Evaluation of the Influence of Various Stream Substrates on Aquatic Biota within Harris County, Texas

Purpose/Objectives

To characterize the hydrology, physical habitat, biological communities, and primary productivity associated with various types of substrates deployed at different stream channel modification projects.

Study Area

Jordan Gully, Baytown Creek, White Oak Bayou, Rummels Creek, Cowart Creek

Project Period

2007 – 2011

Description

Our working hypothesis was that substrate type does influence aquatic communities after adjusting for the effects of water quality and hydrology. The hypothesis that we tested was that there is no difference between treatment and control sites in respect to hydrological, water quality, instream habitat, and biological characteristics. We explored through multivariate methods and correlation analysis the relationship between the various measured parameters.

We were interested in comparing various substrate types (treatments) historically used in stream channel modification against "background" natural conditions within the watershed. During each sampling event we conducted an assessment of hydrological conditions and instream and riparian habitat following protocol outlined in the TCEQ surface water quality monitoring procedures and receiving water assessment manuals (TNRCC 1999; TCEQ 2003 and TCEQ 2005). We also used a combination of digital photography and GPS based surveying techniques to document site characteristics including substrate complexity and stream cross-sectional profiles.

During each sampling period, we made water quality measurements at each site. Our invertebrate community characterization consisted of seasonal collections at each site. Our sampling approach consisted of d-frame kick samples (TCEQ 2005 and TNRCC 1999). Our fish community assessment consisted of seasonal collections made at each site using techniques outlined in TNRCC (1999). Sampling consisted of seining and electro-fishing using a backpack shocker. We provided an assessment that documents the suitability and comparative utilization, by aquatic organisms, of various common substrate materials used by HCFCD for stream modification projects.

Sampling was conducted during spring and summer months, since these months represent months of highest recruitment, diversity, and growth for many aquatic organisms. This period also exhibits potentially stressful conditions due to seasonally hot temperatures, low flows, and depressed dissolved oxygen levels.

Publications

Guillen, G. and Oakley, J.W. 2013. Response of aquatic communities in urban areas of Harris County to stream substrate: 2007–2010. EIH Technical Report 13-005:153.

Knothe, G.J. 2012. The influence of urbanization on streams: the use of GIS spatial analysis to study land use influence on fish communities, water quality and physical habitats in Southeast Texas. University of Houston Clear Lake, Houston.

Sandefur, J. 2008. Evaluation of the influence of various stream substrates on fish Communities within Harris County. University of Houston-Clear Lake, Houston.

Project Sponsors

• Harris County Flood Control District