Edwards YMCA Camp
and Conference Center
N8901 Army Lake Rd
East Troy, WI 53120
Phone: (262) 642-7466
Fax: (262) 642-5108
Email: camped@campedwards.org
Pond Mucking
Summary
What is a pond? A pond is a rather small, shallow body of water with little difference in temperature between the surface and the bottom. Each pond may be small in size, but the total area of ponds in the U.S. is very large. They are important wildlife habitats. Each pond is different and diverse containing a variety of plants and animals, making them fun to explore. Pond zones are places in the pond that have their own special features. Each zone is characterized by the type of plants that grow there. The organisms in a pond are influenced by the presence of different kinds of plants so it is worth investigating the different zones. Zone 1: Emergents Closest to the shore, this zone is dominated by semi-aquatic plants that are rooted in shallow water and emerge out of it. i.e.: Arrowhead, cattails, river bulrush, etc. Zone 2: Floating-leaf This zone occurs in slightly deeper water. Because it does not dry out, the plants are truly aquatic and can not survive out of water. i.e.: Yellow and white water lily. Zone 3: Submerged This zone occurs furthest from shore and contains plants that remain completely under water except when they flower. i.e.: Milfoil, pondweed, coontail, elodea, etc. Zone 4: Free-floating This zone can actually occur throughout the pond. It contains floating plants that are not rooted in the mud. A pond surface may be completely covered by these plants making the surface look solid. In deeper ponds this may be the only plant that can survive where the water is at its greatest depth. i.e.: duckweed and water-meal Pond Succession Nature undergoes many changes; ponds are no exception. It is possible for the birth, development, and death of a pond to take place during a human lifespan or it may take hundreds of years. Succession is the sequence of plant communities that replace one another as the pond matures and finally disappears. In the beginning a new pond is colonized by pioneer plants that need few nutrients to survive. As these plants die and decay they add more nutrients, which allows different plants to become established. If left undisturbed by man, a pond will eventually fill up with silt and become solid land. As the plants and conditions change so do the animal populations that inhabit the area. A pond is always changing and we can see gradual changes from one year to the next. The boat bay was dredged out in the early 80's, which set back natural succession. Warm-up Activities Our Aquatic Ecosystems Conduct a preliminary discussion about aquatic systems. Explain differences between lake and pond ecosystems - most of these differences are visual and the kids can actually see them for themselves. Lake - Bigger Deeper (Lake Beulah is about 60 feet deep in its deepest area) Colder (the water can only be warmed where the sunlight can reach, usually up to 10 feet) Different kind of bottom (look at sand and gravel) Animals are spread throughout the lake Pond - Smaller Shallower (plants growing all the way across) Warmer (warm up quickly and uniformly due to lack of depth) Mucky bottom (dead vegetation in various stages of decay) Animals concentrated (sheltered habitat, a nursery for many kinds of animals) Activities Aquatic Food Chains Introduce producers and consumers to the students. Producers are green plants that make their own food. Consumers are animals that feed on producers. Discuss the concept of food chains. Food chains are when a larger animal eats a smaller one and the smaller animal eats yet a smaller animal and so on. It can generally be traced down to a plant. Share and discuss an example of a terrestrial (land based) food chain that could exist at camp; have the students give examples as you work through a food chain from top to bottom Example: Cooper's hawk: » Deer Mouse » Grasshopper » Prairie grasses Discuss the quantity differences as you move down the food chain: Few hawks, but many prairie grasses and grass-eating insects. (The higher up the food chain the fewer number of predators.) Have the students try to come up with a food chain from an aquatic ecosystem. Example: Northern pike: large fish, which preys on medium sized fish » Sunfish or bluegill: Dragonfly nymph: aquatic "teenage" stage of dragonfly » Mayfly larva: aquatic insect larva » Water flea: larger aquatic zooplankton » Green algae: phytoplankton Are You With Me? The idea of this activity to introduce students to various plants and animals found in wetlands and to help them understand more about these species. 1. Hand out a picture card to each student. 2. Have students find their match and stand together. 3. Hold cards together and read about the plant/animal. 4. Have each student tell the group something interesting about their topic. You can also allow the students to explore the boathouse. There are several interpretive panels that describe common plants and animals of the pond as well as information about some of their life cycles. Build a Pyramid Have the students use their "Are You Me?" cards to put together a simple food chain. The students could also arrange the cards so as to build a pyramid of life. There will be more organisms with roles in the upper end of the food chain; with so many tops and so few bottoms the pyramid won't be stable - have them try anyway so they see that it won't work. Some predators will have to give up their status to build a new pyramid that will easily support all the members, challenge your students to try to change their roles correctly without your help. The higher up on the food chain, the fewer the number of animals. Demonstrate the importance of plants by pretending to pull one of them out of the pyramid. Pond Exploration 25 - 45 minutes Separate the students into groups of 3-5 and pass out equipment. Explain the sampling procedure below and show the sampling area (along canoe launch pier, the boat bay and the beach area of the lake.) Please stay off the rock wall for safety! Remind students we are studying the organisms and returning them to their environment. We do not want to kill them. If another group is canoeing please allow them to use the pier when launching and returning the canoes. Fill your trays and 5 gallon pail with water from the boat bay. Use the large pond nets to scoop through water plants - this is where most organisms live. Demonstrate proper techniques of sampling with the aquatic nets (not too deep and plenty of vegetation). They need to swish the weeds around in the water in the pan. Look carefully for tiny organisms hiding in the weeds. Emphasize that all organisms found in the water rely on water to live and breathe and need to be put in a water tray or pail as soon as they are collected. The ice cube trays work great for holding and viewing insects. The small aquarium nets can be used to aid in catching and transferring the insects to the pan. The organisms can be identified through the use of laminated Pond Critter ID Guides. Tell students to save one of every organism that they find by putting it in water in their ice cube trays or buckets, to later show their classmates. (Not everyone is going to find the same things.) Inform the students that aside from snapping turtles and certain large fish (that probably aren't going to be found in the boat bay) there aren't any organisms in the water that will hurt them. After collection and identification allow about 10 minutes for quick clean up and to go over what was found. Have each group name and describe one or two of the organisms that they found. Go through any insects not identified. Remember to return the organisms to the boat bay when finished, and rinse all nets, trays and buckets before returning them to the Program office. Wrap-Up Hold a wrap up discussion to review the themes and objectives. Here are some questions to get started: - What kind of an aquatic ecosystem have you investigated? A pond - What are its characteristics? Small, shallow, warm, larger quantity of organisms - Describe species discovered: encourage discussion of some of the more commonly found organisms such as dragonfly and damselfly nymphs, water boatman, and snails - Where do they belong in the food chain of this ecosystem? Predators or prey or both, eaten by what, what do they eat (e.g. Boatman eat insects and are eaten by larger insects or fish - Can students describe a sample food chain? - Define and give examples of three producers and consumers in the pond environment. - What would happen if there weren't any mosquitoes - something killed them all off? (consider their predators in the food chain) - How would this affect humans and animals that aren't directly a part of the aquatic food chain? Each of the mosquito's life stages provides food for different organisms - aquatic and terrestrial. Pre Activities Teach these vocabulary terms -
This game stresses predator and prey relationships in an aquatic ecosystem. Divide the students into groups of 5-7 per group. Here are the guidelines: 1. Each person is to play the role of a plant, animal or natural phenominum (rain, earth, sun) 2. Each succeeding 'person' in the chain must depend on the previous one for its life. 3. All 'persons' in the chain must live in the same environment, a pond or lake ecosystem Give them about two minutes to group themselves into a food chain. Check and discuss the results. Resources Project WILD and WILD Aquatic National Audubon Society Nature Guides WETLANDS Golden Guide Pond Life book |