Thursday, August 9, 2007 - 1:30 PM

COS 138-1: The Effects of Sargassum sp, a brown alga, on dune plant growth of species Panicum amarum

Amy M. Williams and Rusty A Feagin. Texas A&M University - College Station

Dunes are an integral part of coastal ecosystems because they provide habitat, food and protection to the structures landward.  However, in many coastal communities, dunes are being destroyed by development and eroded by natural processes.  Dune stabilization and restoration is often accomplished by establishing vegetation, which traps sand through roots and surface structures.  In Galveston, TX, Sargassum sp, a brown algae that is naturally deposited from May to August, is another inconvenience for beach managers because it obstructs the beach face that attracts tourists.  Typical practice is to rake the Sargassum using a tractor and place it at the face of the dunes.  This study analyzes the effects of Sargassum on the dune plant Panicum amarum.  Plants were asexually grown in a greenhouse by field samples taken from Galveston Island.  Plants were grown in sand without Sargassum (control) and with Sargassum on top of the soil, mixed in, washed by tap water and unwashed.  A combination of 9 treatments were done on 72 plants (8 plants per treatment) for 3 months beginning in July 2006.  The results indicate that any type of addition of Sargassum increased plant growth.  When the same treatment was done with double the amount of Sargassum, the plants showed further increased growth.  The study indicates that Sargassum does provide benefits to dune plants and therefore has potentially to help increase the stability of dune systems.  Coastal managers may be able to capitalize on the natural fertilizing aspects of Sargassum instead of viewing it as a nuisance.