A Framework for Developing Regional Nutrient Criteria for Wadeable Streams

Streams present a variety of unique challenges for the development of scientifically defensible, numerical nutrient criteria.  We identify key factors that modulate stream ecosystem responses to nutrient enrichment.  We also present a framework for selecting an appropriate study design, important physical, chemical, and biological measurements, and data analyses using a multi-year field study of wadeable streams in Texas as an example.  The case study highlights the significance of seasonal variability of stream flows in controlling biological responses to nutrients as well as the value of in situ and mesocosm experiments for validating field responses.