This classroom resource provides clear, concise scientific information in an understandable and enjoyable way about water and aquatic life. Spanning the hydrologic cycle from rain to watersheds, aquifers to springs, rivers to estuaries, ample illustrations promote understanding of important concepts and clarify major ideas. Aquatic science is covered comprehensively, with relevant principles of chemistry, physics, geology, geography, ecology, and biology included throughout the text. Emphasizing water sustainability and conservation, the book tells us what we can do personally to conserve for the future and presents job and volunteer opportunities in the hope that some students will pursue careers in aquatic science. Texas Aquatic Science , originally developed as part of a multi-faceted education project for middle and high school students, can also be used at the college level for non-science majors, in the home-school environment, and by anyone who educates kids about nature and water. To learn more about The Meadows Center for Water and the Environment, sponsors of this book's series, please click here. RUDOLPH A. ROSEN is a professor at The Meadows Center for Water and the Environment at Texas State University. He is author of Money for the Cause: A Complete Guide to Event Fundraising (Texas A&M University Press, 2012). Texas Aquatic Science By Rudolph A. Rosen Texas A&M University Press Copyright © 2015 Texas A&M Unversity Press All rights reserved. ISBN: 978-1-62349-193-2 Contents Foreword, by Andrew Sansom, Acknowledgments, About the Texas Aquatic Science Project, 1. Water Is Life, 2. The Ultimate Recyclable: Water, 3. What Is Your Watershed Address?, 4. Living in Water, 5. From Sun to Sunfish, 6. Texas Aquatic Ecosystems, 7. Aquifers and Springs, 8. Streams and Rivers, 9. Lakes and Ponds, 10. Wetlands, 11. Bays and Estuaries, 12. Oceans: The Gulf of Mexico, 13. Fishing for Conservation, 14. Water for People and the Environment, Appendix A: Guidelines for Teachers, Appendix B: TEKS in Texas Aquatic Science, Glossary, Index, CHAPTER 1 Water Is Life Questions to Consider • What is water, and why is water important? • What are the special properties of water, and why are they important? • What is the hydrosphere, and what is its importance to life on Earth? • How do we use water? How much water is available for human use? • What are natural resources? What are aquatic resources? • What is conservation? Why is it important? • How can we tell if water is polluted or clean? How does water pollution affect aquatic life? • How does the temperature of water affect the amount of oxygen in it? • What is water quality? How do humans affect water quality? CHALLENGE QUESTION What is the source of your drinking water? Are there any water quality or water quantity issues about your water source? What will affect your water source in the future? Who makes decisions that affect your water source? Did you know that plants and animals are made up mostly of water ( fig. 1.1 )? Humans need clean water to keep them healthy. Without drinking water you would die in about one week. Our need for water links us to the past and to other living creatures. Since ancient times, societies have succeeded or failed according to their ability to get clean water and protect it for future use. Today's modern cities still depend on water for everything from flushing toilets, to fighting fires, to building the cars we drive. Your community depends on water, too. Using water wisely is critical to our survival. Water sustains life on Earth. Life is impossible without water. What Is So Special about Water? Water is made up of molecules that have two hydrogen atoms and one oxygen atom joined together ( fig. 1.2 ), so we also call water H2O (pronounced "h-two-oh"). Water can take three forms: liquid, solid (ice), and gas (vapor). Water exists in all three forms on Earth. Water can travel great distances. For example, clouds are made up of tiny ice crystals and water droplets. Water can move up plant stems, keep animals and plants alive, break rocks, and dissolve or erode almost anything. The chemical structure of water gives it these amazing powers. Water molecules attract one another in a way that makes them form drops. Have you ever watched raindrops creep across a window? When the droplets get close to each other, they join to form one larger drop. Water molecules cling to other things, too. This ability to cling allows water to move up plant roots and enables blood to flow through tiny blood vessels. It also enables bugs and other small things to rest on the surface of water without sinking ( fig. 1.3 ). Water boils at 212 °F (100 °C) and freezes at 32 °F (0 °C). Water can absorb a lot of heat before its temperature begins to rise. A large body of water heats up very slowly, and it cools down just as slowly. This property allows living things to survive in water's fairly const