Temperature: Max 27oC
This day consisted of a long drive down to the Florida Keys but with a couple of stops along the way, including one in Miami which gave us a chance to take in some of the human habitats of Florida.
Invasive species talk
We started the day with a talk on invasive species by Jake Edwards; a non-native Wildlife Technician for Florida Fish and Wildlife Conservation Commission (FWC). This gave us the chance to understand what was being done in Florida to deal with the abundance of non-natives.
In Florida there are 600 species of non-native wildlife as a result of the ideal warm climate, the numerous ports and the exotic pet trade.
When an invasive species first arrives in an area it follows an invasion curve where as time passes the cost of dealing with the situation increases. Therefore the approach with regards to invasive species goes as follows;
- Prevention of invasion: e.g. exotic pet amnesty days.
- Early detection: monitoring for non-native arrival and use of the “I’ve got 1” app for reporting invasive species.
- Rapid response: “throwing as much money at the problem at the beginning”.
- Control/ manage: keep a population at a controllable level.
- Education/ outreach: educate the public on the release of non-natives
We were then given some classic examples of invasive reptiles for example the Nile monitor lizard (Varanus niloticus), native to Africa and released due to the exotic pet trade. In Florida there are three confirmed separate breeding populations which generally inhabit canals. These are a particular problem as a result of their varied diet which means they are a risk to Florida’s native species.
These are a conditional species meaning that they are not allowed to be possessed personally, the case for many invasive and potentially invasive species. In response to the invasion a live trapping programme is underway, although we were told it is a lot more effective to shoot them. Those that are caught have their gut contents examined to see what they are eating and their reproductive health is also examined.
We were shown a live Argentine black and white tegu (Tupinambis merianae) native to South America. 600 of these were caught last year and rapid response actions were undergone in Bonita Springs to remove a small population of tegus. This was effective at removing the population before it became impossible to eradicate.
We were also shown frozen specimens of a black spiny tailed iguana (Ctenosaura similis) and a panther chameleon (Furcifer pardalis) which had been caught in invasive species control programs.
Invasive species which are endangered in there native range can be an issue for control. For example the barasingha deer (Rucervus duvaucelii) native to India which are known to spread disease to Florida’s native deer but cannot be shot or controlled.
A case where eradication is not attempted is the Burmese python (Python bivittatus) native to Southeast Asia. A species with a large breeding population within the Everglades has been near to impossible to control as a result of the inaccessibility of the Everglades. In 2016 the Python Challenge was undergone lead by the FWC with the aim to increase public awareness and catch as many pythons as possible. This entailed public training on removal of pythons of which 1,066 people registered, however only 106 pythons were removed.
After the talk we got back into the van and made the decision to take a detour that would take us through Miami. This gave us a chance to take in the human side of things and we had a short visit to the beach. We then continued our journey towards the Florida Keys.
The Florida Keys is an an archipelago consisting of 1,700 islands located off the southernmost coast of the continental US. These are primarily composed of ancient coral reefs and oolite (a sedimentary rock) which are formed behind reefs.
The Keys have a tropical savannah climate with a frost having never been reported. They boast a diversity of both native and non-native wildlife including the endangered and endemic Key deer (Odocoileus virginianus clavium) and the critically endangered American crocodile (Crocodylus acutus).
The water surrounding the Keys is part of the 9, 600 km 2 Florida Keys National Marine Sanctuary. This includes the Florida Reef which is the only barrier coastal reef in North America. It also consists of mangrove forests and seagrass fields which are the largest in the world.
Key Largo was the particular island we visited which is located in the upper Florida Keys. It is the largest section of the keys spanning 53 km and connected to the mainland by two road bridges.
We were taken out on a boat to White Banks Dry Rocks reef, a shallow inner reef within the National Marine Sanctuary located 3.5 miles offshore. The guide instructed us that we were not to touch any of the coral or to pick anything up from the bottom. We were also told that at no point were we to stand up when in the water, so as not to damage the coral in any way.
As we got in the water we swam across a seagrass bed towards the reef where we came across our first great barracuda (Sphyraena barracuda) and southern stingray (Dasyatis americana) which I had really been hoping to come across.
Once I had arrived at the reef I came across a variety of coral species some of which I was able to identify. Including the common seafan coral (Gorgonia ventalina), the labyrinth brain coral (Diploria labyrinthiformis) and the Palmers sea rod (Eunicea palmeri). Amongst these we came across many classic coral fish species including the yellowtail snapper (Ocyurus chrysurus), blue tang (Acanthurus coeruleus). We also saw two species of parrotfish; the Queen parrotfish (Scarus vetula) and the stop-light parrotfish (Sparisoma viride).
Some interesting fish behaviour I came across when in the water was some territorial behaviour by a female rock beauty (Holacanthus tricolor). A member of the angelfish family these are protogynous hermaphrodites meaning they change sex from female to male. They begin life as a female as the until they reach around 12 cm. I thought that this fish could potentially be guarding its eggs as whenever any small fish came near to the spot it was defending it would chase them off.
Exploring the reef allowed us to see a wetland habitat contrasting to that we had seen up until this point and was one of the trip highlights. Once our time was up we headed back to land where we came across some rather expensive houses, which had been built in areas where mangroves would previously have lined the coast. We had a chance to get some Key Lime Pie before the long drive back to Vester.