by Rick O'Connor | Sep 15, 2021
Six Rivers “Dirty Dozen” Invasive Species
Red Lionfish (Pterois volitans)
Lionfish in tank. Photo credit: Laura Tiu
Define Invasive Species: must have all of the following –
- Is non-native to the area, in our case northwest Florida
- Introduced by humans, whether intentional or accidental
- Causing either an environmental or economic problem, possibly both
Define “Dirty Dozen” Species:
These are species that are well established within the CISMA and are considered, by members of the CISMA, to be one of the top 12 worst problems in our area.
Native Range:
The Indo-Pacific and Red Sea.
Introduction:
The first record of lionfish in U.S. waters was in the late 1980s off the coast of Davie, Florida. It is believed the release was connected to the aquarium trade but whether it was accidental or intentional is unknown.
EDDMapS currently list 3,029 records of lionfish in the U.S. This is certainly under reported. Few invasive marine fish are reported to EDDMapS. Most are reported to a NOAA website which reports area of lionfish rather than individual records. It is known that the lionfish is well established all along the eastern seaboard of the United States, Bermuda, the Caribbean, and the entire Gulf of Mexico – including the coastal areas of Six Rivers CISMA. In 2014, it was reported that the densities of lionfish off the Six Rivers CISMA were some of the highest in the entire south Atlantic Region1. At a regional workshop in 2018, it was reported these densities had declined in waters less than 200 feet2.
Description:
Lionfish are deep bodied fish with large dorsal and pectoral fins and a truncate caudal fin. It is a slow swimmer. The body has a white/maroon vertically striped pattern that includes the head. The dorsal spines extend above tissue of the dorsal fin and possess a neurotoxin that is quite painful. The enlarged pectoral fins resemble wings and are used by the fish to corral prey into corners. There are no venomous spines on the pectoral fins but there are on the pelvic and anal ones. Lionfish have a large gaping mouth that can swallow a variety of prey using an engulfing/vacuum method.
Issues and Impacts:
These are voracious predators and have been known to consume over 70 different species of small demersal reef fishes. These small fish play an important ecological role on the reefs they inhabit, such as prey for larger commercially sought-after fish species as well as those that graze algae and keep the corals from being smothered by such. The decline of these populations can have both ecological and economic impacts. Studies have found that the popular red snapper will stay further away from reefs inhabited by lionfish, and they are also known to inhabit lobster traps in the Florida Keys, impeding the entry of the much sought-after spiny lobster.
Management:
The high reproductive rate has made lionfish management difficult. Adult females are known to produce an average of 30,000 fertilized every four days. The fertilized eggs are encased in a gelatinous sac that drifts with the currents and disperses the young to new territories. There are toxins associated with this sac and consumption of larvae is not currently known. In addition to high reproductive rates, the currents disperse the developing young great distances and lionfish are known to tolerate salinities found in estuaries.
They rarely bite hook and line making the most effective of removal being the diver with a pole spear. There are very good lionfish hunters, and prize-winning tournaments are well attended, but studies have shown that removals using spear must be repeated about once a month to be effective. Effective here meaning keeping the population stable, lionfish is a “Dirty Dozen” species, it will not be eradicated.
Test using traps are currently being conducted and these may prove to be more effective than removing by spear alone. There are a few native species that have been known to consume lionfish, but not at a rate to impact their invasion. Since 2018 lionfish in the south Atlantic region have been reported with skin lesions. It is not known at this time how this will impact their numbers, but early studies suggest it is.
For more information on this Dirty Dozen species, contact your local extension office.
References
Early Detection and Distribution Mapping System (EDDMapS)
https://www.eddmaps.org/
Six Rivers CISMA
https://www.floridainvasives.org/sixrivers/
by Laura Tiu | Sep 9, 2021
A Lionfish Removal and Awareness Day festival volunteer sorts lionfish for weighing. (L. Tiu)
The northwest Florida area has been identified as having the highest concentration of invasive lionfish in the world. Lionfish pose a significant threat to our native wildlife and habitat with spearfishing the primary means of control. Lionfish tournaments are one way to increase harvest of these invaders and help keep populations down. Not only that, but lionfish are a delicious tasting fish and tournaments help supply the local seafood markets with this unique offering.
Since 2019, Destin, Florida has been the site of the Emerald Coast Open (ECO), the largest lionfish tournament in the world, hosted by Destin-Fort Walton Beach and the Florida Fish and Wildlife Commission (FWC). While the tournament was canceled in 2020, due to the pandemic, the 2021 tournament and the Lionfish Removal and Awareness Day festival returned to the Destin Harbor May 14-16 with over 145 tournament participants from around Florida, the US, and even Canada. The windy weekend facilitated some sporty conditions keeping boats and teams from maximizing their time on the water, but ultimately 2,505 lionfish were removed during the pre-tournament and 7,745 lionfish were removed during the two-day event for a total of 10,250 invasive lionfish removed. Florida Sea Grant and FWC recruited over 50 volunteers from organizations such as Reef Environmental Education Foundation, Navarre Beach Marine Science Station and Tampa Bay Watch Discovery Center to man the tournament and surrounding festival.
Lionfish hunters competed for over $48,000 in cash prizes and $25,000 in gear prizes. Florida Man, a Destin-based dive charter on the DreadKnot, won $10,000 for harvesting the most lionfish, 1,371, in 2 days. Team Bottom Time secured the largest lionfish prize of $5,000 with a 17.32 inch fish. Team Into the Clouds wrapped up the $5,000 prize for smallest lionfish with a 1.61 inch fish, the smallest lionfish caught in Emerald Coast Open History.
It is never too early to start preparing for the 2022 tournament. For more information, visit EmeraldCoastOpen.com or Facebook.com/EmeraldCoastOpen. For information about Lionfish Removal and Awareness Day, visit FWCReefRangers.com
“An Equal Opportunity Institution”
by Rick O'Connor | Sep 1, 2021
EDRR Invasive Species
Hydrilla (Hydrilla verticillata)
Hydrilla Photo Credit: Vic Ramey, UF/IFAS Center for Aquatic and Invasive Plants
Define Invasive Species: must have ALL of the following –
- Is non-native to the area, in our case northwest Florida
- Introduced by humans, whether intentional or accidental
- Causing either an environmental or economic problem, possibly both
Define EDRR Species: Early Detection Rapid Response. These are species that are either –
- Not currently in the area, in our case the Six Rivers CISMA, but a potential threat
- In the area but in small numbers and could be eradicated
Native Range:
India.
Introduction:
Intentionally introduced in 1950-51 as a plant for aquariums.
EDDMapS currently list 3,592 records of this plant in the U.S. and Canada. Most are east of the Mississippi River. There are 370 records in Florida (certainly underreported) and 91% of those are in central and south Florida. There are only 33 records in the Florida panhandle but none of those are within the Six Rivers CISMA (Escambia, Santa Rosa, Okaloosa, Walton, Holmes, and Washington counites. There are four records from the Mobile delta, which lies in Baldwin County Alabama and is part of Six Rivers.
Description:
This is a submerged aquatic plant that will grow up to and across the surface of freshwater habitats. It can grow to lengths of 20 feet. Small whorled, saw-toothed, and pointed green leaves grow from the stem. Small solitary white flowers grow from extended threadlike stalks coming from the stems and resting on the surface. Can form dense mats at the surface.
Issues and Impacts:
The fast growing dense mats of Hydrilla block out sunlight needed by native submerged plants and cause their decline. These thick mats can reduce the natural flow of rivers and springs it invades altering the hydrology and ecology of the system, often reducing the dissolved oxygen levels. It has been known to clog irrigation and flood control canals as well as actually impede boating on some waterways.
The plant is extremely hardy being found in canals and ditches as shallow as a few feet to rivers, lakes and springs up to depths of 20 feet.
It is listed as a Florida Noxious weed and is prohibited from being sold.
Management:
Small infestations can be removed by hand or pulling out using a rake. The plant should be placed in a location where it can completely dry out and die. Those who can manage the levels of their lakes and ponds and draw down the water and kill the plant that way.
For larger infestations of lakes and springs, mechanical “mowers” can be used to cut and remove large areas of the plant. The removed pieces are then deposited into trucks on shore for further desiccation and disposal. Large mats not removed can increase hypoxia in the waterway. One issue with this method is fragments that are missed can generate into new plants.
There are six insects and one fish (Chinese Grass Carp) that have been used to biologically control the plant. However, establishment of these insects have been problematic. The Chinese Grass Carp do well on hydrilla but will feed on other aquatic plants and breeding populations could be a problem for the native ecology. Thus, only sterile triploid carp are allowed to be used and only with an FWC permit. Read more about these biological control agents at the reference below2.
There are several chemical herbicides that have had some success. For more information on using those, contact your local county extension office.
If you are in the Florida panhandle area and believe you may have hydrilla, please contact your county extension office to let them know and report the siting to www.EDDMapS.org. If you have questions on how to do this, your county extension office can help.
For more information on this EDRR species, contact your local extension office.
References
1 University of Florida IFAS Center for Aquatic and Invasive Plants. Hyrdilla. https://plants.ifas.ufl.edu/plant-directory/hydrilla-verticillata/.
2 Biological Controls. Plant Management in Florida Waters: An Integrated Approach. 2021. Center for Aquatic and Invasive Plants. University of Florida IFAS. https://plants-archive.ifas.ufl.edu/manage/control-methods/biological-control/.
Early Detection and Distribution Mapping System (EDDMapS)
https://www.eddmaps.org/
Six Rivers CISMA
https://www.floridainvasives.org/sixrivers/
by Rick O'Connor | Aug 27, 2021
Six Rivers “Dirty Dozen” Invasive Species
Mimosa (Albizia julibrissin)
Define Invasive Species: must have all of the following –
- Is non-native to the area, in our case northwest Florida
- Introduced by humans, whether intentional or accidental
- Causing either an environmental or economic problem, possibly both
Define “Dirty Dozen” Species:
These are species that are well established within the CISMA and are considered, by members of the CISMA, to be one of the top 12 worst problems in our area.
Native Range:
Tropical Asia
Introduction:
Intentionally introduced into the United States in 1745 as an ornamental plant. It was popular due to its showy flowers.
EDDMapS currently list 18,546 records of this plant spread across the United States. The vast majority are from the southeastern U.S. 3,323 records are from Florida and 944 within the Six Rivers CISMA. It is most likely under reported.
Description:
This is a small trunked tree with an expanded canopy that reaches about 40 feet in height. It is easily identified by the compounds leaves that can have 20-60 leaflets per branch. The flowers are a brilliant pink and resemble poms-poms. The tree flowers in spring and early summer. Seed pods are present in winter. They are about six inches in length and are light brown in color.
Issues and Impacts:
The primary impact is direct competition with native species. Mimosa does very well in open areas and along the edges of disturbed forested areas. It produces numerous seeds and can take advantage of available native habitats.
Management:
Mechanical removal of saplings is recommended before the plant goes to seed. It is important to remove all roots when pulling by hand to reduce the chance of resprouting.
Chemical treatments (herbicides) will be needed if cutting trees. A 2% solution of glyphosate, or triclopyr, can be used but retreatments may be needed. Application will require a surfactant and contact with the leaves will be enough. 15% Garlon 4, or 100% Pathfinder II, on the bark covering an area of 2 feet can be effective. Trees with trunks larger than 3 inches in diameter may require re-treatment.
There are no known biological controls at this time.
For more information on this Dirty Dozen species, contact your local extension office.
References
Early Detection and Distribution Mapping System (EDDMapS)
https://www.eddmaps.org/
Six Rivers CISMA
https://www.floridainvasives.org/sixrivers/
University of Florida IFAS Assessment
https://assessment.ifas.ufl.edu/assessments/albizia-julibrissin/.
University of Florida Center for Aquatic and Invasive Plants
https://plants.ifas.ufl.edu/plant-directory/albizia-julibrissin/.
by Rick O'Connor | Aug 11, 2021
EDRR Invasive Species
Green Mussel (Perna viridis)
This cluster of green mussels occupies space that could be occupied by bivavles like osyters.
Define Invasive Species: must have ALL of the following –
- Is non-native to the area, in our case northwest Florida
- Introduced by humans, whether intentional or accidental
- Causing either an environmental or economic problem, possibly both
Define EDRR Species: Early Detection Rapid Response. These are species that are either –
- Not currently in the area, in our case the Six Rivers Cooperative Invasive Species Management Area (CISMA), but a potential threat
- In the area but in small numbers and could be eradicated
Native Range:
Green mussels are native to the Indo-Pacific region extending from India to Southeast Asia.
Introduction:
Green mussels have been cultivated as an aquaculture product and were introduced to other parts of the world as such. They were first reported growing wild in the waters of the Caribbean in the 1990s reaching Venezuela by 1993. The first report in Florida was in the Tampa Bay region in 1999. They have been slowly dispersing south along Florida’s Gulf coast. In 2003 they were found on the Atlantic coast near Crescent Beach and the Jacksonville-St. Augustine area. That same year a few single specimens were collected off the coast of Georgia and by 2006 there were records in Charleston SC. There are only a couple records from the Florida panhandle. In 2008 a couple of specimens were reported in the Panama City area and one record in 2011 came from Perdido Key (this one may have been misidentified).
EDDMapS currently list 128 records of green mussels in the U.S. All 128 are from the state of Florida, though the USGS reports one from the state of Washington. There is only one record within the Six Rivers CISMA (that from Pensacola Bay region).
Description:
Mussels are sessile bivalves attached to the substrate using thin byssal threads. This is a large mussel, reaching lengths of 3-4” and some up to 6”. Its shell is not ribbed like our native ribbed mussel often found in salt marshes, but rather smooth and possesses a brilliant emerald green color. In larger/older individuals the green is found more on the margins of the shell with the rest taking on a brownish coloration. The inside of the shell resembles our native mussel in having a bluish iridescent coloration.
Issues and Impacts:
The primary issue with green mussels is fouling. Like zebra mussels, green mussels can foul boat bottoms, overgrow on marina pilings, and clog intake pipes for water treatment and power plant facilities. They can clog crab traps, shellfish aquaculture bags, and will displace native species such as oysters – making oyster restoration projects harder. There is evidence of predation by blue crab and sheepshead, but there does not seem to be enough predation to control populations where they are currently found.
Management:
First, check your boat hull and bilge water before trailering to another water body. It is recommended that you scrap the hull and empty your bilge on land so as not to provide any live material entering the waterways. Be sure you are removing at a location at the ramp where the animals, or even sections of the animals that may contain gametes, cannot reach the waterways during a rain event or other run-of situation.
Second, if found on a seawall or piling, use a paint scraper or flat shovel to remove from such. You want to collect AS MUCH MATERIAL AS YOU CAN into a 5-gallon bucket and remove from the water system. Again, any gamete material remaining could continue the population. At this point you can allow them to dry out and then dispose of.
Third, if in intake pipes there are several methods to remove but many are expensive and options depend on the system that is fouled. It is recommended that you contact your county extension office for advice.
In either case, it is important to report the record to EDDMapS – https://www.eddmaps.org/.
For more information on this EDRR species, contact your local extension office.
References
Dr. Shirley Baker, University of Florida, personal communication.
McGuire, M., J. Stevely. 2018. Invasive Species of Florida’s Coastal Waters: The Asian Green Mussel (Perna viridis). University of Florida IFAS Electronic Data Information System (EDIS). https://edis.ifas.ufl.edu/publication/SG094.
United States Geological Survey. Nonindigenous Aquatic Species Series. Green Mussel (Perna viridis). https://nas.er.usgs.gov/queries/FactSheet.aspx?speciesID=110.
Early Detection and Distribution Mapping System (EDDMapS)
https://www.eddmaps.org/
Six Rivers CISMA
https://www.floridainvasives.org/sixrivers/
by Rick O'Connor | Jul 27, 2021
Six Rivers “Dirty Dozen” Invasive Species
Callery Pear – Bradford Pear (Pyrus calleryana)
Callery Pear
Photo: University of Florida IFAS
Define Invasive Species: must have all of the following –
- Is non-native to the area, in our case northwest Florida
- Introduced by humans, whether intentional or accidental
- Causing either an environmental or economic problem, possibly both
Define “Dirty Dozen” Species:
These are species that are well established within the CISMA and are considered, by members of the CISMA, to be one of the top 12 worst problems in our area.
Native Range:
Korea and China
Introduction:
The Callery Pear was introduced to the United States in the early 1900s intentionally as an ornamental plant. Its fruits were sterile because they do not self pollinate and spreading was not an issue. New cultivars were produced to reduce the tendency of the tree to split when covered with snow, or in high winds. The ‘Bradford’, and other cultivars, have hybridized with the Asian Pear (P. betulifolia) and produced fertile fruit that have spread into natural areas and become an ecological problem.
EDDMapS currently list 6,112 records of this plant spread across the United States. 1,837 are listed in the southeastern United States and 164 of those are in Florida. All 164 are found within the Six Rivers CISMA in Santa Rosa and Okaloosa counties. It is most likely under reported.
Description:
It is a tree that can reach 50 feet in height. It grows very quickly and the branches are close together forming a dense round-ish canopy. The leaves are glossy, simple, ovate in shape, serrated on the edges, and alternate on the branch. It is a deciduous and will turn all sorts of colors in the fall. It produces a beautiful white blossom tinged in pink. It does produce an aroma that some find unpleasant. The fruits are round, about 0.5-1.0” in diameter, and golden brown in color. The bark is dark to light brown in color and very smooth to the touch.
Issues and Impacts:
The primary issue with the Bradford cultivar is the ecological problems it has caused in natural areas. The University of Florida IFAS Assessment considers it a high risk as an invasive species.
Management:
Trees should be cut down and stumps treated with either glyphosate or triclopyr products. Multiple treatments will be needed.
For more information on this Dirty Dozen species, contact your local extension office.
References
Callery (Bradford) Pear. Invasive Plant Atlas of the United States. https://www.invasiveplantatlas.org/subject.html?sub=10957.
Early Detection and Distribution Mapping System (EDDMapS)
https://www.eddmaps.org/
Gilman, E.F., D.G. Watson, R.W. Klein, A.K. Koeser, D.R. Hilbert, D.C. McClean. Pyrus calleryana, “Bradford” Callery Pear. University of Florida Electronic Data Information System publication.
https://edis.ifas.ufl.edu/pdf/ST/ST53700.pdf.
Six Rivers CISMA
https://www.floridainvasives.org/sixrivers/
University of Florida IFAS Assessment
https://assessment.ifas.ufl.edu/assessments/pyrus-calleryana/
