Key West is an island surrounded by the Gulf of Mexico and the Atlantic Ocean. Located 150 miles south of Florida’s mainland, the island and its waterways make up a dynamic, diverse and important ecosystem supporting a wide variety of marine life. The deep waters of the Atlantic Ocean are home to the Florida Straits coral reef, which is the third largest barrier reef in the world, as well as the powerful Gulf Stream current, while the Gulf of Mexico is composed of shallow sand flats, mangrove islands, and seagrass beds.
The ocean’s coral reefs support as much as 40 percent of the world’s marine life. Since the 1970s, the Florida Keys and Caribbean basin has lost as much as 90 percent of their indigenous coral covering. There are a number of factors that play into this staggering statistic, including climate change and global warming, water quality and pollution and diseases that arise from these stressors.
What is Seagrass?
Seagrasses are submerged flowering plants found in shallow marine waters, such as bays and lagoons and along the continental shelf in the Gulf of Mexico. Found on the bottom of protected bays, lagoons, and other shallow coastal waters; a vital part of the marine ecosystem due to their productivity level, seagrasses provide food, habitat, and nursery areas for numerous vertebrae and invertebrate species. The vast biodiversity and sensitivity to changes in water quality inherent in seagrass communities makes seagrasses an important species to help determine the overall health of coastal ecosystems.
Although they are not “true” grasses, they appear grass-like with 3-5 leaf blades a horizontal stem. Seagrass is more closely related to the lily and while there are 52 species in existence only 7 are found in Florida; Turtle, manatee, shoal, Johnson’s, paddle, and star grasses. They form large underwater meadows, flowering and producing seeds that are quickly dispersed through the current and tides.
The Importance Of Seagrass
Sea grasses provide numerous essential functions:
- stabilizing the sea bottom with their roots and rhizomes
- providing food and habitat for other juvenile and small fish, as well as many other marine organisms
- maintaining water quality and clarity by trapping fine sediments
- supporting local economies
Furthermore, they serve as feeding grounds for bottlenose dolphins and the organisms that grow on them provide food for wading and water birds.
Turtle grass is an important seagrass found from Bermuda and southern Florida to the Gulf of Mexico, the West Indies, Central America, and Venezuela. It can form very extensive beds in protected shallow waters that serve as both habitat and a food source for a tremendous diversity of organisms, among them sea turtles, which graze on turtles grass and are the source of its common name.
The canopy of seagrass protects smaller marine animals, including the young of such species as drums, sea bass, snappers, and grunts from larger predators.
While there are approximately 2.2 million acres of seagrass in Florida waters today, that population has declined by more than half since the 1950s due to coastal engineering, boating impacts, and water quality.
Currently, the most common form of physical destruction to seagrasses is the dredging of plant material by boat propellors and vessel groundings on shallow seagrass beds. This form of seagrass destruction, known as prop scarring, occurs in shallow water areas throughout South Florida.
In leading the State in total seagrass coverage, Monroe County also leads in scarred seagrass beds with almost 30,146 acres. Zieman (1976) estimated that it takes several years for turtle grasses to begin recovery from prop scarring.
Another cause, which is lesser known to the public, but widely studied by marine biologists is the mysterious loss of 98 percent of the basin’s spiny urchin population during the 1980s. Spiny urchins are grazers, meaning they eat algae accumulated on hard coral keeping it clean and healthy for coral spawning. Without them, the coral substrate is covered in algae, which leads to bacteria and infections, and prohibits coral from spawning and growing.
These ecosystems are unique and interconnected, creating breeding, nesting and feeding environments for countless species of fish, migratory birds, and crustaceans. That’s why it’s essential that coral reef and seagrass ecosystems are conserved.
Many organizations like Mote Marine Lab and the National Oceanic and Atmospheric Administration (NOAA) are working tirelessly on conservation, restoration, and education initiatives to help save the coral reef not only in the Florida Keys but around the world.
For instance, Mote has developed a revolutionary coral restoration process used in its lab on Summerland Key to successfully spawn and grow thousands of pieces of coral with an 85 to 90 percent success rate. These coral nurseries and forests are then installed at an ailing reef focusing on reef-building corals, like staghorn, elkhorn, brain, and star coral.
Understanding that seagrass must be protected is the first step in conservation efforts. It’s important for boaters to realize that propeller scars caused by running aground or clipping the shallow seafloor is incredibly damaging to the ecosystem. It can take up to 10 years for seagrass to regenerate.
The office of Coastal and Aquatic Managed Areas is experimenting with a variety of replanting and restoration methods throughout the Florida Keys and the entire state of Florida in an attempt to reverse this damage.
For anyone who cherishes the natural beauty of the Florida Keys and a day on the water, the conservation of coral reef and seagrass ecosystems should be a cause close to your heart. Of course, a visit to the Key West Aquarium is an excellent place to learn more about our ocean’s ecosystems and what you can do to help.