Submerged Aquatic Plants
This section of Aquatic vegetation covers a wide variety of diverse and
unique plants. Some of which will wildly vary from one another while
others are very difficult to distinguish from others. Some are very
aggressive and others pose little to no threat. The trick to managing
submerged vegetation is first knowing the species, associated threat and
the management goals you wish to achieve.
Eliminating all vegetation is often unadvisable in ponds used for sport
fishing. The vegetation's value as fish structure and habitat should
always be calculated before deciding to eliminate it all together. As
stated above you must keep your management goals in view and know how
each vegetation type can contribute to meeting your goals but you must
also know what risks each vegetation may pose.
As with all vegetation, proper identification is of the utmost
importance. Unfortunately this group of vegetation is often the most
difficult to ID. The picture below shows some of the subtleties between
hydrilla and three plants that closely resemble it. If you have any
questions at all about whether or not you have properly identified your
vegetation please have it confirmed by a professional before moving
forward with a treatment regiment that may not be successful.
Common Submerged Aquatic Plants
Coontail, Bushy Pondweed and Sago Pondweed are the most commonly found
submerged plants throughout Texas and particularly on the Gulf Coast.
Bladderwort and Cabomba are more often found in the eastern portion of
the state while Variable Leaf Water Milfoil and Curly Leaf Pondweed are
more frequent in the Hill Country. Keep in mind that none of this is
written in stone so don't rule out any plants based on this
generalization, this is only intended as a starting point.
Hyrdilla is by far the most recognized name in aquatic plants. While
there are Hydrilla infestations spread far and wide over the state its
reputation often exceeds it as it's often falsely
named the culprit
Control of Submerged Plants
The treatment of such plants can be broken down into a few distinct
categories. Contact Herbicides, Systemic Herbicides, and Mechanical and
Contact Herbicides are aptly named as they require direct contact with
target species for a set amount of time. These products can be used at
anytime of the year as long as the plants are present and often offer
quick results. Some Contact Herbicides will show results in as little as
3-5 days with complete die off within 2 weeks. There are times when
Contact Herbicides are the best option but generally speaking they don't
control the roots systems and can allow regrowth within 2 months time.
With the prolonged growing season that is dominate over most of Texas
this can make the cost of multiple applications a big limitation.
Systemic Herbicides are often a better choice. Systemic means that the
entire plant is controlled, all the way down to and including the roots.
Because of this systemic action these products are usually slow to show
results, however the results often last an entire season. Another
limitation of Systemic products is that the plants MUST be actively
growing in order to absorb the chemical and have it be effective. This
gives a definite time window for successful applications of Systemic
Mechanical Controls such as raking, dragging and other means of manually
removing vegetation offer instant results. The drawback to this method
is the extreme labor involved and short lived results, this can be
accurately compared to mowing your yard. Additionally some species are
capable of spreading by fragmentation. This means that should you break
the plant into multiple pieces each piece can form a new plant.
Biological methods include, Grass Carp, Tilapia and other natural
methods of vegetation consumption. Grass Carp can be effective at
controlling certain types of plants but they are very picky eaters and
have a set preference of desired species. Should you have one of highly
preferred species Grass Carp should be a consideration. Tilapia will
also consume vegetation and are less picky eaters than the Carp. Tilapia
also come with their own set of limitations, being a tropical fish they
are susceptible to winter kills with water temperatures in the low 50s.
Tilapia are very prolific and can spawn every 7-14 days, the bulk of
thier young survive as they are what's called mouth brooders. Tilapia
will hold their young in their mouths to keep them safe from predators,
this can lead to population explosions and can cause your water to
become muddy. These fish will also compete with your natural forage
species and potentially reduce their numbers, having a negative effect
on your fishery.
A successful management plan will often include the use of Herbicides,
some form of Biological means and a preventative maintenance regiment.
Contact your Lake Manager for more information on building the
appropriate Management Plan.
Aquatic Plants Factsheets