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ARS Home » Southeast Area » Stoneville, Mississippi » Warmwater Aquaculture Research Unit » Research » Publications at this Location » Publication #171149
Title: CYANO-TOXIN PRODUCTION AND FISH KILLS IN RESERVOIRS ALONG THE SALT RIVER, ARIZONA, USA

Author
item WALKER, D - UNIV. OF ARIZONA
item BOYER, G - SUNY SYRACUSE
item Zimba, Paul

Submitted to: American Society of Limnology and Oceanography
Publication Type: Abstract Only
Publication Acceptance Date: 1/10/2005
Publication Date: 2/25/2005
Citation: Walker, D., Boyer, G., Zimba, P.V. 2005. Cyano-toxin production and fish kills in reservoirs along the Salt River, Arizona, USA. Limnology and Oceanography Book of Abstracts.

Interpretive Summary:

Technical Abstract: Multiple-species fish kills have occurred during the summer of 2004 in a run-of-the-river reservoir system along the Salt River in Central Arizona. These reservoirs have received large nutrient loading due to runoff from the Rodeo-Chedeski Fire which has increased trophic status, changed the algal community structure, and caused cyano-toxin related fish kills. The majority of kills have occurred in the riverine portion of these reservoirs where algal biomass and production are elevated. Pre- and post-fire data show elevated levels of several suspect organisms including Cylindrospermopsis raciborskii, species of anabaena, and Oscillatoria planktothrix. Relatively small amounts of cylindrospermopsin and microcystin have been detected in aqueous samples. Anatoxin-a and microcystin has been found at toxic levels in fish stomachs. Etiology of the kills makes anatoxin-a suspect but aqueous samples have all been below detectable limits. We believe that anatoxin-a production in these reservoirs is extremely sporadic, that high alkalinity and intense sunlight quickly degrade this neurotoxin, and that stomach and tissue analyses from aquatic organisms show the most promise as both an early warning system and evidence of past exposure.