Print this Web Links Activity Log to record your findings. In order to view and print these activities, it is necessary to have Adobe Acrobat Reader. If you do not have this, get the free download now.   Click the Techie Toolbox for tips and help to make the most of your time on the Web. Chapter 5: Population Biology  Zebra Mussel Watch What do Zebra mussels look like? Click on "A Field Guide" to view photos of Zebra mussels as they appear in the field. Why are Zebra mussels such a big problem? Zebra Mussel Information This USGS site provides detailed information on Zebra mussels. Scroll down the page and click on "progression" to witness the spread of Zebra mussels from 1988 to the present. Write a plan to reduce the spread of Zebra mussels. Make sure your plan includes steps to prevent any loss of native species or habitat. Population Index Search for information on human populations by state, country, or region of the world; includes summaries of articles about changes in population. U.S. Census Bureau How many people do you think there are in the world today? Go to this site to find an estimate of the world population. Why do you think the number is only an estimation? Gypsy Moth in North America Information about the biology and spread of gypsy moths in North America. How to Manage Deer Populations This article, written by David C. Guynn Jr. of Clemson University, discusses the different techniques used to manage deer populations. How can wildlife officers estimate the size of a deer population?