Status and Trends of Wetlands and Aquatic Habitats on Texas Barriers: Upper Coast Strandplain Chenier System and Southern Coast Padre Island National Seashore

Wetland and aquatic habitats are essential components of barrier islands along the Texas coast. These valuable resources are highly productive both biologically and chemically and are part of an ecosystem on which a variety of flora and fauna depend. Scientific investigations of wetland distribution and abundance through time are prerequisites to effective habitat management, thereby ensuring their protection and preservation and directly promoting long-term biological productivity and public use.

This report is the latest in a series of wetland status and trend investigations of barrier islands along the Texas Coast (White et al. 2002, 2004, 2005, and 2006). Presented in this report are results of two status-and-trend studies: one of the upper Texas coast along the strandplain-chenier system from Sabine Pass to East Galveston Bay, and the other of the southern Texas coast along Padre Island National Seashore (PINS) that includes the central section of Padre Island (Fig. 1).

The two study areas are very different. Geologically, the upper Texas coast is characterized by a modern strandplain-chenier system with well-preserved chenier beach ridges with interlying marsh-filled swales (Fisher et al. 1973). Relict beach ridges and intervening swales have an orientation roughly parallel to today's shoreline marked by the Gulf beach. The swales are the sites of extensive linear estuarine marshes. The strandplain-chenier system has gradually evolved through erosion, deposition, compaction, subsidence, and locally faulting. The strandplain extends along the Gulf shore toward the southeast to High Island. High Island is a salt dome near the Gulf shoreline with elevations exceeding 75m (25ft) (Fig. 1); The study area extends landward to the Gulf Intracoastal Waterway.