Aquatic Ecology On-site Activities

Aquatic Ecology - On-site Activities/Ranger Led

Grade Level: 5
Content Area: Science
Time to Complete: 2 hours
Title of Lesson: Aquatic Ecology

South Carolina State Standards Addressed:

5-1.1	Identify questions suitable for generating a hypothesis.
5-1.4	Use appropriate tools and instruments (including a timing device and a 10x magnifier) safely and accurately when conducting a controlled scientific investigation.
5-1.6	Evaluate results of an investigation to formulate a valid conclusion based on evidence and communicate the findings of the evaluation in oral or written form.
5-2.2	Summarize the composition of an ecosystem, considering both biotic factors (including populations to the level of microorganisms and communities) and abiotic factors.
5-2.3	Compare the characteristics of different ecosystems (including estuaries/salt marshes, oceans, lakes and ponds, forests, and grasslands).
5-2.4	Identify the roles of organisms as they interact and depend on one another through food chains and food webs in an ecosystem, considering producers and consumers (herbivores, carnivores, and omnivores), decomposers (microorganisms, termites, worms, and fungi), predators and prey, and parasites and hosts.
5-2.5	Explain how limiting factors (including food, water, space, and shelter) affect populations in ecosystems.

Lesson Description:

As “Aquatic Ecologists,” students will conduct field investigations by collecting, analyzing, comparing, and interpreting data from both a piedmont stream, and a lake environment. Biotic and abiotic factors, such as organisms collected, temperature, pH, as well as qualitative observations will be used to make a hypothesis about the water quality of the specific investigation sites.

Focus Questions for Students:

1.	What are two abiotic and two biotic factors that influence the type of life found in the streams and lakes at Paris Mountain State Park?
2.	What does a pH of 7 tell us?
3.	What does temperature tell us?
4.	How can humans, for better or worse, influence water quality?
5.	Based on the data collected, what hypothesis can you make about the water quality of Paris Mountain’s streams and lakes?

Culminating Assessment:

1.	Students will be able to name two abiotic and two biotic factors that influence the type of life found in the streams and lakes at Paris Mountain State Park (see background information).
2.	Students will be able to identify pH as a measure of how acidic or basic a substance is, with a range of 1 – 14 (see the on-site and pre-visit background information for details).
3.	Students will be able to state that pollution can cause temperature to rise, as can clearing of forested areas around lakes and streams. Animals have ranges of temperature within which they can survive.
4.	Students will be able to make a hypothesis about the water quality at Paris Mountain State Park, based on the organisms collected, temperature, pH, as well as qualitative observations.

Materials/Equipment:

clipboard, sheet and pencil for each student	rubber boots
student collecting nets	pH strips in containers
thermometers	collecting pans
buckets	microscope
flex-cam microscope	video monitor

Teacher Preparation:

1.	Call for reservations.
2.	Complete pre-site activities.
3.	Read background information and be prepared to participate in activities and discussions.

Background Information:

Paris Mountain is located in the northeastern part of Greenville County, within the piedmont region of South Carolina. It is the southernmost extension of the Blue Ridge mountains. The area is a watershed: a region in a green mountain valley, where water drains into a common area, often a river or lake. Lake Placid is one of four lakes in the park, created in the 1890s as a source of drinking water for the people of Greenville. The park land has been protected since the 1890s, originally to protect the drinking water. The protection of forests around an aquatic area prevents muddy run-off, pollution, and flooding, with rainwater being slowly filtered through the forest soil, into the lakes and streams.

The students will be ‘aquatic ecologists,’ studying water ecology: the relationship between living aquatic organisms and their environment. The environment is determined by biotic (living) and abiotic (nonliving) factors. Biotic factors include plants and animals in or around the water. Leaves that fall into the water, and the park’s beaver populations that dam up streams, are both biotic factors. Students will collect macro-invertebrates such as insects, and possibly some vertebrates such as fish and salamanders. At the stream site, students get in the water wearing rubber boots! The aquatic animals found live in or on the water for all or part of their lives. They have various structures that allow them to survive in particular habitats, and are important members of the food webs that allow large predators to survive. The animals collected are used as biological indicators of the quality of the water.

Abiotic factors include temperature, pH, quantity of light, amount of dissolved oxygen, and soil composition. At a stream and at a lake, students will measure temperature, and measure pH, and use their data to make a hypothesis about the water quality at Paris Mountain State Park

Some of the fish and aquatic insects have a very low tolerance for changes in abiotic conditions. A rise in temperature or a decrease in dissolved oxygen can stress these organisms to the point of death. The absence or removal of trees, resulting muddy run-off, a beaver dam that slows down the water, or pollution which reacts chemically or clouds the water are all possible reasons for changes in temperature.

The pH is a measure of how acidic or basic a substance is, with a range of 1 – 14, and is related to hydrogen ions (for more detail, see pre-visit activity background). A pH of 7 is neutral, and generally considered to be a sign of good water quality. A lower pH number can result from the soil (normal soil pH in the park area is between 5 and 6), acid in leaves, or from man-made causes such as acid rain, or other pollution. Some animals can live in water that is fairly acidic, while others cannot. By testing pH, temperature, and collecting organisms over time, the water quality can be assessed. Student data collected will be recorded at the park as part of ongoing water quality assessment.

Procedures:

1.	Students are introduced to the park and its role as a watershed. Students are also introduced to their role as aquatic ecologists, and told what they will be doing: collecting organisms, as well as measuring temperature and pH in a stream and a lake, to assess the water quality in the park. Emphasis is on biotic and abiotic factors. Safety rules for themselves and for the park are discussed. All students are given a clipboard with an aquatic ecologist data form. Note: If two classes, one class will then go around the lake with a Volunteer Naturalist, experiencing a Nature Hike that is based on state science standards. Activities and/or discussion are involved at each of eight stations. A brochure covering the points of the Nature Hike is available to the public, and can be used by the teacher if a volunteer is not available. After lunch, the two classes will switch.
2.	With Park Interpreter, class walks to amphitheatre area. Class is divided into 4 groups. Two groups receive rubber boots. The other 2 groups receive temperature/pH testing kits. Instructions on use of kits and boots are given.
3.	Walk to stream study site, where those with boots sit on benches and put boots on. Pans of stream water are placed beside the stream for organisms collected. The groups with temperature/pH kits gather water from the stream using a bucket, and begin testing (they will have an instruction sheet).After collecting organisms in the stream, the group with the boots switches with the temperature/pH groups, so all have a chance to do all activities.
4.	Class leaves boots and test kits in order, then carefully carries pans with organisms back down the trail toward Lake Placid. Students compare the lake to the stream environment.
5.	The class walks up to the lab with their pans of organisms. Using a microscope and video monitor, the class observes the magnified organisms, noting structures that help them survive in their aquatic environment. Predator/prey roles are discussed. An identification sheet helps students identify aquatic invertebrates. The ID sheet categorizes animals according to pollution tolerance. Temperature and pH data are recorded on a dry-erase board, and analyzed for meaning.
6.	Class compares stream and lake results, then infers biotic and abiotic reasons for differences. Human actions that affect water quality are explored. Finally, class makes a hypothesis regarding water quality at the park.