In the lower portion of the segment, ranching is the predominant agricultural activity with some crop farming. There are 26 permitted wastewater discharges to the entire Laguna Madre, but the majority of these discharges are to the Lower Laguna Madre which is outside of the Nueces-Rio Grande Coastal Basin. No water quality concerns are identified in this segment, but a possible concern for ammonia is identified. Trend analyses show that fecal coliform densities are probably increasing. An algal bloom of brown tide algae continues to affect water quality in the Laguna Madre.
Studies are in progress to determine the causes of the algae bloom's persistence.
This segment is a shallow, secondary bay system that drains an extensive portion of the Nueces-Rio Grande Coastal Basin through a network of intermittent creeks. The area's economy is based on ranching, agriculture, and petroleum exploration. Twenty-one permitted wastewater discharges are in this segment. A brown tide algal bloom continues to affect water quality in this segment. A fish kill was reported in October 1989 in San Fernando Creek due to a chemical spill.