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Timed Travel: Measuring the Relationship Between Stream Temperatures and the Development of Salmon

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

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Water temperature helps regulated aquatic ecosystems and for many aquatic organisms, life-cycle phases are tied to water temperature.  Salmon eggs, for example, generally require a certain number of degree days to hatch. Scientists know that water temperature varies both throughout a day and within and throughout the seasons. In this study, scientists altered water temperatures to explore how water temperature affects Chinook salmon development.

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:
Part of a scientistís job is to develop, establish, or improve methods of collecting, analyzing, organizing, or presenting data. Some scientists are particularly interested in helping to improve scientific methods. In this research, the scientists thought that a different method of collecting data might improve scientistsí understanding of fish development. Have you ever thought of a better way to do something? Before you knew for sure that it was better, you would have to try your new way and compare it with an existing way. That is exactly what the scientists did in this research.
Specific "Thinking About Science" Themes:
  • Characteristics of Scientists

"Thinking About Environmental Themes" covered in this article:
Over many years, decades, and thousands of years, organisms adapt to different factors in their physical environment. Temperature is one of the environmental factors to which organisms adapt. Many organisms live part, or all, of their lives in water. Water temperature, therefore, is a variable that affects the life cycle of many of Earthís organisms. In this research, the scientists studied the relationship of water temperature to the time it took Chinook salmon eggs to hatch and develop as young fish. The scientists also studied how water temperature affected the rate at which the fish developed. Water temperature can change over time as a result of global climate change, dams, irrigation, and changing land use. The scientists in this study, therefore, wanted to understand how variation in water temperature can affect the development of young Chinook salmon (figure 1).
Specific "Thinking About the Environment" Themes:
  • Adaptation
  • Water

NSE Standards covered in this article:
  • Abilities necessary to do scientific inquiry (A)
  • Abilities of technological design (E)
  • Diversity and adaptations of organisms (C)
  • History of science (G)
  • Nature of science (G)
  • Populations and ecosystems (C)
  • Populations, resources and environments (F)
  • Properties and changes of properties in matter (B)
  • Regulation and behavior (C)
  • Science and technology in society (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)