Gunter, G.Transactions of the Thirty-Fourth North American Wildlife and Natural resources Conference, March 2,3,4,5 1969.2010-02-152010-02-151969http://hdl.handle.net/1969.3/22342p. 51-74The last Ice Age, called the Wurm in Europe and the Wisconsin in North America, lasted over 100,000 years. So much water was tied up in ice that the sea level stood 400 feet lower than it does today and the larger part of the continental shelf was exposed around the Earth. During that period the rivers along the present Gulf of Mexico coastline were running at a rather steep gradient in gorges or very narrow deep estuaries, possibly into bays and sounds farther out on the shelf. Prof. Albert Collier and I independently found old oyster shells five and ten miles out in the Gulf off the Texas coast. They were quite abundant, and my specimens were taken in trawls. These shells showed signs of having been buried. Emery and Garrison (1967) found oysters as much as sixty miles offshore from the New Jersey coast. They were said to be almost 11,000 years old. It seems certain that estuarine environments formerly lay many miles seaward of what they do now on the Gulf Coast; presumably they moved landward as the sea level rose.reefshell dredgingmudshell dredgingoyster cultureenvironmental impactArticle