We are hear at the L31W canal. It is a canal that borders Everglades National Park. And, what we see in this area is a large aggregation, a big school of these Brown hoplo catfish. These are an exotic catfish from South America. They were first found in Florida in 1995. And, in 2002 we first collected an individual in Everglades National Park. They got to Florida, not exactly sure if it was through the aquarium industry or if it was specialty food market, aquaculture industry, or people releasing them to create a place where they could catch fish that they would like to consume. It would be nice to remove them because of the proximity of the canal to Everglades National Park marshes and because the canal will overspill the marsh during the wet season. So, in the wet season, this will overflow and flood into the marsh and you know, these are not native to the marshes of Florida. In Everglades National Park, we are trying to preserve for the native and natural and having the exotic species is against what the national park is mandated. We are about 15 meters from the Everglades National Park boundary. So, very, very close.
A tour guide recounts the cultural history about Watson Place, a ground site for picnicing and camping along the Wilderness Waterway on the Gulf Coast (3:21 minutes).
I have been in Florida for…just starting my eighth year. And, I have been working exclusively in the national park for about three years now. I am part of an operation called Everglades Area Tours. There is a couple of us that work for it. But, it is all basically a educational based kayak tours. We try to make sure that everyone leaves here realizing that the national parks are a little bit more than sawgrass, airboats, and alligators. Because that is what most people expect whenever they get here. You know, ‘When are we going to see the park?’ Dude, you are in it. Well, we are hanging out at Watson’s Place having lunch. This is a relatively popular campsite on the Chatham River. You see a lot of people using it in transition between the outside and the inside campsites. Historic site because it was basically a well-known sugar cane plantation. This whole side to the left was all basically clear-cut and slash and burned and turned into a nice sized sugar cane plantation. Then, the gear over here, basically the plantation home would have sat behind us where the picnic tables are. You know, just a beautiful, beautiful plantation style home, you know, monstrous. Yeah, he had a Model-T that he would put the truck back here by the cane mill and had a big strap that ran off the axle. And, basically, when he ran the vehicle, it would turn the mill and mash up the cane. And, then it would be transported over to the boiler. And, then there it was boiled down and reduced to, well, syrup…like karo. Then, it was taken to Smallwoods because Smallwoods store was the major social hub, the political hub… Well, if you wanted to buy or sell anything, that is where you had to go. So, everything was transported there and then down to the Keys eventually where Flagler had completed the railway really, really early on. So, the cane syrup that came from here in a day and a half would be in Key West probably. And, another two days later, it could possibly be up in New York City. So, a pretty fast rotation. But, the way the story goes, Edgar Watson who owned this plantation was a notorious gunslinger that was popular for killing Belle Starr, a brothel owner in the Midwest. He got acquitted of the murder and came down here. Started the sugar cane plantation and well, I guess he could not get rid of his gunslinging tendencies. There was a group of guys that called him ‘The Barber’, actually. Because they came down here to arrest him one time and he started taking shots with his pistol and trimmed off somebody’s handlebar mustache. So, it was like a running joke in Everglades City that Edgar Watson was ‘The Barber’. But still, nonetheless, a pretty brutal gunslinger. Rumor has it that he had a couple of workers locally that he had killed and thrown into the river here. And, well, Chokoluskee justice system prevailed: He brought his cane syrup in to trade it at Smallwoods and they shot him dead right there in the store. And then, actually what I heard, drug him by boat to Rabbit Key, buried him on Rabbit Key. And then, the state of Florida later came and exhumed the body and moved him to Ft. Meyers and put a statue up and everything. Which I guess that is how you become popular in Florida: Shoot your workers and throw them in the river.
Alex Wolf gives a presentation about Burmese python natural history, research, and management at the Fairchild Tropical Botanical Garden in Miami, Florida (24:21 minutes).
Thank you. First of all, I would like to thank Jeff and Hillary for giving us a lot of background information on the park and on invasive species. It makes my job easier. I am going to be talking about pythons today, particularly Burmese pythons. Obviously, Burmese pythons are a hot topic. They garner a lot of attention because of scenes like this. I think this photo is from Shark Valley. It was taken in the last year. This is an American alligator, native, eating a Burmese python which is a nonnative. Burmese pythons are large constricting snakes. They are natives of Southeast Asia. There is one species, Python molurus and two subspecies: molurus molurus and Python molurus bivittatus. And bivittatus is the Burmese python. Python molurus molurus is the Indian Rock python. Burmese pythons are found more in Southeast Asia and Indonesia whereas the Indian Rock pythons are more northern India, more arid species. Burmese pythons are thought to be able to reach more than 20 feet. They can grow to about 200 pounds and they have been documented at about 19 feet. They mate, at least in Florida, they mate from February to March and they lay eggs from May to June. The eggs hatch in July and August after about sixty days or so of being laid. And, this is a species that grows extremely fast. They have a very fast growth rate, growing or averaging 75mm for each month that they are alive for their first year. And then it slows down to about 40mm per month through maturity. So what that translates into is that a hatchling is about 18-24 inches and they can reach 4-6 feet within the first year of their lives which is bigger than a lot of our native snakes. They are considered a trophic generalist which means that they eat a wide range of taxonomic groups and a large size-range of prey. Obviously growing from 18 inches to 24 feet changes what they are eating. But, as a whole the species eats many different sized species. And they can eat meals that are up to 80% of their own body weight. Where did Burmese pythons come from? Obviously they are native to Asia so how did they become established in Florida? The main thing that we think led to their establishment was reptile extravaganzas like Repticon which is an event held in Florida every year. These are basically pet trade related shows. You can see that there are many, many snakes for sales to whomever would like to purchase them. This is a baby Burmese python right here. And certain vendors are not always completely forthcoming with knowledge of the species that they are selling. So, they will sell an 18 inch Burmese python baby to somebody who does not realize that the snake is going to get to 20 feet, or even 10 feet in the first two years of its life. In terms of South Florida, the number of pythons removed over the last few years has grown exponentially. I think there was one found in Everglades National Park in 1979 which at that point was believed to be released or an isolated incident of some sort. And, in the early 2000’s, you can see that the numbers picked up drastically and they have been going up every year. It really seems to be a population explosion as far as we can tell. Each dot on this map represents a place where a Burmese python has been recovered from. You can see the areas along the Eastern boundary of the park, Main Park Road, Tamiami Trail and the Shark Valley area are all pretty thick with pythons. In addition to the 18-mile stretch down to the Keys. And, this is just a blow-up of the area of interest. What is especially notable is, again, this line of python findings that go down Card Sound Road and US1 into Key Largo. And, I will get into why that is significant later. But, you can see at least 7 confirmed pythons found in Key Largo in addition to one found down here in Summerland Key. The Frog Pond Agricultural Area is a state-owned area that is immediately outside the East entrance of Everglades National Park. It is leased as farm land. So, it is farmed every year. They usually grow from roughly September through May or so, depending on conditions. They let the fields go fallow so every September, they will come and plow over all of the fallow fields. And, they kill large numbers of pythons every time they do this. In 2005, that number was 22 and you can see it has gotten larger over the last few years. And this is significant not only because of the numbers that we find but also because of what is done to the land. You can take a plot of land where there are a lot of pythons and you can mow down all of the vegetation so that it is bare earth and essentially kill all of the pythons that are there. And the next year, they seem to come back in full force. This is an aerial view of the L-67 extension canal which extends southwest into Everglades National Park from some of the Water Conservation Areas that Jeff was talking about. Here is Skip Snow and Lori Oberhofer who are two park biologists. And, they recovered 6 pythons off the L-67 extension levee in one day. These are semi-aquatic snakes and so they like swimming a lot. They are very proficient swimmers. And these canals as far as we can tell just provide highways for them like a lot of the nonnative fish. So, they are really able to expand throughout the region. And they also, as Jeff mentioned, provide thermal refugia. They provide a place for these snakes to go when the weather gets cold, when we have these cold snaps coming through. They can come out and bask on the berms and then dive into the water and they have fairly warm water as a reserve as well. And that also allows them to escape predators and any people that might be trying to find them. Again, this is a retention area on the eastern boundary of the park which Jeff talked about a little bit. And the roads that go along these berms are mowed periodically as well. You can see a python that got chopped up by the mower there. And from the mowing we know that pythons occur in pretty high concentrations along these areas as well. And, one possible reason for that is the farmland that is along the Eastern boundary of the park we think may provide a lot of food for rodents which then allow python populations to expand as well. This is a picture of a python mating ball that was found on one of the berms around the outside boundary of the park. There are actually three pythons in this picture. They are kind of hard to make out. And usually you will have one female python and then several males trying to mate with her. And they form these balls. Captively, the males are known to have male-to-male combat for breeding competition. And then they will all try to get with the female essentially. This is a copulating pair which is again a little hard to make out. So, we have added these lines here. The pinkish color is the female and the bluish color is the male. You can see that the male is on top of the female kind of pinning her down. And then this is his tail flipped over as they are mating at the back end there. So these pictures were all taken as I mentioned on boundaries of the park. So, we know that they are mating in South Florida. Additionally, this is a picture of a large female that was dissected in Everglades National Park. She was found along one of the levees as well. She has 59 eggs, 58 of which are fertile. And these eggs are pretty big, much bigger than chicken eggs for instance. You can see one of the fertile embryos up in the corner there. So again, further evidence that they are fully capable of reproducing in South Florida. The first confirmed python nest was found in the Nike Missile Base area of the restoration, the Hole-in-the-Donut restoration area in the park. So, this is a female. I think there were 44 fertile eggs out of 46. So, again confirmed evidence of nesting in the park. We found another nest along one of the canal banks last summer again with fertile eggs. Both of these females were removed and the eggs were removed as well. But, it is pretty clear evidence that they are breeding in South Florida. So, what effects are they having on the environment? It is, as Jeff mentioned, kind of hard to assess without a lot of research. But, we have been doing dissections on all of the snakes that we recover and were able to remove a lot of hair and feather fragments from the guts of the pythons. And, that allows us to identify what species or at least what families they are eating. So, this is a list of all the mammals that pythons are known to eat in South Florida. The Key Largo Woodrat is found in Key Largo, obviously. It is a federally endangered species and there are only 100-200 individuals left in the wild. They are only found in Key Largo. They discovered that pythons were in Key Largo because they were radiotracking some Key Largo Woodrats and they tracked one to a python stomach. They opened it up and actually found two woodrats in there. And I think the total count if five woodrats have been eaten by pythons since they have been established. And when you have a population of only 100 animals, a loss of five animals is pretty significant. The most common prey items that they eat are the Hispid Cotton Rat, Old World Rat, Round-tailed Muskrat, rabbits are all found very frequently in python guts as well as the other species you see here. I’d like to point out the Mangrove Fox Squirrel is a Species of Concern for the state. And then you will notice that pythons have been documented eating White-tailed Deer and Bobcat. So you can see that they are pretty formidable predators and they can take species from a rat to a White-tailed Deer so it is a very wide range of prey. This is a list of the birds that we have confirmed pythons to be eating in South Florida through gut samples. A lot of this work is done by Dr. Carla Dove, down here. She is up at the Smithsonian Institution in Washington DC. And, we are able to remove feather fragments as well as beaks from these animals and send them up to the Smithsonian to be identified which has been tremendously helpful. The species in the upper left, the Pied-billed Grebe etcetera are some of the most common species eaten by pythons. And, again, the species in white are species of state concern and species in red are federally listed as endangered. So, we did find one Wood Stork feather in one of our pythons that we recovered. So, again, we know that they are eating endangered species. Obviously, one of the things that people really love about the Everglades is all the wading birds and the water birds. And, you can see an abundance of all of those species up here on the list. These dots represent where in the park we have found pythons that have eaten birds. So, again, you can see that there are dots occurring all across the landscape. Predominantly, they are on places, like Main Park Road, Shark Valley, Eastern boundary where people tend to be. There are no roads out in the West side, you know the West coast of the park. So, people are not back there very much. But, from the few people that are out there, there is actually a fair number of python sightings. So, we have reason to believe that they are found throughout the park. So, what can we do about it? Well, we are trying to learn as much as we can about these animals. One way that we do that is through the gut content analysis. Another way is through radiotracking, or radio telemetry. What we do is implant two radiotags into each python. And, we do two as sort of a redundant system so that if anything malfunctions with one of them, we have another way to recover these animals. And, one of the things that we can learn from this is which types of habitats they are using, how far they can travel in a given period of time and that sort of thing. These pythons also lead us to breeding aggregations of pythons, these mating balls that I referred to earlier. So that we can release a male with radiotags and the males are very good at finding females. And, of course, the female will have lots of other males around her so that can actually allow us to remove several pythons just by letting one go. As you can see, it is a pretty expansive landscape and there is some very hard territory. So, it is a real challenge getting to some of the backcountry areas in the park. As Hillary mentioned, it is 1.5 million acres so it is a lot of territory to cover. These are the pythons that we have been radiotracking in the last fiscal year. And, you can see that some of them, like python #12 here is a female, they have pretty significant ranges across the park. So, they can travel wide distances. And, we actually had her for awhile. She was on the island in Paurotis Pond for those of you that are familiar with the park. And that is a known roosting and breeding site for Roseate Spoonbills and Woodstorks and some of the other wading birds that people love so much. So we have reason to believe that they could have serious impact on some of the wading bird species as they are roosting in the park. This is just a brief summary of some of the different movements of the tagged pythons for the past year and just what I want to point out quickly is the total distance traveled in meters. So, you are looking at 26 Km traveled in a year so again, they really move across a wide range of the habitat. They will use pretty much any habitat that they can find. We found them in the marsh, in the pinelands, in mangroves. They seem to pretty tolerant of saline conditions as far as we can tell from the mangrove snakes that we have been tracking. So they seem to be very widespread and very capable of moving across the landscape quickly. This is a summary of what types of habitats they seem to be using the most as far as we can tell. The forest and scrub areas are both areas with a lot of woody vegetation and some canopy cover such as tree islands and mangroves. And, in terms of the marsh, they seem to hang out a lot on tree islands and we think that they may be going out into the marshes, or the prairies in order to feed and then coming back to the tree islands which tend to be a little bit drier for things like basking and breeding. Another thing that we are doing to try and learn more about these animals is implanting temperature dataloggers into each snake that we radiotrack. You can see that here is a US quarter and this is the size of the datalogger that goes into the snake. And this gives us really valuable data about what kind of temperature tolerances that they have. Jeff mentioned the effect of cold snaps on some of the native and nonnative fish. And, we have this same issue with pythons. What we have found is that they are actually quite tolerant of the climate here despite being predominantly tropical species. You can see the blue line is water temperature that we monitor in the marsh in the park and the yellow, green and pink are pythons. And then the gray line is air temperature. So, you can see that the air temperature can dip down quite cold. Zero degrees celsius is freezing so this is, you know, the air temperature is right around five degrees, little bit above freezing. And the pythons that were out during this period stayed well above that in their comfortable range. So, there is reason to believe that they are pretty tolerant of the cold snaps that come through in the winter. One of the control methods and detection methods is thermal imaging. Because these snakes are cold-blooded essentially, there is hope that when they do display different temperatures from the environment that we might be able to detect them more easily that way because they are so well camouflaged otherwise. Another control method that we are working on is trapping. These are all different trapping prototypes that we have constructed over the past few years. And something that we are working on is trying to figure out an effective way to trap these pythons so that we can remove them from as many places as possible. And some of the real important things that we are interested in protecting are the wading bird colonies that I mentioned earlier and the Keys, the Florida Keys have not only the Florida Key Woodrat but Key Deer and a number of other endangered species. So, if we can, at the very least, keep pythons out of the Keys, stop them from extending to areas further north, that would be great. So, that is what we are hoping for with our trapping systems. One of the things that we are doing with our traps is that we have constructed a large enclosure. This is about 100 yards by 100 yards long and we have actually released radiotagged pythons into this area with traps so we can see how they interact with the traps and try to improve our traps as much as possible. Another very important thing that we are doing is environmental education, public awareness, and early detection things. The Florida Invaders website, FloridaInvaders.org, is a great resource for all sorts of invasive species. And, this is a campaign that we have started to try to get awareness out about the issues that are involved with invasive species in South Florida. And, we are trying to develop curricula for schools as well so we can go out and educate children on what some of these issues are. And, another model that we are trying to push forward is this early detection, rapid response model that has been pioneered by the US Geological Survey and The Nature Conservancy down in the Keys. And, what they have done is essentially set up a network of responders, people that are trained to identify and respond to large constrictors in the Keys which is what led to the Summerland Key python being captured, actually. So, that is a system that we are trying to expand to areas farther north of the Everglades so that we can try to stop them from spreading north as they move northward. Can pythons also eat alligators? Good question: The question was ‘Do pythons eat alligators’? As you saw in the first picture, we definitely incidences of pythons eating alligators. We also have a few incidences of pythons and alligators sort of getting into a struggle with one trying to eat the other. And, they have both eventually given up and gone away. But, we know that pythons definitely do eat alligators. And, we know that from the gut contents that we have been recovering from the euthanized snakes. We are looking into figuring out how big of a python it takes to eat an alligator. But, we know that it happens. There is a lot of concern about what kinds of competition pythons are going to provide not only to alligators but also to the American Crocodile which is an endangered species. And then, if there are no other questions, I actually have a small python with me here today. I guess I will give everybody a chance to, anybody that would like to, move to the back of the room or the exit…you are welcome to. I am going to have it under control at the front. How old is he? We are not sure. This is a python that was caught in the wild but best guess is probably a year or two old, probably closer to one year. It is hard to judge the size between the snake and the alligator. Not as big as an Anaconda though!? The larger ones can actually get pretty close to that… I mean, they are amazing creatures. It is a shame… It is ticklish? Little bit, yeah. Oh, wow! Oh my goodness, how old is this one? This one is probably about a year between one and two years old. I was measuring it in my eye. I have seen it from end to end. They tend to be sort of uncomfortable with being handled. This is a snake that was caught in the wild. So, he is probably terrified right now. He has calm down a little bit, partially because he is cold with the air conditioning. And, he is holding his breath. But, you have a good grip on his head, too. If I let him go, I am sure that he would bite me and then make a dash for the door. Oh, so he would bite!? Yeah. It is funny that I have been going in and out of the park, and I have seen deers, I have seen panthers… I have never seen a python. They are very, very hard to see. You want me to hold the baggy? It is a laundry bag. It is. It is a laundry bag but it needs to be opened up more. You pull this little thingy? How much room can he have or does he need? You put his tail in first? Yep. So, it was born into the wild? Yeah.
The park fish biologist gives a presentation about nonnative fish research and management at the Fairchild Tropical Botanical Garden in Miami, Florida (37:04 minutes).
OK, so here we go, here is Jeff. Hi. Well, as she said, I have been working at Everglades National Park for ten years now. And, a good portion of our work revolves around the nonnative species that we have. Before I jump into the nonnative species, Hillary gave a good background on some of the management mandates of the park and I will touch on that just a little bit too. But, jump a little farther back to what the pre-drainage Everglades was estimated to look like. It was this large-scale free flowing wetland that went from the south end of Lake Okeechobee from where it would overflow down to the Gulf of Mexico. And then you have your coastal ridge down here. And, it was changed by urbanization to have a large urban area on the eastern coast along the Atlantic Coastal Ridge. A big portion of this northern area of the Everglades was converted into the Everglades Agricultural Area. Lake Okeechobee was leveed so it no longer overflowed. The Everglades was broken up into a series of reservoirs now called Water Conservation Areas. So, this is Loxahatchee National Wildlife Refuge, Water Conservation Area 2, Water Conservation Area 3. It was also dissected and drained by a series of canals both across the Everglades but also through the urban areas to provide for drainage. And, Everglades National Park is positioned at the very southern end of this system. Everglades National Park’s mandates as Hillary was mentioning is to preserve the flora and fauna in the natural state. That is what Everglades National Park was established for. And, in 1989 with the Expansion Act, this mandate was reinforced to maintain the natural abundance, diversity, and ecological integrity of native plants and animals. So, it is really well-defined that we are working for native and natural with Everglades National Park. So, some of the native freshwater fish, there is about 25 species. Nothing like the thousand plant species that Hillary was talking about. But, there is about 25 species of native freshwater fish. And, I say about 25 because there is some brackish fish that get up into the freshwater areas and some freshwater fish can be down in the brackish water area. So, there is not necessarily a clean, defined line there. But the majority of the species are generally small. Most of them are composed of the killifishes and the pupfish, this is a Jordanella floridae, it is the Flagfish. Sunfishes, particularly smaller sunfishes like the Dollar Sunfish and the Spotted Sunfish. And then the live bearers: Sailfin Molly and Mosquitofish. And then you also have, there is a few big fish that you get but they were probably were never at a huge number within the Everglades but they were always there: The Largemouth Bass and things like the Florida Gar. Well, so we have this native and natural mandate but we also now have nonnative species within Everglades National Park. Oh, just wanted to say that there are 16 nonnative species that have ever been found in the park. They are not all established. Some of them have only been observed once or twice. But there have been about 16 found. Probably about 12 or 13 species are reproducing in the park. The largest family of nonnative fish in the park are the cichlids. These are common aquarium fish. Also, Tilapia. Tilapias are cichlids and they are in from aquaculture. And then the Peacock Bass is also a cichlid. Of the nonnative fish that I have found in the park, these two were the most common: The Spotted Tilapia, this is a juvenile form, the juveniles have the stripes. When they get a little bit larger, the stripes kinda disappear, and you will just have spots that run down the center of the body there. And, the African Jewelfish is also pretty common. That is a pretty small fish. It is a little bit harder to see you. You have to really look close on the edges of the pond, right at the water and the rocks and you will see some of these little guys in these ponds. There are a variety of other families in a variety of forms. You have Armored Catfish, Asian Swamp Eel, Spotfin Spiny Eel, Walking Catfish, a live bearer, the Pike Killifish. So, there is a pretty good diversity of species that are in there. So, how did these nonnative fish get into South Florida and then specifically, Everglades National Park? Well, some of them were unplanned. South and Central Florida, there is a lot of aquaculture, a lot of ornamental fish farms and we have flooding here associated with storm events. So, there has probably been incidences where these aquaculture farms overflowed and connected up to the canal system and fish got in that way. But also, purposeful releases, people sometimes just purposefully release their pets. It is either their pets or from the fish farms. People don’t necessarily know that if they release their animal, it may persist in the environment and build a population and cause a problem later on. There is also some specialty food markets. For example, the Asian food markets often tend to sell live fishes. In this case, this is from California, it has some Channel Catfish and some Mirror Carp. Both of these are not native to California but you could buy them. And there is some suggestion that possibly in some cultures that people would buy two fish and then release one for karma. I am not sure how true that is. But, I have read that in newspapers. There has also been planned releases. Some releases, like the Peacock Bass… It was released by the state of Florida to promote an urban fishery. But also within their justification for it, they claimed that it would feed more on nonnative fish than native fish. Well, the screening for the Peacock Bass was not as strong as the screening for the insects that are released for the plant control. The plant control insects, they are very strenuously studied to make sure they don’t feed on anything but that specimen. The Peacock Bass, it will eat native fish, there is no doubt about that. They also released Grass Carp in the Florida canals to help control vegetation. So, why are these nonnative fish successful? Well, a lot of the fish in the Florida canal system and in Everglades National Park are from a tropical climate. And, South Florida has these wonderful, nice, mild winters that…it does not get very cold here. So, you have that on top of a wet and dry season cycle which is different than what a lot of the native species are originally adapted for. The native fish species are all from the north. They are all temperate-derived, mostly from the southeastern United States. And, these tropical species, they are very well adapted to the wet and dry season cycle where we have a wet season where water overflows the marsh, everything is connected up. And then you have the dry season where in some areas of the park, the water drops below ground surface. You might just have these caverns, in this case, solution holes that hold water throughout the dry season. These nonnative fishes tend to be dietary generalists meaning they can feed on all sorts of different things, be it invertebrates, other fishes. Some of them are able to consume other vegetation or dying plant material and grow from that. They also tend to be very tolerant. This is an example of the Armored Catfish, the Brown Hoplo. It is able to breathe air. I found this…this is a drying pool out in the marsh. And within the center of this last little bit of remaining water was all these Armored Catfish in this slurry of mud. And they were still alive which was absolutely surprising to me. I don’t think they lived too much longer because this was early in the dry season and they dried out. But, it just shows how tolerant they can be. They are also fairly tolerant to the poor water conditions that you get within those isolated pools of water that remain. They are a little bit better at handling the poor water than some of the native species. And then there is also advanced parental care. A lot of the species have nest building and they tend to be very aggressive at guarding their fry. Cichlids are well known for guarding. In this case, this whole cloud over here are the fry of these two, the female and the male Jaguar Guapote. So, there are suggestions that there could be some competition with the nonnative fishes and the native fishes for spawning habitat. And, finally there is a lot of disturbed habitats in South Florida. You have canals that provide both the deep water habitat that some of the larger fishes need. What the canals do, and I’ll show this in the next slide, is that they are deep enough so that they don’t get cold during the winter time. And, this enables a lot of these nonnative fish to persist even during the coldest winters that we have. The other thing about the canals is that they are very well interconnected to help the drainage system in South Florida. And, they are connected directly into Everglades National Park in some areas. So, the canals themselves are potentially corridors for dispersal, kind of like a highway where fish can disperse through South Florida. I just wanted to highlight quickly some of the changes in water management which may have contributed to some of the inputs of nonnative fish into the park. For about twenty, twenty-five years prior to the end of 1999, basically 2000, in this Eastern area of Everglades National Park, they had a system where water would passively flow into this L-31W canal here and be pumped directly onto the marsh into Taylor Slough. And this is Main Park Road right here. These are the first bridges that you come across. This is the road down to Royal Palm. So, they would pump directly onto the marsh from this canal. Well, that is kind of a bad thing because it creates an artificial way for the water to come in. It all comes in at one point. It creates vegetation disturbance. So, the goal was to change this and to create a sheet flow system, that large-scale, shallow flowing marsh. So, what they did was they stopped operating the 332 pump station. Closed this gate here and began pumping at this new pump station up here, the 332 D. What this did was result in raising the canal levels and the canal had more direct connection with the marsh. To highlight that a little more, to zoom in on an actual picture: This is that 332 D pump station. They pumped it into this retention area. And the retention area functions to raise the water level which raises the water canal level. And you get that marsh-canal connection. So, after we see those two management actions happen, we start seeing an increase in the number of nonnative fish. So, this is the timeline of the nonnative fish from 1979 to the present. And we note that once they have this change in water, we have a pretty dramatic increase in the number of nonnative fish after a pretty long period where we had not had any new species coming in. Interestingly, in the late 70’s was a time when the central and south Florida canal system was completed and that provided the connection of a lot of those canals to Everglades National Park. That might be one of the reasons why we have an increase in the number of species coming up at that point. So, how do we monitor the fish in Everglades National Park? There is a combination of sampling programs both within Everglades National Park but with our cooperators, external agencies like USGS, Florida International University, Florida Audubon Society, they all do quite a lot of monitoring and fish-related projects. We use active methods: Throw trapping, electrofishing, drop traps, but also some passive methods: Minnow traps and traps with drift fences and then just visual estimates are pretty useful. Sometimes you can see a fish out there before you can even catch it. And then, opportunistic things like this Cormorant at Anhinga Trail just happened to be out there one day and it grabbed this Spotfin Spiny Eel and it was having so much trouble getting that eel down because it is so squirmy that it crawled up out of the water and onto the bank and up onto the sidewalk to consume it. I wanted to highlight one of the projects that we do. We do a park-wide fish sample one time a year to try and get an estimate of the distribution of fish. For this, we have 50 sites that were placed on a grid. And this grid was placed randomly on Everglades National Park. And then we also have a series of sites along areas where we have inflows, I call these targeted sites, where we are interested in seeing specifically what fish are associated with those areas. So, in 2005, this map is the number of exotic species and the dots are scaled from the small black to being no exotic species collected to the largest dot for exotic species collected. And if we look at the distribution at the number of the exotic species collected, it covers quite a bit of area of the freshwater area of Everglades National Park. But, we see the majority of the highest number of species tend to be associated with these Eastern boundary areas at the L-31W canal, the C-111 canal. Also, associated with the inflows on the northern edge of the park from the L-29 canal up there. So, we have these two new species and then, in 2004, Audubon collected the Spotfin Spiny Eel down here. And then the most recent fish to the park is the Asian Swamp Eel and that was collected in 2007. Subsequently, this Spotfin Spiny Eel has been collected in other areas of the park and the Asian Swamp Eel, we are picking it up in a few more areas. But, at the moment, still associated with this area. I wanted to highlight to, two others of the new species. The African Jewelfish is from Central and West Africa. It is generally a small fish, less than 12 cm, a generalist carnivore eats fish, invertebrates. It has been in Florida since the 1960’s and the Coral Gables area is where it was first found. It was first collected in Everglades National Park in August, 2000. And, we have the Jaguar guapote. And it has a little bit of a contrasting story to the African Jewelfish. It is from Central American, it is a large fish, it can get over a foot long, it is a carnivore. It was first in Florida in the early 1990’s but then rapidly collected in Everglades National Park by August of 2000. Now, that is kind of an interesting point when I look at the distribution of these fish. In 2000, the African Jewelfish was collected up here in the Chekika area on the marsh there is a canal that runs along the road up in here. The Jaguar Guapote was first collected down in this Taylor Slough area and as the year progressed, we subsequently collected it out further to the west. In response to some of these new nonnative fish, we started to add some sampling effort. So, these maps are just to show what happened. The red, the fish was caught, the white, the fish was not caught. By 2004, the African Jewelfish had really expanded in the park to also include over on this western side. Whereas the Jaguar Guapote still only associated with this canal habitat. To highlight it from our 2007 sample, the African Jewelfish continued to expand. This is the number of African Jewelfish from zero, the small black dots, to greater than eleven fish caught at the site. So, real high populations of this fish down south of Main Park Road but also up here in the Chekika area where it started out, pretty high numbers. So, the African Jewelfish really spread out. I don’t have a map for the Jaguar Guapote in 2007 because we didn’t collect it on the marsh. We know that it is still in the canals. It is even in the canals up in this area. We have seen them in the L-67 and in the Shark Valley tram road canal. But, it is not persistent or really doesn’t seem to get in the marsh as much as the African Jewelfish. So, that was kind of an interesting comparison between the two species. You have this fish that has been in Florida since the mid-60s, takes a long time to get into the park, but when it is in here, it is spreading out like wildfire. And, you get this Jaguar Guapote from the early-90s, it takes less than ten years to get into the park, but it is not doing a lot. So, there are some contrasting life histories after they get in. So, what are the influences of these nonnative species? Well, so far, we have had no extinctions of native fish in the park. This probably is not surprising considering the fish that we have. The native fish are all very hardy. They are not necessarily naturally adapted for the South Florida climate because they are temperate-derived species but they are the ones that are able to persist here. Some of them like the Florida Gar, they also have aerial respiration so they can handle some of these poor water quality conditions. We tend to see the nonnative species with the highest biomass in canals, borrow pits, but we are seeing them more and more in the park within the solution hole areas, and the shorter hydroperiod wetlands and also in the mangrove zone creeks. Some of the species, the Mayan Cichlid and Spotted Tilapia can handle the saltwater as well. And there is a study out of FIU and National Audubon where they noted an inverse relationship between Mayan Cichlids and small fish that suggest there might be some kind of impact there. There is also some discussion of what happened at Anhinga Trail. Prior to 1978, Anhinga Trail used to have a lot of aquatic vegetation but after ’78, the Blue Tilapia got in there and the suggestion is the Blue Tilapia consumed the vegetation and now there is no submerged aquatic vegetation. It is basically just an empty pool with water there at Anhinga Trail. So suggestion of some impact there. But, the big thing is that there has not been a lot of research on the impacts of nonnative species in South Florida. We know that in the Great Lakes, nonnative species have had a pretty big impact on the fish. You have some in the Southwestern streams where there is a big impact. But, the majority of research hasn’t focused on the impacts. So, this is something that we need to look at a little more. But, another thing that is important to discuss is that when you have such a dominant wet and dry season cycle that the park gets wet during the wet season and dry during the dry, that has such a huge impact on the fish assemblage that teasing out some of these nonnative fish impacts could be difficult until maybe it is too late. And then we always have Everglades National Park mandates for native and natural. And, if you go to Anhinga Trail, the majority of the fish that you will see during the dry season when it warms up a little bit, is typically nonnative species. You might see some large fish, Largemouth Bass and Florida Gar but you will see a lot of nonnative fish. So, what is next? That is the question that we always ask. We know there is a bunch of nonnative species still in these urban canals that are not yet in Everglades National Park. And, you never know when somebody might release something new as well. And so, what we have a big problem with, and it is a little different than Hillary, is we don’t have the control techniques that she does. We can’t, well we could, take a bunch of chemical and spray it around all the canals. It would cost quite a bit and it might not even work. So, what we are trying to do is focus on prevention. We focus on prevention with education. But also try to consider the exotics in the development of the restoration plans that influence Everglades National Park. Think of new ways to add water to the park without adding these nonnative species that are in the water. And, in some ways, consider these nonnative species as a biopollution somewhat like how they deal with the nutrient issue in the water. Might be a way to approach the nonnative fish. And, we need help with this too. We need to work among the agencies outside of Everglades National Park to help meet our objectives as well. And, the vegetation control program is very interesting because all these agencies work together very well to control and contribute…there is ways to switch money around between the agencies. But, when it comes to the fish and other animals, it is a little bit more difficult to get cooperation because the agencies have different mandates and opinions on what should be done and what you can do. So, prevent them from getting into the park is our first goal. And, we are trying to move forward with that. The second step is to try and develop a rapid response protocol. So what do we do if we see them? Well, first we have to get good monitoring both inside the park and outside the park and then look for opportunities to control. This requires a lot of research but still, if you would get a new fish population in a small area early on in its introduction stages, that is your best opportunity to control the organism. And, then I have a suggestion that we look to control outside the natural areas because the canals are artificial. They are generally, for the most part, except for the ones that overflow the marsh, they are generally isolated water bodies that there is potential to control. Or, it would definitely be easier to control in a canal system versus this open water marsh area. So, lets start thinking in new ways. Lets look at things like the African Jewelfish and the Jaguar Guapote and find out why the African Jewelfish does so well and the Jaguar Guapote does not do so well. Do a risk assessment on that. Assess other species that are out on the aquarium trade and use that information to proactively manage the species or do something to help prevent future introductions. The state of Florida has a list of species that are prohibited, for example Piranha and several other fish species that are prohibited in the state of Florida. If you do a risk assessment, you might be able to determine others that might become successful in the natural environment. Then we need to study the impacts more. Thanks. How did the first jewelfish get all the way from the aquarium into the park? Well, our thoughts are that the canals are all connected and it just takes time. The African Jewelfish is a small fish and small fish don’t seem to do as well in canals because large tend to dominate, it is a big body of water. So, our thoughts are that overtime with reproduction, the population just expanded gradually moving along, be it Tamiami Canal or some others on the eastern side and just gradually moved over. And then, eventually, got in to Everglades National Park. It could have been an independent release, we don’t know for sure. But, the way the jewelfish was spreading around, it looked like, because they were spreading to the south into Homestead along the eastern side. It just looked like a natural progression. Well I noticed that fish congregate in those pipes probably because of the flow and maybe those are providing housing/shelter for some of those nonnatives as well. That is exactly an issue that we have. They were probably put there originally to drain. Well, it was to provide flow. Because, water wants to flow. You have the S12B structure that pumps water in from the canal into the park and then the water wants to flow under the road. So, that is what that is for. Yeah, that is to provide connection. But, those culverts have these deep culvert holes. And, the culvert holes, as you noticed, attract a lot of fish off the marsh and they do tend to have large fish associated with them. So, that is another management things that we need to do in the park to help restore, to get some of those artificial things like culvert holes and borrow ponds to fill them in and reduce those impacts. Since the park is relatively new, how do you know, is it possible fossils, that these fish you call native are truly native and there isn’t really a change over periods of time. What is the native habitat? That is an interesting question because we have that concerning some native species as well. Their distributions historically have been considered Lake Okeechobee northward and we have had two species come into Everglades National Park that had that distribution. There has been a lot of surveys done in the 1800’s where they did original surveys of the freshwater fish around all of the Americas really. This was a lot of European scientists would come over and do this. And, we know from historical records that people brought over the Common Carp into the United States. That was one of the early fish that people brought over. And, you know from the early records that these cichlids were not in the United States from this early research. And, they found their distributions and earlier habitats in Africa or in Central America, South America. So, the old records, they pretty much had a good idea of what was there. And, there was no way for those fish to get here besides people to bring them. Even though some of the cichlids can tolerate saltwater, they can’t swim across the ocean. No, that is understandable. But, those that you consider native, how do you know that they were native 200 or 300 years ago. Well, not necessarily, but people have been doing some archaeological digs in Shark Slough and they are able to find scales of Florida Gar and bones of some of the other species. And, certain species they can identify down to individual species and some they can only say, well this looks like a killifish of some sort. Or, this looks like a sunfish of some sort. So, there is not really a historical record like that. But, they do have some record from the pre-drainage Everglades to know what fish were here when man first got here. Or early on, when European man got here. I would say there is no problem with evolution. But, this is not a natural part of evolution, this is man-induced evolution. And, so you can always go to the National Park Service mandate and I can always argue from the park service that we are supposed to be preserving the native and the natural but yeah, there are things happening. And, you know, we don’t necessarily understand what some of these impacts will be with adding these new fish. Now, will things evolve over time and deal with it? I don’t know. Evolution takes a long time. Species have been naturally moving around and adjusting and that is part of the evolutionary process, certainly. But, the time scale with how these species and the distance and the different numbers of species that are coming in is quite contrary to historically or what evolutionarily would have happened. Thank you. Yeah.
Over fifty-nine color varieties of the Liguus Tree Snail have been seen in and around the Everglades ecosystem. They graze on the algae and lichen that grows on smooth-barked trees. During the dry winter months, they are usually sealed to these trees to conserve moisture.
