Conclusions

• Abundant water star grass & algae in the Kiona reach resulted in DO concentrations and pH levels of concern in 2004 and 2005. In 2006, water star grass biomass was significantly reduced thanks to runoff from an abundant snowpack. While DO and pH conditions improved, they still did not meet state standards.

• Relationship between algae and nutrients in the Zillah reach were more complex than anticipated.

  • There was no relationship between nutrient concentrations and algal biomass, even at fairly low nutrient concentrations.
  • Nutrient concentrations in porewater were generally higher than in surface water.
  • Nitrogen may be the nutrient closest to limiting concentrations.

Notes: