Magnificent Mangroves: How Mangroves Protect Our Coasts
by Morgan Mathews
Hi! My name is Morgan Mathews, and I’m an environmental education intern at the Tampa Bay Watch Discovery Center. I’m studying environmental science and policy at the University of South Florida. In this article I’ll be talking about mangroves, salt-tolerant trees that protect shorelines and create habitats and nurseries for marine life. They are prevalent in Tampa Bay, shaping the estuary ecosystem.
There are three types of mangroves in Florida: red, black, and white. Red mangroves thrive in the water off the coast, using their aboveground rhizophores, or prop roots, to anchor themselves in the sandy soil and transport oxygen to their belowground roots. Black mangroves are found further inland, and they live in a variable environment with fluctuating water and salinity levels. As an adaptation, they have distinctive pneumatophores, also called “knees,” that grow vertically from the soil and allow the plant to take in more oxygen. White mangroves live furthest from the water, and they have rounded, smooth leaves. Each leaf has two glands, called nectarines, at its base that excrete sugar. Both black and white mangroves excrete salt from their leaves.
Mangroves protect our shorelines from storms by absorbing wind and wave energy. The Tampa Bay Watch Discovery Center has a demonstration of this at its living shoreline exhibit. By anchoring the ground, mangroves stabilize the land and prevent erosion. They create a low-maintenance barrier that slows wind, and their absorption of water reduces waves. Mangroves also improve water clarity and quality. Their roots trap sediment and debris and filter pollutants such as nitrates and phosphates, which are common in runoff.
Mangroves create habitats for a variety of organisms. 75-90% of recreationally and commercially important marine species require mangrove habitats for at least some portion of their lives. The estuary exhibit at the Discovery Center showcases some of our vital species, such as Snook and Snapper. Mangrove roots serve as a habitat for sessile organisms such as oysters, barnacles, and mussels that require a hard surface to attach to and colonies to grow with. They also provide spaces for juveniles to hide from predators. Mangrove branches serve as a nesting site for coastal birds such as the Brown Pelican and Great Blue Heron. Guests can see mangroves in action by visiting Bird Island during Tampa Bay Watch’s Eco-Tour.
Considering all that they do for us, mangroves are often undervalued. Much of Florida’s mangrove forests have been lost to coastal development. Agriculture and climate change have also contributed to their degradation. Legislation has been enacted on the state and local level to protect mangroves from direct human impact; however, there is more to be done to address the indirect impacts. Be an advocate for mangrove conservation and allow mangroves to protect our coasts! Visit the Tampa Bay Watch Discovery Center to learn more.
