Information on this page was developed for the October 2003 Golden Alga Workshop and was current at that time; additional information (including numbers of fish killed and locations of fish kills due to golden alga) has been gathered. Please see the main Golden Alga page and Current Bloom Status for more updated information.

Golden Alga Workshop

What Do We Know or Suspect?

David Moduline, TPWD Game Warden, photo: Joan Glass, TPWD
Photo: Joan Glass, TPWD
David Moduline, TPWD Game Warden
Possum Kingdom Reservoir

In the fish kills in Texas due to golden alga,

Factors include:

Field Diagnostics

foam at waters edge
Photo: Joan Glass, TPWD
Characteristic foam at water's edge
  1. Macroinvertebrates are unaffected while all fish species and sizes are killed.
  2. Water chemistry is within normal ranges (perhaps slightly elevated dissolved oxygen).
  3. Persistent foaming occurs in water at edges, riffles, and structures (Toxin suite resembles long chain fatty acids similar to soap.).
  4. Water shows increased golden or copper color (more visible near shallows later in bloom).
visible golden water in shallows
Photo: Greg Conley, TPWD
Lubbock City Lakes
Golden water viewed in shallows

Note: Diagnostics may be more pronounced in different habitats and environmental conditions:
Foam needs agitation to form (moving water, wind, etc.).
Golden color may depend on angle of view and distance from the water.

Confirmation of Golden Alga

  1. Microscopic examination is difficult but possible with light microscope (Small cell size is on the edge of light microscope range.) Both Joan Glass ((254) 867-7956) and Dave Buzan ((512) 912-7013) are adept at microscopic identification.
  2. TPWD Inland Fisheries successfully apply a fish toxicity test using fathead minnows and a cofactor.
stained water in shallows
Photo: Joan Glass, TPWD
Water colored from Golden Alga.

What Do We NOT Know?


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