Mudshell Dredging

Dredging of mudshell (a mix of mud, silt, sand and shell) in Texas bays began in the late 1800s, originally to deepen navigation channels. By the 1910s, more extensive dredging began for cement production, magnesium extraction, and road building, reaching high mining rates in the 1930s through 1960s. An estimated 300 million cubic yards of material were removed statewide, with some mined areas dropping 20 feet below the original bay floor. Due to the increase in turbidity and loss of major oyster reefs and fish nursery habitat, a public outcry (please see Cecil Reid discussion) led to the state discontinuing new dredging permits by 1969. As trucking, rails and roads improved, demand switched to lime from Hill Country limestone quarries and aggregate from gravel mines in the coastal prairies. While mudshell dredging continued into the early 1980s in San Antonio Bay, Texas Parks and Wildlife is carrying out restoration efforts at one Bay site, Josephine’s Reef.