Understanding the Inflence of Nutrients on Stream Ecosystems in Agricultural Landscapes

The current report, “The Quality of Our Nation’s Waters—Understanding the Effects of Nutrients on Stream Ecosystems in Agricultural Landscapes,” presents a summary of results from USGS investigations conducted from 2003 to 2011 on processes that influence nutrients and how nutrient enrichment can alter biological components of agricultural streams. This study included collecting data from 232 sites distributed among eight study areas. This report summarizes findings on processes that influence nutrients and how nutrient enrichment can alter biological communities in agricultural streams. These findings are relevant to local, State, regional, and national decision-makers involved in efforts to (1) better understand the influence of nutrients on agricultural streams, (2) develop nutrient criteria for streams and rivers, (3) reduce nutrients to streams and downstream receiving waters, and (4) develop tools for tracking nutrient and biological conditions following nutrient reduction strategies.

Foreword iii

Chapter 1. Overview of Findings and Implications 1

Chapter 2. Nutrient Primer 9

Chapter 3. Approach to Assessing Nutrients and Their Ecological Effects in Agricultural Streams 21

Chapter 4. Nutrients in Surface Waters—Pathways and Processes 31

Chapter 5. Influence of Nutrients and Habitat on Aquatic Vegetation in Agricultural Streams 43

Chapter 6. Influence of Nutrients and Habitat on Biological Communities  55

References Cited 69

Glossary 77

Farmers, Agriculture officials at the national, state, and local level, Agricutural College instructors and prfessors, agricultural scientists and environmentalists.