Part 2: Measuring light at the Flower Gardens Scientists and managers who look after the Flower Garden Banks need to know how much light is reaching the bottom among the corals. Why would this be important? Just like flowers on land, the corals at the Flower Garden Banks depend on sunlight. Knowing how much light reaches the corals is an important indicator for the purity of the water and the health of the corals. Li-Cor spherical light sensor (the light-bulb shaped device) and data logger.78 ft (23.8 m) down on the East Flower Garden Banks. This graph shows the differences between light measured among the corals and light measured at a nearby Mobil energy platform.  By comparing the light levels at the bottom with the light coming in at the sea surface, we can monitor how the water is affecting light transmission over time. It turns out that a number of different factors affect how much light reaches the bottom. These include time of day (obviously), cloud-cover, and time of year. In addition to these predictable changes, there are other differences that indicate how the ocean at the Flower Gardens is responding to the seasons. To begin to understand theseresponses, we need to analyze the data in more detail.   Can you look at the graph of light measurements (directly above) and see the effects of cloudy days? Of the changing seasons? (Click for hints.)   Back: The color of water    Next: How light fades in the water

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Page updated 4/24/98
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