This week’s article is a bit different… it is about nature we hope you DO NOT see – but hope you let us know if you do. Most of you know that Florida, along with many other states, continually battle invasive species. From Burmese pythons, to lionfish, to monitor lizards, we have problems with them all. Many of our invasive species are plants, which grow aggressively and take over habitats. They have few, if any, predators to control their populations and can cause environmental or economic problems for us.
The pretty, but invasive, beach vitex. Photo: Rick O’Connor
The best way to tackle an invasive species is to detect it when it first arrives and remove it as quickly as possible – this provides you the best chance of actually eradicating it from an area at the lowest cost. One such invasive plant that has recently invaded Escambia and Santa Rosa county beaches is Beach Vitex (Vitex rotundifolia).
Beach vitex is a vine that grows along the surface of sandy areas, like dunes. It has a main taproot from which the runners (stolons) extend in a radiating pattern, like a skinny-legged starfish. The stolons will develop secondary roots, which can form smaller deep root systems, and the entire maze of vines grows very quickly in the summer. The leaves are ovate, more round than elongated, and have a grayish-blue-green color to them – they tend to stand out from other plants. The plant can grow vertically to about three feet, giving it a bush appearance.
Another key characteristic for identification are the lavender flowers it produces, few other plants in our dunes do – so this is a good thing to look for. The flowers appear in late spring and summer. They are actually quite pretty. In the fall, the flowers are replaced by numerous large seeds, which form in clusters where the flowers were. These seeds are problematic in that they can remain viable for up to six months if they fall into the water – increasing their chance for dispersal.
So what is the problem?
In the Carolina’s this species was planted intentionally. They quickly learned of its aggressive nature and have had a state task force to battle it. The plant is allopathic – it can release toxins that kill neighboring plants allowing them to move into that space – this includes sea oats. Beach vitex has a taproot system, unlike the fibrous one of the sea oat, and cannot stabilize a dune as well – which is a problem during storms. In the Carolina’s there are numerous beach fronts where this is the only plant growing, a problem waiting to happen. Though there are no reports of it happening, it also has the potential to affect sea turtle nesting.
Beach Vitex Blossom. Photo credit: Rick O’Connor
So what do I do if I see it?
Contact us… You can contact me at roc1@ufl.edu, or call (850) 475-5230. Try to give us the best description of where the location is as you can. Many phones now come with an app that has a compass. This app also gives you your latitude and longitude. If your phone does not have this, again, give us the best description of the location you can. If you can include a photograph, that would be great. There are numerous other invasive species roaming our area, and you are welcome to report any you find to us. We hope to stay on top of these early arrivals and keep them under control.
Holli tells us about the Wildlife Assistance program for homeowners and property owners. Holli helps out find solutions for negative encounters with Wildlife. Most problems are easily solved and she provides a few tips. Holli also tells us about the FWC Pet Amnesty Program for Exotic Pets. Watch to learn more. http://myfwc.com/conse…/you-conserve/assistnuisance-wildlife
Kira shows off the tokay gecko we found at the Extension office on the front porch earlier in May. The Gecko moved in with Kira and her other reptiles at the Science and Discovery Center.
…http://myfwc.com/wildlifeha…/nonnatives/reptiles/tokay-gecko
Derek Fussell with FWC Invasive Aquatic Plant Management talks about Giant Salvinia, a species of concern for Deer Point Lake in Bay County, Florida. Here’s a link to a story about the discovery of giant salvinia in Bay County from 2016 https://nwdistrict.ifas.ufl.edu/…/nisaw-2016-working…
Derek Fussell shares a behind the scene’s view of their new boat for controling aquatic plants in Bay County and Northwest Florida. We will visit with Derek and Jamie later and show some of the aquatic invasives they work to control everyday!
By L. Scott Jackson and Julie B. McConnell, UF/IFAS Extension Bay County
Northwest Florida’s pristine natural world is being threaten by a group of non-native plants and animals known collectively as invasive species. Exotic invasive species originate from other continents and have adverse impacts on our native habitats and species. Many of these problem non-natives have nothing to keep them in check since there’s nothing that eats or preys on them in their “new world”. One of the most problematic and widespread invasive plants we have in our local area is air potato vine.
Air potato vine originated in Asia and Africa. It was brought to Florida in the early 1900s. People moved this plant with them using it for food and traditional medicine. However, raw forms of air potato are toxic and consumption is not recommended. This quick growing vine reproduces from tubers or “potatoes”. The potato drops from the vine and grows into the soil to start new vines. Air potato is especially a problem in disturbed areas like utility easements, which can provide easy entry into forests. Significant tree damage can occur in areas with heavy air potato infestation because vines can entirely cover large trees. Some sources report vine growth rates up to eight inches per day!
Air Potato vines covering native shrubs and trees in Bay County, Florida. (Photo by L. Scott Jackson)
Mechanical removal of vines and potatoes from the soil is one control method. Additionally, herbicides are often used to remediate areas dominated by air potato vine but this runs the risk of affecting non-target plants underneath the vine. A new tool for control was introduced to Florida in 2011, the air potato leaf beetle. Air potato beetle releases have been monitored and evaluated by United States Department of Agriculture (USDA) researchers and scientists for several years.
Air Potato Beetle crawling on leaf stem. Beetles eat leaves curtailing the growth and impact of air potato. (Photo by Julie B. McConnell)
Air potato beetles target only air potato leaves making them a perfect candidate for biological control. Biological controls aid in the management of target invasive species. Complete eradication is not expected, however suppression and reduced spread of air potato vine is realistic.
UF/IFAS Extension Bay County will host the Air Potato Challenge on June 6, 2018. Citizen scientist will receive air potato beetles and training regarding introduction of beetles into their private property infested with air potato vine. Pre-registration is recommended to receive the air potato beetles. Please visit http://bit.ly/bayairpotato
In conjunction with the Air Potato Challenge, UF/IFAS Extension Bay County will be hosting an invasive species awareness workshop. Dr. Steve Johnson, UF/IFAS Associate Professor of Wildlife Ecology, will be presenting “Exotic Invaders: Reptiles and Amphibians of Concern in Northwest Florida”. Additionally, experts from UF/IFAS Extension, Florida Fish and Wildlife, and the Science and Discovery center will have live exhibits featuring invasive reptiles, lionfish, and plants. For more information visit http://bay.ifas.ufl.edu or call the UF/IFAS Extension Bay County Office at 850-784-6105.
Flyer for Air Potato Challenge and Invasive Species Workshop June 6 2018
It is easy to notice the display of bright pink puffs erupting on low-growing trees along roadsides. This attractive plant is the Mimosa tree, Albizia julibrissin.
These once popular small trees are commonly found in the yards of older homes in Florida where the display of prolific blooms starts up as the weather warms.
This species is also classified as invasive native to southwest and eastern China, not Florida. Many Florida residents may not realize this tantalizing beauty is actually an aggressive invader in disguise.
The beautiful mimosa is found throughout the Florida panhandle. Photo: Les Harrison
It has spread from southern New York west to Missouri south to Texas. It is even considered an invasive species in Japan.
Worse yet, mimosas are guilty of hosting a fungal disease, Fusarian, which will negatively affect many ornamental and garden plants. Some palms as well as a variety of vegetables will succumb to this pathogen.
In natural areas the invader will disrupt not only other plants, but also the birds, mammals, amphibians, and insects which depend on the displaced plants for food, shelter and habitat. Other negative traits include the disruption of water flow and aiding the incidence of wildfires.
In natural areas, mimosas tend to spread into dense clumps blocking the light to native plants which prevents them from growing. They are prominent along the edges of woods and wetland areas where seeds scatter easily and take advantage of sheltered, sunlit spots.
Mimosa tree seeds can stay viable for many years in the soil. These seeds will float without damage to their germination potential until they wash ashore to colonize a new site.
Additionally, Mimosa tree seeds are attractive to wildlife. One tree in a yard can infest many acres with the aid of birds and small mammals.
Cut or wind snapped trees quickly regrow from the stump, making this one invader that is difficult to eradicate.
Fortunately, there are a variety of small trees which can replace the Mimosa tree in home landscapes. Many are attractive, but without the unrelenting need to populate the entire subdivision.
This is a beauty-and-the-beast combo tree with too many problems to compensate for its looks.
Adult grass carp, Ctenopharyngodon idella Val. Credit: Jeffrey E. Hill, University of Florida
Spring is only days away. Everywhere you look, plants of all kinds are awakening to recent rains, longer days, and fertile soils; and this includes aquatic plants as well! Florida has hundreds of aquatic plant species, and they are an often-overlooked feature of Florida’s landscape. Overlooked that is, until the growth of non-native (or even some native) species interferes with use of our waters. Some aquatic plant species can become problematic in Florida waters as their growth interferes with fishing, flood control, navigation, recreation, livestock watering, or irrigation. For these reasons, being knowledgeable about properly managing aquatic plants is important to the many uses of Florida’s waters, whether it be a state managed public waterbody, or your own backyard farm pond.
Any pest, whether plant, animal, or insect, is best managed using “IPM” or Integrated Pest Management. IPM involves using a variety of available management “tools” to control pests in an economically and environmentally sound manner. As in any IPM effort, the first thing to do is identify what is causing the problem. Next, define what your management goals are. Then, research what tools are available for you to manage the problem. And finally, devise and implement your management plan.
In this article, we will look at one of the IPM “tools” used to manage aquatic plants – the grass carp (Ctenopharyngodon idella Val.). The use of grass carp to manage problematic levels of aquatic plants falls under the general management term of “biological control.” Biological control essentially uses one living organism to control another living organism. Grass carp have become one of the most widely recognized examples of biological control.
The Grass Carp
As the name implies, the grass carp is an herbivorous fish that eats plants. It is native to eastern Russia and China living in large muddy rivers and associated lakes, and is actually one of the largest members of the minnow family. According to the Florida Fish and Wildlife Conservation Commission the largest triploid grass carp taken in Florida was 15 years old, 56″ long and weighed 75 pounds! The grass carp has been introduced into more than 50 countries and is used as a food item in many places around the world. They are used in nearly all states of the USA to manage aquatic plants.
According to the UF/IFAS publication, Grass Carp, the White Amur: Ctenopharyngodon idella Cuvier and Valenciennes (Actinopterygii: Cyprinidae: Squaliobarbinae), “Use of the fish was limited from 1970 until 1984 due to tight regulations surrounding concerns of escape and reproduction, and the potential impacts that colonization of the fish could have on native flora and fauna. These concerns led to research that developed a non-reproductive fish, which was equally effective in controlling hydrilla.” This non-reproductive fish is known as the triploid grass carp. Through a process of subjecting fertilized grass carp eggs to heat, cold, or pressure, the resulting fish have an extra set of chromosomes rendering the fish sterile. Triploid carp have the same herbivorous characteristics as the normal diploid carp, but they are unable to spawn and reproduce. Their inability to reproduce is what makes them a viable tool to manage aquatic plants, and that is because their numbers and feeding pressure can be controlled, they cannot overpopulate a waterbody, nor if they escape, will they overpopulate un-managed areas.
The growth of invasive non-native (or even some native) aquatic plant species can interfere with the many uses of Florida’s waters. This is invasive hydrilla mixed with water lilies in a Florida lake. Photo by Judy Biss
What kinds of aquatic plants do they eat?
The grass carp grazes on many types of aquatic plants, but it does have its preferences. Its most preferred aquatics plants are hydrilla, chara (musk grass), pondweed, southern naiad, and Brazilian elodea. Its least favorite aquatic plants are species such as water lily, sedges, cattails, and filamentous algae. It will, however, graze on many types of plants even shoreline or overhanging vegetation in the absence of its preferred foods. Another reason the grass carp is an effective plant management tool is because it eats many times its body weight in plant material. As stated in Grass Carp, the White Amur: Ctenopharyngodon idella Cuvier and Valenciennes (Actinopterygii: Cyprinidae: Squaliobarbinae), “every 1 lb. increase in fish weight requires 5–6 lbs. of dry hydrilla (Sutton et al. 2012), which—considering hydrilla is 95% water—is a great deal of live plant material.”
Use of Grass Carp as a Biological Control:
Integrating the use of grass carp in aquatic plant management plans is usually cost effective. In many cases involving the use of grass carp, overabundant aquatic weed infestations are first treated with an aquatic herbicide to reduce biomass. The carp are then stocked to control regrowth and to extend the time between herbicide treatments. This can be up to 5 or more years, depending on the situation. One factor in long term control is the survival of the stocked grass carp. They are not without predators as largemouth bass, otters, birds, etc. readily prey on small grass carp. Stocked fish should be at least 12 inches long to help avoid predation and provide plant control. Other considerations to factor into your management plans are the long term, yet non-specific, control that grass carp can provide. If not stocked in the correct manner, they may end up eating aquatic plants that you wish to maintain. Also, if they eat all the aquatic plants, your once clear water may become dominated by algae instead.
How can I get grass carp for my lake or pond?
The Florida Fish and Wildlife Conservation Commission (FWC) administers the Grass Carp program for Florida. A permit is required before you can purchase carp, and only the sterile triploid carp are permitted for use in Florida. The FWC can answer many questions about the use of grass carp and if this aquatic plant management “tool” is the right one for you to use in your particular situation. In north Florida, the regional FWC office is located at 3911 Highway 2321 Panama City, FL 32409, Phone: 850-767-3638.
Cost: Triploid grass carp cost between $5 and $15 each and are usually stocked at three to ten fish per acre, resulting in costs as low as $15 per acre. In comparison, herbicides cost between $100 and $500 per acre and mechanical control may cost more than twice that.
Time: Grass carp usually take six months to a year to be effective in reducing problem vegetation, although they provide much longer term control than other methods, often up to five years before restocking is necessary. When used in conjunction with an initial herbicide treatment, control of problem vegetation can be achieved quickly, and fewer carp are required to maintain the desired level of vegetation.
Overstocking: Once stocked in a lake or pond, carp are very difficult to remove. If overstocking occurs, it may be ten years or more before the vegetation community recovers. Even after carp are removed, other herbivores such as turtles may prevent the regrowth of vegetation.
Water Clarity: Aquatic plants remove nutrients in the water. When plants are removed, nutrients may then be utilized by phytoplankton, turning the water green. Clarity may be improved by reducing or eliminating sources of nutrients into the lake such as road runoff and lawn fertilizer.
Inflows/Outflows: It is in the best interest of people stocking carp to keep them in the desired lake or pond. It is also a required condition of the permit. Any inflows or outflows through which carp could escape into other waters require barriers to prevent fish from escaping into waters not permitted.
For more information on this topic, please see the following resources used for this article:
As we come to the end of National Invasive Species Awareness Week (NISAW), I need to educate everyone on a potential invasive threat, a classic Early Detection Rapid Response (EDRR) species – the Cuban Treefrog.
is this a Cuban Tree Frog? Do I have to rely on DNA barconding to know for sure – before I decide to euthanize it? Could I be making a mistake? Image by Dr. Steve A Johnson 2005.
This treefrog was first introduced into to south Florida in the 1920’s. Like lionfish, it quickly became established and began its slow dispersal northward. It is a large predatory frog (reaching about 5”) which began to consume native treefrogs, reducing their populations wherever they were found. In addition to consuming native frogs, Cuban Treefrogs eat snails, millipedes, spiders, and many other small creatures. They can produce a call that is somewhat annoying to many residents where it is found. It is currently listed as established as far north as Gainesville FL.
A few years ago, I received a call from a resident near Big Lagoon in southwest Escambia County. They had just purchased plants from a local chain store to plant in their yard the following day. They had left the plants on the front porch that night and, at some point, noticed this large treefrog on their front door. They wanted to know if this was a non-native frog. It was – it was the Cuban Treefrog. The animal was collected and sent to the University of Florida.
This is a common method of transporting this frog north. They attach to ornamental plants grown in nurseries in south Florida. The plants are loaded on trucks and shipped to the panhandle and locations north and west. There are probably numerous species hitching rides this way, including the Cuban Anole (an invasive lizard). Lucky for us, in many cases these tropical problem species cannot tolerate our cold winters – this could also be said for some of the invasive plants. However, in recent years, the winters have been milder and some of these species are surviving. Most of us know and understand the impact lionfish have had on local small reef fish; no one is interested in another “lionfish problem” in the panhandle.
About a year ago, a second Cuban Treefrog was reported in Crestview.
Early this year I attended an amphibian/reptile conference in north Georgia. There was a presentation given by a scientist from the U.S. Geological Survey in Lafayette LA. He had a call from the Audubon Zoo in New Orleans about a strange frog they had been finding. They had recently purchased palm trees from south Florida for the elephant exhibit. The caretakers of the exhibit began to see strange frogs and reported it. When USGS arrived, they meandered through the park searching. They stopped by the public bathroom to look (a place I have found them in south Florida myself). They happen to pass an electric panel outside the restroom and decided to take a peak – 13 Cuban Treefrogs were within.
They began an exhaustive search and found CTFs everywhere. Most had moved into a public park between the zoo and the river called Riverview. I cannot remember how many they had found but it was in the hundreds, the animals were beginning to establish themselves in this area of New Orleans. USGS is currently working on the problem.
Just a few weeks ago, a Cuban Treefrog was found on Davenport Bayou off Bayou Grande.
There are many reports of single, individual CTFs across the northern Gulf coast, but none were established populations. However, as reports increase we should be looking for these animals and try to keep them under control before they do. No more “lionfish problems”.
How do we do this?
The following link provides information about the frog, how to identify it, how to set traps to determine if the animal is in your neighborhood, and what to do if you do find one. I would include reporting the finding on www.EDDMapS.org. I also recommend as you purchase plants for this spring’s landscaping projects, check the plants carefully for any hitchhikers. This “early detection” method is the most effective way to battle the movement of invasive species.
If you have questions about Cuban Treefrogs, let me know.
Johnson, S.A. 2017. The Cuban Treefrog (Osteopilus septentrionalis) in Florida. University of Florida Extension Electronic Data Information Source (EDIS) document WEC218.
