Red Tide

What is red tide?
Red tide is a naturally-occurring, higher-than-normal concentration of the microscopic algae Karenia brevis (formerly Gymnodinium breve). This organism produces a toxin that affects the central nervous system of fish so that they are paralyzed and cannot breathe. As a result, red tide blooms often result in dead fish washing up on Gulf beaches. When red tide algae reproduce in dense concentrations, also known as a "bloom," they are visible as discolored patches of ocean water, often reddish in color.

What causes red tide?
Red tide is a natural phenomenon not caused by human beings. When temperature, salinity, and nutrients reach certain levels, a massive increase in Karenia brevis algae occurs. No one knows the exact combination of factors that causes red tide, but some experts believe high temperatures combined with a lack of wind and rainfall is usually at the root of red tide blooms. There are no known ways that humans can control it, but many scientists around the world are studying red tide at present. It's important to remember that red tide has happened before and the Texas marine environment has always recovered.

How, when, and where do red tide blooms start?
Texas red tides have occurred from August through February. They typically begin in the Gulf of Mexico. Currents and winds then transport blooms toward shore. The blooms mainly come up along Gulf beaches, and less frequently into bays and estuaries.


Where is the red tide on the Texas coast right now?
It's almost impossible to say exactly where the red tide is at any given moment because blooms constantly expand, contract, and move around in response to winds and tides. It's important to realize that red tides are typically isolated patches that don't blanket every stretch of beach. They often concentrate around wind- or tide-protected areas like man-made jetties.

How can I get the latest information on the current red tide?
Texas Parks and Wildlife has set up a menu item on its main toll-free information line to provide regularly updated reports on the current red tide event. Phone 800-792-1112, press 4 for fishing, then 9 for red tide information. Red tide updates will also appear on this website each time that an update is provided by biologists: http://www.tpwd.state.tx.us/landwater/water/environconcerns/hab/redtide/.

Should I consider postponing a trip to the coast right now?
Jack Ralph, head of the Texas Parks and Wildlife Department's Kills and Spills Team, had this to say on the subject... "If it were my family heading to the coast, I would not cancel a vacation because of red tide. It's an isolated, patchy phenomenon that does not blanket every stretch of beach. On any given day, there are generally miles of good beach and clean water for beach-goers and anglers to enjoy. However, we encourage all travelers to heed the advice of the Texas Department of State Health Services, get the current facts and draw their own conclusions, since different people have different comfort levels with these kinds of situations."

Is it safe to eat fish that I catch in or near the red tide?
It's usually okay to eat fish, crabs, and shrimp during a red tide bloom because the toxin is not absorbed into the fleshy tissues of these animals. This advice from the Texas Department of State Health Services is based on the assumption that only the "edible" portions are being consumed (the fillet or muscle). Keep in mind that you should never eat fish found sick or dead, whether or not they are caught during a red tide.

Why doesn't the state post signs on the beach warning the public about red tide?
The eye and throat irritation caused by red tide results from high concentrations of the algae and rough surf. These conditions cause the red tide's irritant to become suspended in the air in the salt spray. There typically is little or no irritation when surf conditions are relatively calm. In most red tides in Texas, these conditions vary a lot within the space of days or even hours. As a result, the same part of the beach may have irritating conditions in the morning and those conditions may be gone by afternoon. On a calm day, even with red tide in the surf zone, many people can enjoy the beach because there is not a lot of salt spray from the surf carrying irritant to the beach. The best advice for beach visitors is if they feel effects in an area, leave that area and try another one. Some local authorities will post signs on beaches that they manage. Be aware of all beach warnings when visiting the beach.


This information is from the Texas Parks and Wildlife website: