Influence of Vessel Passages on Tidal Creek Hydrodynamics at Aransas National Wildlife Refuge (Texas, United States): Implications on Materials Exchange

Abstract

Abstract The impact of commercial vessels on coastal hydrodynamics and sediment movement has been measured and simulated in shipping channels and rivers. However, little empirical data exist on the temporal variation in vessel-generated forces in addition to the ecological implications for natural waterways such as tidal creeks and bayous. Along the U.S. Gulf of Mexico coast, these ecosystems may be highly susceptible to unnatural currents created by commercial vessel traffic. We sought to characterize and quantify the impact of large vessel traffic in the Gulf Intracoastal Waterway (GIWW) on tidal creek hydrodynamics at Aransas Wildlife Refuge (ANWR). Creek water level was monitored at 1-minute intervals in three different tidal creeks at ANWR during the summer of 2004. We also conducted preliminary measurements of bedload sediment flux associated with vessel passages. Vessel-induced fluctuations in water level in at least one site were the equivalent or greater than the diurnal tidal range (about 0.1 m)...