SAV Me!

Natural Resource Restoration / Grades 9-12 / Earth Science, Life Science




Focus Question

Why is submerged aquatic vegetation (SAV) important in coastal ecosystems, and how can SAV be restored in areas where it has been depleted?

Learning Objectives

Links to Overview Essays and Resources Useful for Student Research

http://oceanservice.noaa.gov/topics/coasts/restoration
http://noaa.chesapeakebay.net/HabitatSAV.aspx

Materials

Audio/Visual Materials

None.

Teaching Time

One or two 45-minute class periods, plus time for student research.

Seating Arrangement

Classroom style or groups of three to four students.

Maximum Number of Students

30

Key Words

Resource restoration
Submerged aquatic vegetation
Coastal habitats

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Background Information

Coral reefs, estuaries, fisheries and other coastal resources are frequently threatened by damage from storms, ship groundings, oil spills, chemical releases, and many other natural events and human activities. In recent years, science and technology have been used to protect and restore coastal resources affected by this damage. Such efforts can include removing pollutants and invasive species (species of plants or animals that are not native to the ecosystem and cause economic harm, environmental harm, or harm to human health) repairing damaged habitats, restoring natural ecosystem processes such as water flow, and re-introducing native organisms. In addition, restoration projects often include monitoring activities to evaluate long-term success. Benefits from these projects include improved habitats for fish, birds and other wildlife, protection against flooding, better water quality, enhanced recreational opportunities, and increased economic opportunities through activities such as commercial fisheries and tourism. Restoring coastal resources is a primary responsibility of the National Ocean Service’s Office of Response and Restoration and the National Marine Fisheries Service’s Office of Habitat Conservation, which take active roles in restoring injured resources as well as providing data, science and tools needed for restoration planning. For more information about a wide variety of restoration projects, see “Fix It!” at http://oceanservice.noaa.gov/education/lessons/fix_it.html.

In many coastal areas, restoration initiatives have focussed on a group of underwater grasses known as “submerged aquatic vegetation” (SAV). These plants provide food and habitat for many aquatic animals, help maintain water quality, and protect shorelines from erosion. As a result, SAV is directly important to fishing, hunting, birdwatching, and many other human activities on the coast. Particularly in the Chesapeake Bay, SAV abundance and distribution declined dramatically in the 1970’s and 1980’s, but recovered to some extent in the late 1990’s. Intensive restoration and monitoring efforts have been undertaken to help accelerate this recovery. Many of these efforts involve citizen volunteers who work in partnership with professional ecologists. School groups are particularly important in some programs, with students raising SAV plants in their classrooms and eventually transferring the plants to restoration sites.

In this activity, students will investigate the importance of SAV, as well as SAV restoration projects, and will design and (optionally) conduct a research project that could provide information to help improve SAV restoration programs. [Note: SAV can also be a serious nuisance in some locations, since an overabundance of plants can cause waters to become oxygen-depleted when the plants die and decompose. This situation most often occurs when SAV species are introduced to waters where they do not normally grow (in which case, the species are called “exotic” or “alien;” see “Alien Invasion!” and “The Lionfish Invasion” at http://oceanservice.noaa.gov/education/lessons/alien_invasion.html, and http://oceanservice.noaa.gov/education/stories/lionfish/, for more information).

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Learning Procedure

  1. To prepare for this lesson, review:

You may also want to review Jessie Campbell’s thesis on “Influences of Ecological Factors on the Germination of Vallisneria americana Seeds” (http://web.vims.edu/library/Theses/Campbell05.pdf; 174 pages, 1.3mb).

Make copies of these resources for student research, unless you plan to have students obtain these for themselves.

  1. Briefly review the importance and inherent vulnerability of coastal resources. Ask students to list some of the benefits obtained from these resources and examples of events that can damage them. Make sure students include natural events as well as anthropogenic damage (damage caused by human activities; e.g., construction, oil spills, nonpoint source pollution). Tell students that their assignment is to learn about a particularly important and often-damaged resource called “SAV.” Don’t offer more information at this point, but refer students to the “SAV Inquiry Worksheet,” at the end of this lesson, and say that their assignment is to find answers to the worksheet questions. Click here for a seperate printable version of the worksheet.

  2. Lead a discussion of students’ answers to questions on the worksheet. Key points include:
  1. Tell students that in November, 2005, Jessie Campbell (a graduate student from the Virginia Institute of Marine Science) won an award for her presentation to the Estuarine Research Federation about her study of seed germination in a type of sea grass called wild celery (Vallisneria americana). Campbell’s experiments showed that wild celery seeds germinate most successfully when oxygen is present, water temperatures exceed 70° F , the water is only slightly salty, and seeds are buried less than one-half inch deep. Her results are important to help improve SAV restoration projects in the Chesapeake Bay as well as other locations. You may want to have students review the abstract of Campbell’s paper in Appendix 1 at the end of this lesson.

Tell students that their assignment is to design a research project that could provide information to help improve sea grass restoration programs. You may want to refer students to the “Bay Grasses in Classes 2006 Wild Celery Protocol” (http://www.dnr.state.md.us/bay/sav/bgic/download/wild_celery/wc_protocol_06.pdf; 23 pages, 296kb) and/or Jessie Campbell’s thesis on “Influences of Ecological Factors on the Germination of Vallisneria americana Seeds” (http://web.vims.edu/library/Theses/Campbell05.pdf; 174 pages, 1.3mb).

Alternatively, you may choose to have students discover these (and other) resources for themselves. You may also want to provide a rubric for assessing the project designs. Key points could include:

  1. Have each student group present their research project. If you plan to have students actually conduct their projects, encourage suggestions from other students as to how the proposed project could be improved. Be sure students have identified suitable sources of materials. You may want to suggest that they contact your state’s department of natural resources, and/or your county extension agent, as these organizations often have specific information about local species and restoration programs, and may be able to suggest local sources of SAV plants or seeds. To minimize stress on organizational resources, it may be best to have a single representative make the contacts and then report back to the class as a whole.

[Note: The following sources may be able to provide SAV plants or seeds:

http://www.kestersnursery.com/

http://www.kollarnursery.com/

John J. Lemberger
Wildlife Nurseries, Inc.
PO Box 2724
Oshkosh, WI 54902
(920) 231-3780]

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The Bridge Connection

The Bridge is a growing collection online marine education resources. It provides educators with a convenient source of useful information on global, national, and regional marine science topics. Educators and scientists review sites selected for the Bridge to insure that they are accurate and current.

http://www.vims.edu/bridge/sav.html

The “Me” Connection

Have students write a brief essay describing personal actions that might have a negative impact on aquatic vegetation, the potential personal consequences, and what actions they could take to reduce these impacts.

Extensions

  1. See Ducks Unlimited’s “Teacher’s Guide to Wetland Activities” for more activities related to SAV and wetland habitats (http://www.epa.gov/gmpo/education/pdfs/DUTeachers4-6.pdf; 35 pages, 2.7mb).

  2. Visit http://www.response.restoration.noaa.gov/kids/kids.html#exper for experiments, projects, and teaching resources related to oil spills, including a Sediment Penetration Exercise, Mearns Rock Graphing Project, and a project on Oil Spills at the Water Surface.

  3. Visit http://www.response.restoration.noaa.gov/esi/exercise/index.html for instructions and materials for an exercise in planning a protection strategy for a coastline threatened by an oil spill using environmental sensitivity index maps.

  4. Visit http://oceanservice.noaa.gov/education/stories/lionfish/ for a case study about “The Lionfish Invasion.”

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Resources

http://nerrs.noaa.gov/Education/pdf/EstAquKeepwriteup.pdf – Chesapeake Bay National Estuarine Research Reserve publication, “Estuarine Aquarium Keeping for Beginners” by Bob Carroll (19 pages, 156kb)

Granger, S., M. Traber, S.W. Nixon, and R. Keyes. 2002. A practical guide for the use of seeds in eelgrass (Zostera marina L.) restoration. Part I. Collection, processing, and storage. M. Schwartz (ed.), Rhode Island Sea Grant, Narragansett, R.I. 20 pp. available online at http://seagrant.gso.uri.edu/bookstore/eelgrass_seed_one.pdf (1.4mb)

http://www.epa.gov/gmpo/education/pdfs/DUTeachers4-6.pdf – “Teacher’s Guide to Wetland Activities” from Ducks Unlimited (35 pages, 2.7mb)

http://www.dnr.state.md.us/bay/sav/bgic/download/wild_celery/wc_protocol_06.pdf – Maryland Department of Natural Resources publication, “Bay Grasses in Classes 2006 Wild Celery Protocol” (23 pages, 296kb)

National Science Education Standards

Content Standard A: Science as Inquiry

Content Standard C: Life Science

Content Standard E: Science and Technology

Content Standard F: Science in Personal and Social Perspectives

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Ocean Literacy Essential Principles and Fundamental Concepts

Essential Principle 1. The Earth has one big ocean with many features.

Essential Principle 5. The ocean supports a great diversity of life and ecosystems.

Essential Principle 6. The ocean and humans are inextricably interconnected.

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SAV Me!

Student Inquiry Worksheet

Click here for a seperate printable worksheet

  1. What is SAV?



  2. List at least five benefits that SAV provides to humans and other species:






  3. Why are the presence, abundance, diversity, and health of SAV considered to be primary indicators of the health of the Chesapeake Bay?






  4. How do estimates of historic SAV coverage in the Chesapeake Bay compare with coverage in the Bay in 1978?






  5. What change in the Chesapeake Bay environment caused the decline of SAV in the Bay?






  6. What two factors have the greatest effect on the amount of light that reaches SAV?






  7. How do these factors act to reduce the amount of light that reaches SAV?






  8. What human activities affect these two factors?






  9. List three aquatic animals that use SAV for habitat.






  10. What strategies are used to help restore SAV to the Chesapeake Bay?






  11. How can individuals help protect and restore SAV?





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SAV Me!

APPENDIX 1:
Sexual Reproduction of Wild Celery (Vallisneria americana): Why it’s Worth the Effort

by Jessie J. Campbell and Ken A. Moore
Virginia Institute of Marine Science
College of William and Mary
presented at the
Annual Meeting of the Estuarine Research Federation
Norfolk, Virginia
October 19, 2005

Abstract:

Vallisneria americana is a submersed macrophyte found in freshwater systems across North America. Despite considerable annual seed production, the role of seeds in the ecology of this and other SAV species are not well known although recent research has highlighted the importance of seeds in long distance dispersal and restoration. Our objective was to address this gap by quantifying environmental conditions for V. americana seed germination to explain both population dynamics and improve our restoration efforts. We investigated the effects of sediment organic content (1-8%), seed burial depth (2-100 mm), light (present/absent), dissolved oxygen (DO <2 or >4 mg l-1), temperature (13-31°C), and salinity (0-15 psu) on total percent germination under controlled conditions and relate these to field dynamics. Seeds were found to germinate under a wide variety of conditions indicative of a species with a wide habitat range. Germination percentages increased significantly when oxygen was present, temperatures were >19°C, salinities were <5psu, sediment organic content was <3%, and seed burial depths were <15mm. The presence/ absence of light had no significant effect on germination. These results represent an important step in understanding the seed ecology of V. americana and its role in SAV population dynamics.

Click here for a seperate printable version

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