A Guide to Invasive Species of Corkscrew Swamp Sanctuary

Feeling inspired by National Invasive Species Awareness Week, I wanted to create a guide to invasive species of Corkscrew Swamp Sanctuary. Because there are many invasives that affect the sanctuary, I decided to focus on some of the most common, most problematic, or most managed species at Corkscrew.

What is an invasive species?

According to the USDA Executive Order 13112, an invasive species is a non-native species (including seeds, eggs, spores, or other propagules) whose introduction causes or is likely to cause economic harm, environmental harm, or harm to human health.

MAMMALS

Common Name(s): Wild Hog, Wild Boar, Feral Pig

Scientific Name: Sus scrofa

Origin: Europe, Asia, North Africa

Introduction: brought by Spanish explorers and settlers in the 1500s

Ecological Impacts: compete with native animals for food, consume native plants and animals, disturb soil and ground vegetation

Management Strategies: permitted hunting on private property and in wildlife management areas

REPTILES

Common Name(s): Brown Anole, Cuban Anole

Scientific Name: Anolis sagrei

Origin: Cuba, Bahamas, Cayman Islands

Introduction: first reported in 1880s, introduced by cargo

Ecological Impacts: competes with and consumes eggs and juveniles of the native Green Anole

Management Strategies: capture and removal, public reporting


AMPHIBIANS

Common Name(s): Cuban Tree Frog

Scientific Name: Osteopilus septentrionalis

Origin: Caribbean

Introduction: 1920s by cargo

Ecological Impacts: competes with and preys on smaller native tree frogs

Management Strategies: capture and removal, public reporting

FISH

Common Name(s): Brown Hoplo

Scientific Name: Hoplosternum littorale

Origin: South America

Introduction: 1950s, aquarium release and/or aquaculture escape

Ecological Impacts: possibly competes with native fish, consumes native invertebrates

Management Strategies: capture and removal, public reporting

Common Name(s): African Jewelfish

Scientific Name: Hemichromis letourneuxi

Origin: Africa

Introduction: 1960s, aquarium release and/or aquaculture escape

Ecological Impacts: aggressive behavior, consumes small native fish and invertebrates, may compete with native fish

Management Strategies: capture and removal, public reporting

INVERTEBRATES

Common Name(s): Island Apple Snail

Scientific Name: Pomacea maculata

Origin: South America

Introduction: 1980s, pet trade

Ecological Impacts: consumes native plants, competes with the native Florida Apple Snail

Management Strategies: collection and removal of adult snails and egg masses

PLANTS

Common Name(s): Melaleuca

Scientific Name: Melaleuca quinquenervia

Origin: Australia, New Guinea

Introduction: early 1900s, landscape ornamental

Ecological Impacts: fast growing, displace native plants

Management Strategies: regiment of prescribed fires, manual removal, herbicide application

Common Name(s): Old-World Climbing Fern

Scientific Name: Lygodium microphyllum

Origin: Africa, Southeast Asia, South Pacific islands, Australia

Introduction: 1960s, landscape ornamental

Ecological Impacts: dense canopies smother native plants

Management Strategies: regiment of prescribed fires, manual removal, herbicide application

Common Name(s): Brazilian Pepper

Scientific Name: Schinus terebinthifolius

Origin: Argentina, Brazil, Paraguay

Introduction: 1800s

Ecological Impacts: produces dense canopy which shades out other plant life, poor habitat for wildlife, alters natural fire regimes, related to poison ivy and may cause allergic skin reaction

Management Strategies: regiment of prescribed fires, manual removal, herbicide application

Common Name(s): Water Hyacinth

Scientific Name: Eichhornia crassipes

Origin: South America

Introduction: 1880s

Ecological Impacts: produces dense canopy on water surface, shades out native submerged plant species, lower dissolved oxygen concentrations, can increase flooding

Management Strategies: manual removal, herbicide application

POTENTIAL THREATS (no confirmed sightings at Corkscrew Swamp Sanctuary, but may become present in the future)

Common Name(s): Burmese Python

Scientific Name: Python bivitattus

Origin: South Asia

Introduction: 1980s, pet trade

Ecological Impacts: very few predators, prey on and reduce native species populations, prey on threatened and endangered species

Management Strategies: monitoring of bird and mammal populations, capture and removal, public reporting

Common Name(s): Green Iguana

Scientific Name: Iguana iguana

Origin: Central and South America, Caribbean

Introduction: 1960s, pet trade

Ecological Impacts: consumes a wide variety of vegetation, considered a nuisance by property owners, burrows can damage infrastructure

Management Strategies: capture and removal, public reporting

Common Name(s): Argentine Black and White Tegu

Scientific Name: Salvator merianae

Origin: Argentina, Brazil, Paraguay, Uruguay

Introduction: Early 2000s, pet trade

Ecological Impacts: preys on native species, consumes the threatened Gopher Tortoise juveniles

Management Strategies: capture and removal, public reporting

HOW CAN YOU HELP?

Volunteer at Corkscrew Swamp Sanctuary

At Corkscrew, removal of non-native plants and animals is an ongoing process. One way you can help is to volunteer with our resource management team. 

Be a responsible pet owner

Before buying an exotic pet, please ask yourself a few questions. How big will this animal eventually get and what does it eat? Will you be able to care for this animal for the length of its life? If you have an exotic pet already and are no longer capable of caring for it, please don't release it. There are hobby groups, local museums, zoos, pet shops, and other programs that can assist. For additional help, contact FWC's adoption hotline at 888-IVE-GOT1.

Educate yourself

Educating yourself and others on the invasive plant and animal problem is also a great way to help. Another avenue is contacting your local, state, and/or federal representatives and voice your concerns about the impacts invasive plants and animals are having. To learn more about the Audubon Florida's efforts in the war on invasives, please visit the Florida Invasive Species Task Force page. 

Report sightings

-Amy, Education Intern

Additional resources: Corkscrew Swamp Sanctuary Invasive Species, Florida's Nonnative Fish & Wildlife, USDA National Invasive Species Information Center

Newest Intern- Kendall

Hello Everyone!

My name is Kendall Williams and I am the newest Corkscrew Conservation Intern! I am very excited to be here.

I am originally from Tampa, FL and I just graduated from the University of Florida in December of 2018 with a degree in Wildlife Ecology and Conservation. Throughout my time at UF I did some really cool things. I took a class that was all about learning wildlife techniques such as the capture of mammals, herpetofauna, and birds, and how to perform vegetation surveys. One of the highlights of this class was catching alligators off an airboat with my bare hands! This class was the thing that cemented in my head that conservation was what I wanted to do. It also opened my eyes to my true passion: Fisheries. This passion hit me so hard and so fast that the next week I had added a Fisheries and Aquatic Sciences minor to my degree. The dream right now is to work on freshwater fish in the pacific northwest of the United States.

Another cool thing I was lucky enough to do while at UF was study abroad. I went to Melbourne, Australia for a semester and absolutely LOVED it. I took mostly classes that pertained to my conservation major but also took an Australian history class that was very interesting. I traveled around the country a lot, including to Brisbane, Sydney, Cairns, Uluru, and camped under the stars in the Australian Outback. I made many good friends and many great memories. It was a trip I will never forget.

Although college and UF was a great experience, I am excited to be in the workforce and focusing on the conservation work performed here at Corkscrew. I can't wait to see where these next six months will take me!

Thanks!

Kendall

Beyond the Backcountry

One of the many rewards working for a great organization such as Corkscrew is their partnership with other conservation groups! Through the sanctuary's relationship with Rookery Bay Reserve a few other interns and myself had the opportunity to go shark tagging as well as trawling with the reserves fisheries biologist. Shark tagging involved going out about two and a half hours before sunset to get into the bay were we would be setting up our longlines and gill net. The first photo below is a gill net, a large net hanging from a line with buoys on each end and smaller floats along the length of the net to keep it at the surface of the water. The longlines are pretty much the same except instead of a net hanging from the line there are baited hooks. The deployment of these two devices is very similar. From the back end of the boat you set the anchor located on one side of the line, as the boat moves forwards you slowly let out the line or gill net making sure they are not twisted.  We set the gill net between two baited longlines. 

Once your survey equipment is all set up you sit and wait, constantly checking to see if any of the floats are bobbing or underwater. This means that something is either caught in the net or on the line. We wanted to be able to know exactly when a fish got caught so that our reaction time was quick and they wouldn't be struggling on the line or net too long helping to prevent injury and stress. After seeing a float go under, we approach a few floats away and grab the line on top of the water, slowly lifting each portion slightly out of the water to check and see if we had anything caught. Not 10 minutes after being out there we caught a smalltooth sawfish! Now, we had to be very careful when bringing this endangered species on board because they could cause injury easily with their rostrum. The sawfish was placed into a kiddie pool on the boat that was prefilled with saltwater. This is so the gills can be kept underwater allowing them to breathe. A few measurements were taken and a tag was inserted just below the dorsal fin, then the 6 foot sawfish was released back into the water a little ways away from the gill net and longlines to avoid recapture.  

After processing a captured fish the protocol is to recheck the gill net starting at the end and lifting the net up out of the water working your way through the entire length. This is to make sure no other animals were captured while processing your previous catch. Nothing was found in the gill net and none of the longline floats were down so we went back to waiting. About a half an hour before it was time to start bringing in all the equipment excitement struck! One of the floats on the gill net was frequently moving up and down. As we checked the net we found a juvenile lemon shark! This catch was exciting because after we got him into the pool we were able to see he still had his umbilical cord scar, meaning this little was only a few months old! Due to the presence of the pool this lemon shark was able to swim around in circles keeping water moving over its gills reducing the stress of processing. Again, the shark was measured and tagged before being set free and bringing an end to our evening! but not before posing for a quick snap shot :)