Despite its name, giant salvinia (Salvinia molesta) is actually pretty small. The floating plant starts out with a cluster of leaves no bigger than a dime. They don’t stay that way, though, and perhaps their outsized influence and spread gives the “giant” a little more credence.
Giant salvinia is an invasive aquatic plant that was introduced to the United States as an ornamental plant (for aquariums and backyard ponds) from South America. Once it managed to escape to the wild, however, salvinia really took off. More than 20 states report salvinia popping up in their waters, although Texas and Louisiana seem to have the biggest battles with it. The plant has choked up entire freshwater lakes and sections of rivers, requiring a major eradication effort just to regain access to the water. Even small craft like kayaks and canoes cannot make it through a water body clogged with this plant. It is often spread by small pieces lodging in boat motors and trailers, so if you boat frequently in an area of known salvinia, be sure to remove any fragments of the plant once you are back on land. Preventing the spread from one water body to another is crucial.
Our native birds, fish, and aquatic mammals don’t eat giant salvinia—it appears not to have much nutritional value—and therefore its growth goes unchecked. The thick mats of plant growth block sunlight into the water column, preventing other aquatic plants from growing. Die-offs of large numbers of salvinia can eat up oxygen levels in the water, causing fish kills.
Giant salvinia overgrowth in a backwater section of Bayou Chico in Escambia County. Photo credit: Escambia County Natural Resource Management
There are several approaches to managing the plant. Mechanical or hand removal can take out significant amounts of salvinia, but is ineffective in the long run. Any small piece of chopped up plant left behind in the process will regrow into new spreading plants, so leaving any fragments in the water ends up increasing the population. More effective methods include applying herbicides or using a biocontrol insect called the salvinia weevil. This South American beetle (Cyrtobagous salviniae) is very small (only 2 mm as an adult) but feeds exclusively on salvinia plants, stunting their growth and causing them to sink underwater. A well-established salvinia weevil population can effectively manage large infestations of the plant, dropping coverage by 90%.
One natural check to unfettered growth in our area is that salvinia tends to thrive only in freshwater or very low salinity water bodies. We have identified populations of salvinia in the upper reaches of local bayous in Escambia County, but as salinity levels increase closer to the bay, the plant seems unable to establish itself.
Identification of giant salvinia is rather fascinating, as you need a hand lens to definitively distinguish it from a very similar nonnative species called water spangles or water fern (Salvinia minima). Both species have small clear-white, upright hairs covering the leaves. When examined closely, the observer will note that in giant salvinia that double pairs of hairs form a structure very similar to an egg beater, whereas in water spangles the leaf hairs do not connect.
Giant salvinia can be distinguished from its cousin, common salvinia (Salvinia minima) by the shape of its trichomes, or leaf-hairs. Giant salvinia’s leaf hairs (right) are closed at the tip, forming an “egg-beater” shape, whereas common salvinia’s leaf hairs (left) are branched at the tip. Giant salvinia is a larger plant that forms thicker, denser mats. Common salvinia can cover large areas but typically forms thinner mats and does not pose as much risk to boating traffic. Photos and caption courtesy LSU AgCenter
If you think you see giant salvinia in a local water body, we would love to know. It is an aggressive invasive plant that is relatively new to the area, and we have a chance to keep this from spreading with your help. What can you do?
Contact the Escambia County Division of Water Quality and Land Management – (850) 595-3496
Contact the Escambia County Extension Office – (850) 475-5230 ext. 1111
Report in the EDDMapS national database – https://www.eddmaps.org – select “report sightings”
If you find just a small amount, remove it and allow to dry out on your property. Once dried you can double bag and dispose of it.
Are you a Florida homeowner connected to a private well and/or septic system? Do you know want to learn more about your water and wastewater management systems at home?
If so, please join the UF/IFAS Central and Northwest Florida water resources regional specialized agents Yilin Zhuang and Andrea Albertin, in our four free private well and septic system webinars in February and March:
Thursday, February 9 at 2:00 p.m.: Private Wells 101
Thursday, February 16 at 2:00 p.m.: Septic System 101
Thursday, February 23 at 2:00 p.m.: Private Well Care Before and After Storms
Thursday, March 2 at 2:00 p.m.: Septic System Care Before and After Storms
After completing the webinars, attendees will also receive free mail-in well water screening for total coliform bacteria and E. coli.
To register, please visit our Eventbrite page: https://2023FWON.eventbrite.com. These webinars are free, but we ask all attendees to register.
For more information, please contact Dr. Yilin Zhuang at yilinz@ufl.edu, or Dr. Andrea Albertin at albertin@ufl.edu or via telephone: (850) 875-7111.
GUEST AUTHOR: PRUDENCE CASKEY – 4-H Agent in Santa Rosa County
The hot, Florida summer is approaching, and we all need to make sure we focus on hydration in the heat. Dehydration is very common in hot, humid environments. Many people do not drink the recommended amount of water. Many of us have our coffee in the morning and unless we go out to lunch and someone gives us water, we seldom think about water during the day. Another confusing concept is how much water we should drink. Growing up we were told to get eight glasses of water a day. That is 64 ounces. Let’s see if that adage still holds true today.
Animals are well aware of the need for water. Photo: Prudence Caskey
How much water should I drink?
The best way to calculate how many ounces of water to drink is to multiply your weight by .67 or 67%. For example, a person weighing 150 pounds would need 100½ ounces or a little over 12½ cups. On the other hand, a person weighing 200 pounds would need 134 ounces or 16¾ cups.
Is that all the water I need?
No, as you sweat, you lose the water that you have already consumed. If you are sweating for 30 minutes, you need to replenish your hydration with 12 additional ounces of fluid.
What fluid should I drink?
The main thing when it comes to hydration, is to remember, just because it is wet, does not mean you are being hydrated. Different fluids are absorbed by our bodies differently. Some alcoholic beverages remove hydration from our bodies as we drink them. Below is an example of how our bodies absorb some common beverages:
Water absorbed at 100%
Sparkling Water absorbed at 100%
Skim Milk is absorbed at 90%
Buttermilk is absorbed at 90%
Whole Milk is absorbed at 80%
Apple Juice is absorbed at 88%
Decaffeinated Coffee is absorbed at 90%
Coffee is absorbed at 80%
Sports Drinks absorbed at 50%
Energy Drink absorbed at 40%
Wine is absorbed at negative 150%
Beer is absorbed at negative 60%
Sake is absorbed at negative 180%
Liquor is absorbed at negative 300%
This is a huge concept to grasp, if you plan on being out at the beach with your friends this summer. With this example, a well-hydrated 150-pound person consumes the required 100½ ounces of fluid. Then at a gathering, they have three, glasses of wine. The standard five ounces per glass would mean they have removed 22½ ounces from their hydration after drinking only 15 ounces of wine. Be cognoscente of what you add to your coolers this year.
What are the signs of dehydration?
There are many signs our bodies will give us to signal dehydration. Headache, nausea, and muscle pains are common. However, the most common sign of dehydration is thirst. That’s right, if you are thirsty, it is your body’s way of letting you know you need fluids. Just be careful which fluids you chose this summer when you are out and enjoying the Florida sun.
The local Community Collaborative Rain, Hail, and Snow network is seeking interested citizen scientists to participate in the collecting weather data. See the notice below from local coordinator, Larry McDonald, for more information:
Citizen scientists interested in collecting rain data utilized by organizations all over the country use this type of rain gauge. Photo credit: Larry McDonald, CoCoRAHS
Weather forecasting depends on taking readings and measurements from the atmosphere. And it’s not just professionals, like meteorologists, who measure rainfall, temperatures, and humidity levels. You can, too! The Community Collaborative Rain, Hail, and Snow network (CoCoRaHS) allows everyday citizens to participate in weather data collection by measuring daily precipitation/rainfall totals at their own homes or workplaces. Using a special rain gauge that provides great detail in detecting rain amounts, CoCoRaHS observers submit rain observations online to a national network… along with over 20,000 participants in the U.S., Canada, and the Bahamas. Precipitation amounts are then evaluated for many needs by national, regional, and local weather forecasters, researchers, drought and flood monitoring, and agricultural interests. Rainfall data submitted can also be used in forecasting to predict the possibility of flash flooding for local flood prone areas.
A CoCoRaHS observer simply needs to purchase the approved rain gauge (costing from $30 to $40), mount the gauge in an open area away from roofs, fences, and vegetation, and simply collect rain that falls directly from the sky over a 24-hour period. Once each day, between 5:30 AM and 9:00 AM, the gauge is checked for rain with the amount recorded and submitted to the CoCoRaHS website. Missing a day or more is okay, but the more you report, the better the overall data becomes for your area. New and active CoCoRaHS observers are needed throughout Escambia and Santa Rosa Counties.
Those interested in possibly joining CoCoRaHS as an observer can obtain more information by visiting https://cocorahs.org/. You can also contact the CoCoRaHS local volunteer coordinator for Escambia and Santa Rosa Counties by emailing escambia_fl_cocorahs@icloud.com
Jackson Blue Springs discharging from the Floridan Aquifer. Jackson County, FL. Image: Doug Mayo, UF/IFAS Extension.
Florida has one of the largest concentrations of freshwater springs in the world. More than 1000 have been identified statewide, and here in the Florida Panhandle, more than 250 have been found. Not only are they an important source of potable water, springs have enormous recreational and cultural value in our state. There is nothing like taking a cool swim in the crystal-clear waters of these unique, beautiful systems.
How do springs form?
We have so many springs in Florida because of the state’s geology. Florida is underlain by thick layers of limestone (calcium carbonate) and dolomite (calcium magnesium carbonate) that are easily dissolved by rainwater that percolates into the ground. Rainwater is naturally slightly acidic (with a pH of about 5 to 5.6), and as it moves through the limestone and dolomite, it dissolves the rock and forms fissures, conduits, and caves that can store water. In areas where the limestone is close to the surface, sinkholes and springs are common. Springs form when groundwater that is under pressure flows out through natural openings in the ground. Most of our springs are found in North and North-Central Florida, where the limestone and dolomite are found closest to the surface.
Springs are windows to the Floridan Aquifer, which supplies most of Florida’s drinking water. Image: Ichetucknee Blue Hole, A. Albertin.
These thick layers of limestone and dolomite that are below us, with pores, fissures, conduits, and caves that store water, make up the Floridan Aquifer. The Floridan Aquifer includes all of Florida and parts of Georgia, South Carolina, and Alabama. The thickness of the aquifer varies widely, ranging from 250 ft. thick in parts of Georgia, to about 3,000 ft. thick in South Florida. The Floridan is one of the most productive aquifer systems in the world. It provides drinking water to about 11 million Floridians and is recharged by rainfall.
How are springs classified?
Springs are commonly classified by their discharge or flow rate, which is measured in cubic feet or cubic meters per second. First magnitude springs have a flow rate of 100 cubic feet or more per second, 2nd magnitude springs have a rate of 10-100 ft.3/sec., 3rd magnitude flows are 1-10 ft.3/sec. and so on. We have 33 first magnitude springs in the state, and the majority of these are found in state parks. These springs pump out massive amounts of water. A flow rate of 100 ft.3/sec. translates to 65 million gallons per day. Larger springs in Florida supply the base flow for many streams and rivers.
What affects spring flow?
Multiple factors can affect the amount of water that flows from springs. These include the amount of rainfall, size of caverns and conduits that the water is flowing through, water pressure in the aquifer, and the size of the spring’s recharge basin. A recharge basin is the land area that contributes water to the spring – surface water and rainwater that falls on this area can seep into the ground and end up as part of the spring’s discharge. Drought and activities such as groundwater withdrawals through pumping can reduce flow from springs systems.
If you haven’t experienced the beauty of a Florida Spring, there is really nothing quite like it. Here in the panhandle, springs such as Wakulla, Jackson Blue, Pitt, Williford, Morrison, Ponce de Leon, Vortex, and Cypress Springs are some of the areas that offer wonderful recreational opportunities. The Florida Department of Environmental Protection has a ‘springs finder’ web page with an interactive map that can help you locate these and many other springs throughout the state.
Senate Bill 712 ‘The Clean Waterways Act’ was signed into Florida law on June 30, 2020. The purpose of the bill is to better protect Florida’s water resources and focuses on minimizing the impact of known sources of nutrient pollution. These sources include septic systems, wastewater treatment plants, stormwater runoff as well as fertilizer used in agricultural production.
Senate Bill 712 focuses on protecting Florida’s water resources such as Jackson Blue Springs/Merritt’s Mill Pond, pictured here. Credit: Doug Mayo, UF/IFAS.
What major provisions are included in SB 712?
Primary actions required by SB712 were listed in a news release by Governor Desantis’ staff in June 2020 as:
Regulation of septic systems as a source of nutrients and transfer of oversight from the Florida Department of Health (DOH) to the Florida Department of Environmental Protection (DEP).
Contingency plans for power outages to minimize discharges of untreated wastewater for all sewage disposal facilities.
Provision of financial records from all sanitary sewage disposal facilities so that DEP can ensure funds are being allocated to infrastructure upgrades, repairs, and maintenance that prevent systems from falling into states of disrepair.
Detailed documentation of fertilizer use by agricultural operations to ensure compliance with Best Management Practices (BMPs) and aid in evaluation of their effectiveness.
Updated stormwater rules and design criteria to improve the performance of stormwater systems statewide to specifically address nutrients.
How does the bill impact septic system regulation?
The transfer of the Onsite Sewage Program (OSP) (commonly known as the septic system program) from DOH to DEP becomes effective on July 1, 2021. So far, DOH and DEP submitted a report to the Governor and Legislature at the end of 2020 with recommendations on how this transfer should take place. They recommend that county DOH employees working in the OSP continue implementing the program as DOH-employees, but that the onsite sewage program office in the State Health Office transfer to DEP and continue working from there. DOH created an OSP Transfer web page where updates and documents related to the transfer are posted.
How does the bill impact agricultural operations?
SB 712 affects all landowners and producers enrolled in the Florida Department of Agriculture and Consumer Services (FDACS) BMP Program. Under this bill:
Every two years FDACS will make an onsite implementation verification (IV) visit to land enrolled in the BMP program to ensure that BMPs are properly implemented. These visits will be coordinated between the producer and field staff from FDACS Office of Agriculture and Water Policy (OAWP).
During these visits (and as they have done in the past), field staff will review records that producers are required to keep under the BMP program.
Field staff will also collect information on nitrogen and phosphorus application. FDACS has created a specific form, the Nutrient Application Record Keeping Form or NARF where producers will record quantities of N and P applied. FDACS field staff will retain a copy of the NARF during the IV visit.
FDACS-OAWP prepared a thorough document with responses to SB 712 Frequently Asked Questions (FAQ’s). It includes responses to questions about site visits, the NARF and record keeping, why FDACS is collecting nutrient records and what will be done with this information. The fertilizer records collected are not public information, and are protected under the public records exemption (Section 403.067 Florida Statutes). For areas that fall under a Basin Management Action Plan (like the Jackson Blue and Wakulla Springs Basins in the Florida Panhandle), FDACS will combine the nitrogen and phosphorus application data from all enrolled properties (total pounds of N and P applied within the BMAP). It will then send the aggregated nutrient application information to FDEP.
Details of how all aspects of SB 712 will be implemented are still being worked out and we should continue to hear more in the coming months.
