Mobilians’ relationship status with bay mud is complicated. The powerful Mobile River cuts a deep, carving path as it flows but fans out and weakens once in Mobile Bay, depositing silt and mud in formidable quantities. Since the early 1800s, Mobile has deployed various types of dredging machines with the intention of creating a more accessible port. Some were more successful than others in fighting and clawing against the muck. But take a peek over the side of the Bayway, and you’ll see that the same mud we dredge plays host to a multitude of life, from clams to gators. Or, look at a map of Gaillard Island, Mobile Bay’s man-made mud island and bird sanctuary. It all just goes to show that sometimes it’s a good thing to be playin’ in the mud.
MUD RUNS DOWNHILL Unfortunately, human development along our waterways can have a negative impact on the Bay’s ecosystem in the form of thick, muddy runoff. Heavy rains cause an influx of mud from new developments to flow into the Bay, making the water cloudy and affecting all forms of marine life. Such mud is responsible for the loss of much of the Bay’s seagrass, thereby affecting the fish and shellfish who rely on the grass for shelter.
THE LONG AND WINDING ERODE Created by the perpetual weathering of rocks and soil, the mud in Mobile Bay is a combination of sand, silt, clay and organic matter. These materials are deposited in the Bay by the vast network of rivers spilling out of the Mobile-Tensaw Delta.
DOWN THE DRAIN Mobile Bay is the sixth largest drainage basin in the United States, catching the water flow from more than 44, 000 square miles. In fact, the Apalachee, Blakeley, Middle, Mobile and Tensaw rivers deliver 41 billion gallons of fresh water to Mobile Bay every single day. If you add up all the sediment those rivers carry, it equals a whole lot of mud!
Our history in the muck & Mire
- In the early 19th century, mud made navigating Mobile’s port a tricky and sometimes dangerous affair. In 1826, Congress finally set aside funds to dredge a portion of the port; however, that did not immediately resolve the problem. As historian John Sledge recounts in his book “The Mobile River, ” one British traveler, John W. Oldmixon, described his experience on a schooner leaving Mobile Bay. Stranded on an area known as Choctaw Bar in the 1850s, Oldmixon bluntly wrote, “It was very tedious in the bay on the mud.”
- You know those long stretches of mud you can see from the Bayway when the tide is low on a winter’s day? These “mudflats” aren’t as barren as they might seem. In fact, these growing layers of sediment, delivered by the many rivers of the Mobile-Tensaw Delta, provide the foundation for Mobile Bay’s entire ecosystem. Snails, worms, crabs and clams wiggle and scamper as ever-watchful birds plummet for a quick snack. Scientists agree that these expanses of mud, and the life they support, are the backbone of Mobile Bay as we know it.
- The triangular Gaillard Island, located in Mobile Bay, was created in 1979 as a disposal site for the mud dredged for a shipping channel between Mobile Bay and Theodore Industrial Park. Named after the Mobile environmentalist Dr. M. Wilson Gaillard, the island is made up of 31 million cubic yards of dredged material and is considered a huge environmental success for its positive impact as a nesting haven for numerous bird species, particularly the brown pelican. Once placed on the Alabama and federal endangered species list, the brown pelican was removed from both lists by 1998, partly due to their propagation on Gaillard Island.
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Text by Breck Pappas
