Innovative Technology Seaweed Prototype Dunes

Duration: February 2014-August 2015
Sponser: Texas General Land Office and Galveston Park Board of Trustees
Funding Amount: $148,775
PI: Jens Figlus
Co-PI: Tom Linton and Robert Webster


A healthy beach-dune system is the economical and the most aesthetically pleasing natural coastal protection against storm surge and wave attack. Unfortunately, large stretches of Galveston Island lack a proper dune system. At the same time Texas beaches experience frequent seaweed (Sargassum) landings that can be up to 2 feet in height for a single landing, practically blocking access to the water for beach users. The intent of this project is to utilize the seaweed wrack material of heavy landings to build and reinforce coastal dunes in a sustainable fashioon without disturbing the upper beach template. The whole project includes several components: prototype construction, monitoring, development of a seaweed baler, and wave flume testing. Two prototype dunes will be constructed at the high tide line, one on the western part (Spanish Grant) and one on the eastern part (Apffel Park) of Galveston Island. Each of those dunes will be comprised of two sections-one with new seaweed reinforcement, one without. The seaweed reinforcement will be in the form of compacted Sargassum, i.e. "seabales" which will be incorporated into the berm of the dune and covered with sand. The evolution of these test dunes (seabale composition, spurred vegetation growth, erosion due to storms, etc.) will be monitored throughout the project lifetime. The hypothesis to be put to the test is whether the seabale reinforced dunes provide more resilience against storm surge and wave attack due to the added strength of the compressed Sargassum material in the short term and the enhanced growth of dune vegetation in the long term. Additionally, continued application of the process could help to sustain and grow healthy dune systems over time. In order to prepare seabales from Sargassum wrack landings a specialized machine will be developed based on modified hay baling and beach cleaning equipment. Laboratory tests will be conducted to determine the mechanical properties of the Sargassum material in its natural and compressed states. Furthermore, wave flume tests of model dunes will aid in finding the optimal configuration of the fortified dunes. After successful completion of this pilot project the concept could be extended to large stretches of the Texas coast potentially improving currently employed coastal maintenance strategies and providing an answer to the question many Texas beach goers have: "What to do with the Sargassum?"


For questions about the Center:

Dr. Sam Brody
Ocean and Coastal Studies Building
1001 Texas Clipper Rd
Galveston, TX 77551
Bldg. 3029, Room 366
Phone (409) 740-4939
Fax (409) 740-4429


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