History of Golden Alga in Texas

In the past three decades, golden alga blooms have killed an estimated 34 million fish in five river basins (Brazos, Canadian, Colorado, Red and Rio Grande). Although golden alga appears worldwide, it's a comparatively recent problem in North America. Scientists still aren't sure whether it's an introduced species or a native that has been here all along. Some research suggests that changes in weather, water chemistry, or other environmental conditions have contributed to an increasing incidence of toxic blooms.

1980s

• In 1985, golden alga was identified as the cause of a series of fish kills on a 660-kilometer stretch of the Pecos River (Rio Grande basin). It was the first confirmed golden alga kill site in the Western Hemisphere. An estimated 110,000 fish died that fall.
• Although not confirmed, fish kills in the upper Brazos River in 1981-1982 and in Red Bluff Reservoir in 1985 are suspected to have been caused by golden alga.
• By the end of the decade, Texas Parks and Wildlife Department documented 15 fish kills in the Brazos, Colorado and Rio Grande river basins that were suspected or confirmed to be caused by golden alga blooms. An estimated 2.6 million fish died as a result of those blooms.

1990s

• Blooms occurred less frequently in this decade with only five confirmed golden alga fish kills involving an estimated 680,000 fish.

2000 and beyond

• In 2001, a series of golden alga blooms caused serious damage to some Texas fisheries.
  • A winter bloom on the Brazos began in Lake Possum Kingdom, spread downstream to Lake Granbury, then finally to Lake Whitney, causing massive fish kills along the way. Those reservoirs experienced recurring winter blooms and fish kills for the next seven years.
  • Fish kills occurred in reservoirs of the upper Colorado River, including E.V. Spence where more than two million fish died.
  • In May, golden alga got into the source water of the Dundee State Fish Hatchery, located along the Wichita River in the Red River Basin. Toxins killed more than 5 million striped and hybrid striped bass fry that were being reared for stocking in Texas waters.
• In 2003, the alga appeared in the Canadian River basin, causing a small fish kill in the Meredith Stilling Basin.
• To date, more than 30 reservoirs have been affected, some repeatedly, by golden alga fish kills. Kills have also occurred in several community fishing lakes and private ponds.

Articles and News Releases about golden alga, 1991 – present