Lesson 4 - Lake and Pond Study

Students will:

1. Understand ecological systems.

2. Provide experiences to assist citizens to increase their sensitivity and stewardship for the environment.

3. Understand the cause and effect relationship between human attitudes and behavior and the environment.

Students will:

1. List the types of places to live in a pond or lake habitat.

2. Classify living things according to the location in which they live in the lake or pond habitat.

3. Use a flow chart type key.

4. Explain how aquatic habitats are divided into various micro-habitats or communities.

• habitat
• phytoplankton
• benthic
• sessile
• photosynthesis
• zooplankton
• nekton
• benthos
• surface
• water column
• aquatic
• submergent
• emergent
• neuston
• plankton
• euphotic
• larval
• communities
• vertical
• horizontal

For the classroom:

• Community Cards
• Flow Chart Key
• Word Detective Worksheet

For the field trip:

• light colored plastic dishpans
• strainers (from a kitchen store or biological supply company)
• nets (biological supply company)
• hand lens (biological supply company)
• small plastic containers (yogurt, cottage cheese, etc..)
• one Golden Guide Pond Life book for every two students

Ospreys live in a variety of habitats depending on the time of year. This lesson plan will familiarize students with the pond and lake habitat. Each plant and animal lives in a unique place within this aquatic area. The kinds of organisms present are greatly dependent on the non-living aspects of the body of water in which they inhabit. These non-living characteristics of water including, length, width, depth, dissolved oxygen, temperature, and acidity, will be covered in other lesson plans as a part of the Highway to the Tropics project.

This activity introduces students to the different places available to live in a pond or lake and familiarizes them with the words that scientists commonly use when working in this type of habitat. Students trade "identity cards" to fill out a flow chart type key which then can be used to further study any one part of this type of aquatic habitat. Students may also visit a pond or lake in their area and do a couple of activities.

Ponds and lakes are found all over the state of Minnesota. They can be very small and not even included on the map or extremely large, such as Lake Superior. Ospreys may use ponds and lakes to find fish, their favorite food. What is the closest pond or lake to your school? Have youn seen Ospreys there? Is that body of water a pond or a lake? According to the Minnesota DNR, a pond is identified as a body of water, under 10 acres, and in some cases, under 2 + acres, where the shoreline does not have any "washed" areas, only a shoreline with emergent vegetation. A body of water with a shoreline which includes a "washed" shoreline and is larger than 10 acres, in some cases 2 + acres, is considered a lake. Minnesota has 12,034 lakes and countless ponds, thanks to our proximity to the last glacial movement, which covered most of Minnesota and the northern parts of North America.

Environments and habitats in them are divided into many communities that are used by different types of animals and plants. Affecting what community an organism lives are many factors including available food sources, light, depth, bottom features, as well as mobility, weight, age and size of the animals and plants themselves.

A habitat is the place where an animal or plant normally lives. Aquatic habitats are broken down into three basic communities: benthos, or the bottom; surface, the top; and the water column, the area between the top and bottom. These three can be categorized even further by light, vegetation, closeness to shore, depth, food resources, and other plants and animals.

The different plants and animals living in or on pond or lake bottoms can be identified as benthic. The animals which live in the bottom sediment and plants which have roots "anchored" in the bottom sediment would in turn be called benthic plants and animals. These plants which are rooted on the bottom sediment can be submergent or emergent, and still be considered benthic.

The plants and animals that float or move on, in, or just below the surface of the water are called neuston. Plankton are small plants and animals that live in the water column, either drifting or weakly swimming. Phytoplankton (phyto- means plant) are microscopic organisms that change inorganic nutrients into food and release oxygen when they undergo photosynthesis. Like all plants, they only grow in the euphotic zone, where light can penetrate the water to allow photosynthesis to occur.

Phytoplankton are eaten by zooplankton (zoo- meaning animal) and by filter feeders such as clams and mussels, as well as some small fishes. Zooplankton range in size, from very small, one-celled animals to larger creatures. This includes both temporary and permanent residents. Many freshwater creatures spend the early larval stages of their lives as tiny animals and later may settle to become slow moving or sessile (anchored) adults or grow into free-swimming mobile animals like fish. Strong swimmers which can move vertically and horizontally in the water column are called nekton. These animals can move against the currents and go where they want.

Many things can be seen and shared at a pond or lake edge. Once the students are focused into what they are doing, it becomes easy to discover a multitude of sights, sounds and experiences. The activities below are designed as a progression from a classroom activity prior to a field trip, as well as activities which can be conducted on a field trip. One need not to travel far to find a suitable place for outdoor inquiry.

Before Class

Prepare the 15 Community Cards. You may need to make an extra set since there are only 15. Cut them out, and glue them to poster board. You can decorate the reverse side with photos from magazines such as National Geographic, Ranger Rick, etc..You can do this without the pictures, but it is more fun with them.

In the classroom:

Draw a cross section of a pond or lake. Ask students to name some plants and animals which call a pond or lake home. Be sure to include some plants on and near the shore, as well as some animals in the water and on the bottom of the water. (Do not introduce terms discussed in the Background section. Let them discover the terms when filling out the flow chart key.) Explain that plants and animals call home lots of different locations in a particular body of water, whether it is a lake, pond, river, or ocean.

Distribute the Flow Chart Key to each student. Note that the students must start at the left and work their way carefully to the right on this handout page. Pick an example from your drawing and use it as an example for the class. Have the students work with you to determine where it lives.

Give each student a Community Cards and have them read it carefully and discover where that particular plant or animal lives in the pond or lake. Write down the number located on the card in the space provided on the flow chart key. Trade cards with other students until each place to live has been visited by the students. If you do not have enough time, do a couple of examples and move on. If you have more time, you can invent new cards and try them out with your class.

Distribute the Word Detective Worksheet on scientific names. Challenge your students to think of everyday names which are made up of old Greek and Latin words. Some ideas are auto (self) mobile (auto), sub (under) marine (salt water), photo (light) graphy (drawing), zoo (a place where animals live). There are many more. Can they think of others? In the space on top of the worksheet, list these words that we use everyday. Then list words from towns or places which you believe are derived from other languages, such as Native American, French, Spanish, and others. Then lead a discussion about classification and how scientists use words from ancient languages to identify plants and animals in like groups, or as a name of a process or concept. An example would be photosynthesis. Photo from the Greek word for "light", and synthesis from the Greek word "put together." Photosynthesis means "put together with light" and is a chemical process in which plants put together small chemicals to make bigger chemicals using the sunlight for energy.

Before the Field Trip

First and foremost, prepare yourself and the students that getting wet and dirty is a part of the exploration process. This doesn't mean it's a swimming exercise, but don't be afraid to get a little wet and dirty. Your role and enthusiasm in the field trip will ultimately dictate how the children react while exploring.

Gather together your field trip materials.

Review and familiarize yourself with the Pond Life book by Golden Nature Guide Series. This is a great introductory book which will help you and the students "know" the pond and lake life. It is also small enough to put in a pocket, and is written so that most people can begin to understand the complex habitat of ponds and lakes.

During the Field Trip

Students will almost always be very excited, and you must control that excitement to a certain degree. In order to focus their attention to the tasks at hand, ask the group to quietly gather near the edge of the water and sit down. Ask them to sit and listen to all the sounds which can be heard at the shoreline. Ask the group to close their eyes and concentrate on the various sounds. Ask them to count, using their fingers, the different sounds they hear. It is not important, at this point, whether they can identify the sounds. When most of the children have five fingers up, ask them to open their eyes and remain quiet. Try to impress that the pond or lake is a special place. In order to do this, try not to pick a study place which has lots of boat traffic or commotion, although if this is your only choice much can still be observed and learned. Once they have counted sounds and opened their eyes, discuss the various sounds and try to identify what has ,made those sounds. Which sounds are actual pond or lake sounds? Which are human generated? Which are natural? Are any of the sounds seasonal, or could they be heard year-round? Which did they like the most? Least?

Next, divide up into work groups. This can be pairs or whatever arrangement you wish. At this time, set the rules, the "do's" and "don'ts" of the exploration exercise. After you set the parameters, distribute a dishpan to each group. Ask them to fill the dishpan with water from the pond or lake you are visiting. Have them explore the different communities found in a pond or lake and find, observe, and possibly collect examples from the different areas which were discussed before the field trip, and place them in the dishpan. (A word of caution-- Some pond/lake plants and animals are endangered species and should not be collected. As a rule, only collect one item if ten others exactly like it are present. This will ensure that you are not depleting a resource which could be lost forever.) Watch the collected creatures and identify whether or not they crawl, swim or sink to the bottom of the dishpan. How would scientists classify these animals? Using the Pond Life guide, try to identify what you have collected. Small containers can be used to isolate an individual organism for easier identification. It is best done with ,containers which are white in color. This will allow the organism to "show up" better for identification purposes. If you cannot determine what something is, you can bring it to the DNR or similar organizations for positive identification by professionals.

Gather the students into a large circle, as in the beginning of the field trip. Ask each student to tell one thing they learned about the pond and lake environment which they did not know prior to the trip. Have each student complete the following sentence: "I would like (or not like) to live in this pond, because........." Ask them to tell you whether they think this pond or lake is a clean body of water or a dirty one which contains pollutants. **You can go back to this body of water later to confirm your guesses using the water quality exercises contained in the Highway to the Tropics lesson plans.**

1. Set up a pond/lake aquarium in the classroom. A 10 - 50 gallon tank would work well. Establish a rotating list of "caretakers." Keep a journal about who eats what and who eats who. Get your samples at the pond or lake which you have studied. **Check with the DNR to see if permits are needed**. A local pet shop will be a good resource for filters, air pumps, and other supplies. Be careful not to spend more than you have to, keep it simple. After a brief observation period, release your critters back to the body of water where you collected them.

2. Have the students make a pond mural. Make sure each community is represented.

3. Use microscopes to look at plankton, the smallest creatures in the pond or lake.

4. Have each student write a poem about a critter who lives in the pond, collect all the poems, and post them.

Northwoods Wildlife, A Watchers Guide to Habitats. Janine M. Benyus, NorthWoods Press, 1989. ISBN 1559710039.

A Field Guide to Wildlife Habitats of Eastern United States. Janine M. Benyus, Simon and Shuster, 1989. ISBN 0671659081.

Wetland Plants and Plant Communities of Minnesota and Wisconsin. Steve Eddgers and Donald M. Reed, U.S. Army Corps of Engineers, St. Paul District.

How to Know the Freshwater Algae. G. W. Prescott, Wm. C. Brown Comp., 1978. ISBN 069704755.

National Audubon Society Nature Guides: Wetlands. William A. Niering, Alferd A. Knopf, Inc., 1985. ISBN 039473147.

A Golden Guide: Pond Life. George K. Reid, Herbert S. Zim, Golden Press, 1967. ISBN 0307240177.

• Office of Water- EPA