Pond Boss Forums INTRO Questions & Observations poisoning fish eggs/cutrine

we are having some crazy warm weather here, so i was applying a little cutrine granular and got to thinking. i wonder if this got in a fish bed would it hurt the eggs? if so, could this be a way to control the bass population. my bass are pointing the banks really hard now. it would be easy to target them. i would love to skip a year or two of recruitment.

Cutrine granular could kill fish eggs and pre-swimup fry if enough was applied. I do not know the dosage required to kill eggs and fish fry. Some, as much of it, would depend on the alkalinity of the water. Copper sulfate in rock salt size and maybe course fertilizer size (small) would work better than fine or powered CuSO4 because the CuSulfate is not buffered like Cutrine and more reactive and more toxic. Both algaecides tend to be more toxic in lower alkalinity water. The lower the alkalinity the more toxic the copper becomes.

FYI LMB are more resistant to copper than BG, BG more resistant than CC, CC more resistant than FHM & grass carp. Most sensitive are trout. Thus resistance to Cu from low to high: trout, minnows - goldfish, catfishes - sunfishes - LMB as most tolerant to copper toxicity.

A recent PB Mag article covered the idea of helping control LMB populations by various methods of spawn/yoy control. Partial rotenone of beds (by a professional) , seining the beds while fry are present etc.

You guys need to subscribe to Pond Boss Magazine !!!!!
I am not going to do this very often. Here is an example of ideas/topics covered.

The Cutting Edge - Science Review


Spawning Survival Manipulation


The Pond Boss Forum has numerous threads on aiding spawning by such things as making beds (nest sites), adding cover (brush or dense trees) near nesting sites or supplemental feeding to increase numbers and growth of hatchlings. However the methods of how to decrease hatchling numbers and survival are not often considered. For example removing Yellow Perch egg ribbons from the pond to reduce potential hatching numbers is a method of population control.

Male Bass create shallow nests in the substrate where females then deposit their eggs .The male fish guards the fertilized eggs from predators until after they hatch, grow, and become free swimming or “swim-up” fry often staying with the swim-up fry until the school of fry (or fry ball) disperses. Knowing what can disrupt nesting and survival is a must to use this tool. A new study titled Factors Influencing Nest Survival in Florida Bass by Z. Slagle and S. L. Shaw in Transactions of the American Fisheries Society 146:696–702, 2017 Volume 146, 2017 - Issue 4 ) (© American Fisheries Society 2017 gives insight.

The survival of both Largemouth and Smallmouth Bass offspring can depend on a number of physical and biological factors, including the size and age of the guarding male, bed fishing pressure, and environmental changes during the nesting period. Many nest attempts fail, and hatchling abandonment is common due to storms, sudden temperature changes, angling, and nest predation. If the male bass abandons the brood (or is fished or runoff off of the nest), the brood is unlikely to survive long. Often Bass nests are easily visible and can be fished. If the guarding male is removed you have likely eliminated his hatchlings from increasing the Bass population. This can be an effective tool in reducing Bass recruitment and overcrowding.

Two additional methods of reducing Bass spawning success are seining the nesting area or a partial rotenone treatment of the nest area. Seining and bed fishing can be easily accomplished by pond owners while rotenone application is best left to professional fisheries managers.

ewest, in your opinion, would mechanical disturbance of a nest, prior to swim-up of fry, with a rake, a hoe, a shovel, achieve a significant reduction in spawning success?
Thanks for your consideration.

On occasion, I've removed the guarding male from a ball of free swimming LMB fry, and smiled as the marauding GSF moved in for the kill.

Yes if you disturb enough nests. However keep in mind that LMB in some places will attempt to spawn again if the first attempt fails.