Estuarine Ecosystems / 9-12 / Life Science, Earth Science
How are estuarine research reserves used as “natural laboratories” to improve our understanding of estuarine systems?
- Students will describe the National Estuarine Research Reserve System, and will explain how to obtain information on the 26 sites in the System, including the research projects undertaken at these sites.
- Students will explain how a biological organism can be used to detect excess nutrient inputs to estuaries.
- Students will interpret technical data to make predictions about the distribution of nutrients in specific estuaries.
Links to Overview Essays and Resources Useful for Student Research
- Copies of “Natural Laboratories Student Worksheet” found at the end of this lesson plan, one copy for each student or student group. (Click here for a separate printable worksheet.)
- (optional) Computers with Internet access; if students do not have access to the Internet, direct them to local library resources, and/or download copies of materials cited under “Learning Procedure” and provide copies of these materials to each student or student group
One 45-minute class period, plus time for student research.
Classroom style if students are working individually, or groups of 3-4 students.
Maximum Number of Students
National Estuarine Research Reserve System
Nutrient Pollution Indicator
Estuaries are water bodies and adjacent wetlands found in areas where rivers flow into much larger bodies of water, and include bays, sounds, marshes, inlets, lagoons, and sloughs. Most estuaries are formed where a river meets the sea, but there are also freshwater estuaries where rivers flow into much larger bodies of freshwater (such as the Great Lakes). Estuaries provide many benefits, including:
- essential spawning and nursery areas for many species, including fish and shellfish important to commercial and recreational fisheries;
- protection for upland areas from flooding and shoreline erosion; and
- habitat and food for estuarine species as well as species that live in other habitats.
Unfortunately estuaries (and the benefits they provide) are threatened by impacts from human activities such as coastal erosion, water pollution, and habitat destruction, as well as a variety of natural disturbances such as winds, waves, heavy rainfall, and severe storms.
The National Estuarine Research Reserve System (NERRS) is a network of 26 estuaries that was established to represent different biogeographical regions of the United States and support long-term research, education, and stewardship of estuarine resources. Within each reserve, field staff work with local communities and regional groups on issues such as nonpoint source pollution, habitat restoration, and how best to cope with invasive species. For more information on these topics, see:
Many researchers working in NERRS are supported through the Cooperative Institute for Coastal and Estuarine Environmental Technology (CICEET), a partnership between NOAA and the University of New Hampshire. The CICEET Web page (http://www.ciceet.unh.edu/) includes a searchable database of more than 100 projects to develop and apply innovative technologies for understanding and reversing the impacts of coastal and estuarine contamination and degradation.
This activity is intended to introduce students to some sources of information about the National Estuarine Research Reserve System and applied research projects that are part of NERRS. In addition, students will gain practice in reading and interpreting scientific reports.
- Preparation: If students do not have access to the Internet, download and copy:
- Introductory essay on National Estuarine Research Reserves
- Pages on Great Bay Reserve, New Hampshire: Site Description, Flora, Endangered Species, Tidal Range, and “Geology & Soil Types” (linked from http://www.nerrs.noaa.gov/GreatBay/Overview.html);
- Project Profile and Final Report for the project “Eelgrass as an Indicator of Nutrient Over-Enrichment in Estuaries” (from the CICEET Project Explorer Web page, http://ciceet.unh.edu/searchprojects.html, click below the Project Explorer icon, then enter “Short” in the Coordinator box, select “Nutrient Enrichment” in the Issue box, select “Great Bay” in the NERR box, then press the Search button. “Early Detection of Nutrient Over-Enrichment Using Eelgrass Community Response” should appear in the Title box. Click on this title to display the Project Profile and a link to the Final Report (note that the Final Report is 59 pages long and approximately 5.5 Mb).
- You may want to have students review the tutorial in the “Estuaries Tutorial” http://oceanservice.noaa.gov/education/tutorial_estuaries/, and complete one version of the subject review.
- Introduce the National Estuarine Research Reserve System, and tell students that they will be investigating one of these reserves and one of the many research projects that use these reserves as natural laboratories;
- Provide each student or student group with a copy of the “Student Worksheet,” as well as copies of the materials downloaded in Step 1 if students do not have access to the Internet.
- Stewardship, research, and education are the three primary purposes for which National Estuarine Research Reserves are established.
- The eight habitats found in the Great Bay Reserve include upland forest, upland field, salt marsh, mudflats, tidal creek, rocky intertidal, eelgrass beds, and channel bottom/subtidal.
- The Great Bay Wildlife Refuge has the greatest diversity of habitats within the Great Bay NERR.
- Spartina alterniflora and Spartina patens dominate saltmarsh habitats.
- The Great Bay Reserve region is characterized as a transition zone between deciduous forest and coniferous forest.
- The Great Bay Reserve estuary is critical to the wintering of the American bald eagle.
- Tidal flow dominates over freshwater influence in the Great Bay Reserve estuary throughout most of the year.
- Large outcrops of slate provide an important source of stable substrate for macroalgal attachment and contributes to the beaches in the Great Bay Reserve.
- The Great Bay Reserve estuary is representative of a drowned river valley.
- Marsh soils bordering streams within the Great Bay Reserve generally contain high amounts of organic matter and sulfur-containing minerals.
- Man-made loading from coastal watersheds is the major cause of excessive nutrients in estuarine and coastal waters.
- It is difficult to directly measure excessive nutrients in estuaries because they become diluted and dissipate through tidal and current action, as well as plant uptake.
- Dr. Short used eelgrass, Zostera marina, as an indicator of nutrient over-enrichment.
- In addition to Great Bay, Narragansett Bay (RI) and Waquoit Bay (MA) were used as research sites for Dr. Short’s project.
- Plant morphology and nutrient content of leaf tissue were used to create an early indicator of nutrient over-enrichment.
- Plant morphology and nutrient content were combined to provide a single measurement of early nutrient over-enrichment by calculating the ratio of leaf tissue nitrogen content to leaf mass. This ratio is called the Nutrient Pollution Indicator (NPI).
- Leaf mass is negatively related to leaf tissue nitrogen content; so, higher concentrations of nitrogen in leaf tissue correspond to a reduction in leaf mass. This is a good opportunity to distinguish between correlation and causality: This research shows that a reduction in leaf mass coincides with higher tissue nitrogen concentrations, but does not show that one response causes the other.
- Dr. Short’s project developed an interactive CD-ROM to explain the step-by-step procedures for determining gradients of nutrient over-enrichment within estuaries; monitoring long-term changes in nutrient over-enrichment at specific sites; identifying sources of non-point nutrient pollution; and comparing the nutrient status of different estuaries.
- In samples from Waquoit Bay, leaf mass was highest in plants from down-estuary, while tissue nitrogen was highest in plants from up-estuary.
- Between April 1998 and April 2000, leaf nitrogen content in plants from Great Bay Estuary was highest during the spring.
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 - Click on “Ocean Science Topics” in the navigation menu to the left, then “Habitats,” then “Coastal,” then “Estuary.”
The “Me” Connection
Have students write a brief essay describing three ways in which estuaries are personally important (e.g., recreation, fishing, source of seafood, protection from erosion caused by storms, etc.), and how they might directly benefit from the National Estuarine Research Reserve System.
- Have students select other NERRS estuaries or projects in the CICEET project database, and prepare brief reports about these systems or projects.
- Visit http://oceanservice.noaa.gov/education/tutorial_estuaries/ and http://nerrs.noaa.gov/Education/Curriculum.html for more information and activities related to estuaries.
http://oceanservice.noaa.gov/education/tutorial_estuaries/ – NOAA’s Estuary Tutorial, with an annotated roadmap to resources.
http://nerrs.noaa.gov/Education/k12Educators.html – Information on education programs offered at National Estuarine Research Reserve sites, including curricula, Powerpoint presentations, and lesson plans.
http://ciceet.unh.edu/searchprojects.html– The CICEET Project Explorer, which provides a visually-stimulating and user-friendly way to experience the CICEET project database.
http://www.epa.gov/owow/estuaries/kids/ – Games and activities about estuaries produced through the National Estuary Program.
http://www.northinlet.sc.edu/estnetweb/estnet.html – “Estuary-Net Project;” an online project to develop collaborations among high schools, community volunteer water quality monitoring groups, local officials, state Coastal Zone Management (CZM) programs and National Estuarine Research Reserves (NERRS) to help solve non-point source pollution problems in estuaries and their watersheds.
National Science Education Standards
Content Standard A: Science as Inquiry
- Abilities necessary to do scientific inquiry
- Understandings about scientific inquiry
Content Standard C: Life Science
- Interdependence of organisms
Content Standard D: Earth and Space Science
- Geochemical cycles
Content Standard E: Science and Technology
- Understandings about science and technology
Content Standard F: Science in Personal and Social Perspectives
- Personal and community health
- Population growth
- Natural resources
- Environmental quality
- Natural and human-induced hazards
- Science and technology in local, national, and global chal;lenges
Ocean Literacy Essential Principles and Fundamental Concepts
Essential Principle 5. The ocean supports a great diversity of life and ecosystems.
- Fundamental Concept f. Ocean habitats are defined by environmental factors. Due to interactions of abiotic factors such as salinity, temperature, oxygen, pH, light, nutrients, pressure, substrate and circulation, ocean life is not evenly distributed temporally or spatially, i.e., it is “patchy”. Some regions of the ocean support more diverse and abundant life than anywhere on Earth, while much of the ocean is considered a desert.
- Fundamental Concept i. Estuaries provide important and productive nursery areas for many marine and aquatic species.
Essential Principle 6. The ocean and humans are inextricably interconnected.
- Fundamental Concept a. The ocean affects every human life. It supplies freshwater (most rain comes from the ocean) and nearly all Earth’s oxygen. It moderates the Earth’s climate, influences our weather, and affects human health.
- Fundamental Concept b. From the ocean we get foods, medicines, and mineral and energy resources. In addition, it provides jobs, supports our nation’s economy, serves as a highway for transportation of goods and people, and plays a role in national security.
- Fundamental Concept c. The ocean is a source of inspiration, recreation, rejuvenation and discovery. It is also an important element in the heritage of many cultures.
- Fundamental Concept d. Much of the world’s population lives in coastal areas.
- Fundamental Concept e. Humans affect the ocean in a variety of ways. Laws, regulations and resource management affect what is taken out and put into the ocean. Human development and activity leads to pollution (such as point source, non-point source, and noise pollution) and physical modifications (such as changes to beaches, shores and rivers). In addition, humans have removed most of the large vertebrates from the ocean.
- Fundamental Concept f. Coastal regions are susceptible to natural hazards (such as tsunamis, hurricanes, cyclones, sea level change, and storm surges).
- Fundamental Concept g. Everyone is responsible for caring for the ocean. The ocean sustains life on Earth and humans must live in ways that sustain the ocean. Individual and collective actions are needed to effectively manage ocean resources for all.
Essential Principle 7. The ocean is largely unexplored.
- Fundamental Concept d. New technologies, sensors and tools are expanding our ability to explore the ocean. Ocean scientists are relying more and more on satellites, drifters, buoys, subsea observatories and unmanned submersibles.
- Fundamental Concept f. Ocean exploration is truly interdisciplinary. It requires close collaboration among biologists, chemists, climatologists, computer programmers, engineers, geologists, meteorologists, and physicists, and new ways of thinking.
Begin research for the following questions at http://oceanservice.noaa.gov/topics/coasts/reserves.
- What are three primary purposes for which National Estuarine Research Reserves are established?
- What are eight habitats found in the Great Bay Reserve?
- Which area within the reserve has the greatest diversity of habitats?
- Saltmarsh habitats are dominated by which plant species?
- Are forested areas within the Great Bay Reserve classified as deciduous forests or coniferous forests?
- The Great Bay Reserve estuary is critical to the wintering of what protected species?
- Does tidal flow or freshwater flow have the dominant influence on water movement in the Great Bay Reserve estuary throughout most of the year?
- What geological formation provides an important source of stable substrate for macroalgal attachment and contributes to the beaches in the Great Bay Reserve?
- The Great Bay Reserve estuary is representative of what type of geological formation?
- Marsh soils bordering streams within the Great Bay Reserve generally contain high amounts of what substances?
- What is the major cause of excessive nutrients in estuarine and coastal waters?
- Why is it difficult to directly measure excessive nutrients in estuaries?
- What biological species did Dr. Short use as an indicator of nutrient over-enrichment?
- In addition to Great Bay, what other NERRS sites were used in this project?
- What responses of the indicator organism were used to create an early indicator of nutrient over-enrichment?
- How were these responses combined to provide a single measurement of early nutrient over-enrichment?
- Is the mathematical relationship between these responses positive or negative?
- Dr. Short’s project developed an interactive CD-ROM to explain the step-by-step procedures for what four types of investigation?
- In samples from Waquoit Bay, were leaf mass and tissue nitrogen highest in plants from the mouth of the estuary (down-estuary) or near the head of the estuary (up-estuary)?
- During what season was leaf nitrogen content highest in plants from Great Bay Estuary between April 1998 and April 2000?
One of the major sources of water pollution in the United States is contaminated runoff. Estuaries in the National Estuarine Research Reserve System provide natural laboratories for studying this problem. From 1997 to 2000, Dr. Frederick Short of the University of New Hampshire led a research program to develop a biological method for detecting excess nutrient inputs to estuaries. Use the CICEET Project Explorer (http://ciceet.unh.edu/searchprojects.html) to answer the following questions. (Hint: the Project Profile and Final Report for Dr. Short’s project contain all the information you need).