Weekly Online Lesson Online Lesson Archive Grade Level: 6-10 Subject: Marine Ecology

Artificial Reef

In Key Largo, Florida, a retired Navy ship set to be scuttled (sunk) with explosives began sinking on its own ahead of schedule, forcing workers to abandon ship before completing their preparations. Everyone onboard got away safely.

Water had been pumped into the ship for a few days to make it sit low in the water and sink easier. It ended up resting upside down in about 130 feet of water, its bow sticking up out of the sea. It wasn't immediately known what went wrong

The goal has been to completely sink the decommissioned vessel, named the Spiegel Grove, to create an artificial reef. It is the largest ship ever to be intentionally sunk for this purpose. Such reefs attract underwater wildlife and are popular with scuba divers, who collectively represent $33 million per year to the local economy.

Plans are underway to turn the Spiegel Grove on its side and sink it completely.

This week's online lesson is about artificial reefs, how and why we create them, and how they benefit marine life and the marine ecology.

Importance of Reefs

Your first task is to find out why reefs are so important to marine ecology, so much so that we sink ships and other debris to help create artificial ones. A great place to start is the Hawai'i Coral Reef Network. Click Slide Shows and choose Importance of reefs. You can click the title or the picture below it. To see the slide show, read each page and then click on the red arrows. What are the three main benefits or reefs (you'll find out on slides 2-4). How much are reefs estimated to be worth just to the state of Hawaii?

When you reach the end of the first slide show, view the next one entitled Food webs. This slide show will help you understand the importance of reefs as fisheries. What are the three major producers on coral reefs? What are the two types of consumers? Name several herbivores and corallivores.

What do you think would happen to our oceans if all reefs, especially coral reefs, were destroyed?

One of the many organizations trying to save the world's reefs is Reef Check. Read the home page to learn about threats to the world's coral reefs. After reading, name at least three factors threatening coral reefs.

Artificial Reefs

Now that you know how important reefs are, you can understand why people would want to create artificial reefs. An artificial reef is any ocean structure or habitat that is man made or not caused by nature. Decommissioned ships like the Spiegel Grove are often used for creating large reefs because they float and are relatively easy to tow to the right place. Shipwrecks are also popular among scuba divers. Learn more by visiting Artificial Reefs of the Florida Keys at Indiana University. Read the short introduction, and then click USS Spiegel Grove. This site has plenty of information about the ship and the ambitious project of creating the largest artificial reef ever. Read Spiegel Grove History and view Spiegel Grove Pictures. What kind of ship was the Spiegel Grove? Where did the ship get its name?

From this site you can link to the USS Spiegel Grove's Official Key Largo Site and read the latest Update. This page contains a good summary of the whole project.

Another site with great artificial reef information is Artificial Reefs of the Keys. If you visit this site you can learn about another ambitious artificial reef project, the USAFS Gen. Hoyt S. Vandenberg. Looking at the photos of this ship, why do you suppose it would be a popular dive site? Click Inside the Ship to see photos inside and outside. What would it be like to see this underwater? Go to Other Artificial Reefs for a few underwater photos.

Ships aren't the only things that make good artificial reefs. Oil platforms provide excellent habitat during and after use. Visit the Artificial Reefs page at the Department of the Interior. This page tells how the Gulf of Mexico has very little reef habitat, and how oil rigs provide vital new habitat for an abundance of marine species. Why is the MMS in favor of converting rigs into reefs? What are the three methods for reefing a platform?

© Copyright 2002
Learners Online, Inc.