be so variable. This high variability occurs from lake to lake but can also occur within the same lake year to year. General movements are easy to figure out such as moving to the shallows for the spawn or concentrating along deep structure or channels in December but I'm guessing you are not asking the 'general' movements!

Habitat will dictate a lot of how far a crappie will travel in a year's time. If spawning habitat, forage, and winter habitat are all available within a small region of a lake then a crappie won't have to move very far to meet its life requirements. On the flipside, a crappie may have to cover large distances to find habitat that meet the seasonal requirements. As far as tagging goes, I've seen fish move large distances in short periods and I've seen some fish pretty much stay put. Not all fish act the same and there are always individuals on the edge of both extremes.

Forage availability also causes crappie to travel. The best habitat in the lake isn't very useful to a crappie if there aren't any vittles to be had! Crappie can sometimes be found on large flats that are basically devoid of much of any structure but they are there to feed, whether it be on forage fish or invertebrates. Lakes will usually have 'high percentage areas' that offer desirable habitat and forage on a regular basis throughout the year. These are usually the 'honey holes' known to area fishermen as the spots that produce fish on a regular basis. Knowing or being able to 'read' what trips a crappie's trigger at certain times of the year will help an angler break away from the 'honey hole' mentality and find fish when they are reacting to other influences within the lake thus utilizing more of the lake for productive trips.

If an area gets heavily pressured with high harvest over a long period time it may be possible to thin those fish out. However, if it was a good enough area to hold good numbers of fish it will certainly be desirable to other crappies that will move from other areas of the lake. Fish do concentrate in areas that meet the majority of their life requirements and they will stay there until they are harvested or move on to greener pastures. How quickly the pressured area is repopulated will depend on the size of the area, duration and extent of angling pressure, size of the lake, density of the fish population, availability of other good habitat and so on. Fish can and do move around quite a lot. What may be a hot spot one day can be cold as ice the next as the fish have moved on.

Crappie spawn in many different habitats in Kansas waters. Flooded willow or timber is super hot in some lakes while gradually sloping gravelly banks with scattered stumps are best in another lake. Crappie aren't super particular on the substrate on which they spawn but they usually like to have 'their backs covered' with some sort of cover. It is doubtful that a crappie that is currently near the dam at El Dorado will expend all the extra energy to swim in to the creeks to spawn...but it could! Usually a crappie will head to the best AND closest spawning habitat. For some fish this equates to coves off of the mainlake and to other fish the creeks offer the nearest and best spawning habitat. Walleye are the same way, some will run up the creeks to spawn, others concentrate on rip rapped dams, and others prefer the rocky shoreline or mainlake points.

In short, individual crappie do what they need to do to survive. Sometimes this involves a large percentage of the population and an angler can establish a good productive pattern. Other times the event may include only a small number of fish or occur over a very short time period and the angler may only briefly stumble upon a hot but short lived pattern. I understand that I didn't provide any very good direct answers to your questions but I'm not totally sure that those would even exist!! I hope my attempt to relay some of the factors that affect crappie activity/movements is of some use to you. Since the factors vary so greatly from lake to lake in Kansas it is pretty tough to nail it all down to one answer for questions such as these. Again, GREAT questions!!

Craig,

Great info, I find this really interesting. I look at many of the lakes that I fish and you see lakes like Hillsdale where thousand of crappie come out of the water around the little bull area and dam area but you don't seem to find consistant bigger fish in other parts of the lake. It just seems like no matter what the bigger fish just don't make it event thought other parts of the lake don't get as much pressure (still more than most thought).

On the flip side, you look at other lakes the crappie just seem to disapear over the summer. You can't find them on the graph or on the breaks or any where. I know they don't leave the lake but it just make you wonder where the travel to when you have a big open lake with no standing timber and it's fairly shallow like Redman. Only real structure is the channel, dam and river with a few arms. They can't all or even many swim up the river.

Craig - I was out fishing Harvey Co East yesterday and couldn't help but notice the large number of dead or dying shad around the lake. Some of them you could tell had been there for a while and others were on the surface still kicking...kind of, all of them were 10+in long. I was thinking the shad kill offs where more in the dead of winter than the warming of early spring. I saw no small dead shad, but these could of been gobbled up by the birds or predator fish. The fish don't have to eat my lure because the dying shad are easy pickings? What are your thoughts.
Otherwise, weather corporate beautifully yesterday but not so much the fish.
Tim.

Originally Posted by fishingtim

Craig - I was out fishing Harvey Co East yesterday and couldn't help but notice the large number of dead or dying shad around the lake. Some of them you could tell had been there for a while and others were on the surface still kicking...kind of, all of them were 10+in long. I was thinking the shad kill offs where more in the dead of winter than the warming of early spring. I saw no small dead shad, but these could of been gobbled up by the birds or predator fish. The fish don't have to eat my lure because the dying shad are easy pickings? What are your thoughts.
Otherwise, weather corporate beautifully yesterday but not so much the fish.
Tim.

Tim,

Sounds like you witnessed the aftermath of a typical Kansas winter shad kill. Depending on conditions, the duration of the shad kill can be spread over a long period of time. Some times it is the 'ice out' conditions and warming temps that push the already stressed shad over the cliff resulting in the kill.

Some anglers anxiously await these shad kills, especially at reservoirs. During windy conditions the dead and dying shad are concentrated along downwind shorelines which concentrates fish like channel catfish and blue catfish which gorge on the abundance of forage. This can equate to some great catfishing action. Like you mention, this abundance of easy prey may make fishing difficult for other species but this all depends on the size of the shad that have died.

Thanks for the question!

A KDWP Mike Blair video on the 2011 fishing forecast for El Dorado.