On May 6, 2009, the Seven Coves Bass Club, in conjunction with Texas Parks & Wildlife, the US Army Corps of Engineers and the San Jacinto River Authority, presented information regarding the planting of “native plants” in Lake Conroe. As the majority of the LCA Board attended this meeting and gained information, we thought we should share this information with you.
The “Lake Conroe Aquatic Vegetation Management Plan” for 2008-2009 outlines the need to reduce invasive species such as Hydrilla, Giant Salvinia and Water Hyacinth as well as maintain a healthy native plant community. This Plan was developed by Texas Parks & Wildlife and the San Jacinto River Authority, and similar Plans have been in place since the return of Hydrilla some 7-8 years ago.
“Native plants” are an important part of ourLake’s ecosystem. Without “native plants”, we experience lake bank erosion and increased sedimentation. “Native plants” utilize nutrients in our Lake which would otherwise be used by invasive species or fast-growing algae. “Native plants” also provide oxygen needed by healthy fish communities.
Given sunlight, warm temperatures, nutrients and shallow waters, some form of plant life is always going to grow in ourLake. With the reduction of Hydrilla from over 2,000 acres to virtually no acres and Giant Salvinia from over 628 acres to approximately 150 acres and Water Hyacinth from over 335 acres to approximately 50 acres, some form of plant life is going to move into the space vacated by these reduced invasive plant species. The question for us is “What plants do we want in ourLake?”. It would seem obvious that we do not want invasive species to again take over our Lake. A healthy native plant community, in conjunction with a “maintenance level” of White Amur grass carp and herbicide applications as needed, is the answer to holding back the “invasive plants”.
“Native plants” have been added to ourLakefor the past 25 years. If you visit the northern end of theLake, you’d have seen them protected by metal cages or fences in small coves. Since the addition of over 123,000 White Amur grass carp over the past 3 years to battle the invasion of Hydrilla, the “native plant” community has dramatically reduced from 1,078 acres in 2007 to 140 acres in 2008. A survey is currently being undertaken by Texas Parks & Wildlife to estimate the number of acres of “native plants” as well as Hydrilla, Giant Salvinia and Water Hyacinth. It is anticipated that the number of acres of “native plants” will show a further decrease.
The Seven Coves Bass Club grows “native plants” in a nursery located near the dam at the San Jacinto River Authority facility. Seedlings are obtained from theLewisville,TexasResearch Facility and grown in contained water gardens until they can be separated (split in two). One half of the plant stays in the nursery (for further propagation) and the second half is planted in the northern, uninhabited portions of the Lake in protective cages. Over time, these “native plants” expand by either colonization around the cage site or by seed dispersion. 1,200 “native plants” were placed in ourLakein 2008, and an estimated 4,500 will be added in 2009. To put this in perspective, 4,500 plants will cover approximately one quarter of an acre of shoreline. As stated by Texas Parks & Wildlife, “It may take 3 to 5 years until we see noticeable vegetation outside of the cages due to the slow growing rate of these natives.”
The “native plants” utilized are preferably grass carp resistant (meaning the grass carp prefer not to eat them). “Natives” being utilized under this program include American Pondweed, Illinois Pondweed, Wild Celery (Vallisneria), Water Stargrass, Coontail, White Water Lily, Spatterdock, Watershield, American Lotus, Bulltongue, Arrowhead, Pickerelweed, Water Willow, Softstem Bulrush, Flatstem Spikerush, Squarestem Spikerush, Slender Spikerush and Maidencane. As the Lake Conroe Association is not familiar with each plant, we are currently undertaking a study to better understand each plant and its characteristics. In particular, we are interested in understanding the growth rate of each species and how it may disperse along our shorelines in the future. We will have dialogue with the Seven Coves Bass Club, Texas Parks & Wildlife and the San Jacinto River Authority regarding these issues. We will release our findings and summaries of these dialogues to our LCA Members in future correspondence.
Not to get “the horse before the cart”, but Texas Parks & Wildlife has stated that they will issue permits to homeowners (through licensed applicators) for herbicide treatments to kill “native plants” which grow at your boat dock and limit your access to the Lake….should this even happen. Such treatments would be at the expense of the homeowner. Texas Parks & Wildlife has selected these specific “native plants” not only because they may be grass carp resistant but also because they typically do not act in an invasive manner and create access issues for lake users. We will all be closely observing the behavior of these “native plants” in the future.
With Hydrilla almost gone and an estimated 70,000 grass carp still alive in Lake Conroe, the issue of “Should grass carp start being harvested from theLake?” has arisen. Texas Parks & Wildlife commits to keeping a “maintenance level” of grass carp in Lake Conroe“forever” and won’t consider any harvesting of grass carp until it completes its current survey of levels of “native plants”, Hydrilla, Giant Salvinia and Giant Salvinia. Should Texas Parks & Wildlife determine they desire to harvest grass carp, they propose to do so only through licensed grass carp tournaments (typically via bow and arrow) (and assumed by me to be only in uninhabited shorelines) which may harvest 30 – 40 grass carp per tournament (not “per person”….”per tournament”) based on previous results of Texas Parks & Wildlife grass carp tournaments. We’ll further address this topic should it actually be proposed by Texas Parks & Wildlife.
I hope I haven’t overwhelmed you again with all of my detail, but the Lake Conroe Association Board feels that part of our job is to keep you informed. I’ll write again soon when we have more information to share. Until then, you may share your thoughts with us through our website at “lakeconroeassociation.com”. Enjoy your Summer use of the Lake Conroe and remember to always be careful on the Lake.
Mike Bleier, President