Looking at the distribution map above, one can easily see these little guys are adaptable to a wide range of waters and temperature ranges, making them the preferred forage stocking option in most of the country, although that option does come with caveats.
They have high growth rates and if they live to age 3, they are starting to reach the size where they are too big of forage for most fish.
If they do reach this size, they then can rapidly become a detriment on the waters ecosystem, straining available resources for almost every other species of fish. Quite simply, introducing them is the easy part. Managing their numbers and size effectively is quite another.
A BRIEF LOOK INTO SHAD IN MY AREA
I fish a few lakes that have shad present. Chief among these are the Lake Sharpe, Oahe and Lewis and Clark Lake, all reservoirs on the Missouri River system, so I am going to use them as an example
From what I have researched, Gizzard shad were already present throughout the Missouri River system before any of the dams were built. Once they were built, Gizzard shad were not present in after Oahe was finished. Thus, it seemed that Oahe seemed to be the northernmost limit of their range.
It wasn't until the late 90's that gizzard shad suddenly started appearing in survey nets that biologists knew something had changed.
That something was shad stockings in western South Dakota reservoirs. Shadehill and Angostura. These stockings happened in the 1990's in an effort to help increase the forage base for walleyes in those reservoirs.
Mother Nature had other plans. The mid- late 90's saw a lot of high water years and as a result, gizzard shad passed through or over those spillways and found their way into both the Cheyenne and Grand Rivers. Once they were present in those systems, it was only a matter of time before they followed the tributaries to Oahe.
Since then, Oahe has had a growing shad population. Lake Sharpe already had a healthy shad population. Lewis and Clark shad were stocked a while ago and from I hear, are doing well.. They are now an important part of those ecosystems and for now, it seems that they are in a healthy balance.
So, in an effort to actually use this to our advantage, we need to understand some basic facts and info on their patterns and behaviors.
Since I fish both these reservoirs quite frequently, I wanted to know all I could about them.
SHAD QUICK FACTS
It seems through all the documentation I've read through so far that Gizzard Shad in these reservoirs tend to spawn in mid to late May or when the water temps heat that magic mark of 64-69 degrees F.
They prefer to spawn during stable or warming trends.
By August or September, the young shad become large enough to attract the attention of predators like Pike, White Bass, Smallmouth, and walleye. Its unclear if Chinooks or Atlantics (In Oahe) prey upon them at this point, but my instincts tell me if they do, it would be juvenile fish only.
Shad prefer quieter open waters or the edges of strong currents. Optimum habitat for them is fertile shallow bodies of water that are warm, with soft muddy bottoms, low predator counts and high turbidity. Unfortunately, if they find such places, that almost always leads to an overpopulation of shad.
Changing water levels, deep clear water, steeper shorelines and moderate to heavy predation all lead to lower gizzard shad populations according to several papers I researched.
Another item of note is that Gizzard Shad typically feed during the day and try to minimize their activity in low light periods.
They also feed on detritus and mud. One can make a fairly logical assumption if you can find mud flats with a few of those optimum habitat variables present, shad should be present or somewhere near by, at various times of the year..
The behaviors I have mentioned are fairly typical of gizzard shad. How they apply to the bodies of water each individual fishes is open to each individuals interpretation of available shad preferences.
Make educated guesses, get information from the locals, observe surface activity (gulls tend to be good locators of shad)...try to put all those pieces together and give yourself a better chance of connecting fish.
Just remember, those predators feeding on shad may not be immediately nearby, but chances are pretty high they are relatively close. Look at structural elements, cover, current etc to try and further define viable fish locations.
Keep those lines wet, those hooks sharp and the fish afraid.
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