FWC Correspondence

The following is the email sent from FWC Biologist John Kunzer to Eddie Flicker regarding re stocking grass carp in our lake.

Hi Eddie,

Thank you for your hospitality in helping me tour Lake Iola this past Monday, especially in the foul weather.We sampled at five points on the lake: Off your dock, near shore in the western cove, just off the northern shore by the old boat ramp, at the eastern edge near the drainage work being done, and at a shallow point in the middle between deeper pools. The only place we did not find hydrilla was in the middle. The hydrilla concentration we found was not high, but it presence is still concerning.As you described in our last visit, the water level in Lake Iola increased quickly and dramatically (by more than a foot) toward the end of the summer. Southern naiad subsequently colonized this area that had previously been dry riparian area. I suspect that the grass carp (TGC) had been foraging on the hydrilla prior to the naiad population boom, and this increase in naiad diffused and distracted the TGC foraging, thereby allowing the hydrilla to expand. The hydrilla probably also expanded into the new areas made available by the rise in lake level, even further reducing the effectiveness of the TGC.

 Also, some respectably large black bass have been caught in the lake recently, raising the possibility that they could have been preying on some of the newly stocked TGC you released last year. My recommendation is to apply for

stocking of another 100 fish, of the largest size you can get. Try stocking 50 fish first, and see what kind of control they provide. If the control they provide is still insufficient, then stock the remaining 50 fish.I’d rather approach this conservatively, while still moving quickly enough to keep the hydrilla from expanding further.

 Please don’t hesitate to let me know if you have any questions.

Thanks!

John