The influence of sargassum on west-end beach sand accretion: Galveston Island, Texas. Progress and status report May 15, 2006

The beaches of Galveston Island experience an annual beach cast of Sargassum (“seaweed”) during late spring/early summer – a season of significant economic input to the island and county. This accumulation inspires much debate among numerous stakeholders including property owners, business owners, recreational fishers, tourists, and local, county and state governmental entities. Several management options have been suggested, but as yet, there is no holistic management program for the island. Many locations are raked or scraped (e,g. Pirates Beach), and other locations are left in the natural condition (Galveston Island State Park). At this time, there appears to be no scientific data regarding the impact of beach cast on the Gulf beaches of Galveston Island. There have been recent studies pertaining to these issues along the coast of Kenya Africa, Eastern Indonesia and Western Australia. The study in Kenya using surface studies found that raking of beach cast had substantial impacts on the beach stability thus increasing the possibility of beach erosion. In order to facilitate informed decision making regarding the management of the “sargassum issue”, the Coastal Geology Laboratory at Texas A&M University at Galveston is in the process of quantifying the influence of sargassum on beach morphology. This data will be of utility to the numerous stakeholders involved and the decision making and management of the island’s beaches. This study will take the above research a step further by pulling several one meter depth cores along specified sites four times per year with each core being analyzed for organic content and sand grain size The specified sites will have the beach profile measured on a monthly basis to help locate potential accretion areas for future coring. The collection of data from February thru April is essential in developing base line data that will be used for comparison to the data collected during September and November after the conclusion of the sargassum season.