Researcher ORCID Identifier


Graduation Year


Document Type

Open Access Senior Thesis

Degree Name

Bachelor of Arts


Organismal Biology

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Microcoleus is an anatoxin-producing genus of cyanobacteria found globally. Anatoxin (ATX) is a high potency neuromuscular toxin. Fatalities caused by ingesting ATX- contaminated water, or the ATX-producing algae, have been recorded since the 18th century, but have more recently increased in magnitude and frequency. This experiment is intended as a pilot study to explore how future conditions of the Russian River under increased agricultural and industrial pollution, and climate change might affect the growth and toxin production of M. anatoxicus. M. anatoxicus underwent 12 treatments made up of 3 treatment groups targeting increased salinity and nutrient gradients. The only significant correlation found was a negative relationship between intracellular ATX concentrations and phosphates. Tendencies however showed that ATX production increased at high salinity levels despite the reduced biomass. Biomass was greater with increases in nutrients, however toxin concentrations decreased with increased nutrients. This study has suggestive potential towards more accurately predicting how human activities affect future freshwater ecosystems.


Supplemental Material included.