Thus far, even TP&WD research shows a positive correlation between the presence of tilapia and an above average bass fishery in Texas waters.
This is BS.
I'm just going by what I've seen happen on Calaveras and Braunig lakes where once the Talapia got a foothold the bass fishing went into total decline.
You can go out and look at the natural bass spawning areas and you can see the fanned out nest where the talapia make their nest and it's the same places that used to be used by the Largemouth. That is direct competition by an invasive species that wouldn't be there before.
Yes, maybe TPWD research might be on a larger body of water who knows but on those two power plant lakes the bass fishing is no longer and not near even close to what it was before those talapia took hold.
Even with the commercial netters they can't seem to reduce the numbers.
They eventually introduced the redfish which now thrive in those same lakes and hardly anyone fishes for LMB anymore but you can catch talapia anywhere on the lake and all you need is a castnet.
TPWD also require that you have to gut the Talapia when you remove them from the lake and it is illegal to take them as bait to another body of water.
So if they are beneficial why the above regulation?
Taken from the TPWD website:
•Possess tilapia, grass carp or any other fish listed as harmful or potentially harmful, without immediately removing the intestines.https://tpwd.texas.gov/regulations/outdo...aquatic-species
Doesn't sound like a positive correlation to me?
Indeed there is a disconnect between the "rules" and the situation as it exists in the field. But why then the huge market for tilapia to be stocked into all manner of private lakes and ponds for the express purpose of improving the largemouth bass fishery?
What one has to actually review is not what popular media and politically driven motivations inside state government, but what is the actual case and what has actually occurred here and elsewhere with the introduction of tilapia (which includes over 100 species of fishes that are very different from one another).
Sure, it hasn't all been a positive, but it has not been all negative either.
I've spent a lot of time working on reservoirs in the past and have seen for myself positive and negative impacts of newly introduced species, not just tilapia, and not just from another continent. Any movement of a species or sub-species from one watershed to another is an exotic introduction. Hence "Florida Bass" being as exotic as tilapia in Texas watersheds.
Tilapia are ubiquitous in our aquatic environment, and their impact has been both positive and negative, and not nearly so severe as another species that is considered nowadays "indigenous" the common carp.
Ask yourself this question with respect to the rule listed above....
"Who makes the list of "harmful or potentially harmful" species and what are the motivations behind the species on that list?" Are these motivations purely biological in nature or may politics have a play in the construction of such a list?
Also ask yourself, "What manner of pristine fishery habitat are lakes like Braunig, Calaveras, Martin Creek, Alcoa, Fairfield, Monticello, and others like them?" Might such habitats actually be more suited to a different group of species, than say a lake like Caddo or even Toledo bend?
It is easy enough to give a blanket statement such as , "Tilapia have taken over the lower Rio Grande," than to think about it and say, The deteriorization of the lower Rio Grande habitat and water quality has gotten to the point that only a fish like a tilapia can thrive in it."
A google search will yield plenty of information with respect to the positive correlation between the presence of tilapia and largemouth bass growth, reproduction and recruitment.
While I strongly support TPWD and applaud them for much of what they do for our state (We got state parks, fishing and hunting to make most states jealous) I also recognize that much of what they do and say is politically rather than biologically driven.
BTW, most species of tilapia (Genus Oreochromis
) spawn readily at water temperatures above 77 degrees F. I've seen them still spawning just fine at temps approaching 95, so it is unlikely that it will get too hot for them. They'll slow down again below 75 and be done by the time it gets close to 70.