Dallas Zoological Society Partnership : Texas Ecology

Texas Aquatic Communities

Topic Overview
Quick Facts
Water is key to all life on Earth. The oceans occupy over 317 million cubic miles.
Humans rely heavily upon potable water from rivers. Earth has about 300 cubic miles of river water.
Texas’ Gulf Coastal region is over 300 miles long.
Nearly 500 species, including neotropical migratory birds, shorebirds, raptors, and waterfowl, can be found along the last 275 miles of the Rio Grande River Valley.
South Texas is home to over 300 species of butterflies.
Balmorhea State Park, located in west Texas is home to a rare desert wetland.
Artesian wells in the west Texas desert are home to many unique speices and even allow recreational scuba diving.
Caddo Lake State Park in northern Texas, near the Louisiana border is home to one of the most spectacular wetlands in Texas.
Begin the Lesson
When you think of aquatic environments in Texas, what environments can you name? Rivers, lakes, wetlands, marshes and the Gulf of Mexico should come to mind. These are the subject of our lesson – those regions and the animals found within. An interactive map that you might wish to use at various points of the introduction can be found at:
http://www.traveltex.com/TexasMap.aspx
Whole Class Introduction to the Lesson
You will need at least one computer with Internet connectivity and a projection device, a classroom with more than one computer, or access to a computer lab. This introduction will take approximately 10 minutes to complete.
Present pictures of several aquatic environments in Texas to the learners.
(several images can be found on:
http://www.texasexplorer.com/)
Ask them to identify what each can be classified as (a river, lake, marsh/wetlands, or Gulf Coast). Discuss the difference between each and the importance of each to humans.
Sample Questions:
Where does the water originate that flows across Texas? Answers will vary but the learners should realize that the oceans are the ultimate source of water on this planet and water is recycled to the land by the water cycle.
Which way do the rivers flow in Texas? Can you prove it? The rivers flow towards the Gulf of Mexico.
What characteristics might an animal living in/near water in northern Texas have from an animal living in Gulf of Mexico waters near Brownsville? The animal living near Brownsville must be adapted to salt water. The animal living in Northern Texas must be adapted to fresh water and to greater annual temperature variations.
As part of the introduction, you may want to review some of the glossary terms in advance of students going online. At this point you can launch the WebLesson as whole-class activity using a projection device, or you can assign students to work individually or in teams in a computer lab.
WebLesson Sites
Introduction
From the western high plains and prairies to the Gulf Coast and the coastal wetlands, Texas is a large and biologically diverse state. The pages that follow enable you to explore the river systems that carry water across the state, the kinds of life found within and along those rivers, and how conditions change as one approaches the brackish and salt waters found along and near the coastline. The coastal region is also dotted with extensive wetlands. Wetlands are marshy regions that host a wide variety of life forms, including animals that live there year-round and migratory birds that spend their winters in the Texas coastal wetlands and then migrate north in the Spring. The lesson ends with an opportunity to learn about the impact of the recent floods seen across much of the state and the long-term effects of these floods.
Scenario
You are a journalist for a national science magazine. You are on an expedition in Texas chronicling aquatic life across the state. What aquatic animals are dominant in the interior? What animals are found near or along the coastline? Watch for opportunities to create journal entries as you take a virtual journey across the state of Texas.
Lesson Pages
Texas State Map Collection
http://geology.com/state-map/texas.shtml
Where pollution occurs in Texas
http://www.texasep.org/html/wql/wql_1swq_303d.html
Texas Ecological Regions
http://www.texasep.org/html/lnd/lnd_1reg.html
Rich Media
The Edwards Aquifer Website
http://www.edwardsaquifer.net/intro.html
Bays and Estuaries
http://www.cbbep.org/estuary/estuary.html
Rich Media
Travel Texas - Gulf Coast
http://www.traveltex.com/Region.aspx?ID=4
Conclusion & Project
Conclusion
Texas is home to literally thousands of miles of surface water. The water is as varied as conditions across Texas. Freshwater rivers dominate in Texas higher elevation interior. As land elevations decrease, the rivers flow towards the coast. Large segments of several Texas rivers are threatened by various pollutants. Texas can be divided into several regions, each with its own characteristic climate and surface environment. Aquifers are found in the middle of the state. Aquifers contain highly adapted species to this unique environment. Within about 50 miles of the coast, the land flattens out and extensive wetlands occur. Near the coast, interaction between tidal forces and flowing river waters results in the formation of brackish waters in the form of brackish wetlands or estuaries. These wetlands are home to many varied species from shrimp to catfish.
Project
Study your journal entries; create a summary that describes how conditions change from west Texas and the panhandle region to the Gulf Coast region. Identify specific species found in each region. Describe how they are adapted to their environment.
Glossary
elevation - measure of a land surface’s location above (or below) sea level
orientation - pertaining to the flow of a river: compass orientation such as “north to south” or “east to west”
nutrients - any substance that provides nourishment
toxic - containing a poison or a toxin
aquifer - layer of permeable rock, sand, or gravel through which groundwater flows
topography - study and mapping of the features on the surface of land, including natural features such as mountains and rivers
aquifer - layer of permeable rock, sand, or gravel through which groundwater flows
subterranean - underground, beneath the surface
buffer - something that reduces shock or impact
sporadic - occurring occasionally
evaporation - process in which water is changed from a liquid to a vapor without its temperature reaching the boiling point
hypersaline - highly saline or very salty environment
compass - a device designed for finding directions
migration - a group of animals moving together from one region or country to another
salinity - measure of the concentration of dissolved salt in water
thermal - measure of temperature levels