By Olivia Allread, DNREC’s Wetland Monitoring and Assessment Program
Magical forest, walking trees, mangals, snorkeling roots – this habitat can be called by many names. With a worldwide distribution in tropical to warm temperature latitudes, mangrove forests are not only incredible ecosystems, but a key player in climate resiliency and human livelihood. If you’ve been to the lower half of the United States, specifically southern Florida and the Gulf Coast of Texas, you may have come across this type of coastal wetland. If you’re more of a world traveler, it’s likely you may encounter a mangrove along your journey, as these wetlands reside on five out of seven continents on the globe.
Let’s get to know mangrove forests from root to tip. These coastal wetlands consist of groups of shrubs and trees that are uniquely adapted to estuarine tidal and marine conditions. Living in these ecosystems means that mangroves must be able to survive not only in waterlogged soils with oxygen-poor sediment, but also in saltwater experiencing daily tidal cycles. In order to grow in such harsh conditions, the roots are often sprawled above the water and below in sediment – a bit different than most plants. Along with the unique structure of their roots, mangroves can also filter out the salt from water as it enters their roots by secreting salt out of special glands on the leaves. This dynamic duo of adaptations allows the flowering part of the plant (the branches and leaves) to live above the water line, while the above and below ground root system maintains stability under the water.
When it comes to overcoming growth challenges, mangroves have really thought this one through. Regular coastal flooding can make most plants reproduction a more than difficult task. However, mangroves have adapted to use the tides and proximity to waves to their advantage through vivipary. This simply means that the offspring begin to grow while still attached to their parent plant, and in this case, far above the salt water. After pollination and germination, the seedlings fall into the water to then be swept away by the tides and wave action nearby. Next stop, the bottom of a muddy tidal wetland to grow out of the water and hopefully play a role in another mangrove colony.
According to The Nature Conservancy, there are approximately 70 species of trees and shrubs that make up mangrove plants communities of the world. Chilly or freezing waters are a big no no for mangroves, so it’s not a surprise that their distribution is only in tropical and subtropical latitudes near the equator. The various species across the globe are not necessarily closely related but do all share the distinct capability of growing dense roots out of the water in salty and often unstable conditions. For us here in continental United States, only three species of mangrove grow: black, red, and white mangroves.
Now, we’ve discussed the benefits and necessity for coastal wetlands on our blog before. But in standard fashion, each wetland habitat comes with its own intricate set of ecological and societal benefits. The fact that mangroves thrive in such harsh conditions is already remarkable; below are even more reasons to give them credit.
Habitat and Biodiversity
A mangroves maze of woody roots creates an intricate network of available habitat for numerous plants and animals. They are dense aquatic forests, a few miles in size, that provide areas for migratory birds, exotic fish and reptiles, heathy trees, and even furry friends like lemurs and panthers. As a nursery habitat, many small fish and invertebrates such as crabs and shrimp grow safely in mangroves and later move on to open water areas such as coral reefs. Recent data from The Nature Conservancy shows that mangroves are home to 341 internationally threatened species. And if you haven’t recognized their wonder yet, just Google a sloth swimming in a mangrove to really see the “wow factor”.
Blue Carbon Sequesters
Like all trees, especially in wetlands, mangroves absorb and store carbon from the atmosphere. What sets these habitats apart from the rest is how they store it. Once leaves and older trees die in a mangrove forest, they fall into the water and take the stored carbon with them to be buried in the soil. This is what we call “blue carbon” because it is stored underwater in the coastal ecosystem. Storing substantial amounts of carbon has proven to offset carbon emissions that drive the current climate crisis. The Smithsonian Ocean predicts one acre of mangrove forest can store about 1,450 pounds of carbon per year – roughly the same amount emitted by a car driving straight across the United States and back. Another reason to love mangroves and wetlands; they keep our air cleaner.
This is a big one. Mangroves protect our shorelines and coastal areas more than we can imagine. As natural infrastructure, they provide protection to populated coastal areas by reducing flood impacts and property damages during extreme weather events. Mangrove forests buffer wave and wind energy as a first line of defense during strong storms. Also, their dense, aboveground roots slow down water flow and hold deposited sediment in place mitigating impacts from sea level rise. Last, their complex, underground root systems help cycle and filter excess nutrients reducing pollution and improving water quality.
Recreation and Culture
It’s a universal truth; the outdoors can bring people joy. Kayaking, snorkeling, fishing, birding, the list goes on. Mangroves can provide an invaluable natural experience because of their biodiversity and geographic location in some of the most tropical places on Earth. In addition to the everyday recreation, the traditional use of mangrove habitats dates to the BC times. These highly sustainable practices for hunting, timber, and food production are still in use today in some South American and African countries but may be lost with ecosystem degradation. The livelihoods of coastal cultures worldwide have become intertwined with mangrove forests whether it be through living spaces to nature clubs, small scale businesses to historic heritage sites.
Like many coastal ecosystems, these habitats unfortunately face a variety of threats and are being lost at a rapid rate. Whether experiencing habitat destruction from human impact like aquaculture or development, threats from sea level rise, damages from coastal storms and flooding – mangroves are up against some tough odds. The hard times of the modern age have brought on bigger and better ideas in conservation for mangroves, but all the answers are not clear yet. Science and education, reforestation projects, monitoring, policy adaptation – these are some of the ingredients to the recipe for success. But if there is a future for mangrove forests in our world, it may be useful to look at them as part of the solution. After all, they are masters at adaptation and overcoming intense challenges daily. From The Sundarbans of India and Bangladesh to the Galapagos Islands and The Everglades in southern Florida, mangroves are wetland wonderlands like no other.
By Beatrice Arce, MANO Project Fellow with the Hispanic Access Foundation In celebration of Hispanic Heritage Month, we partnered with the Hispanic Access Foundation’s MANO Project (My Access to Network Opportunities) to share Latino communities experiences and work with natural resources. Conservation or environmental jobs, relationships with nature, climate change – the MANO Fellows have […]
By Alondra Ureña, MANO Project Fellow with the Hispanic Access Foundation In celebration of Hispanic Heritage Month, we partnered with the Hispanic Access Foundation’s MANO Project (My Access to Network Opportunities) to share Latino communities experiences and work with natural resources. Conservation or environmental jobs, relationships with nature, climate change – the MANO Fellows have […]
By Olivia Allread, DNREC’s Wetland Monitoring and Assessment Program Imagine yourself at one of these places in Delaware: up a rooted trail in the Piedmont region, down a sandy path near the coast of the Atlantic Ocean, or along a pondside trail in a mature upland forest. You snap a few photos and stop along […]
By Alison Rogerson, DNREC’s Wetland Monitoring and Assessment Program Summer means warm weather (ok hot), spending more time outside, exploring the woods, wading in streams, and fishing. This makes it more likely that you will encounter one of Delaware’s 14 species of turtles! Safe to say that there is a turtle in every type of […]
By Brigham Whitman, Delaware Wild Lands’ New Castle County Conservation Programs Manager Taylors Bridge in southern New Castle County perfectly characterizes Delaware’s coastal flood plain: a mosaic of agricultural fields interspersed with patches of upland hardwood forest and the occasional residential development, surrounded by the waters of the Delaware Bay with fingers of marsh snaking […]
By Joe Schell, DNREC’s Delaware Community Conservation Assistance Program (DeCAP) When you think of the word habitat – what is the first thing that comes to mind? Is it the dawn light painting your favorite meadow with wisps of amber and gold? Or maybe it’s the cool, crisp water of a stream full of fish […]
By Kayla Clauson, DNREC’s Watershed Assessment and Management Section When you think of submerged aquatic vegetation (SAV), Delaware may not be the first state that pops into mind (we can’t be the first state all the time!) When SAV comes to mind, you may first think about the world-famous seagrass, Eelgrass (Zostera marina). In a […]
By Olivia Allread, DNREC’s Wetland Monitoring and Assessment Program Celebrate good times, come on! Yes, it’s the holiday we’ve all been waiting for – American Wetlands Month. This May marks the 32nd anniversary of recognizing the vital importance and need of wetland habitats across the United States. Now our program is out here everyday living […]
By Kenny Smith and Alison Rogerson, DNREC’s Wetland Monitoring and Assessment Program The most widely recognized migrations in the world involve animals: the red knot, monarch butterflies, salmon, wildebeest. But there is another migration happening everyday along the U.S. coastlines: marsh migration. This migration is not driven by the seasons, or daylight but is instead […]