Honey Island Swamp

Category: Inland Aquatic Biomes.

Geographic Location: North America.

Summary: Once heavily logged for its cypress trees, today Honey Island Swamp is a healthy second-growth swamp supporting a variety of wildlife.

Honey Island Swamp is a cypress-tupelo gum swamp, located approximately 50 miles from New Orleans. Honey Island Swamp gets its name from swarms of honey bees that were once seen on a nearby island. This subtropical, low-elevation ecoregion is a well recovered wetland more than 27 miles (43 kilometers) long and approximately 7 miles (11 kilometers) across, situated between the Pearl and West Pearl Rivers in the southern coastal plain of Louisiana.

Considered one of the least altered river swamps in the country today, Honey Island Swamp was logged for its cypress when timber industries moved in starting in the early 1700s. The swamp now exhibits the characteristics of a healthy, mature second-growth forest.

Cypress-tupelo gum swamps such as Honey Island Swamp are flooded year round. These wetlands are comprised of muddy-bottom channels with silty, tidal-driven waters. They are characterized by low-gradient elevations that, along with tidal currents, slowly move the water so that aquatic habitats are intermediate between streams and lakes in their morphology and biological characteristics. Regular flooding prevents the forest from being overtaken by upland tree species.

Spanish moss can be seen hanging from the cypress trees that emerge from shallow water that is often covered with a layer of green algae. This blanket of algae on the surface is able to grow because of the slow or stagnant movement of the waters. The water here is often tea-colored from tannic acid produced during the slow decomposition of the large amounts of detritus that remain in the swamp as the tree limbs and twigs age and fall away.

Biota

Honey Island Swamp encompasses dense loblolly and slash pine forests and mixed hardwood forests located in the uplands; these include a robust array of tree species. Among the oaks are water, overcup, nuttall, cow, obtusa, and live oak; other hardwood varieties are bitter pecan, hickory, American elm, and swamp red maple; additional types featured are sweetgum, magnolia, and beech. Mid-story in the mixed hardwoods stands are found ironwood and arrowwood, as well as Virginia willow, swamp privet, buttonbush, and water elm. In the lowest elevations of swampy floodplain grow the bald cypress and tupelo gum, along with swamp blackgum.

The bald cypress is Louisiana's official tree, named in 1963. This deciduous tree's falling foliage adds to the decaying material that adds nutrients to the swamp waters. Adaptations of the cypress tree to the swamp are their flared or buttressed lower trunks. This wide base helps anchor the tree and prevent damage from the wind. Also, as a result of the constant submersion in water, the cypress tree develops “knees” that allow the roots to spread over a larger area. Cypress's ability to resist decay is what make it such a valuable resource as lumber.

Honey Island Swamp supports everything from alligators to bald eagles. This ecoregion sustains a variety of habitats for animals that move through, live on top of, or along its edge. These are low-oxygen waters with little current or mixing. Mosquitoes lay their eggs in the stagnant water, providing part of the base of the food web here. Honey Island Swamp also provides habitat for deer, squirrel, rabbit, fox, beaver, nutria, mink, opossum, raccoon, and bobcat—as well as a population of feral pigs. Cougar and wolf are seen occasionally.

Bald eagle and golden eagle are seen occasionally; swallowtail kite and osprey are more common, as are the red-shouldered hawk, barred owl, and eastern screech-owl. Other year-round resident avians include wood duck, wild turkey, yellow-billed cuckoo, carolina chickadee, tufted titmouse, carolina wren, gray catbird, and brown thrasher. Waders include the yellow-crowned night heron and great egret.

Adding to the variety are northern cardinal and eastern towhee; and a range of woodpeckers such as red-headed, red-bellied, downy, hairy and pileated. In 1999 there was thought to be a sighting of the thought-to-be-extinct ivory-billed woodpecker, but there was little proof of any sightings. The news, however, brought much attention to the area.

A variety of reptiles—including alligators—and amphibians are also found within the swamp's boundaries. The ringed map turtle, designated as a threatened species, is only found in this region. Reptiles and amphibians are especially suited to swamp life, because of their ability to adapt to the changing environment, and to take advantage of a range of water levels. Fish here include largemouth bass, bluegill, warmouth, red-ear sunfish, alligator gar, freshwater drum, flathead catfish, and buffalo fish. Enormous quantities of crawfish thrive in Honey Island Swamp.

Human Impact

In 1980, President Jimmy Carter authorized the 37,000-acre (15,000-hectare) Bogue Chitto National Wildlife Refuge (NWR), located north of and adjacent to Honey Island Swamp. The swamp is now a permanently protected wildlife area under the control of this refuge, and managed by the Louisiana Department of Wildlife and Fisheries. A larger part of the swamp is claimed as the Pearl River Wildlife Management Area (WMA). The Pearl River WMA, at 35,000 acres (14,000 hectares), is comparable to the Bogue Chitto NWR in size.

Honey Island Swamp remains intact except for its waterways. The swamp is accessible only by boat or on foot; few roads exist in the area, and none within the borders of the swamp. As designated by the Nature Conservancy, Honey Island Swamp is Louisiana's first Nature Preserve (with the pine forests of the northern portion of the area controlled by the Bogue Chitto NWR). This ecosystem provides habitat and food sources for the surrounding plant and animal life, water preserves, water filtering, spawning and fishing areas, as well as flood control from major storm surges.

Global warming poses a real and growing threat to the Honey Island Swamp biome, in particular from the projected impact of sea-level rise. At the most pessimistic estimates, the swamp could remain substantially inundated, such that areas today fed and refreshed by tidal flows would become entirely different, permanently submerged habitats. Saltwater intrusion, and its habitat-changing dynamic, is an associated impact risk that seems imminent.

Bibliography

"In Louisiana, Celebrating the Beauty of the Swamps." AFAR, 2 May 2022, www.afar.com/magazine/touring-louisiana-swamps-a-meditation-on-climate-change. Accessed 6 Aug. 2022.

Keddy, Paul A. Water, Earth, Fire: Louisiana's Natural Heritage. Bloomington, IN: Xlibris, 2008.

NatureWorks. “Swamps.” New Hampshire Public Television, 2012. http://www.nhptv.org/natureworks/nwep7i.htm.

Nickell, Joe. “Tracking the Swamp Monsters.” Committee for Skeptical Inquiry 25, no. 4 (2001).