Amphibians And The Fishless Ponds Of Florida
December 18, 2018
The habitats that reptiles and amphibians depend on are species specific and reliant on the adaptive ways of the animals. “Niches” are specialized habitats made only for these specifically adapted creatures. In Florida, it is seemingly flat with little-to-no evidence of these niches, at a glance. Even though Florida IS the flattest state in the US, its warm weather and “microtopography,” (or small changes in ground elevation) make it a unique and special place for amphibians and reptiles. In this article we explore the diversity of Florida’s ephemeral ponds in regards to the 28 native and endemic amphibians that rely on it. Ephemeral ponds can be simply described as a fishless pond habitat. “They are small, isolated, wetlands that dry periodically.” They are able to dry up seasonally or be present all year round in some cases.
If you’re planning a summer trip to South Florida, expect rain! Water is the most transient or changing part of a habitat which can be influenced by both man made and natural events like pollution runoff, climate change, and weather. The wetland, marsh, and estuarine habitats of Florida hold many species both common and endangered which rely on the management and protection of these transitional areas. Some of the species who depend on these ephemeral ponds of Florida include the Eastern Spadefoot Toad (Scaphiopus holbrookii), Southern Leopard Frog (Lithobates sphenocephalus), the Striped Newt (Notophthalmus perstriatus), and the Tiger Salamander (Ambystoma tigrinum). Amphibians, because of their porous sensitive skin, and commonly referred to as “indicator species” because they detect pollution. This fragile habitat supports the fragile life of many species who start in water, and transition to a life on land. Preservation is important and imperative for the survival of these indicator species.
Working as a field biologist for Palm Beach Atlantic University in Florida, I was able to further understand and appreciate these unique habitats as we surveyed for reptiles and amphibians in the state parks. With the proper permits, we used the dipnetting technique to survey for amphibians in these fishless retention ponds. During the wet season of Florida (Summer), many of these ponds fill up and provide an important home for overlapping habitats of dry and wet, especially for amphibians. Florida is usually referred to as the “sunshine state,” but in reality it should be called the water state since almost 20% of it is covered with some type of water. This can be wetlands, lakes, rivers, marshes, estuaries, and of course, the ocean. The aquatic habitats of Florida, like the wetlands, are especially unique because they rely on natural “hydroperiods” or water fluctuations. Even when these areas “dry up,” the soil is commonly used for burrowing amphibians, making this area especially important for amphibian life cycles. It is not uncommon to find 10-20 different species of amphibians using these ponds!
While dipnetting over the summer in both fish dominated and ephemeral ponds, we discovered multiple species of tadpoles in the ephemeral ponds, while we came across none in the fish dominated ponds. Because of these unique “depressions” in the earth that are filled with fishless water year round or seasonally, many species of frogs, toads, and salamanders are able to breed, deposit their eggs, and grow here without worry. Since no fish are present, it dramatically decreases the risk of predation on the babies! Without these ephemeral ponds, many species of amphibians would not have the chance to reproduce with stable population numbers, because the larvae would quickly be eaten. It is important to preserve this system because not only does it support a variety of transitional (metamorphosing) species, it also supports a transitional habitat that connects the aquatic and terrestrial lives of many species of amphibians, reptiles, inverts and even mammals and birds. Florida is filled with one-of-a-kind species diversity, including many reptiles and amphibians. The adult amphibians come to breed or live here both exclusively or opportunistically, while the young larvae are provided a safe nursery to live and grow until they (possibly) crawl out of the water themselves. These babies are supplied with a variety of invertebrates like mosquitos and beetles to eat, which we also caught during our dipnet surveys.
Dipnetting is an efficient method for surveying amphibians