here are some links my dad sent me after collecting some plants at a local private fishing pond.
We determined the collected species to be Egeria,Hydrilla,Eelgrass, and moneywort (had to look that up in our plant finder, wasn't on there lists)
of the four only one (eelgrass) is native to texas, and one (hydrilla) is illegal to posses or transport in the state of texas
http://aquaplant.tamu.edu/index.htm
(hydrilla has a video about its invasivness and control methods)
http://aquaplant.tamu.edu/GiantSalvinia/index.html
(also has a video on the salvinia secies)
its quite evident that someone placed these plants there, probably thinking that it would provide more places for fish to hide. moneywort is not listed in the aquaplant link and i've never seen it in a pond or lake before. before i even collected them i recognized hydrilla as an invasive non-native species but didnt know what it was called.
The introduction of these plants has caused a lot of issues in this pond IMO. I have not caught one single fish, I've lost every lure and most of my hooks that I've thrown out, and there is a lot of decaying plant matter, far more then ussual.
In the sylvaina vedio the gentelamn states that he has kept it in a sealed plastic bag for over 18 months still alive, wikth no introduction of co2 oxygen or nutrients , doing nothing more then feeding off the dieing plant matter and growing.