Florida Keys National Marine Sanctuary

Population growth and urban development may impact the health of coral reefs. Development activities may cause erosion resulting in the runoff of sediments which eventually reach the coral reefs. Storm water runoff may carry fertilizers into the ocean causing damage to the coral reefs, and an increase of nutrient concentrations in the reef may cause an increase of algae which may smother the corals. Sizable foreign objects such as sunken boats and planes provide rich micro-sanctuaries for a plethora of sea life that otherwise would not exist.

The harvest of resources from the sea is ever growing. Overfishing has changed the ecological dynamics of marine communities allowing some organisms to dominate reefs that were once controlled by large reef fish populations.

Tourism dollars help to fund scientific research and environmental remediation activities. Tourism may contribute to reef damage. Divers and snorkelers may harm the corals by touching the polyps, and boats may damage it by running aground and dragging anchors.

Global warming coupled with an intense El Niño has led to higher sea water temperatures throughout the area, that can cause coral bleaching. “Minor paling” of some corals has been observed by local Coral Bleaching Early Warning Network,[2] a program of Mote Marine Laboratory and the Florida Keys National Marine Sanctuary.[3]

One of the Florida Keys' most ecologically damaging invasive species is the lionfish. First discovered as an introduced species in 2009,[4] the lionfish population affects the original flora and fauna of the Florida Keys in three major ways. The lionfish has an appetite for native fish and crustaceans is able to spawn year-round. Originating in the Pacific Ocean, the lionfish has no known predator in the Atlantic Ocean. The lack of natural predators to control the lionfish population allows the lionfish population to grow to disruptive numbers. Lionfish are predators of juvenile fish, such as commercially important grouper and snapper, as well as juvenile parrotfish, which graze on algae in coral reefs, preventing the algae from overgrowing and killing corals.[4] The lionfish’s dietary consumption of native species of the Florida Keys not only affects the species diversity of the Florida Keys, but also causes detriment to the environment due to a decrease in fish who help maintain the coral reefs. The regular spawning of the lionfish further impacts the environment of the Florida Keys;[5] which therefore always maintains a stable reproductive population. A female lionfish can produce 30,000 to 40,000 eggs every few days; lionfish become sexually mature by the time they are a year old.[6] The regular spawning of the lionfish creates a constant pressure on the Florida Keys ecosystem.

The Australian pine is a nonnative species that poses risks to the original flora and fauna of the Florida Keys. The Australian pine "outcompetes native vegetation by producing a dense leaf litter beneath them;"[8] therefore the Australian pine does not allow the native plants to obtain needed nutrients. The Australian pine also has a comparative advantage over native species: the Australian pine can quickly "invade newly accreted beaches, beaches where dredge spoil has been deposited, and beaches where a storm has destroyed existing vegetation."[8] The Australian pine displaces native flora of the Florida keys, and displaces native fauna by providing no native wildlife habitat.

The Brazilian pepper tree is native to Argentina, Paraguay, and Brazil, but was brought to Florida in the mid-1800s as an ornamental plant.[9] The introduction of the Brazilian pepper has disturbed the biodiversity of the Florida ecosystem, as one of the most widespread of the invasive non-indigenous pest plants in Florida. The Brazilian pepper tree has invaded over 700,000 acres in Florida. The tree produces a dense canopy that shades out all other plants and provides a very poor habitat for growth to native species. "The Brazilian pepper invades aquatic as well as terrestrial habitats, reducing the quality of native biotic communities."[9]