Search for lessons > Go back to search results > Lesson

Project title or topic of activity

Where oh where have all the fish gone? Oh where oh where can they be?

Author(s): Corey Fitzgerald

Date: Fall 1999


Summary of Activity
50-100 words

You will focus on 12 different species of fish and shellfish and see how overfishing and some other environmental factors have impacted these individual populations. Using colors (blue, orange, red, yellow, brown and green) and shape (plain and peanut) combinations of M&MÕs you will establish your own community of fish and then role-play different scenarios that depict fishing practices by eating or discarding certain M&MÕs. Your class should be able to see how certain species of fish are targeted and more aggressively fished than others by noticing a decline of certain type of fish in their pool of M&MÕs


Grade levels

grades 2-4.

General description or introduction
The scientific principles that the activity is founded on.

The activity revolves around the issues concerning overfishing and marine environment conservation. While marine sanctuaries have been established in some places around the world, there are currently few laws or regulations protecting populations of fish under severe survival stress. Despite the fact that there are minimum size requirements for the sale and trade of juvenile fish, fisherman are not penalized for the amount of bycatch that they haul in. Bycatch is usually in the form of undesired fish or fish too small to for the fishermen to legally keep, so they dump them (usually dead or injured) back into the sea when their survival rate has been greatly compromised. The overall goal is to raise the awareness of our society to the threats and other dangers we pose to certain fish populations and the stability of the oceanÕs environment.

Background information

Some important background information must be supplied in order to understand and complete this activity. Teachers must also have some knowledge of marine biology and accompanying concepts which will better prepare them to field questions from their students that may deviate from this subject. One must be able to decipher which fish populations are in peril (category 1) and which ones are still relatively stable (category 2). For this activity you will be using 12 different types of fish to represent these two different categories.

Category 1 (Peanut M&MÕs): Over fished and threatened species of fish. Swordfish and Marlins (Blue): These large and impressive fish are widely hunted for sport fishing and have become over fished and depleted in the Atlantic ocean. Fishing for these fish produces high bycatch because they are caught on long lines that contain thousands of hooks or in long drift nets that consequently catch many other unwanted species of fish and marine life. Orange Roughy (Orange): Most Orange Roughy come from deep waters off New Zealand and Australia. Their populations have been greatly depleted and will require many years to recover because of their slow growth and maturity rate. Orange Roughies can take up to 20 years to reach spawning age and live to be more than 100 years old. Lobsters and Shrimp (Red): In and around the U.S. lobster and shrimp populations are over-fished. The main concern with shrimping is the large amount of bycatch. For every pound of shrimp caught, an average of seven pounds of other marine life is killed and shoveled overboard. The sea floor habitat is also severely disturbed by the trolling nets that are used to catch shrimp. Salmon (Brown): Healthy populations still exist in Alaska, but elsewhere they are in severe danger. Several salmon populations are listed as endangered, and many are extinct. Salmon farming is also detrimental to the environment because of large volumes of pollutants that it adds to the water. Scallops (Yellow): Atlantic Sea scallops are over-fished and depleted. Bay scallops are in danger because their environment is compromised by algal blooms. Dredging for scallops is very harmful and disrupts habitat on the ocean floor. Tunas (Green): Bluefin Tuna are severely over-fished and Albacore, Yellowfin and Bigeyes are declining in some regions. Bycatch is also a concern because marine mammals like dolphins and porpoises are also caught in the nets. This is because the tuna and dolphins tend to be found together and fishermen mistakenly set their nets on the dolphins.

Category 2 (Plain M&MÕs): Relatively stable fish populations. Some of these fish are not as popular or valuable as Category 1 fish. Striped Bass (Brown): Abundant. Half of all fish sold are now farm raised. Striped bass farms tend to be relatively benign where water pollution is controlled and population sizes are stable. Mackerels (Green): Most Mackerels are in the safe zone. King, Atlantic and Spanish Mackerels have been over-fished in the past, but good management has improved population sizes. Squid (Orange): Squids are abundant because of their ability to mature fast. They also live in a wide range of habitats and can function under variable conditions. Crabs (Red): There are very large and diverse groups in many regions. Some suffer from water pollution and Alaskan King crab has been over-fished.. Overall crabs are in good shape. Clams and Oysters (Yellow): Many clams and oysters are farm raised which help to regulate the population and maintain habitat because they are grown in racks.. Catching wild shellfish is a concern because the ocean floor is disrupted by nets and dredges. Dolphinfish (Blue): aka Mahimahi or Dorado. Widespread and abundant. The dolphinfish is fast growing and highly fecund.

Credit for the activity

I was inspired to address this topic because of an exhibit on over-fishing that I saw at the Monterey Bay Aquarium. They have an elaborate fact filled set up that really caught my attention. I thought that I could help make a difference by creating an activity that raised the awareness of children to the plight of certain fish populations and the marine ecosystem. My facts and information were taken from the journal Audubon, "The Audubon Guide to Seafood" May-June 1998., and Encyclopedia of Fishes, Paxton, Dr. John R., and Eschmeyer, Dr. William N. et al. Academic Press San Diego CA. 1995.

Estimated time to do the activity


Goals of Activity:

Goal A
Give students a better understanding of over-fishing and other current issues concerning the stability of marine ecology.

Goal B
Get students thinking on a higher level that makes them more aware of how their actions directly and indirectly effect global concerns.

Goal C
Show students that it is not to late to make an effort to implement changes and reduce that rate at which we consume the products and byproducts of the ocean.

Goal D
{Goal D}


National Science Education Standards. (NSES)

Two content standards that this lesson plan covers:

Standard 1
NSES Grades K-4 Content Standard A, Science as Inquiry: This acvtivity has students doing inquiry based science. They are presented with a topic and activity that involves high level thinking and a hands-on activity that forces the student to visually identify and make connections between the activity and lecture based material.

Standard 2
NSES Grades K-4 Content Standard C, Life cycles of organisms and their environment. This activity shows the student the importance maintaining an organisms population and environment to ensure its survival well in to the future. Through this activity the student can see how changes in the ecosystem and food-web can have dramatic effects on the organisms ability to function and survive.


Materials Needed

Materials needed for this exercise are as follows:

  • Paper and Colored Pencils to make Fish Cards.
  • One 1lb. bag of Plain M&MÕs.
  • One 1lb. bag of Peanut M&MÕs.
  • Paper plates or bowls in which to place your populations of fish.
  • Plastic spoons for each student.
  • Audubon Guide to Seafood. (See or contact Dr. Katrina Mangin for a copy of this material) Department of Ecology & Evolutionary Biology BSW 310 University of Arizona Tucson, AZ 85721 Phone: 520-626-5076 Fax: 520-621-7630
  • Pictures obtained from the Encyclopedia of Fishes or Audubon Guide to Seafood of each fish species represented in this activity.
  • A key that identifies which color and shape of M&M corresponds to each fish species.
  • A data table which will be used to record and track the population sizes and other pertinent information for these 12 fish species.


To prepare for this exercise the teacher will need to begin with a short lecture that gives an overview of what the activity entails and get and inquiry from the students as to what they think are important issues in marine conservation and over-fishing practices. The teacher should also include in the lecture highlights and important topics in marine ecology. Discussing ecosystem and food-web structures, population dynamics, and various fishing practices will give the students a better understanding of this material and allow them to make connections to other related subjects. For the activity, start by having the class draw and color the twelve fish described as a set of flash cards or just visual reference. The teacher should make and distribute the populations of fishes (M&MÕs) for the students to work with to ensure count accuracy. Each population should be made up of at least twice as many Category 2 fish as there are Category 1 fish to represent the difference in population size between these two categories.

Step-by-Step Procedure for the Activity

Have class draw and color the 12 fish depicted in this activity and display them on the chalk board. Break the students up into groups of four. Have them tally how many and which kind of fish are in their population. Allow them to eat or discard at random three M&Ms from the population (This can be accomplished by having the students use a spoon to "catch" their fish). For every two of the same kind the group collectively removes from Category 1 they should add one. For every one removed from Category 2 they should replace it with equal amounts. Have the students tally the population and record it. Repeat this process ten times and take a final tally from each group. Write the beginning totals and the end totals on the board to refer to and compare initial and final population sizes. Discuss the results with the class and invite ideas and the students conjectures from the activity. Evaluation/Assessment: The teacher may want to asses what the students have learned by preparing a quiz (short-answer and true/false) and/or having each student write a short essay describing what they have learned by doing this activity.

Images, work sheets, additional web pages

{none available}

Items for discussion or conclusion

1st question

What kind of differences do you see in the population sizes?

2nd question
Did anyone prefer one color/shape of M&M to another? How would your preference relate to preferences in the fishing community?

3rd question
Can depleted populations of fish recover from over-fishing? If so, how? If not, why?

4th question
What will happen if we continue to take more fish than are replaced?


If current fishing practices continue to deplete fish populations faster than they can recover we will soon see a severe crash in the entire marine food chain. Why might the loss of a couple of fish species effect entire communities of marine life? You can make a difference by getting involved with preservations groups within your community. "Think Globaly, Act Locally".

Beyond the Activity
Further activities which relate to and extend the complexity of the experiment.

Other activities may include having the students alter their eating habits for a week. Have them minimize or eliminate foods from their diet that they consider to be non-essential or luxury foods. This will show them that there are alternatives and adjustments they can make to thier diet that are just as satisfying as their previous diet. They can relate this to people cutting back in the amounts of threatened fish that they eat and look for sensable alternatives.

Alert students to the vast amount of conservation groups and other organization that are involved with habitat and species preservation. You may even want to have the class start it's own conservation group and have them set goals and ideas for preserving the school grounds.

Web Resources
A web address with information on the topic of the activity.

Web Address

Additional References

Biology in Progile: A Guide to the Many Branches of Biology, by Peter N. Cambell. Pergamon Press. 1985.