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All over the world, people depend upon natural
resources, whether derived from the land or the sea. For many years the
resources obtained from the ocean were thought to be infinite. Fish,
shellfish, plants, and minerals were extracted or harvested without thought
to the ability of that resource to renew itself. Because they are used
worldwide as a food source, fish are one of the most important resources
humans derive from the sea. Approximately two thirds of the fish caught and
sold worldwide are consumed by people. The remainder of the fish catch is
used as feed for animals or in other products.
In the last several decades, fishing fleets from across the globe have
dramatically increased their catch. Although there are thousands of species
of marine fish , only about 30 percent of those species account for
most of the fish caught intentionally (Greene, 1998).
The increase in worldwide fish catch has resulted in the decline of many
species of marine fish. All organisms that are harvested must be given
sufficient time to grow and reproduce. Also, the amount of fish that can
be removed from a population, without having a negative effect on the size
of that population, must be determined. This is known as the maximum
sustainable yield (MSY). The federal government of the United States is
currently in the process of determining the MSY for many of the large
fisheries. This will enable the government to manage many fish stocks.
Hopefully, this will provide populations with time to stabilize or rebuild, ensuring viable stocks for the future.
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Students will be able to do the following:
- Become aware of the problems of overfishing the oceans.
- Generate possible solutions or extensions to aid in solving the problem
of over-utilization of the ocean's resources.
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- Ten-gallon aquarium
- One bottle of food coloring (for looks only)
- One glass or clear container
- Two measuring cups-one to accommodate 8oz. and 16oz., respectively
- Reference materials
Note: The search engines on the Internet would provide students with the
opportunity to use computers and would provide pertinent information to
complement this activity.
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Activity
Divide the students into cooperative learning groups. Have each
group research fisheries management practices in the United States. Allow
the groups to choose one example of a resource from the ocean that has
been over-harvested and a resource that has not been fully utilized. Have
the students develop hypotheses on ways the over-utilized resource
can be managed more fully and how the under-utilized resource could be put
to a more productive use.
- Set up the ten-gallon aquarium and add the bottle of food coloring to
the water.
- Have one student volunteer to be the fisherman and one student volunteer
to be the fish.
- Provide the student who is the fisherman with the one-cup measure and
the student who is the fish with the two-cup measure.
- Have students predict the outcome of who will be able to remove more
from the system, the fisherman or the fish.
- Have the fisherman remove one cup of water from the aquarium and place
it into the glass bowl.
- Have the fish remove two cups from the glass bowl and place it into the
aquarium.
- Repeat steps five and six at least ten times.
- Stop. Ask the students what they have observed.
- Discuss what will happen if the fisherman and the fish trade places.
- Switch the roles of the fisherman and the fish.
- Repeat steps five and six at least ten times.
- Discuss the results as a class.
- Compare and contrast the results as a class.
- Discuss what human interventions could be enacted to gain a more
balanced harvest.
- Have students list other solutions to harvesting the ocean.
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Repeat the above procedure, this time modifying the
fisherman's catch because of more strict fishing regulations.
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- Students will have to justify their predictions in writing.
- Class participation.
- Discussion of findings.
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Marine & Aquatic Resources Activities - Maximum Sustainable Yield