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Invasive Species Unit Plan

Invasive species pose a serious risk to many ecosystems throughout the world. The Hudson River is no exception. Why should we be concerned about invasive species? How do they change the dynamics of plant and animal assemblages? How do they change the chemistry of a water body like the Hudson River?

Start this module using the power point presentation. In it are the answers to these and other questions. Students will learn the importance of invasive species and how they have changed the Hudson River, possibly forever. Students view photos of different ecosystems and try to determine which photos show invasive species, generating a discussion about the definition of an invasive species. Then, students watch a powerpoint presentation about Invasive Species and discuss the possible implications of invasions in the Hudson River.

Overview

Day 1:

Invasives Overview:

Objective: Students will know what an invasive species is and be able to explain the effects of at least one invasive species on an ecosystem.

Activities:
1. Students view a collection of photos of invasive and native plants, making a list depending on their own ideas about which plants are invasive. 2. Students use a powerpoint presentation to learn about invasive species around the world as well as in the Hudson River. 3. In groups, students discuss the possible impacts of an invasive species on a hypothetical ecosystem.

Assignment: Respond to prompt: How do invasive species change ecosystems? Read “Invasive Species”

Materials: photos of invasives/natives, powerpoint handouts. Optional: samples of invasive and native species such as shells.

Day 2-3:

Invasive Plant Survey:

Objective: Students will know what invasive plants exist in their area and will be able to identify at least three invasive plants along a trail or transect.

Activities:
1. Students brainstorm invasive plants that they know about. 2. Students work in groups to identify invasive plants along a trail or transect. 3. Students estimate abundance & infestation rates in a quadrant along a transect. 4. Students explore herbivory rates on invasive plant leaves and compare it to native plant herbivory rates.5. Students share their results.

Assignment: Complete lab sheets

Materials: Laminated sets of invasive plant cards, copies of student lab sheet, measuring tapes, transparency sheets cut into 4x6 inch cards with 1cm square grid.

Zebra Mussels

The zebra mussel, so called because of the stripes on its shell, is a mollusk that arrived in the US in 1985 and in the Hudson River around 1991. It arrived in the ballast water of a ship that unloaded its ballast into Lake Erie. Since that introduction, it has spread rapidly throughout the eastern US and parts of Canada. It has drastically changed the Hudson River and caused millions of dollars in damage.

Zebra Mussels Invasion:

Day 4-5:

Objective: Students will know how to design an experiment to test how a pond ecosystem changes over time due to an invasive mollusk and be able to develop a testable hypothesis, create the experimental set,up, collect data, and carry out the experiment.

Activities:
1. Students brainstorm the effects of invasive species 2. Students design and create an experiment to test the effect of an invasive mollusk (mystery snails) on a pond microcosm 3. After one,two weeks of observations and monitoring, students report and discuss their results

Assignment: Complete lab report

Materials: pond water, lab handouts, wide,mouth one quart mason jars, permanent markers and tape, tongue depressors, water soluble plant, fertilizer solution (1t Miracle Gro/qt), salt solution (1t table salt/qt) , 25 or 50 ml graduated cylinders, mystery snails

Graphing Zebra Mussels:

Day 6:

Objective: Students will know how the zebra mussel changed the Hudson River, and be able to explain their answer based on a graph.

Activities:
1. Students will discuss the possible impacts of zebra mussels on the Hudson river 2. Students will graph zebra mussel data 3. Students report results and discuss

Assignment: Complete graphing activity

Materials: copies of the lab handout, computers with Excel (or graph paper)

Water Chestnut

The water chestnut (scientific name Trapa natans) is an aquatic plant called a "macrophyte", which literally means large plant. It is a native of Eurasia that was introduced to the US as an ornamental plant in the 1800's.

It first appeared in the Hudson River in the 1930's. It favors quiet, non,moving waters like bays and inlets and near docks. Its leaves float on the surface of the water thus blocking light to water below. In blocking light and reducing dissolved oxygen in the water column, it out,competes native species like water celery (Vallisneria americana) and alters the conditions for macroinvertebrate species. It was identified as a nuisance plant in the 1950's and there have been many attempts to eradicate it, none successful. Perhaps its most distinctive feature is its hard, spiny seed pod that can cause great pain if stood upon.

In these lessons, students will learn how this very important invasive aquatic plant has changed the Hudson River ecosystem in many unforeseen ways.

Simulated Aquatic Plant Invasion:

Day 7-8:

Objective: Students will know the relationship between light and dissolved oxygen and be able to predict what will happen when a plant does not receive enough light.

Students will know what happens to an aquatic ecosystem when a floating macrophyte is introduced as an invasive species, and be able to design an experiment to test their hypothesis

Activities:
1. Students discuss the impacts of living without light 2. Students learn about the impacts of light on plants using a demonstration or overnight observation 3. Students view photos of water chestnut 4. Students create an experiment to test the impact of a floating plant on dissolved oxygen 5. Over a one,week or two,week period, students take measurements of the water 6. Students report and discuss conclusions

Assignment: Complete lab report

Materials: jars or 2 liter bottles with the tops cut off (at least 2 jars per group), aged tap water, fertilizer (phosphate-based dish detergent works well), algae culture, Elodea, aluminum foil, plastic wrap, thermometers, styrofoam

Graphing Water Chestnut Data:

Day 9:

Objective: Students will understand the impacts of water chestnut on the Hudson River and be able to explain their answers based on a graph.

Activities:
1. Students discuss possible impacts of water chestnut invasion 2. Students graph data on water chestnut 3. Students report and discuss results

Assignment: Complete graphing activity

Materials: copies of the lab handout, computers with Excel (or graph paper)

Invasives & Macroinvertebrates:

Day 10-11:

Objective: Students will know that aquatic communities change composition based on vegetation types and be able to explain the differences.

Activities:
1. View macroinvertebrates, or discuss previous collection activity 2. Graph data on macroinvertebrates in the Hudson River 3. Discuss relationship between habitat, environmental changes, and invertebrate diversity/density

Assignment: Complete worksheet

Materials: macroinvertebrates (live, or collected and preserved), microscopes, hand lenses, computers with Excel, worksheets

Water Chestnut and Hypoxia :

Day 12:

Objective: Students will know how a water chestnut bed changes the dissolved oxygen levels during the year and will be able to explain changes using graphs.

Activities: 1. Students predict changes in dissolved oxygen during the year 2. Students use scientific data to answer questions about water chestnut

Assignment: Complete worksheet

Materials: copies of “Water Chestnut Beds & Dissolved Oxygen”

Common Reed

Common Reed:

Day 13-14:

Objective: Students will know that invasive plant removal can have a variety of impacts and be able to explain this by using graphs.

Activities:
1. View maps of vegetation change on Iona Island. 2. Discuss implications of changes on marsh birds using data and photos 3. Analyze graphs of the effects of invasive plant removal

Assignment: Read Kiviat article and complete packet

Materials: Iona Island maps, transparencies of chart, worksheets, bird data handout, powerpoint

Invasive Species Research Report

Research Report:

Day 15-16:

Objective: Students will know how one invasive species has changed the Hudson River and be able to explain those changes to their peers.

Activities:
1. Students choose a plant or animal to research from a provided list 2. Students develop a project based on their research 3. Students present their findings

Assignment: Complete research project

Materials: list of Hudson River invasives, library time, internet

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