The Florida Keys, as part of south Florida, is home to a variety of introduced species.

Oscar. Photo courtesy U.S. Geological Survey/Howard Jelks
Oscar. Photo courtesy U.S. Geological Survey/Howard Jelks

Introduced species are those organisms that are native to somewhere else that have been introduced through human activities.

Many of these 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, introduced species are often referred to as invasive species.

Australian pine. Photo courtesy National Park Service
Australian pine. Photo courtesy National Park Service

Australian Pine

Non-native trees and vines threatened the native flora of the Florida Keys. The worst offenders are the Australian pine and the Brazilian pepper. Australian pine (Casuarina equisetifolia) was introduced into Florida during the late 1800s, planted as windbreaks and shade trees.

It has since spread rapidly, displacing many native species due to its quick growth. This pine has shallow root systems and suffers damage from the frequent storms as well as soil erosion.

Brazilian Pepper

The Brazilian pepper, (Schinus terebinthifolius), was originally introduced as an ornamental plant during the mid-1800s. Its range has been extended primarily through seed dispersal by birds as far north as St. Augustine and Cedar Key. As a successful invader, the Brazilian pepper poses a serious threat to the native flora and fauna of the Florida Keys.

Brazilian pepper. Photo courtesy U.S. Department of Agriculture
Brazilian pepper. Photo courtesy U.S. Department of Agriculture
Burma reed. Photo courtesy National Park Service
Burma reed. Photo courtesy National Park Service


Other Introduced Plants

Other introduced plant species include the latherleaf (Asiaic colubrina), Burma reed (Neyaudia reynaudiana), lead tree (Leucaena leucocephala), seaside mahoe (Thespesia populnea), and melaleuca (Melaleuca quinquenervia), among numerous ornamentals used in landscaping.

Pacu. Photo courtesy USAID
Pacu. Photo courtesy USAID

Fishes

Although it is illegal to release non-native species into state waters, introduced species are on the increase. One such example is the collection of two orbicular batfish (Platax orbicularis) from Molasses Reef off Key Largo. These fish, native to the Pacific Ocean, were probably released by home aquarists when they grew too large for their aquariums. Other introduced fishes found in the Keys include pacu (Colossoma macropomum) and oscars (Astronotus ocellatus).

Other Introduced Animals

Iguana. Photo courtesy National Park Service
Iguana. Photo courtesy National Park Service

Terrestrial introduced species include the Mediterranean gecko (Hemidactylus turcicus), common house gecko (Hemidactylus frenatus), iguana (Iguana iguana), brown anole (Anolis sagrei), and Cuban treefrog (Osteopilus septentrionalis), among numerous others.

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