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Project title or topic of activity

Human Disturbance of Marine Environments


Author(s): Miguel Lerma, Jeff Dinning, Brian Billiack, and Paul Matson

Date: Spring 2001

 

Summary of Activity

This lesson plan was developed with third through eighth grade students in mind. The activity is designed to teach the students about the various effects that humans have on ocean ecosystems. We have established three activities to allow for hands-on learning pertaining to real threats to marine ecosystems. As the students perform each activity, we expect them to gain knowledge of these threats, and to generate ideas for possible solutions through visual representations and encouragement of critical thinking. Before, during, and after the activities, the instructors will engage the students in discussion that will help them to see some aspects of the problems caused by human disturbances.

 

Grade levels

3rd through 8th grade students.

Background information

Throughout our existence, human beings have taken advantage of the resources that the ocean provides. As a result of global industrialization and a boom in population size, this once seemingly inexhaustible resource has become threatened by human activity. Oil spills and pollution, careless commercial fishing practices, and general disregard for delicate marine ecosystems has given rise to several serious problems.

  • Oil Spills:

When people picture an oil spill in their mind, they see an enormous ship crashed upon the rocks, oozing thousands of gallons of crude oil into the surrounding water. Unfortunately, as our demand for energy rapidly increases and more oil is transported across our oceans, this scenario is becoming all too common. Accidents during shipping are inevitable. The number of oil spills will continue to increase with our demand for fossil fuels. When these oil spills occur they have devastating effects on marine organisms nearby. Also, due to inadequate methods for containment, spills tend to have far reaching effects, as the contaminants spread. Organisms that have been in contact with the oil suffer greatly. Sea birds, for example, become matted in the oily water, and cannot maintain body warmth or buoyancy. Those that do not drown or freeze to death often die from ingestion of oil as they desperately attempt to clean the goo from their feathers; marine mammals such as sea otters and seals experience similar problems. Though whales and dolphins are not effected in this manner, they are often poisoned by ingesting contaminated fish. The entire food web is damaged as oil builds up at different trophic levels.

Fortunately recent technological improvements have allowed us to respond to oil spills relatively quickly, and perform a clean up with modest success. The methods we use today for oil spills in the water include booms, burning, dispersants, and skimming. For beach cleanups, bioremediation, chemical cleaning, hot water/high pressure, manual treatment, and mechanical treatment are the methods used.

Boom: long links used to surround and collect oil

Burning: ignites gaseous oil slicks to reduce to tarry residue

Dispersants: Chemicals that breakup oil into small concentrations, even

Individual molecules

Skimming: skims oil off the surface

Bioremediation: fertilizers stimulate the growth of microbes that eat the oil

Chemical cleaning: chemicals used to clean oil from the beach (detergents)

Hot water: high pressure blasts oil off beach for skimming

Manual Treatment: Shovels, rakes, and manpower to remove oil

Mechanical: Heavy machinery used to "scoop" oil off the beach

*These methods are not perfect, and are considered by many environmentalists to be inadequate.

  • Bycatch:

Another problem facing marine animal populations is bycatch from the commercial fishing industry. While seeking a target species, untargeted species of marine life are caught and killed. While these species pose no loss to the fishermen, they are very valuable to the ecosystem. Drift netting, seine netting, and trawling are several of the methods that contribute to the large amounts of bycatch. Shrimp trawling is probably the most destructive method, claiming ten pounds of bycatch for every pound of shrimp. Drift netting and seine netting entrap air-breathing animals such as dolphins and turtles that drown before they are discovered in the nets. In addition, drift netting entangles animals such as sharks that must continue swimming in order to breathe. These organisms suffocate when they become entrapped in the net. Such indiscriminate fishing techniques are rapidly depleting many marine organisms including the highly endangered Vaquita, whose numbers are thought to have dwindled to several hundred animals.

  • Run-off and Pollution:

Pollution is an obvious problem faced by ocean ecosystems as large quantities of garbage and waste continue to be dumped into the sea. Many pollutants such as broken glass, plastic bags and six-pack rings cause the untimely death of animals that mistake them for food or become entangled in them. Runoff is a specific form of pollution that is often in the form of industrial and agricultural waste. These toxic substances leech into the sea through storm drains, sewer systems, rivers, and the water table. Such substances include chemicals such as lead, mercury, cadmium, chromium, soaps, detergents, pesticides, herbicides, fertilizers, and other inorganic byproducts of industry. They can also include living matter such as viruses, bacteria, and other microbes. Needless to say, these compounds disturb the ecosystem once they reach the ocean. With the coastal populations growing larger every year, larger amounts of runoff are causing serious problems for marine biota.

There are many different ways to measure the amounts of these destructive chemicals in the ocean. Excessively high levels of certain elements can lead to an unhealthy marine environment. The marine environment has a range of levels of different chemicals that are acceptable for living organisms. One good method to test the chemical health of the ocean water is pH testing. While this does not pin point the exact chemical or chemicals (cause) that may be polluting the water, it does offer a mechanism by which we can quantify their effects.



Credit for the activity

The oil pollution activity is an adaptation of a laboratory project developed for Dr. Thompson’s biology 183 class. The bycatch activity is an adaptation from the shrimp bycatch display in Dr. Mangin’s Ecology 497 class. The pH/pollution activity is an original creation of ours, and if this activity already existed it is purely coincidental, and a testament to convergent evolution.


Estimated time to do the activity/activities

This activity should take approximately twenty-five minutes with as much additional time as necessary in order to discuss the topics thoroughly.



Goals of Activity/Activities:

Goals:
  • Educating students about the issues facing the destruction of the ocean by human activity.
  • Promoting critical thinking and problem solving skills.
  • Enlightening students to the delicate relationship between man and the ocean.
  • Promoting creativity.
  • Educating about serious issues without activities being too morbid for students.


 

Materials Needed

  • Detergents(laundry detergent will do)
  • Aquarium
  • Small pieces of synthetic fur
  • Cooking Oil
  • Marbles
  • Fish net
  • 16 oz cups
  • pH testing kit
  • Ammonia
  • Baking Soda
  • Can of soda
  • Sponges
  • paper towels

* All of these items, with the exception of the fish tank, can be purchased at a store such as Wal-Mart or target. We purchased all of the items at these two stores for less than thirty dollars. The fish tank was obtained from the classroom in CBS.



Preparation & teacher "heads up"

Setup:

  • Oil Spill

Objects used in the demonstration (feathers, rocks, fur, shells) will be placed in a large plastic tub. A minimal amount of oil will be poured on the objects so that they are covered. Sponges are then placed next to the tub. The sponges range from being dry, wet, or wet with detergent. These three methods will represent soak up, hand clean up with detergent (dispersants), and spray off with water methods. The other methods will be discussed in the background info. After the demonstration, the objects are placed in a plastic bag and taken to a proper disposal location.

  • pH

Six cups, plastic or Styrofoam are placed on a table and filled halfway up with water. Different household chemicals are placed next to the cups to be added by the students. A pool or aquarium pH test kit is used to test the water after the students add the chemicals.

  • Bycatch

An aquarium is filled three-quarters of the way up with water. Add the marbles and the "target species". Place net in tank and set up poster/blindfold.



Step-by-Step Procedure

  • Oil Spills:

The kids will start off by executing this experiment. They will have no background information at this point. After attempting to clean up, students will be asked to determine the effectiveness of the different cleanup methods. Then the kids will be asked engaging questions that will be accompanied by the background info about oil spills and their effect on the environment. Other methods will be demonstrated verbally or with visuals. Again, the students should evaluate which method was the most important. It should then be explained that no method is 100% effective. Finally, the piece of synthetic fur will represent a marine mammal’s coat and oil will be placed on it. The obvious method used is detergent that the students will be allowed to try. Again, the students will observe that the detergent does not completely remove the oil. This can then be discussed by the students. The overall effectiveness of oil spill cleanup can then be discussed, with possible solutions proposed. Since many of these solutions by nature are associated with higher costs, the concept of trade-offs will have to be proposed to the students. For example, do we invest into research of new materials, different transport methods, or alternative energy sources? Which will be the best investment in the long run, and can is there a realistic short-term solution? How can economics and conservation be balanced in such a way that makes sense locally, and globally? What can we do as individuals and communities to help?

  • Bycatch:

Students once again gather around an aquarium half filled with water. Inside, multiple colors of marbles will cover the bottom. Students will assign a color of their choice to a species representing a desired food animal. Students, one at a time, will be blindfolded and asked to use a fish net to scoop out as many marbles as they can get into the net in one sweep. This represents the indiscriminate methods of modern fishing. Students will then evaluate their "catch" and discuss the ineffectiveness of pinpointing one species. Since this is a quick activity, time will be available to discuss fishing methods and propose alternatives.

  • Runoff(pH):

A very brief explanation of pH and its effect of marine organisms will be explained. Since the concept of pH can be confusing to all ages of students, the concept of ranges, and extremes should be explained. The teacher should draw a scale of the relative acidity of things that students will readily identify with. For example, cola, pool water, shampoo, and soap could all be drawn on a scale in such a manner that a student could see where they fit in on a ranges of pHs. Students will gather around several cups filled with water and various "pollutants". The cups will then be tested for their pH levels using the test kit. The results of these tests will then be discussed with the students to see how much the pollutants would effect marine life.



Images, work sheets, additional web pages

We will have a poster of different images of oil spills, commercial fishing boats, and oceanic pollution. This will give the students a visual picture of threats faced by the oceans of the world.


Items for discussion or conclusion

Questions:

By actually trying to clean oil from different representations of marine materials the students will be able to see that oil is incredibly difficult to clean up. Prevention of oil spills and balancing tradeoffs are more realistic approaches to cleaning up the ocean than the physical act of cleaning the water.

The bycatch tank will undoubtedly surprise students. It is hard to fathom that this simulation is an accurate representation of an actual method. Again, there are ways to curtail the abhorrent waste that commercial fisheries accumulate. Turtle exclusion devices and sonar pingers that scare away large mammals are some economically viable options. However, more legislation, and better enforcement of existing laws could be more effective. Also, the idea of "think globally, act locally" applies here. One of the best ways to control the amount of bykill is to reduce the demand for the product. This can be accomplished individually by not being a consumer of a target species associated with excessive bykill.

Since the pH/pollution activity incorporates so many different sources of pollution, there are many different take home messages. Educating students about the multiple ways in which we dump chemicals into our oceans is perhaps the most important aspect of this project. We need to start thinking of all the indirect ways in which we contribute to polluting the environment, and this activity is a good start.

The emphasis of this workshop station has to be on solutions. Although it is very important to educate young people about the current problems themselves, the real problem is the lack of viable resolutions. We hope educational settings such as this will manifest in the creative problem solvers of tomorrow.




Assessment

Ask the students about different threats to the ocean and its organisms. Have a discussion about the possible solutions to some of these threats. Ask if they can come up with any solutions that have not been mentioned, and that are uniquely theirs.

 

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

Having the students be conscious of how we individually effect the environment on a day to day basis is perhaps the most effective activity that can be done after they leave the classroom. For example, they can watch what gets poured down the drain at their own homes, and come up with alternative ways of disposing caustic cleaners, and chemicals. They can tell their parents that it is important to fix the leaks in their cars and boats. They can suggest alternatives to their families’ seafood meals. Also, being active in community clean up projects, and local government goes a long way toward helping the environment and the oceans.



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

Web Address
 



Additional References

Reference

  1. "Fisheries in Trouble: Bycatch Solutions" E-Quarium: Endangered Oceans.
  2. 11 Apr. 2001. Monterey bay Aquarium. http://mbayaq.org/efc/efc_oc/dngr_trbl_by_solution.asp

  3. "Interesting Facts about Oil Spills." Great lakes Commission: Advisor. 10
  4. May 1996. http://www.glc.org/docs/advisor/95/oil/dyk.html

  5. "Joint Statement: Seanet Helps Commercial Fishermen Tackle Bycatch."
  6. Agriculture, Fisheries, and Forestry Australia. 28 Nov. 2000.

    http://www.affa.gov.au/ministers/truss/releases/00/00218wtj.html

  7. "Marine Pollution."Ask a Scientist. 21 Sept. 2000. Oceanlink 11 Apr. 2001.
  8. http://oceanlink.island.net.ask/pollution.html

  9. Marty, Danielle, Armand Bianchi and Claude Gatellier. "Effects of Three Oil
  10. Spill Dispersants on Marine Bacterial Populations." Marine pollution Bulletin. Vol. 10, No. 10 (Oct. 1979): 285-287.

  11. McAllister, Don. "Opinion: Trawlers are Strip-Mining the Oceans"
  12. Environment News Service 23 Dec. 1998.

    http://ens.lycos.com/ens/dec98/1998L-12-23-03.html

  13. Murray, James D., James J. Bahen and Roger A. Rulifson. "Management
  14. Considerations for By-Catch in the North Carolina and Southeast Shrimp Fishery." Fisheries. Vol. 17 No. 1 (Jan-Feb 1992): 21-2

  15. Perra, Paul "By-Catch Reduction Devices as a Conservation measure."

Fisheries. Vol.17, No. 1 (Jan-Feb 1992): 28-29.

9.) "World Disasters: Oil Spills" Looksmart: FastFacts. 11 Apr. 2001.

Infoplease.com. http://looksmart.infoplease.com/ipa/A0001451.html

 

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