Giant Salvinia Control Team
Caddo Lake Control and Management
Lower Colorado River Control
|New Posting - July 25, 2012|
|The following photos were posted by Turner And McCoy in a story that first appeared on July 22nd on the "Kiss Country 93.7" website. They were taken from the Lake Bistineau State Park.|
|The following photo was taken at the Bistineau State park and posted to the State Park's facebook page.|
|Update Oct. 9, 2011|
|The following photo was taken at the Bistineau State park and posted to the State Park's facebook page.|
|Common Name:giant salvinia, Kariba weed, African pyle, aquarium watermoss, koi kandy
Brief Description: Its rapid growth, vegetative reproduction and tolerance to environmental stress make it an aggressive, competitive species known to impact aquatic environments, water use and local economies. It can literally grow to such thickness as to kill all other vegetation and fish in fresh water lakes, ponds, bayous, etc.
Giant salvinia has the potential to alter aquatic ecosystems in several ways. Rapidly expanding populations can overgrow and replace native plants. Resulting dense surface cover prevents light and atmospheric oxygen from entering the water. Meanwhile, decomposing material drops to the bottom, greatly consuming dissolved oxygen needed by fish and other aquatic life.
Pic From Spillway Dam
Under optimal conditions (light, temperature and nutrient) in the laboratory, plant populations have been found to double in size every 2-4 days. Under favorable natural conditions, biomass doubled in about one week to 10 days.
A single plant can cover up to forty square miles in three months.
|This plant is already causing problems on Toledo Bend, Caddo Lake, Cross Lake, Lake Bistineau just to name few.
We are now at the threshold of loosing one of this state's most picturesque lakes to this aquatic plant. That is Lake Bistineau. James Seales, the district biologist, has tried everything that is at his limited disposal. With little results.
As it stands right now ... have no doubt, without a quick change in strategy, this lake is lost.
Pic From Little Red Chute Boat Row
What is being done?
Lake level control -The LDWF will once again conduct a draw-down of Lake Bistineau beginning July 15, 2009. The one thing I am sure of is that the lowering of the lake does very little to control salvinia growth. If lowering the lake worked, then there would be less salvinia this year than last year. After-all the lake was down almost 8 feet from June until March.
Lowering the lake has very little impact on the plant. Once the water returns to normal levels, the plants that were left on the lake bed turn green and start growing again. Lowering the lake is a cheap method, that appears to combat the plant for short periods of time. But in reality, has very little effect.
Spraying The Plants -James Seales needs to be commended in his efforts to control the plant growth thru spraying. The spray works under ideal conditions. The problem with spraying is 4-fold. 1. The plant floats and therefore moves with the wind direction. Thus its hard to return to a point from a previous spraying and continue. 2. The plant itself is made up of a covering of tiny hairs which is difficult for the spray to penetrate. Wind and waves have a tendency to wash off the spray before it has time to soak into the plant also. 3. Wind carries the poison into the cypress trees which has caused the trees to already start turning brown. 4. There is not enough money or man-power to stay even with the rate of new growth.
Salvinia Beetles or Weevil - In other areas such as Florida and South Carolina where salvinia first appeared, there are several lakes that have been successful in controlling the plant. You never eradicate it completely, but you can control its massive growth. The only thing that seems to be able to control the plant is the Salvinia Weevil.
This tiny insect causes immense damage to plants by tunneling through rhizomes and feeding on terminal buds. Such feeding acts to greatly reduce large infestations of salvinia and to maintain low plant population levels. But there are certain problems that the weevil presents. 1. The plant itself survives well during cold weather, the weevil does not. 2. It takes several years to establish a colony that can have any impact on the plant.
But in all of my basic research ..... no program has been successful in controlling the plant growth except the weevil. Once again though, it takes money and large sums. The weevil needs to be introduced into the lake by the hundreds of thousand and over period of several years until substantial numbers can be self-maintaining.
|Very Unscientific Experiments|
|Here is what I do know.
Last year we took some salvinia from Lake Bistineau and put it into a sealed plastic bag and put it into a freezer for several weeks. It was then taken out of the freezer placed in a 5-gallon bucket of lake water and within 3 days was green again.
We then took some salvinia and placed it directly into the sun and left for several weeks. It was dry enough to crack and flake in your hand. Once again, we added it to a 5-gallon bucket of lake water and within days it was green again.
|What Can Be Done|
|We better start trying new "stuff".
For instance, we can suck oil off the top of the water during oil spills, or suck sand from the bottom of the ocean. Why can't we suck this stuff up and dump it in some land fill somewhere.Find a commercial use for it..... would cattle eat it when dried? Or, can it be processed and rolled into fireplace logs. Put a bounty on it, $1.00 per lb for every pound that is turned into a collection site. Collect it and burn it .... Something!!!!
Perhaps A Half-Dozen of These Would Help!
UPDATE March 21, 2010 - Read Erica Bennett's latest report from Lake Bistineau State Park
UPDATE July 5th, 2009 - The chemical "Galyon" WORKS!
The Wildlife and Fisheries Department has been studying the use of the chemical, Galyon, in an area located at the State Park. The good news is that it works, it actually kills the plant, .... the bad news is that it is costly. Estimated cost to treat the entire lake - $10 to $15 million. But compared to other government expenditures, $15 million is nothing, especially if it works and can save a complete source of fresh water. It's a bargain!
UPDATE Sept. 7th, 2009 - The scheduled lowering of Lake Bistineau has been delayed for a week.
The one thing that this writer is sure of is that lowering the lake level of Lake Bistineau has very little effect on controlling the growth of salvinia. Lowering the lake does create a current and that current does move salvinia, but it doesn't remove it from the lake.
The spillway gates lift upward, allowing the water from the bottom to flow from the lake, not from the surface where the salvinia grows.
Lowering the lake in this manner leaves salvinia floating on top and not flowing over the spillway. It creates isolated pockets of the stuff that now cannot be reached to spray. It leaves the salvinia that was trapped in the cypress breaks, still trapped in the cypress breaks. The salvinia that gets stranded along the exposed lake banks does not die it just lays there until the water level returns.
There are those of us who believe that creating a current in the lake is the correct approach, but not from the bottom of the lake. The current has to be created at the surface level in order to carry the salvinia over the spillway.
To do this, the lake has to be brought up above its normal level and then allowed to flow over the spillway. This is a cheap, easy, and we believe an effective way to control the growth.
Simply sand-bag the spillway bringing the lake level up 2-ft. Then remove the sand-bags allowing the water to flow over the spillway carrying the salvinia away. This should be a continous process throughout the year.
Raising the water level would also enhance the flow of the salvinia from the trapped cypress breaks. A cypress tree's trunk is much smaller above the water line. By forcing the large root base below the water's surface, you have now created more space between the cypress trees that would allow more of the salvinia to flow freely with the wind and current.
A simple and we believe an effective approach to controlling this plant. The truth is that the salvinia in Lake Bistineau will never be eradicated, but it can be controlled in this cost effective manner.
UPDATE Sept. 20th, 2009 - Smoke and Mirrows
Pleasae see the video: http://www.bayouducks.com/huntphoto6/OpenGates/OpenGates.html
If you are perceived to be doing good, then can you actually be doing harm instead?
The gates of Lake Bistineau were opened this week and what has now become the annual draw-down has begun. The 1st part of the video shows the salvinia in the Lake as we drive over the dam. The 2nd part of the video shows the water pouring through the gates as they begin the lowering of the lake.
As stated in my previous blog entry of Sept. 7th. Drawing the lake down has very little to do with controlling the growth of salvinia. If those in power truly believed that leaving the salvinia stranded on the dry lake bed has any effect on the plants ability to survive, then these persons would be lowering the lake during the summer when it is hot and dry. Not during the winter when most of the rainfall occurs. But lowering the lake does go to "perception". The public perceives that the State is doing its best to control the growth.
Does it make sense that the State would spend so much money and man power to introduce the salvinia beetle to the lake and then take a chance of the beetle being destroyed as the salvinia drys up while stranded on the dry lake bed. Of course not, this is all smoke and mirrows. Everyone who has spent any time on this lake knows that the plant goes dormat while lying in the "moist" lake bed and then springs back to life when water becomes available.
Does lowering the lake wash out any of the salvinia from the lake? The answer to that question is a resounding "No", as evidenced in the video. You will notice that there isn't one "raft" of salvinia being washed downstream. In fact you will see it stacked up against the flood gate as the water pours out under it. Opening the gates as they are now, insures that the salvinia will remain as the water is removed. Please read my previous entry of Sept. 7th which explains why.
The only way to control the growth of this plant is by "flushing" the lake through a series of controlled flooding. The lake has to be brought above its normal level and then allowed to drain taking the salvinia downstream. Where, by the way, it cannot survive. The raising and lowering has to be a continued program throughout the year. Please refer to my previous entry of Sept. 7 as to the benefits and ease of accomplishing this "controlled flooding".
I may be proven wrong, we'll never know because it will never be tried. But the one thing I am sure of is that the continued lowering of the lake will contribute in the lake dying almost as fast as being overtaken by salvinia.
Trapping the salvinia on the lake side of the dam is the wrong approach. Last year the public was told that there was only 800 acres of salvinia left after the drawdown of the lake. This number increased to 14,000 acres by mid July despite of the State's spraying efforts. I would not even venture a guess of how many acres of salvinia is now present in the lake.
Why would the results be any different this year? The public will be told that the decrease in surface water will make it easier to get to and spray the salvinia that is left in the lake. When in actuality the opposite is the truth. Lowering the lake creates scattered pools of water covered in salvinia that are inaccessible and therefore untreatable. The salvinia that is left on the dry lake bed does not die. When the lake is lowered there are only 2 points of access where you can launch a boat which creates another set of problems. Navigating a tricky (now stump filled) channel is one and the time, manpower and fuel needed to cover the area another.
Simply put, lowering the lake is "smoke and mirrors". The only way that lowering the lake will have any effect on the salvinia is if the dam were removed, the lake would then be allowed to drain down to its original creeks and bayous. It would need to be down 2 to 3 years before being allowed to fill up again.Before undertaking this method, be aware, that once removed the dam may never get rebuilt. The State can't afford the chemicals and equipment required to spray. The State barely could afford the cost required to lower the lake, much less the cost of rebuilding a dam. The lake will be surely lost. But what the heck, it's just as lost using the present method.
UPDATE Oct. 18, 2009 - I would never say I Told You So
Pleasae see the video: http://www.bayouducks.com/huntphoto7/salvinia_spillway/salvinia_spillway.html
|Check Out the following site: http://www.lakebistineau.com/|
Write and urge our politicians to provide the needed money and manpower
Photos From Lake Bistineau
Watch This Site For Updated Photos & Information
Pic From Pete Camp - Catfish Pond
Pic - Pine Cove
Pic from Catfish Pond
|Pic Shows Salvinia Matting Up|
|The Following Photos - Black Lake near Hosston, LA|
|Photos Courtesy - Jerry Newman|