Trouble in Paradise: Factors that Impact Coral Health

Part A: Reefs at Risk in the Caribbean

World view of reefs at risk. Map from World Resources Institute (WRI). Click on image for a larger view.

In the late 1990s, as little as 2% of corals were considered to be endangered. By 2008, an article in Science wrote that over 30% of the world's 700+ species of reef-building corals were threatened with extinction, making coral the most endangered species on the planet. What could possibly be to blame for this overwhelming and rapid decline in coral reef health and stability? Unfortunately, local threats, including fishing, pollution, and coastal development, and the global effects of climate change are largely at fault. Even as you read this sentence, these threats are continuing.

In this part of the lab, you will use Google Earth to examine the locations and severity of risks faced by coral reefs around the globe.

Download and save the Reefs at Risk project files

1. Before beginning to download the files and data for this lab, set up a folder to store all of your work. Name it "Coral Reefs at Risk" and place it such that you can it locate easily, such as on your Desktop or Documents folder.

2. Download the Reefs at Risk Revisited 2011.kmz file to your computer. To accomplish this, right-click (PC) or control-click (Mac) the link below. Choose the option that will download the file to your computer. "Download Linked File..." "Save Link As..." or "Save Target As..." are common browser commands to accomplish this task. This is a large data file, so it may take several minutes to download. Reefs at Risk Revisited 2011.kmz (KMZ File 3.1MB Feb5 20)

3. When the file has downloaded, locate it and place it in the folder that you set up for this lab.

4. Repeat steps 2 & 3 for the files Reefs at Risk Revisited 2030.kmz and Reefs at Risk Revisited 2050.kmz.

Reefs at Risk Revisited 2030.kmz (KMZ File 3.1MB Feb5 20) Reefs at Risk Revisited 2050.kmz (KMZ File 3.1MB Feb5 20)

5. Install Google Earth. Note: If you already have Google Earth installed on your computer, skip to step 6.

6. Launch Google Earth by double-clicking its icon or choosing it from the Programs list under the Start menu.

7. In Google Earth's menu panel on the left, under the Layers list, check the box in front of Borders and Labels to turn this layer on.

8. Choose Google Earth > Preferences (Mac) or Tools > Options... (PC) in the window that opens, click the General tab, and set the display option to allow files to "Show web results in an external browser." Click Apply and OK to save the settings.

9. Choose File > Open and navigate to the desktop or Documents folder to open and view the Reefs at Risk Revisited 2011 file, which you downloaded earlier.

The project will open showing a map of the world. If this is your first time working with Google Earth, take time to practice turning layers on and off and using the navigation tools (Zoom and Move map) to move around the globe. The Google Earth Users guide contains helpful instructions to get you started.

The Reefs at Risk Revisited 2011 map displays a view of threats to coral reefs containing the most recent data available. Take a few minutes to view the locations of the reefs around the globe. The colors on the map represent the estimated threat level faced by each reef. The key below will help you to decipher the colors.

Stop and Think

1: Describe your initial impression of the status of coral reefs in 2011 in the area of the globe you examined. Are the overall threat levels higher or lower than you expected?

2: Predict which human activity you think is the largest contributor to coral reef threats. Explain your choice.

Watch this video about the threats to coral reefs and the Reefs at Risk Revisited data you have just been exploring.

If the video doesn't play visit World Resources Institute Reefs at Risk Revisited

Reefs at Risk - a Threat Forecast for the Future

While the Reefs at Risk Revisited project examined current local threats to reefs in the year 2011, the scientists also used the data to try to forecast where the reefs could be in the years 2030 and 2050. The 2011 data was used as the base and the future maps included the projections of stress from several factors due to climate change. The 2030 and 2050 maps assumed there would be no increase in local pressure on reefs but also no reduction in local threats due to improved policies or management.

1. Choose File > Open and navigate to the desktop or Documents folder to open and view the Reefs at Risk Revisited 2030 and Reefs at Risk Revisited 2050 files, which you downloaded earlier.

2. In the Places panel, click the layer for 2050 off for now. Click the layer for 2030 off and on to compare with the map for 2011 to see how the reef threats shift. Choose a reef area on the map and compare the two assessments. The key below will help you decipher the colors.

3. Now click on the layer for 2050 and return to the reef area you looked at before to now compare the three layers. Take note of any areas that remain the same threat level. For the areas that change, note if the threat level is forecast to increase or decrease. Note if the change will be a lot or a little. How does the 20-year assessment for 2030 compare to the 40-year assessment for 2050?

Stop and Think

3: Describe how the 2050 threats map differs from the 2011 threats map. What do you think this means for the outlook of coral reefs globally? Explain.

Keep these Reefs at Risk maps in mind as you proceed through the rest of the lab and refer back to them when helpful. As you learn about the current state of and science regarding the different coral reefs and threats, consider how the 2011 map might look if it were done today. Consider, as well, that 2030 was 20 years away when the forecast for that map was completed in 2011, but 2030 is now less than 10 years away. How do you think the forecasts may have held up with the science available in 2011 and what we may know now we didn't know then? What about any policies or local pressures that have changed since the maps were created? Keep this in mind as you continue through the lab.

Move on to Part B to explore how various local activities contribute to putting reefs at risk.