What creature lives in salty or brackish water, provides an ideal breeding ground for countless organisms, and helps maintain a thriving planet?
Mangroves, once thought of as the inhabitants of useless swamps, live in estuaries with salty or brackish (mix of salt and fresh) water where few other plants can survive. With partially submerged root systems that look like part elegant statue, part intricate web, they act as protective, food-abundant sanctuaries for a myriad of fish and other life.
Although I do not live near them now, I feel grateful for their power and presence on our pale blue dot. Find out what makes these creatures so magical – and vital to protecting our planet – below.
What are mangroves?
Mangroves are tropical halophytic (salt-loving) trees, shrubs, and plants that live along coastlines in intertidal zones where the tide continually ebbs and flows. Typically, they live in low-oxygen, high-saline coastal environments (where most plants struggle to survive) in tropical and subtropical countries near the equator and grow most abundantly in Indonesia. In North America, you can also find mangroves from the southern tip of Florida to the Gulf Coast in Texas.
It is currently unknown how many types of mangroves exist, but estimates range from 50 to 80+ species. We have much to learn about these creatures, so we can protect and work with them in harmony to benefit all life on Earth.
One of mangrove forests’ most prominent ‘superpowers’ is their ability to store a tremendous amount of carbon, which is key for mitigating excess greenhouse gas emissions that exacerbate global climate change. They also provide unique underwater habitats for thousands of marine creatures, as well as resting and hunting grounds for birds and animals. On top of that, they protect coastlines from erosion and act as storm-surge safeguards.
There are many species of mangroves each with their own unique adaptive mechanisms for thriving in low-oxygen, high-saline environments. In general, they either secrete or filter salt and are thus categorized as secretors or non-secretors.
The Ecological Role of Mangroves
When discussing the role of mangroves, a fisherman from Trang Province in southern Thailand said: “If there are no mangrove forests, then the sea will have no meaning. It is like having a tree with no roots, for the mangroves are the roots of the sea.”
The roots of mangrove forests filter out nitrates and phosphates, which prevents saltwater from flooding inland rivers and streams. They also help protect coastal land from damage caused by heavy winds and powerful waves. Furthermore, they stabilize coasts by collecting silt and sediment that hold soil in place, stopping erosion.
In true nature superhero fashion, these forests closely collaborate with other species, including seagrass beds and coral reefs. Many fish, crab, shrimp, and shellfish begin their lives in these areas. Mangroves’ extensive propped root systems effectively trap nutrient-rich sediment as well as pollutants. In turn, seagrass beds protect reefs from being covered with excessive amounts of sediment, silt, and mud, while reefs protect both seagrass beds and mangroves from powerful waves.
Mangrove forests act as the ideal habitat for a variety of bird, animal, and marine species, from bacteria, filter-feeders, decomposers, insects, and fish to mammals. They provide shelter, nesting, and food. A few of the many creatures that live in and rely on them include:
- Birds: Kingfishers, herons, & egrets, as well as other coastal & migratory birds
- Animals: Macaque monkeys, fishing cats, monitor lizards, & Bengal tigers, etc.
- Marine Life: Tree climbing fish, shrimp, crabs, snails, clams, oysters, & anemones, etc.
When mangrove leaves fall and start to decay, they provide the basis for an elaborate food web. The nutrients are then dispersed by the changing tides. This effective distribution system feeds invertebrates and algae that feed smaller creatures—and on up the food chain to predatory mammals, including humans.
Experts estimate that nearly 75 percent of commercially caught fish either spent time in a mangrove forest or depended on one for survival. Many people walk through mangrove swamps to collect shellfish during low-tide and fish during high-tide. Mangrove wood can also be used for medicinal purposes, to build homes and boats, and to create fuel providing fire.
How You Can Help Protect Mangroves and the Ecosystems They Support
The first time I learned about mangroves was also the first time I explored them. I was working as an experiential education program guide in the Dominican Republic for the summer. During one of the 2-week sessions, our group went out for a day trip to a local mangrove forest. We traveled out to them in long, slender canoes, carving elegant chevron wave patterns along the way.
Once at the edge, we got out to swim around and climb over the roots where we saw fish, crabs, and other marine life busily going about their daily routines. I felt the magic of the mangroves wash over me as I plunged my head through the surface of the briny water. Our local guides taught us about the importance of these miraculous ecosystems, issues impacting their health, and how they affect our coasts.
Like nearly every species on our climate, mangroves are vulnerable to the multi-faceted effects of climate change. Whether you live on a mangrove-protected coast or not, these magnificent creatures likely support life and landscapes you rely on and interact with in indirect ways.
The goal of the afternoon I spent in a mangrove forest was to plant mangrove seedlings, which was immensely difficult because the tide was up past many of our chests. Later, I learned that many restoration attempts like this one are largely ineffective.
At the same time, communities and organizations around the world are working on innovative, collaborative solutions to protect and restore mangrove forests. Dr. Krishna Ray from West Bengal State University in India is leading and studying transplantation projects. This process is one of the most promising ecological restoration practices. It involves growing mangrove seedlings in greenhouses, planting them in mudflats along the ocean, and restoring companion species like seagrasses with them.
In general, the best way to protect mangrove forests is still through preservation and conservation, including stopping or limiting cutting and trimming them. Additionally, it is critical to stop creating shrimp farms that make them more vulnerable to the effects of cyclones and tidal waves, which also prevents them from protecting coastlines.
Photos by Maya Dutta
Complex Species, Interconnected Solutions
As with anything in the natural world, when you look closer, there is much more than meets the eye. Along with being a striking and complex species, mangroves are intricately connected with human life. Systems-level issues like poverty, food scarcity, lack of opportunity, and ongoing violence put people in immensely challenging situations caused by forces outside their control.
We need multisystem solutions that address these large-scale issues and effective, sustainable changes that enable everyone to access what they need. To learn more, check out the links below and spread the word about the value mangroves provide to human and non-human life across the globe.
Allison holds a Graduate Certificate in Science and Medical Writing and over 3.5 years of professional writing and editing experience. She is passionate about supporting the complex, interconnected needs of people and the planet. Her specialties include marketing copy and website content, as well as environmental, health, and nonprofit communication. When she isn’t writing, you may find her hiking in the Blue Ridge Mountains, devouring a novel, or dancing to live music.