Florida Keys

The Florida Keys Coral Reef is the third-largest coral reef system in the world and the only coral barrier reef in North America. The reef is located in the Florida Keys National Marine Sanctuary, which spans over 2,900 square nautical miles and includes coral reefs, seagrass beds, mangrove forests, and other important marine habitats.

The corals on the Florida Keys Coral Reef are incredibly diverse and play a crucial role in maintaining the health and productivity of the ecosystem. There are more than 45 species of stony corals found on the reef, including massive star corals, brain corals, elkhorn corals, and staghorn corals.

Corals are the exoskeleton of a colony of animals called polyps. These animals live in a symbiotic relationship between themselves and a type of algae called zooxanthellae. Coral polyps provide the zooxanthellae with a protected environment to live and grow, access to carbon dioxide for photosynthesis, and the removal of waste products. In return, the zooxanthellae provide the coral polyps with energy in the form of sugars, which they produce through photosynthesis, as well as oxygen and other essential nutrients.

The bright and vibrant colors of coral reefs come from the pigments produced by the zooxanthellae living inside the coral polyps. These pigments can range from greens to yellows to browns, and even blues and purples.

Ocean currents act as underwater highways, carrying marine organisms, their offspring, heat, nutrients and whatever else is is in them around Florida and beyond. These ocean currents play a vital role in shaping Florida's climate, ecology, and economy, as well as the wider global ocean system and are influenced by a range of factors, including winds, tides, and temperature gradients.

The state is surrounded by several major ocean currents, including the Gulf Stream, which flows northward along the eastern coast of Florida, and the Loop Current, which flows southward from the Gulf of Mexico along the western coast and the Florida current which flows along the eastern coast of Florida and into the Gulf Stream.

Pollution, including nutrients, sediment, chemicals, and other contaminants, can enter the ocean through a variety of sources, such as wastewater treatment plants, agricultural runoff, and coastal development. Once in the ocean, these pollutants can be transported by ocean currents over long distances, affecting marine ecosystems and human health.

In addition to these major currents, there are also smaller currents and eddies that can influence the movement of water, nutrients, and organisms along the West and East coasts of Florida - Image courtesy of the National Academies of Science.

The destruction of the Florida Keys coral reefs is a story of death by a thousand cuts. The Florida Keys face a variety of threats, both natural and human.

Coral disease, climate change and frequent storms are natural threats that damage the reefs. Coral diseases such as black band and stony coral tissue loss disease can quickly spread and cause irreparable damage, storms can cause physical damage to reefs by breaking and dislodging coral colonies and stirring up sediment that can smother corals. Rising sea temperatures and ocean acidification caused by climate change stress corals and lead to coral bleaching events.

Pollution, anchoring and overfishing are direct threats to the reefs caused by humans. Polluted runoff from agriculture, urban areas, and wastewater treatment plants can carry chemicals, sediment, and nutrients into the water that can harm corals, while overfishing disrupts the balance of the reef ecosystem. Both pollution and overfishing cause an overgrowth of algae that smothers corals. Improper anchoring can cause physical damage to the reefs, as boats and anchors can crush and break coral colonies.

Coral bleaching is a natural process that can occur in response to a range of stressors, including changes in water temperature, light, or nutrient availability. However, in recent years, coral bleaching has become more frequent and severe, and is often linked to human activities such as climate change and pollution.

Coral bleaching occurs when corals expel the algae, known as zooxanthellae, that lives in their tissues. Zooxanthellae gives coral its color; when corals become stressed, such as from high water temperatures caused by climate change, they can expel the algae, causing the coral to turn white or bleached.

When corals bleach, they become more susceptible to disease and death which can disrupt the entire food web and biodiversity of the surrounding ecosystem. In severe cases, coral bleaching can lead to the death of entire coral reefs, which can have significant ecological and economic impacts.

With the loss of the algae (Zooxanthellae) that provides corals with food, over time the coral will starve to death, causing it to die - Photo by Karen Neely, Florida Fish and Wildlife Conservation Commission.

Stony coral tissue loss disease (SCTLD) is a relatively new disease that has been affecting coral reefs in the Florida Keys and other parts of the Caribbean since 2014. It is caused by a unknown pathogen and primarily affects stony corals, including important reef-building species such as pillar coral, brain coral, and star coral.

The disease starts as small white patches of tissue loss which then spreads rapidly and can lead to complete colony death within weeks to months. Transmission and spread can occur through direct contact and through the water column; other mechanisms such as sediment or transmission via shipping routes are topics of active research.

SCTLD has had a significant impact on coral reef ecosystems in the Florida Keys, where it has affected over 20 coral species and caused widespread mortality in some areas.

Stony Coral Tissue Loss has had a devastating impact on pillar coral - Photo by Dr. Karen Neely, Nova Southeastern University.

Climate change is a common link between both the increased frequency of coral bleaching events and the rise of coral diseases, like black band disease. Warmer waters stress corals causing them to bleach, making them more susceptible to disease.

Climate change is also increasing the frequency and intensity of storms. Storms physically damage corals, and cause changes to water quality and ocean chemistry that can negatively impact coral health.

Coral bleaching can affect corals reproductive ability for years afterward threatening the existence of the new generation- Photo by Karen Neely, Nova Southeastern University.

There are a variety of efforts being made to help protect and restore the coral reef ecosystems in the Florida Keys including coral restoration, water quality improvement, marine protected areas, and education and outreach.

Propagation and transplantation of corals to restore damaged or degraded reefs, reducing pollution and improving water quality to reduce stress on coral reefs, establishing marine protected areas to limit human activities that can damage or destroy them, and raising public awareness about the importance of coral reefs and the threats they face can all contribute to the conservation of coral reef ecosystems in the Florida Keys.

Divers plant staghorn coral at Carysfort Reef in the Florida Keys - Photo by Alexander Neufeld/Coral Restoration Foundation

Home

Appreciate

Credits:

Created with images by miami2you - "7 mile bridge. Aerial view. Florida Keys, Marathon, USA. " • edb3_16 - "Beautiful coral reef in the Atlantic Ocean. Located near Key West, Florida, United States." • tyler - "HawksBill Turtle In Florida Keys"