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?
In the fish kills in Texas due to golden alga,
- Majority (but not all) have occurred in winter.
- All have been west of I-35.
- Frequency and area of fish kills are increasing.
- Decreased competition from normal algal community (probable)
- Water temperature extremes
- Increased salinity
- Low flows
- pH above 7
- Macroinvertebrates are unaffected while all fish species and sizes are killed.
- Water chemistry is within normal ranges (perhaps slightly elevated dissolved oxygen).
- Persistent foaming occurs in water at edges, riffles, and structures (Toxin suite resembles long chain fatty acids similar to soap.).
- Water shows increased golden or copper color (more visible near shallows later in bloom).
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
- 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.
- TPWD Inland Fisheries successfully apply a fish toxicity test using fathead minnows and a cofactor.