Virtual Lab

Coral Reefs 1 – Abiotic Factors © Explore Learning


Background Information:

Often referred to as “the rainforests of the sea,” coral reefs are ecosystems of incredible biodiversity—home to over 25% of all marine organisms. These reefs have been threatened by human activities and are quickly disappearing around the world. This simulation will help you explore how human activities are affecting coral reefs through pH, storm severity, and temperature.

Please note: if you scroll down while in the Gizmo you will see a list of questions. You DO NOT need to complete these questions. You are able to complete them for extra practice if you would like.


  1. Click the play button to open the Gizmo. Print students can access the Gizmo in the Online Resources for Print Student Section of their online course.
  1. Change from the “CONDITIONS” tab to the “SUMMARY” tab and write down the current reef conditions using the a chart similar to the following.

    Factor
    		No Changes
    		Storm Severity Change
    		Temperature Change
    		pH Change
    		All Changes
    storm severity (%)
    		80 80
    temperature (°C)
    		32 32
    pH 7.6 7.6
    sediment load (ppt)
    nutrient load (ppt)
    water clarity (%)
    coral cover (%)
    coral stress (%)
    total fish species
    observations

©Explore Learning
D9.9 Location of summary tab
  1. Go back to the “CONDITIONS” tab.
  2. Spend some time clicking on the different organisms seen. Note the size of each organism that you look at and make sure you look at some coral species as well as fish species. Write down your observations in the row titled “observations” in your data table.
  3. Change the storm severity from 20% to 80%.
  1. Click the “Advance year” button until the year reads “10.”
  2. Spend some time looking at the different coral and fish species and write your observations in your data table.
  3. Go to the “SUMMARY” tab and record the results for this change.
©Explore Learning
D9.10 Control buttons
  1. Go back to the “CONDITIONS” tab and click the “Return to original settings” button and the “Restart” button.
  2. Change the ocean temperature to 32 ËšC.
  3. Repeat steps 6 to 9.
  4. Change the ocean pH to 7.6.
  5. Repeat steps 6 to 9.
  6. Change the storm severity to 80%, the ocean temperature to 32 ËšC, and the pH to 7.6.
  7. Repeat steps 6 to 9.
  8. Please return to the top of this page and click on analysis to complete the analysis questions.
  1. What are the major changes that you saw with each change made in the lab?

    When the storm severity was increased, the clarity of the ocean decreased due to an increase in sediment stirred up by the storms. This reduced the coral cover from 49% to 20% and the total fish species from 442 to 227.

    When the ocean temperature was increased, the coral cover changed from 49% to 27% and the stress on the coral reef increased from 2% to 18%. This reduced the total fish species from 442 to 325.

    When the ocean pH was lowered to 7.6 from 8.1, coral reef cover decreased from 49% to 31% and the stress on the coral reef increased to 31%. This decreased the total fish species from 442 to 348.

    When all the changes are combined, the sediment load increased to 20 ppt and the clarity decreased to 84%, blocking out sunlight. The coral cover was then decreased from 49% to 8% and the stress on the coral reef increased to 47%. This caused the total fish species to decrease to just 170 species.
  2. Why do you put all the changes together at the end of the lab?

    With climate change, the changes seen will not occur individually, they will all change together. This means that the effects of each will work with the effects of the other to amplify or make the overall effects bigger.
  3. Which environmental disturbance has not been linked to climate change?

    1. increased storm severity
    2. higher sea-surface temperatures
    3. ocean acidification
    4. excess nutrient levels

  4. In the 1970s, staghorn corals dominated Caribbean reefs. Since that time, staghorn corals have declined by over 90% and are now classified as critically endangered. What do you think are the causes of this decline?

    You will need to find a staghorn coral in your simulation to click on. This will provide you with more information about this type of coral. One cause of this reduction is higher ocean temperatures. During extreme temperatures, the coral undergoes coral bleaching. This affects the relationship between the coral and the algae that photosynthesizes for them. This cuts the coral of from its food supply, causing it to die. Another cause of this reduction in staghorn coral is the increase in storm severity seen over the past few years. The storms that come through churn up the water, increasing the sediment and reducing the clarity of the water. This blocks the sun from reaching the algae that photosynthesize, starving the coral.