TX Overview Bottom sediment serves a sink, as a result of deposition, and as a source of pollutants to the water column and organisms. Sediment is an integral component of aquatic ecosystems, providing habitat, feeding, spawning and rearing areas for many aquatic organisms. Benthic organisms are in direct contact with bottom sediments and pore waters.
Sediment quality is a key environmental indicator of status and trends for estuaries.
In order to interpret the degree of contamination, and the need for management, it is important to utilize available assessment tools such as sediment quality guidelines. The purpose of utilizing sediment quality guidelines in assessing the bottom sediments is to estimate the effects of toxic pollutants on benthic communities. Water quality criteria or standards, which are designed to protect aquatic organisms residing within the water column, may not be protective of benthic organisms. For this reason it is appropriate to integrate sediment quality guidelines, along with benthic community assessment and toxicity testing to evaluate impacts to these communities. This paper presents guidelines for selected pollutants applicable to Galveston Bay and other Texas estuaries, and provides recommendations on assessing the degree of contamination.