For Educators

Order Products

Login / My Account



Mussel Mania: How Streamflow Affects Freshwater Mussels Over Long Periods of Time

This article is from Issue Freshwater - Vol. 18 No. 1.

* Note: All editions of the Natural Inquirer starting with Volume 5 and including future editions require the newest version of Adobe Acrobat Reader 6.0 in order to be downloaded. We have upgraded in order to ensure greater accessibility to PDF files. Please click on the following link if you need to upgrade your Adobe Acrobat reader: Upgrade now to Adobe Reader 6.0. It is a free upgrade.



Mussels are very sensitive to changes in the environment which makes them good indicators of the health of an aquatic ecosystem.  Mussel shells, like growth rings from a tree, can show scientists the age and growth rate of the animal. The scientists in this study wanted to know how streamflow affected mussels and their growth.

Welcome to the Freshwater edition

Note To Educators



Graph Paper

Journal Lesson Plan

Reflection Section Answer Guide

Education Standards Correlation  

Additional Resources for this Article:
Meet the scientists that contributed to this article:

"Thinking About Science Themes" covered in this article:
When scientists identify a problem they must sometimes find new methods to study the problem. Sometimes scientists come up with a new method based on some other method they know about or have used before. One new field of study is called sclerochronology (skler ə krə nä lə jē). This new field of study is based on dendrochronology.Dendrochronology is a field of study in which scientists learn about trees by studying the tree’s growth rings (figure 1). The field of sclerochronology similarly enables scientists to learn about any organism that leaves growth rings in hard tissues like bones or shells. Some scientists examine fish scales and mussel shells to learn more about the animal (figure 2). The growth rings in mussel shells can provide information about how fast the animal grew, how old it is, and how growth changes with changes in climate.
Specific "Thinking About Science" Themes:
  • Scientific Topics

"Thinking About Environmental Themes" covered in this article:
Bottomland hardwood forests are unique ecosystems (figure 3). These ecosystems have a lot of diversity and are highly endangered. Bottomland hardwood forests are river swamps. These forests are found along rivers and streams and typically include large floodplains. The way in which water moves and flows through these rivers and forests has an effect on the entire ecosystem. Hydrology is the study of how water moves and flows. Changes to the hydrology of the rivers and streams may cause problems for the entire ecosystem. In earlier studies, scientists learned that periods of flooding are important to this ecosystem. One reason these periods of flooding are important is because carbon deposits from the land, in the form of leaves and other organic matter, are transferred into the river during these periods. Carbon is important for the plants and animals in and along the river. The scientists in this study wondered if flooding provides other benefits for this ecosystem. One way to study flooding is to look at the amount of water in a stream or river at different times. The amount of water and the velocity, or speed, of water in a stream or river is called streamflow (figures 4a, 4b, and 4c). You will learn more about streamflow in the “Introduction” section. The scientists were particularly interested in how freshwater mussels responded to changes in streamflow.
Specific "Thinking About the Environment" Themes:
  • Ecosystems

NSE Standards covered in this article:
  • Abilities necessary to do scientific inquiry (A)
  • Diversity and adaptations of organisms (C)
  • History of science (G)
  • Nature of science (G)
  • Populations and ecosystems (C)
  • Populations, resources and environments (F)
  • Risks and benefits (F)
  • Science as a human endeavor (G)
  • Structure and function in living systems (C)
  • Understandings about science and technology (E)
  • Understandings about scientific inquiry (A)