Events where dissolved oxygen concentrations are below 2 mg/l (hypoxia), is becoming a wide-ranging phenomenon that may reduce habitat quality in estuarine and coastal waters.  Hypoxia may reduce habitat quality and this may have cascading effects through ecosystems.  Many of the shallow estuaries in the Gulf of Mexico experience seasonal episodes of hypoxia.  A NOAA eutrophication survey of the Gulf of Mexico from Florida Bay, FL to Baffin Bay, TX and the lower Laguna Madre determined that 30 of 37 estuaries experience periodic hypoxia from June to October and that hypoxia is persistent in the lower Laguna Madre.  This survey estimated 5.2-29.3% of the total estuarine area between Anclote Key, FL to Rio Grande, TX was affected by low DO conditions.   Seasonal hypoxia has been detected annually in Corpus Christi Bay, TX since 1988 however, the impacts on the fish population community structure are unknown. The goal of this study is to examine the effects of low oxygen on the nursery value of estuarine habitat types, to identify community level responses, and predict the magnitude of change associated with anticipated increases of hypoxic events in estuarine ecosystems using both laboratory and field-based experiments.