Pond Boss Forums MANAGING AN EXISTING POND Evaluating and adjusting fish populations Out-Year Tilapia Pond Management

Now here's the thoughts my limited fish experience intellect came up with on long-term Tilapia dynamics:

Using Tilapia every year makes major shifts in the population of other species. Predators benefit directly from the wonderful addition to the forage base. Prey species (like BG) are indirectly affected also; in ML's case a BG base that was (I'm guessing) seriously impacted by LMB predation each year has gotten a much-appreciated relief from bass eating Tilapia instead of bream. Other forage species, or BG in ponds with different LMB-BG initial conditions might react differently (I have been trying to define a starting scenario where BG would be negatively impacted by Tilapia. I'm not finished with that thought experiment yet, but my belief in the innate perversity of the universe convinces me it must exist.)

I think the major change Tilapia make to pond population dynamics is due to their ability to convert a seldom-used biomass portion, FA, into flesh usable by the fish population.

Tilapia's ability to add usable biomass to the foodchain makes the use of Tilapia similar in many ways to supplemental feeding. Not identical, because they aren't adding nutrients and biomass to the pond, but similar.

I think most of us would agree with what I believe Lusk first stated (at least the first time I read it, Bob wrote it): Something like "If you add supplemental feed to a pond, it changes the fish populations so that they expand (in numbers or size - total mass for sure) so that they come to depend on it. If the feeding is halted, fish go hungry and decline in condition, numbers, and/or size."

How long does it take for a pond with Tilapia added each year to reach a new steady state where populations are adjusted to the Tilapia's effects and have come to depend on them? I doubt anyone knows for sure yet. I suspect it is on the same order of magnitude as the length of time a brand new pond takes to reach maturity (few/several years). After 4 years, ML may be getting close to this state if his pond's aren't there.

Now we need someone to stop using Tilapia after several years' stocking to see what the removal effects would be. Any volunteers?