An experimental test of the effects of beach raking on macroinvertebrate communities of Texas beaches

2010-2013 - $70,730

David Hicks
Department of Biology
The University of Texas at Brownsville

Reuben Trevino
Coastal Resource Manager
Town of South Padre Island


Mechanical removal of beach-cast wrack is a highly debated issue within Texas’ coastal counties. Central to the debate is the insufficient, often conflicting data available to natural resource managers and local governments necessary for objective decision making in regards to beach management practices. However, recent research indicates that beach-cast wrack accumulations (e.g., sargassum) are an important source of recycled nutrients and detrital material that form important trophic linkages between the food webs of oceanic, nearshore, intertidal, and terrestrial habitats. The objective of this study is to experimentally determine if the presence of beach-cast wrack influences the abundance, biomass, and trophic structure of swash zone macroinvertebrate communities through comparisons of mechanically raked and unraked beaches on South Padre and Brazos islands. The explicit objectives of this project are (1) to compare the swash zone communities in terms of trophic structure, similarity, diversity, and biomass among raked and unraked beaches; (2) to identify the species and/or trophic guilds principally responsible for recognized sample groupings (as potential stress indicators); and (3) to frame results concerning wrack removal in the context of recommendations to coastal managers.