Red Tide Rangers

The Red Tide Rangers, a dedicated volunteer group formed and trained by Texas Sea Grant, monitor Texas coastal waters for the presence of harmful algal blooms (HABs), such as the red tide caused by the dinoflagellate Karenia brevis.

Karenia produces brevetoxin, a neurotoxin that affects the central nervous systems of fish, birds and mammals. When the Kareniacells are ruptured, such as by waves in the surf zone along the coast, the brevetoxin is aerosolized and can irritate eyes and respiratory systems of people on the beach, potentially creating a serious health hazard for asthmatics and others with respiratory conditions. Even more dangerous, the toxin accumulates in the organs of aquatic animals and is hazardous to humans if they ingest it by eating tainted seafood such as oysters.

Red tide blooms also have a significant impact on the Texas economy by threatening commercial and recreational fisheries and decreasing tourism. Red Tide Rangers are trained to monitor coastal waters daily, checking Karenia cell presence and abundance, noting any fish kills and gauging the severity of aerosolized brevetoxin, and reporting this information to state and federal agencies.

These citizen scientists have provided the State of Texas and the federal government with valuable real-time data needed to manage public health and safety. The state uses the information to issue timely health advisories to the public, to fishermen and to resource managers who regulate state waters and commercial and recreational fisheries impacted by the red tide. Their data are also used to provide critical ground truth to confirm bloom locations for NOAA’s Coastal Services Center and contribute to NOAA’s efforts to forecast red tides.


  • Collected, analyzed and submitted data on 562 water samples to state and federal agencies during two recent red tide outbreaks in 2009 and 2011.
  • Provided real-time information to safeguard public health.
  • Increased safety of Texas beaches, shellfish fisheries and seafood consumers.
  • Ground truthed NOAA’s red tide satellite imagery system.
  • Expanded the program by training 20 volunteers in two Upper Texas Coast counties.
  • Promoted wise use, understanding and stewardship of Texas’ rich coastal and marine resources.
  • Enhanced the public value of science.

For More Information:

Tony Reisinger

Extension Agent

Cameron County