Fish kills in central and northern Texas are usually caused by low dissolved oxygen levels in the water. There are other fish and wildlife kills that result from natural biological toxins and oil and gas production site brine spills. The ever-increasing human population and growing domestic animal populations have caused water quality problems in this region of Texas. Sewage runoff from these dairies and feedyards results in high organic loading and low dissolved oxygen in neighboring streams, rivers, and ponds. The effects are seen in algal blooms and fish kills.
Algal blooms deplete oxygen levels, cause bacterial problems, and cause foul tasting drinking water.