Introduced Species

everglades sunrise panorama

Everglades sunrise. Photo courtesy NOAA

everglades, glades view

Everglades. Photo courtesy U.S. Geological Survey

The Everglades National Park was established to protect the diverse natural habitats of the region which include freshwater marshes, hardwood hammocks, pinelands, cypress swamps, mangrove swamps, and estuaries. However, despite its status as a national park, the Everglades is threatened by introduced plants and animals.

Introduced species are those organisms that are native to somewhere else that have been introduced to new areas through human activities. Many introduced species have detrimental effects on native flora and fauna due to lack of population controls such as predators and disease. As population numbers grow out of control, these introduced species are often referred to as invasive species. The introduction of species began in the late 1800s and has escalated since that time. These species continue to spread due to a lack of predators and disease, outcompeting native species for food and space.


everglades, climbing fern

Old world climbing fern overtaking native vegetation. Photo courtesy South Florida Water Management District

There are over 200 introduced species of plants that have been documented in the Everglades. These plants, including melaleuca (Melaleuca quinquenervia), Brazilian pepper (Schinus terebinthifolius), Australian pine (Casuarina equisetifolia), and Old World Climbing Fern (Lygodium microphyllum) displace native species and alter the natural habitat.


everglades, wild swine

Feral hog. Photo courtesy South Florida Water Management District

Also detrimental to the habitats and communities of the Everglades are introduced species of wildlife. People have released unwanted pets into the Everglades including aquarium fishes, pythons, boa constrictors, parakeets, and parrots. Feral hogs also pose a major disturbance within the Everglades by digging native vegetation and disturbing archeological sites.

everglades, asian eel

Asian swamp eel. Photo courtesy U.S. Geological Survey

Many species of fish originating from tropical and subtropical regions have been introduced into the freshwaters of the Everglades. Most can tolerate low to moderate salinities, allowing them to become established in brackish water estuaries. These fish have been introduced primarily through aquarium and aquaculture facilities, while some species have been released on purpose in hopes of establishing breeding populations. These fish include the Mayan cichlid (Cichlasoma urophthalmus), walking catfish (Clarias batrachus), Asian swamp eel (Monopterus albus), black acara (Cichlasoma bimaculatum), pike killifish (Belonesox belizanus), blue tilapia (Oreochromis aureus), spotted tilapia (Tilapia mariae), and oscar (Astronotus ocellatus).

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