Galveston Bay is the second-busiest port in the nation by overall tonnage. Other major ports utilizing the bay include the Port of Texas City and the Port of Galveston. With its diverse marine life, Galveston Bay also produces more seafood than any bay in the nation except the Chesapeake. The Gulf Coast gained its present configuration during the most recent glacial period approximately 18 ka (thousands of years ago). Low global sea levels allowed the Texas mainland to extend significantly further south than it is presently, and the Trinity River had carved a deep canyon through present-day Bolivar Roads on its way
Galveston Bay snapper. In 2007, the Port of Galveston produced of seafood with a value of $40.1 million. Galveston Bay supports a significant recreation and tourism industry, especially as a result of its proximity to major population centers. Over 40% of Greater Houston residents participate annually in hiking and swimming along the bay, while 20% go fishing and 15% go boating. The five counties surrounding the bay are home to 88,000 registered pleasure crafts. Fishing expenditures (such as the purchase of fishing bait or lodging) along Galveston Bay and Sabine Lake generate approximately $650 million annually. The recreational fishing industry supports over