Environmental impacts of beach raking of Sargassum spp. on Galveston Island, Texas

摘要

Coastlines are active environments molded by me interactions between land and sea. Beach dynamics are managed by both human decisions and natural forces. Pelagic brown algae, Sargassum fluitans and S. natans, deposited by the sea contribute to coastal ecosystem throughout the world. Coastal managers are confronted with the difficult choice of cleaning sargassum off the beach or leaving it alone. The most common technique to remove sargassum from the beach front is to use mechanical equipment to rake the material and deposit it at the base of the dunes. This method is beneficial to the economic aspects of tourism. However, raking may cause adverse environmental effects. Currently, there are a variety of public opinions that exist for and against beach raking. Our study compared raked and unraked beaches in Galveston Island, Texas, a 43-km-long barrier island. Our results indicated that there is not a statistically significant difference in elevation changes between the raked and unraked beaches over a one-year period. We also looked at species that use the sargassum while it is on the beach. Our results indicated the avian, beach-endemic, and terrestrial taxa on the beach may be more dependent on the fresh influxes of sargassum then the older deposits of sargassum at the high tide line. Therefore, beach raking may not cause detrimental environmental impacts to avian and other fauna on the beach that outweigh the economic benefits of raking.