Magnificent Mangroves

True Marvels of Nature

The BVI wasn’t nicknamed “Nature’s Little Secrets” for nothing. Take a drive along the coast, and you’ll inevitably experience something amazing – even if you have called these islands home for a number of years – the mangrove. Recently, for example, while waiting for a friend at the H. Lavity Stoutt Community College’s Marine Center, I took a stroll behind the building and stumbled upon the most beautiful mangrove forest I’ve ever seen.

Photo (left): Mangroves created this calm refuge from the Sir Francis Drake Channel; (right) A wooden walking path makes exploring the mangroves at Paraquita Bay easy and safe.

The BVI’s mangrove “forests” are natural little secrets within themselves. If you are living anywhere in the BVI, you’re sure to have seen a grouping somewhere within your travels. Every major island in our chain has a forest of some degree; Tortola (quite a few) Jost Van Dyke, Virgin Gorda, and Anegada. Often, you may drive right up to them, but for the best view with the least amount of environmental impact you should kayak or stand-up paddleboard to one. You could also try snorkeling them, though the water is often quite shallow and possibly silty.

Mangroves are true marvels of nature, in part because of what they provide to boaters, who know them as ideal places to hole-up during a hurricane. If you can, drive down to Paraquita Bay and see for yourself. If you follow the little dirt road behind the college’s Marine Center, and veer off to the left, the Rotary Club has built a dock and boat launch, with a great view of what Paraquita has to offer: a well-designed system of chains providing a shelter for all kinds of vessels if a storm is approaching. Back in 1989, when Hurricane Hugo struck these islands, this was a designated place to tie up and hunker down. Something like 200 boats chose this spot, for all the right reasons.

To the environmentalists among us, mangroves provide an even greater function, that of birthing ground and nursery for many species of fish. The mangroves’ complicated root system keeps out larger predatory fish, so they are an ideal habitat for growing juveniles. Lobsters and conchs get a great start here, too. Mangroves also provide a habitat for many birds, like the flamingo and the little blue heron.

Florida Oceanographic Society marine biologist Brittany Biber has a poetic take on these sea plants and their benefit to the marine ecosystem.

“I like to think of mangroves as Mother Ocean’s fingers,” she said recently. “They not only hold the shoreline to protect its substrate from the greedy clutches of waves but also harbor many important species in their earliest stages of life. They grasp to the earth with all their might using prop roots (red mangroves) and pneumatophores (black mangroves) to expand their impact.”

As Brittany points out, the mangroves seem downright magical to anyone familiar with the phrase “salting the earth.”

“They are unique in their ability to tolerate high saline environments and have perfected the art of salt excretion. … They consume excess nutrients from the water while their falling leaves dye its swamps a tea stained color known as tannin,” she said.

Three types of mangroves can be seen in and around the BVI: the red, the black, and the white. Don’t expect to be able to differentiate them by colors alone. The easiest way to spot which of the three types you’re looking at is to check out where they’re growing.

Great Egret
A great egret perches among mangrove roots.

Red mangroves grow directly in seawater, welcoming and sheltering many aquatic animals. This root system is so hearty it may support a 50-foot tree! The red mangroves differ from the others in some interesting ways. One example is their mode of propagation. They may go from flower to seedling while they are still attached to the parent tree. Once the seedling is large enough, it will fall off the tree into the water where it may stay put or be carried downstream by the water. A unique feature of red mangroves is their land-making ability. They act as giant filters to silt run-off from the hills during heavy rains. The root system traps the silt and gradually builds it up into solid land. In season, you’ll see land crabs scurrying about on these newly created lands.

Maybe the easiest to pick out at-a-glance are the white mangroves. They are highly salt tolerant and may produce pneumatophores if growing in a swampy area. Pneumatophores are extensions of the root system that grow vertically to a height that will remain above settled water after rains or inundation by the sea. They are what allow the trees to “breathe” despite their being surrounded by water. White mangroves have light bark, as their name implies, and can grow to a height of about 40 feet.

The black mangrove is the most salt tolerant of all the species that proliferate in the BVI. They also grow to impressive size, some as tall as forty feet. This is probably the most utilized type of mangrove in the BVI for things like fence posts and fish pots. It is also burnt for charcoal; a fairly common practice locally. The black mangrove is another of the species that produces pneumatophores.

Though not a true mangrove, buttonwood trees, sometimes called gray mangroves, look somewhat similar and grow in coastal areas where mangroves aren’t present.

Mangroves are important for keeping the local ecology in balance through the wetlands they create, which serve as a filter between our islands and the sea, explains BVI based marine scientist Dr. Shannon Gore.

“This type of mangrove forest is a continuous ‘mangrove wetlands,’ an ecosystem which includes a hypersaline aquatic habitat (i.e. a salt pond), the pond’s shoreline and its fringing mangroves,” Shannon said. “Since the functions of wetlands include storm and flood mitigation, erosion control and the retention of sediments and nutrients from entering coastal waters, the loss of more than 84 percent of the original wetlands for development purposes in the BVI has had several effects. First, the loss of wetlands coupled with reduced vegetation on steep hillsides from developments and unpaved cut roads has contributed to localized flooding in low-lying areas. This flooding often causes erosional gullies to form in which sediment-laden storm water breaches the beach berm and enters coastal waters.”

Even if the runoff soil doesn’t make it all the way to sea, Shannon added, it can still impact our beaches.

“Some of these sediments may end up being trapped by the sand and mixed with terrigenous materials which may be the reason why residents claim some beaches have lost their bright golden appearance,” she said.

Experts agree mangroves are worth protecting not just because of their beauty and the habitat they provide to sea life, but also because they make the coastal environment more resistant to the forces of modern life.

Brittany puts it this way: “These trees enable coastal shorelines to persevere against all the stresses we as humans throw their way. They fight the effects of boat wakes, dredging, and pollution while serving as a haven for numerous species. Mangroves are a critical tree to many aspects of marine life and without them we would truly be swept away with the changing tides.”

Given all this, protecting our mangroves is of high importance. Conservation and replanting efforts are underway by government, non-profit environmental groups, and private. If you want to help in the effort it’s as easy as sticking propagules upright in the soil where the trees occur.

Another important way that we can help mangroves is to avoid littering, especially in these areas. Water doesn’t circulate well in bays, ponds, and lagoons, so live-aboard boats and power boats are discouraged in mangrove areas. Cutting or removal of mangroves for development or any other purpose should be avoided, as should dredging and filling projects, as these can have adverse effects on existing mangrove systems.

If you’d like to learn more about mangroves, the Conservation and Fisheries Department in Road Town can provide useful information, tips, and guidelines for protection purposes. And again, if you have the interest, take that drive out to the college’s Marine Center, where Tortola’s Rotary Club has done a terrific job of constructing and maintaining a boardwalk so you can get up-close-and-personal with the majestic trees.

Should you venture out to observe these natural wonders, the best spots for viewing are:

  •  Tortola and Beef Island- Hodges Creek, Sea Cows Bay, Slaney, Wickham’s Cay, Belmont Pond, North and South sides of the Beef Island Channel, Well Bay, Trellis Bay Pond, and for best walk-through viewing without hurting the forest, Paraquita Bay, with even a boardwalk.
  • Virgin Gorda- Deep Bay
  • Jost Van Dyke- East End
  • Anegada- Flamingo Pond, East End

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Official webpage of The BVI Welcome Guide. Source of information for everything in the British Virgin Islands since 1971.

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