A massive shad kill has occurred beneath Nickajack Dam in Marion County, Tenn.
TWRA Wildlife Officer Russell Vandergriff says that "there are millions of dead shad below Nickajack Dam."
Here's a photo of the Nickajack Shad Kill. FYI, the little white specks are individual fish. The white mass is solid blanket of dead shad.
He says as far as he could tell they are all threadfin shad. They are the smallest species of shad, most are 4-6 inches long.
After conferring with a TWRA fisheries biologist, Vandergriff says they believe this to basically be a "natural occurance," NOT a fish kill due to water pollution.
This year there is an exceptionally large population of threadfin shad being reported in many places, especially below Nickjack Dam. This time of year the threadfins typically migrate upstream to the dams where they spawn.
When there is such a huge population, they will gather in confined spaces such the locks (where barges go through). And at Nickajack there is what fishermen call "the dead lock," a lock that can potentially be used for future expansion. But right now it is a dead-end, with no outlet.
Vandergriff says that there are literally so many shad that they can gather in those confined spaces, depleting the oxygen in the water, literally killing themselves.
It's just like if you put too many fish in an aquarium.
Vandergriff says they do not expect to call in state water quality investigators since they are fairly certain this is not a case of pollution.
Again, the only species of fish Vandergriff found dead were shad.
Of course threadfin shad are a primary food source for many species of game fish, such as rockfish which also congregate beneath Nickajack Dam.
No doubt anglers will be paying close attention in the coming days and weeks to see how the shad kill impacts fishing.
Vandergriff said there are a few dead shad on the upper side of the Dam that most likely got washed through as barges locked through, however the primary "kill area" is beneath the Nickjack Dam.