Reporting Golden AlgaTo report fish kills or suspected golden alga outbreaks, call the Texas Parks and Wildlife Department at (512) 389-4848 (Austin) or (281) 842-8100 (Houston), or your local game warden or Kills and Spills Team biologist.

What can I do when a golden alga bloom or fish kill occurs in my pond?If there are visible signs of a golden alga bloom, you should send water samples to a laboratory that can identify the alga. (Testing laboratories are listed at http://www.tpwd.state.tx.us/landwater/water/environconcerns/hab/ga/.)

The presence of golden alga and its level of toxicity do not always match. High counts of golden alga cells do not always cause fish kills. On the other hand, fish kills can occur when golden alga cell counts are low. Both stress on the alga and water chemistry play a big role in the development of the toxins.

To control golden alga:

Use a copper-based algaecide—either copper sulfate or a chelated copper compound. Copper products can harm fish if not used with care. Do not exceed the application rates listed on the label. Copper-based algaecides are widely available and have few, if any, restrictions on water use after application. A list of algaecides and their labels can be found at http://aquaplant/tamu.edu.

To stop or minimize a fish kill:

• Quickly decrease the salinity of the pond water to 1 ppt or less by adding water from a well or other nearby source of fresh water (assuming its salinity is lower than that of the pond water).

• If it’s not possible to add fresh water, detoxify the pond by adding potassium permanganate. When the golden alga cell count is high, potassium permanganate can be applied before the pond is treated with a copper-based algaecide.

Artificially aerating the pond for a few days after treatment will help maintain oxygen levels for fish. This is important because dead algae and other organic matter deplete the oxygen in the pond.

This publication is an effort of the Harmful Algal Bloom Workgroup, a subcommit-tee of the Toxic Substances Coordinating Committee created by an act of the 70th Texas Legislature, SB 537, Sec. 2(h) of the Health Risk Assessment Act. The infor-mation is in part from the May 2010 issue of Texas Wildlife, published by the Texas Wildlife Association. This publication was made possible in part through support from the State Wildlife Grant program and the Sportfish and Wildlife Restoration Act of the U.S. Fish and Wildlife Service.

Printing was funded by the Texas AgriLife Extension Service, Texas Parks and Wildlife Department, and Texas Wildlife Association.

Are my pond and fish safe?To date, it has not been shown that wildlife or livestock drinking from ponds with golden alga blooms develop any health problems. Researchers believe that golden alga is “acid-labile,” meaning that it breaks down in acidic conditions such as those found in the stomach. This may explain why no ill effects occur in non-gill-breathing organisms.

While no health risks to humans are known, common sense dictates that people should never eat fish found dead or dying.

Where can I get more information?The TPWD Golden Alga Task Force plans to provide diagnostics training to interested people in Texas. For information about these workshops, or to learn more about golden alga, contact the task force coordinator at (512) 389-8750 or visit http://www.tpwd.state.tx.us/landwater/water/environconcerns/hab/ga/.

Learn about treatments and how to identify golden alga at the Texas AgriLife Aquaplant website, http://aquaplant.tamu.edu.

By 2010, more than 34 million fish in Texas public waters had been killed by this toxic alga. The Texas Parks and Wildlife Department conservatively estimates the value of the lost fish at $13 million. This figure does not include indirect costs to local communities in the form of lost angling opportunities and related tourism.

This alga has also killed fish in several private ponds across the state. However, the extent of the problem in private ponds and the financial losses to pond owners are often undocumented.

Besides fish, golden alga toxins also kill other organisms in the aquatic food chain. This threatens not only fisheries but also the ecological well-being of affected water bodies.

Golden Alga and Your PondKNOW THE FACTS

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Educational programs of the Texas AgriLife Extension Service are open to all people without regard to race, color, sex, disability, religion, age, or national origin.

Issued in furtherance of Cooperative Extension Work in Agriculture and Home Economics, Acts of Congress of May 8, 1914, as amended, and June 30, 1914, in cooperation with the United States Department of Agriculture. Edward G. Smith, Director, Texas AgriLife Extension Service, The Texas A&M System.

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What is golden alga?This tiny alga is about the size of a red blood cell (one-tenth the diameter of a human hair). Two hair-like appendages (flagella) are used for movement. A short, peg-like structure (haptonema) is located between the flagella and is used for attachment and feeding.

What does a golden alga “bloom” look like?A bloom is a very dense algal population. Early detection of a bloom is key to preventing a fish kill. To detect the alga, check water regularly during the cool months when outbreaks are most likely to occur.

Signs of a bloom:

• Water may have a distinctive golden yellow to rust color, but this might not be evident during the early stages of a bloom.

• Foam may appear on the water surface when the water is agitated or when there is wave action.

How does golden alga kill fish?During the cooler months when water temperatures are usually below 55 degrees F, golden alga can produce toxins. These toxins damage the gills of fishes and other organisms, which can lead to their death. Gills are important for maintaining water balance inside the fish and for taking in oxygen.

What are the symptoms of a golden alga fish kill?Affected or dying fish may:

• Attempt to jump out of the water

• Congregate near the shore or sources of fresh water, such as inlets or springs

• Look weak and sick

• Lie on the bottom

• Have extremely red or bloody gills, fins, eyes and mouth and scales covered in mucus

Dead fish may float or litter the shoreline.

When is a fish kill most likely to occur?Golden alga fish kills usually occur during winter and spring when water temperatures are close to or below 55 degrees F.

Most fish kills in private ponds are caused by low dissolved oxygen levels. This problem usually occurs during the hot months of June through September, when golden alga is not likely to kill fish.

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flagellum

haptonema

Where are kills most likely to occur?Golden alga occurs throughout Texas, but most of the golden alga fish kills have occurred west of IH 35, where water salinity is 2 ppt or higher and the pH of water is greater than 7.0.

How can I prevent the spread of golden alga?The alga can be spread from pond to pond via water, equipment, pets and humans. To prevent it, take these precautions:

• Do not move fish, water or equipment from contaminated ponds to other bodies of water.

• Drain live wells and clean boats and live wells before moving boats from one body of water to another.

• Disinfect contaminated equipment by

− soaking it in a 10 percent household bleach solution for at least 5 minutes,

− washing it in hot water (220 degrees F or hotter), or

− drying it in the sun for 2 to 3 days.

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Canadian River

Red River

Brazos River

Colorado River

Pecos River

Rio Grande River

Nueces River

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Counties with Golden Alga Fish Kills