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Watermower Presentation. Lake Bistineau – 17,280 Acres. Brief Overview – Giant Salvinia. Giant Salvinia, Salvinia molesta , is an aquatic fern native to South America. It is a small free-floating plant that grows in clusters and develops into dense, floating mats or colonies .
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Watermower Presentation Lake Bistineau – 17,280 Acres
Brief Overview – Giant Salvinia Giant Salvinia, Salvinia molesta, is an aquatic fern native to South America. It is a small free-floating plant that grows in clusters and develops into dense, floating mats or colonies . Giant salvinia does its damage by growing into dense mats that can eventually cover an entire water body with vegetation as thick as three feet. These mats smother native plants and phytoplankton by blocking the penetration of sunlight into the water. With no phytoplankton present and no water surface open to the air, available dissolved oxygen rapidly becomes depleted, killing the fish in the waterbody. Salvinia mats can slow currents, cause increased siltation that fills in water bodies until they disappear. Dead plants that sink from the bottom of the mat may accumulate on the water bottom, where the lack of oxygen prevents decay. It is capable of growing extremely quickly, starting from small fragments and doubling in dry weight every 2.2 to 2.5 days. Under optimal growing conditions, 1 acre of salvinia can become 25,600 acres in just 30 days if left untreated. Ref#-1a
Then Mother Nature Stepped In - 2009 The 100-Year Flood
Where We Are Today Salvinia on Lake Bistineau was first brought to the attention of the Louisiana Department of Wildlife and Fisheries in February, 2006. 7 Years Later We Are Still Fighting A Losing Battle! Lake Bistineau is a 17,200 plus acre lake with contributing watersheds that approach 100,000 acres. The watersheds are located primarily in three parishes and all or parts of several counties in Arkansas. These contributing watersheds are part of the problem when it comes to achieving total eradication as they “feed” salvinia into the main lake. According to LDWF own rehabilitation Plan of 2010:“It would be unrealistic to believe that the actions taken solely by this department in the future will result in any long term solution, or rehabilitation. Rather, long term success will require the formation of tactical alliances among local governments, state agencies as well as private stakeholder individuals and user groups all working together to find ways to implement new strategies.” “By all accounts, the efforts to control giant salvinia coverage on Lake Bistineau have been insufficient, to date.” “……..drawdowns, or water fluctuations have proven to be a very effective method to kill aquatic plants, including giant salvinia. On the other hand, herbicide treatments are expensive and have been less effective.” ref#-4a
Methods Being Used To Combat and/or Control Salvinia Growth • Lake draw downs • Chemical spraying • Cyrtobagous salviniae(Salvinia Beetle) • Mother Nature
Drawdowns – Lake Bistineau Lake Bistineau dates back over 200 years. It began in 1800 when several thousand acres of land were flooded due to a gigantic log jam in the Red River. Gradually, however, as the area was dredged, the lake began to drain. Then in 1935, a permanent dam was built across Loggy Bayou, creating the present-day Lake Bistineau. The dam has since been enlarged, giving the reservoir a surface area of 26.9 square miles, with an average depth of seven feet and maximum depth of 25 feet. History Of Lake Drawdowns July 26, 1945 1951 (exact date unknown) 1956 (exact date unknown) Labor Day 1966 Labor Day 1967 Labor Day 1968 Labor Day 1969 Labor Day 1970 Labor Day 1971 Labor Day 1975 Labor Day 1980 Labor Day 1983 • Labor Day 1996 • September 2000 • July 15, 2004 • July 15, 2005 • July 15, 2008 • September 16, 2009 • July 2011 • August 8, 2012
Benefits and Impacts of Lake Level Drawdown Advantages Impacts The principal benefit of a water level drawdown is to kill aquatic plants that grow in shallow water by exposing them to the sun and stranding them on dry land. Secondary benefit of water level drawdown is to allow access to the shoreline for structural maintenance. Oxidize and compact exposed sediments. Inexpensive to achieve. May not achieve the desired result (Mother Nature has to cooperate). Repeated drawdowns can cause shift from sensitive to tolerant plant species. Sediments exposed to rain can transport nutrients to the lake that can fuel increased salvinia production. If water levels are not returned to normal conditions in time, certain fish species may not be able to reach spawning areas. Limited access for boating, skiing, fishing, hunting, etc. Loss of income from commercial camps Lake Property devaluates Winter drawdowns accomplish nothing
Chemical Applications Advantages – Not many, but it can and does kill salvinia, but there are numerous problems associated with chemical spraying. Problems- Spraying will play a leading role in management and/or eradication strategies against salvinia however to date, traditional chemical techniques have provided limited effectiveness. Herbicides are the most widely used and effective method for controlling infestations of giant salvinia. Diquat, glyphosate, and tank mixes of diquat and glyphosate have been the most widely used herbicides for controlling giant salvinia. Repeated treatments will be required. Ref#-2a Small floating plants like salvinia are difficult to treat chemically in part due to their small size and the fact that they can form dense vegetative mats up to several feet thick which shelter plants from surface-sprayed herbicide applications. In addition, the upper surfaces of giant salvinia fronds are covered with numerous, cage-like hairs which can prevent optimal herbicide coverage.
Chemical Applications – cont’ Spray applications are susceptible to wind, rain, and lake conditions. Plus even under the best conditions, it is hard to thoroughly and adequately cover all of the plants, leaving some surface plants to continue to grow and reproduce. In most cases, an area has to be treated several times to get the desired effect. Ref#-2a-2 Salvinia floats and moves from day-to-day, depending on the wind. This makes it hard to mark where spraying has already been done. In most instances, it takes 30 days or more to see any results. And, once again Mother Nature has to cooperate. Rain and/or rough water will wash the chemicals off the salvinia if it isn’t given enough time to soak through the plant follicles.
Chemical Applications - cont Long term effects? No one really knows what the long term effects will be on animal life or plant life. Years ago there was a defoliant that was deemed safe to humans and animals by the U.S. government … commonly known as Agent Orange
Chemical Applications - cont Glyphosate / Roundup Roundup, based on the chemical glyphosate, is marketed as a “safe” herbicide, based on outdated and largely unpublished studies by manufacturers. But laboratory and epidemiological studies confirm that Roundup poses serious health hazards, including endocrine (hormone) disruption, DNA damage, cancer, birth defects, and neurological disorders. Some of these effects are found at low, realistic doses that could be found as residues in food and feed crops and in contaminated water. The EPA is conducting a standard registration review of glyphosate and has set a deadline of 2015 for determining if glyphosate use should be limited and/or banned. Glyphosate has been banned in just about every European country, Argentina, Denmark, Austrailia, Sweden, Greece, Japan, New Zealand, Russia, and some countries in Africa. Ref#-5a, 5a-2, 5a-3, 6a-1, 6a-2, 6a-3, 6a-4
Chemical Applications - cont Diquat / Reward Diquat is a very fast-acting, contact herbicide that breaks down the plant cell membrane. Diquat effectively controls many submersed, emersed, and floating plants. It also kills most filamentous algaes that may be inside the treatment area. Diquat will kill many terrestrial plants that it contacts also. It bonds strongly to mineral and organic particles in soil and water where it remains without significant degradation for years. However, bound to clays diquat is biologically inactive at concentrations typically observed in agricultural soils. Diquatdibromide is moderately toxic. It may be fatal to humans if swallowed, inhaled, or absorbed through the skin in sufficient quantities. Diquat / Paraquat has been banned in just about every European country, Argentina, Denmark, Austrailia, Sweden, Greece, Japan, New Zealand, Russia, and some countries in Africa. Ref#-5a, 5a-2, 5a-3, 6a-1, 6a-2, 6a-3, 6a-4
Salvinia Weevil Salvinia weevils were introduced into two enclosures on the lake in August of 2007. The weevils survived their first winter and their populations increased in the enclosures. Additional weevil infested salvinia was stocked in Lake Bistineau in October of 2008 from nursery ponds near Gheens. A major weevil stocking effort in Lake Bistineau began on June 15, 2009. During the two-week stocking effort, over 78,000 lbs. of giant salvinia infested with over 1.8 million adult weevils was relocated from LSU’s rearing facility located near Gheens to Lake Bistineau. To Date: - None of these weevils are present on Lake Bistineau. No one knows if they died due to cold weather, or they just up and left. Weevils appear to be one of the most promising tools in controlling salvinia, but we are a long ways from achieving this.
Salvinia Weevil - cont Salvinia Weevils - Cyrtobagous salviniae (commonly referred to as the salvinia weevil) is the only known successful biological control agent for salvinia. Flushing, drawing the lake down, spraying of chemicals, is not the answer to controlling the salvinia growth. Performing these three steps alone would insure that there would be a never ending battle. Without establishing a healthy weevil colony, the fight would continue from now until the end of time. Salvinia weevils were released on Lake Moondarra in Queensland in 1980. They were a spectacular success. Within 14 months, 200 hectares (494 acres) of salvinia had been converted to open water. A density of 300 adults per square meter will control salvinia in most situations. There are 4046.86 sq. meters per acre. This equates to 1,214,058 weevils per acre. Ref# 7a-1, 7a-2, 7a-3, 7a-4, 7a-5
But What If There Was Another Tool? What If There Was Another Weapon To Use? Wouldn’t You Want To Use Every Tool Available? The Watermower
The Watermower It is a harvester/eradicator that immediately kills and disposes of Salvinia. It is a patented 28-foot pontoon barge with a conveyor in-feed that picks up the salvinia or any other floating aquatic plant. The plant is then force fed through three digestive chambers where it is pulverized and blown back into the water where it sinks to the bottom and dies.
About The Watermower • The Cutters and Blenders are hydraulic driven and powered by a diesel engine. • The pick-up width is 5 feet • Is trailerable and can be launched in a minimal amount of time.
Advantages & Disadvantages Advantages Disadvantages • No waiting, instant results it will immediately destroy and eradicate. • Grinds and kills salvinia no matter the thickness • It is environmentally safe, no harm to fish, trees, or wildlife. • The ground up salvinia decomposes rapidly and does not remain. • Does not require multiple treatments of an area • MOST IMPORTANTLY!It kills the salvinia … • Not easily maneuverable in tree filled cypress breaks • Does not operate in less than 2 feet of water • Doesn’t operate well in rough water
Where Can It Be Used Anywhere there is open water, a channel, a ski run, a boat run, even through scattered trees. As You Can See – there is more open water on Lake Bistineau than there are Cypress Breaks
Summary Could or should the watermower replace chemical applications, or fluctuating the lake level by means of a drawdown? Of course Not, but it can and should be used as another method of salvinia control. What about the cost? Everyone has heard that the watermower cost too much to operate or that it does to little clearing to be affective. The LDWF uses the figure of $73 an acre. This is what they claim it costs to chemically spray on Lake Bistineau. This is probably true. ….. BUT, nowhere can you find where they claim to kill an acre at $73 per. The LDWF says they can treat (not kill) 25 acres per day per spray boat. If they could kill 25 acres a day, then you could spray all 17,280 acres on Lake Bistineau for a one-time cost of $1,261,440 and be done with it. Due to all the factors that come into play when treating salvinia with a chemical spray, it is doubtful that a accurate cost of what it takes to kill an acre can be reached .
Summary – Cont How would you get a fair cost comparison …. • There is no easy way. • You could create 2 separate impoundments of 1 acre each. Load each …..impoundment with 4” to 8” of salvinia. • Put the watermower in one impoundment and use chemical spray on the other. • The time required to completely eradicate the salvinia in each impoundment would ….give you a bases for a cost comparison. • My guess is that the impoundment which is using the chemical spray would never be eradicated simply because the under-lying plants of salvinia would continue to grow as the top layer is dying. Plus it would be next to impossible to kill every plant on the top layer with one application. • Whether 4 hours or 4 days …. I believe that the watermower would eradicate the plant in its compound. • Therefore …. A reasonable cost is really not an issue.
Conclusion / End The LDWF should be praised for their efforts, hard work, and dedication to fighting this invasive plant. They have done a remarkable job! Where would we be without them! I for one am extremely grateful for what they have accomplished. Now it is time to load their arsenal with one more weapon. After all, if it doesn’t work, well we have just invested more money and time into a bucket that has eaten up a lot of both in the last 7-years. But what if it does work?! What if it works and we never gave the watermower a try?!
Reference Material Ref# 1 1a-1 – University Nevada Identification and ...........Management of Giant Salvinia 1a-2 - Lake Bistineau Rehabilitation Plan 1a-3 - Indiana Department of Natural ……….Resources – Salvinia 1a-4 - United States Department of ………..Agriculture Giant Salvinia 1a-5 – Washinton Weed Control Board Giant ……….Salvinia Ref# 22a-1 – US Agriculture Toledo Bend 2a-2 - MSU GeoResources Institute fact sheet 2a-3 - Mississippi State University Giant ……….Salvinia Ref# 3 N/A Ref# 4 4a-1 - Lake Bistineau Rehabilitation Plan Reference Material Is In PDF Format and Copies are on the disc Ref# 5 5a-1 – 91 sources listed of Diquat and ………..Glyphosate studies 5a-2 - Roundup Could Be Linked To …………Parkinson's, Cancer And Other Health …………Issues 5a-3 - List of References on the Health Effects …………of Glyphosate 5a-4 - Health and environmental impacts of ………..glyphosate 5a-5 – Why the world should be Ready to …………Round Up glyphosate 5a-6 – Institute of Science in Society Special …………Report Ref# 66a-1 – Hazardous Study Fact Sheet 6a-2 - Banned and Category 1 Pesticides and ………..Herbicides 6a-3 - Diquat/Paraquat Fact Sheet 6a-4 - PANAP Report Ref# 7 7a-1 – A & M Guide to Mass Rearing the …………Salvinia Weevil 7a-2 - Biosecurity Queensland Salvinia Fact …………Sheet
Reference Material - cont Ref# 7 - cont 7a-3 – New South Wales Biological Control Field Guide Giant Salvinia 7a-4 - CSIRO Entomology,Biological Control Field Guide Giant Salvinia 7a-5 - Agricultural Research magazine Attack Of Giant Salvinia 7a-6 - East Texas Waterways Biological Control of Giant Salvinia 7a-7 – Management and Control Methods – Austrailia 7a-8 - USDA-ARS Invasive Plant Research Laboratory Ref# 8 Classic short documentary from 1985 'Assault on the Sepik' about Salvinia management in Papua New Guinea found on the next slide Reference Material Is In PDF Format and Copies are on the disc
Assault on the Sepik View the classic short documentary from 1985 'Assault on the Sepik' about Salvinia management in Papua New Guinea. Click In The Black Square 25 minutes long ….. Extremely interesting
