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TEACHING GUIDES


Voyage to the Galapagos:
"Lizards of the Sea"


Of all the unique animals that make their homes in the Galápagos, few have adapted as successfully to island life as the marine iguana. But there's a problem. During El Niño years, marine iguanas suffer more than any other animal on the islands. Frontiers visits Genovesa to view the devastation caused by the 1997-98 El Niño and its impact on marine iguanas.

Curriculum Links
National Science Education Standards
Activity 1: Meet El Nino and La Nina
Activity 2: Map the World's Ocean Currents




CURRICULUM LINKS


BIOLOGY/
LIFE SCIENCE


adaptations, diversity, reptiles

CHEMISTRY


pH scale

EARTH SCIENCES

climate, ocean currents

ENVIRONMENTAL SCIENCE

habitats

PHYSICAL SCIENCE

Coriolis effect

(Please visit the Subject-Area Search feature on this website for related Frontiers shows and activities!)




NATIONAL SCIENCE EDUCATION STANDARDS

SCIENCE AS INQUIRY / LIFE SCIENCE
5-8: Properties and Changes of Properties in Matter
9-12: Chemical Reactions
LIFE SCIENCE
5-8: Structure and Function in Living Systems; Reproduction and Heredity; Regulation and Behavior; Populations and Ecosystems; Diversity and Adaptations of Organisms
9-12: Molecular Basis of Heredity; Biological Evolution; Behavior of Organisms
EARTH & SPACE SCIENCE
5-8: Structure of Earth's Systems
9-12: Origin and Evolution of Earth's Systems
SCIENCE IN PERSONAL & SOCIAL PERSPECTIVES
5-8: Populations, Resources and Environments
9-12: Population Growth



ACTIVITY 1: MEET EL NINO AND LA NINA

In this episode, meet marine iguana expert Martin Wikelski, who writes, "Marine iguanas are wonderfully unique, the only lizards that feed in the sea, grazing on beds of algae and even diving for submerged seaweed." Darwin himself was impressed by the marine iguana's diving abilities during his 1835 stopover. Wikelski theorizes that the land and marine iguanas of the Galápagos evolved from different ancestors.

As we learn on Frontiers, the 1997-98 El Niño was devastating for marine iguanas in the Galápagos.



PROCEDURE
  • Define what is meant by an El Niño event.

  • Use a globe to show how changes in ocean temperatures affected the Galápagos and other regions of the world during the El Niño of 1997-98. Begin your research at www.pmel.noaa.gov/toga-tao/el-nino/faq.html. This NOAA (National Oceanic & Atmospheric Administration) website will answer all your questions about the global impacts of El Niño and La Niña on climate and society.

  • El Niño is an intermittent phenomenon with global consequences. Research the effects of the 1997-98 El Niño on your region. Find out when the next one is predicted to occur. For definitions of El Niño and La Niña, realtime graphics, current conditions, 3D animation and much more, visit www.pmel.noaa.gov/toga-tao/el-nino/nino-home.html. Click on the "List of impacts and prediction benefits," then scroll down to "El Niño impacts on the U.S. and North America." Here you can plot seasonal effects of El Niño and La Niña.

  • The 1997-98 El Niño phenomenon was almost as destructive as the one that took place in 1982-83, long considered the century's worst. To find out more about the consequences for flora and fauna, visit the Charles Darwin Research Station online at www.polaris.net/~jpinson/welcome.html.

  • La Niña weather events sometimes occur in alternating cycles with El Niño. La Niña, a period of cooling off in the Pacific, may have significant impact on world climate. Early in 1999, forecasters predicted the 1999 hurricane season would be especially severe because of La Niña. Were their predictions on target? What do forecasters predict for the next cycle? What impact did the 1998-99 La Niña have where you live? To begin your research into global weather cycles, visit the Climate Prediction Center at www.cpc.ncep.noaa.gov/index.html or www.publicaffairs.noaa.gov/lanina.html.




ACTIVITY 2: MAP THE WORLD'S OCEAN CURRENTS

Changes in ocean temperature can have significant global impacts, affecting weather phenomena from hurricanes to drought. Modeling weather events like El Niño enables scientists to make predictions about long-term weather forecasts and outbreaks of disease. Understanding the role of the ocean is critical to understanding the world's ecosystems.

  • Two ocean currents, the Humboldt (Peru) and Cromwell (South Equatorial) bathe the Galápagos. The latter current brings more nutrients to the southwestern islands, where marine iguanas grow larger. Demonstrate on a map or globe where these currents flow. (Remember, ocean currents in the Southern Hemisphere flow counterclockwise.)

  • Using a world map or globe, identify the world's major surface ocean currents (see sample below). You'll find a link to a map of these online at geography.miningco.com/library/misc/blcurrents.htm. What ocean currents (undersea and surface) have the biggest impact on your weather?







 

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