We purchased some property with a ~7 acre pond this past year. It looks like we have gizzard shad. I haven't chased them down with the cast net yet, but assuming I'm correct, are they going to be a problem? If so, what are the control options if any?

We're hoping to manage the pond a bit LMB heavy to maintain good BG size structure (looks good now), and there are a few skinny black crappie in the pond (85%-90% RW). We have no idea of the history of the pond other than it's a former limestone quarry.

Thanks for your thoughts,
Dale

Dale, if they are shad they probably are Gizzard Shad. Threadfins won't live thru a winter there. They are susceptible to a light dose of Rotenone, light enough that it won't affect other fish in the pond. Gizzards grow quickly to a size that Northern Strain LMB just cannot eat.

Thanks esshup. Sounds like we need to wipe them out. I have no idea how to do a light dose of Rotenone. How would I go about it?

Dale

Read the bottom of page 4 and page 5.
http://www.in.gov/dnr/fishwild/files/Glenn_Flint_selective.pdf

First step is finding a licensed applicator that can purchase the rotenone and apply it. If you are licensed, then just find it and apply it correctly.

I have a private applicator license in PA. It looks like I could do this myself if I am producing an agricultural commodity. Any idea how fish in a pond would be considered? I understand trees qualify, but not sure how the state would view fish.

The study used 0.13ppm of rotenone, so it's potent stuff especially on shad. I hate to loose the other fish, but it might be something that's required every few years. I suppose the correct procedure would include a significant mix volume, and dividing the pond into sections. I could use prop wash to mix better. Maybe use a poly tank floating in the water for the mix tank so I could do a dilution with several hundred gallons of water prior to distribution?

I hope to find another solution, but nets would not likely be successful in a 7 acre pond. I think I'll do some transects of the pond and come up with an accurate volume estimate for now.

Thanks again,

Dale

USDA pesticide applicators license in PA for aquatic use (category 09 requires a different category certification compared to Ornamentals, Shade trees (06). Turf (07)is separate in PA. Categories vary by state.
http://extension.psu.edu/pests/pesticide-education/applicators/certification/brochure

The correct application method is to insure even distribution throughout the water column especially during thermal stratification. Drop tubes are recommended and/or bottom based aeration for distributing the chemical into the deep water zone.

It's common to draw down the BOW or pump it down to reduce the water volume needed to be treated, and concentrate the fish in a smaller area. If that is done, don't forget to treat any puddles or wet spots left outside of the main pond.

Very good point esshup. Drawdown is best and a very good idea when the acreage is fairly large often over 2 ac. Then when the area is less the water depth is less and thermal stratification is usually minimal or non-existent especially if treatment is in autumn.

I contacted the PA Dept. of Agriculture (sorry for the long post):

"Dale,

To my knowledge, Rotenone is not approved for use in Pennsylvania. I have copied John Lake our pesticide registration expert on this email to confirm the availability of Rotenone in the State.

A private pesticide license is sufficient to apply pesticides to a pond on your property. Selling for profit does not impact the required license. However, a private license does not allow you to apply pesticides on the property of another.

I would also suggest speaking with the PA Fish and Boat commission http://www.fish.state.pa.us/ about applying pesticide to a pond. I believe a permit is required.

Andy"

John Lake from their office confirmed "There is no PA registered rotenone product registered for aquatic use in the state at this time". So, I'm going to look at other options. Any thoughts on super-chilling the water in the winter with aeration / mixing? Hoop net?

Thanks again,
Dale

Yes - try super chilling the water, that should kill a lot of the giz shad, at least a big percent of them. Report your results. The information will be a big help to others. PA is very particular as to what they allow one to put in their pond.

Thanks Bill - I'll try to set up a decent experiment with temp. readings at depths / locations over time, assuming we get a cold enough winter. Any thoughts on how I can baseline the pond for before / after comparison? I could randomly throw the cast net about for as long as my arm holds out, or maybe set up a fyke net a few times. I have zero experience with a fyke / hoop net, but maybe it would be more repeatable? Maybe I should try and quick-chill the pond before ice and just survey the shad that float / wash up?

How to chill a ~7 acre pond with 16'-20' depths will be the next challenge. Any thoughts on a slow super-chill through winter versus a rapid chill before ice forms?

Dale

Dale:

Verify with the State whether that regulation is for private ponds. Michigan has different regulations for private vs. public waters, AND different regulations for private ponds that have no permanent inflow/outflor vs. private ponds that have permanent inflow/outflow.

Also, verify if you are talking to the correct department. In Michigan, private ponds could be governed by the Dept of Ag, or the DNR. In Indiana, I have to talk to the State Chemist to get answers.

You - we are working on new techniques here. No set methods that I know of for killing giz shad with super cooling. What does the bathymetry map of the pond look like? From my experience, if you have basically only one deep area then set the aerator in that area and maybe another one towards the longer basin in 10-12-14 ft of water. This should pretty well circulate the cold water throughout the main pond. Temperature probing the far reaches of the pond away from the aeration will give a good indication of the degree of circulation. Measure the temps at 6 to 8ft deep depending on locations at least 100-200ft away from the diffuser. The longer you circulate during winter the more complete the cold mixing will become - 24/7 if you want the best it can be for diffuser set-up. If you find water that is 38F to 39F then these areas are not being mixed. Plot these temperatures on a map of the pond. This will show were other diffusers need to be placed for more complete circulation and next year's thinning of shad. super chilled water of 36F and below should kill giz shad? Good circulated areas during a PA winter should lower the water temps down to 33F. I think (?) giz shad will live in our Maumee Rv when winter water temps get down to 32-33F.