Part 5 - The Oyster Dilemma

For this part of the lesson you will need a pencil and a copy of the Oyster Dilemma Worksheet. As you read this part of the lesson, jot down any possible benefits (good things) or possible dangers (bad things) about bringing Pacific oysters to our Chesapeake Bay. You do not have to get all of your benefits or dangers from this section of the lesson. You may add any others that you learned about as you visited the Web sites in this lesson.

Because the Eastern oyster population in the Chesapeake Bay is so small, some people believe that it might be a good idea to bring the Pacific oyster into the Bay so that we will have more oysters to harvest. The Pacific oyster is already being "farmed" in parts of Oregon and Washington, and they are very successful there.

It seems that the Japanese oyster is very hardy (healthy) and does not appear to get the diseases MSX and Dermo as easily as our Eastern oyster. If Pacific oysters could fight off disease and grow well, they could help to filter sediments (solids and dirt), excess nutrients (food for algae and other living things), and toxics (poisons) out of Bay water. This is an important reason to have oysters in the Bay, even if you do not care to harvest and eat them.

Oysters can filter the water in the Bay as shown in this simple experiment. The oysters are placed in a tank of cloudy water (left). As they filter the water for food, the clarity improves steadily. At the end of two hours the water is clear (right).

Higher numbers of healthy oysters would mean that the Bay's waters would be cleaner and clearer. Since oyster "beds" provide homes and habitat to lots of other Bay creatures (crabs, worms, and fishes are just a few) they could be a great help to the creatures of the Bay that need that sort of "neighborhood" to live in.

If they grow well and reproduce there would be lots of healthy oysters for watermen to harvest, and more watermen would be able to continue to "work the water." Seafood markets and restaurants would have plenty of these yummy shellfish for their customers.

But, since the Pacific oyster has never lived in the Chesapeake Bay, we don't know exactly what would happen if they were brought here to live. What if they begin to get the MSX and Dermo diseases that our oysters get? Suppose they disrupt the last of our oysters and the Eastern oyster becomes extinct?

Since the Japanese oyster seems to be so healthy, suppose it grew out of balance for the rest of the ecosystem of the Bay. Could other Bay critters (like mussels or clams) suffer because there are too many Pacific oysters living the in the Bay? Some scientists fear that the Pacific oyster could bring in new diseases if it is brought into the Bay. We just don't know what the outcome of such a venture would be.

What do you think? Would you be in favor of bringing the Pacific oyster into the Chesapeake Bay? On the bottom half of your worksheet cast your "vote." Vote "YES" if you think that we should introduce the Japanese oyster to the Bay. Vote "NO" if you would rather see us try to help the Eastern oyster to survive and become more plentiful in the Bay. List at least three reasons for your choice under your "vote." Explain your reasons in complete sentences. (HINT: Remember why oysters are important to have in the Bay, even if we choose not to eat them.) Your teacher will tally the class votes, and let you know what your classmates think.

How will you know that you've done a good job?
The more "YES" answers to these questions, the better job you did:

  1. Do you know more about oysters than you knew before you did this lesson?
  2. Could you tell someone why oysters are important to the Bay?
  3. Could you describe how oyster aquaculture works?
  4. Were you able to decide if you would support Pacific oysters being introduced into the Chesapeake Bay?

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