The accumulation of plastic in the oceans is an ever-growing environmental concern. Plastic debris is a choking and entanglement hazard for wildlife; plastics also leach toxic compounds into organisms and ecosystems. Educating students about the marine debris problem introduces fundamental concepts in toxicology, ecology, and oceanography. Students will learn about the toxicity of plastics, collect and analyze data on plastic debris, and put their new knowledge to work by writing a congressional bill that addresses the problem of marine debris.

The National Oceanic and Atmospheric Administration (NOAA) defines marine debris as "any persistent solid material that is manufactured or processed and directly or indirectly, intentionally or unintentionally, disposed of or abandoned into the marine environment..." (http://marinedebris.noaa.gov/). This issue is but one example of numerous human impacts on the ocean. Unfortunately, most Americans are ocean-illiterate (Ocean Project, 2009) – that is, they do not understand "the ocean's influence on you, and your influence on the ocean" (National Geographic Society, 2006). The activities described below will assist students in making connections to the ocean.

The ever-growing problem of marine debris begins on land, where streams and rivers carry debris to the coast. Ocean currents then transport debris to remote areas, where it may take centuries to break down (Goldberg, 1994). Awareness of the marine debris problem has increased because of recent reports on the Eastern Pacific Garbage Patch (EPGP). The EPGP is an area between California and Hawaii that contains a large quantity of small "microplastic" pieces derived from the breakdown of larger plastic items (Marks & Howden, 2008). The plastic debris both near the coast and in the EPGP can endanger the health of marine organisms (Derraik, 2002).

Plastic debris poses a danger to all forms of aquatic life. Many marine organisms can become entangled or can ingest plastic debris. Certain marine species, such as sea turtles and seabirds, mistake plastic for prey items (Nevins et al., 2005; Hyrenbach et al., 2009; Mrosovsky et al., 2009). For example, adult albatrosses inadvertently feed their chicks plastics instead of natural food items, which affects chick growth and may cause mortality (Ryan & Jackson, 1987; Pierce et al., 2004). Furthermore, an insidious hazard lurks within plastics. The toxic chemicals added to make plastics more flexible, known as plasticizers, can leach out into the environment and into organisms that ingest plastic (Rahman & Brazel, 2004). Other dangerous chemicals can concentrate on plastic surfaces (Mato et al., 2001), increasing the toxicity of plastics.

A major concern about the toxic compounds associated with plastics is that they can disrupt hormone regulation in the cells of organisms (Oberdörster & Cheek, 2001). Hormone disruption occurs when a chemical acts as a natural hormone in a cell (Figure 1); it can change reproductive ability and mating behavior, contribute to tumor development, and negatively affect offspring (van de Merwe et al., 2010; Wuttke et al., 2010). For example, male fish exposed to hormone-disrupting compounds can develop ovaries (Gray & Metcalfe, 1997). Additionally, certain plastics, such as styrene (Styrofoam), are carcinogenic (Vodicka et al., 2006).

Figure 1.

The cellular pathway of hormone disruption.

Figure 1.

The cellular pathway of hormone disruption.

The lessons below (objectives listed in Figure 2, materials and equipment in Table 1) couple process skills with the underlying science of plastic pollution. They can be modified to be appropriate for grades 6–10. Oikonos Ecosystem Knowledge in partnership with many collaborators (see Acknowledgments) created the overall marine debris curriculum. The plastic-pollution curriculum described here was further developed and modified by CAMEOS, a National Science Foundation Graduate K–12 program, at the University of California Davis Bodega Marine Laboratory.

Figure 2.

Ecotoxicology of Marine Debris lesson objectives.

Figure 2.

Ecotoxicology of Marine Debris lesson objectives.

Table 1.

Materials and equipment needed.

Lesson 1Lesson 2Lesson 3
Computer Transect tape "Making a Bill" worksheeta 
Projector Oikonos data sheet for campus debris surveya Computer lab with Internet accessb 
Introduction to Marine Plastics Presentationa Clipboards  
 Trashbags Plastic gloves Stopwatchesb Tables of plastic types and toxic compounds Data sheet for plastic analysisa  
Lesson 1Lesson 2Lesson 3
Computer Transect tape "Making a Bill" worksheeta 
Projector Oikonos data sheet for campus debris surveya Computer lab with Internet accessb 
Introduction to Marine Plastics Presentationa Clipboards  
 Trashbags Plastic gloves Stopwatchesb Tables of plastic types and toxic compounds Data sheet for plastic analysisa  
b

Optional, lesson can be done without

Lesson 1: Introduction to Marine Debris & Toxicology of Plastics

Lesson Time:1 hour

This lecture familiarizes students with key concepts regarding the origin and transport of debris, the chemical structure of plastics, and the toxicology of plastic-associated chemicals and how they can affect marine organisms. The presentation, found on the CAMEOS website (http://bml.ucdavis.edu/education/cameos/resources/ecotoxicology/) includes extensive teacher notes. Following Lesson 1, students will be able to define terms (e.g., plasticizer, bioindicator species) and understand concepts (e.g., how certain compounds disrupt hormones).

Lesson 2: Campus Debris Survey & Plastic Analysis

Lesson Time: 90–120 minutes

Lesson 2 involves a campus debris survey and analysis of debris found. Students will formulate a scientific protocol; collect, analyze, and interpret data; and compare results.

Campus Debris Survey

  • Assemble debris collection teams of 4 or 5 students. (Alternatively, students can bring in a variety of plastic debris from home).

  • Give students the list of materials in Table 1 and discuss the importance of each debris-collection team using the same protocol. For example, in order to have comparable data between groups, students should be collecting in areas of similar size and over similar time intervals.

  • Assign each team to a distinct area, such as a sports field (equivalent areas approximately 20 x 20 m are best).

  • Teams should measure and mark their collection area. One student will record data (using clipboard with data sheet) while others wear protective gloves and place trash collected into two bags, one for plastics and one for nonplastics. All debris should be recorded and students should collect as much debris as possible in their designated area during the collection time (~15-minute collection period is best).

  • Remind students to record any observations as they are conducting the survey. Students should save plastic trash for part 2 of this lesson.

Plastic Data Analysis

In the second part of this lesson, students will categorize and analyze the plastic debris to understand the kinds of plastics and associated contaminants found on their school campus.

Groups will sort collected plastics into categories described in Table 2 and note the contaminants associated with each category (Table 3), following the example in Figure 3. Upon completion, data can be graphed using Microsoft Excel or by hand. Data sheets and Excel lessons with step-by-step instructions can be found on the CAMEOS website. Students can summarize Lessons 1 and 2 in a laboratory report assignment, using the background information from Lesson 1 and the methods and results developed in Lesson 2.

Table 2.

Types of plastics.

Plastic TypeFull NameCodeExamplesRecyclable?
PETE Polyethylene terephthalate Soda bottles Yes 
HDPE High density polyethylene Milk jugs, shampoo bottles, yogurt containers Yes 
PVC Polyvinyl chloride Clear food packaging, candy wrappers, some bottles Sometimes 
LDPE Low density polyethylene Squeezable bottles, shopping bags Yes 
PP Polypropylene Caps, straws, some bottles Yes 
PS Polystyrene Disposable plates and cups, CD cases Sometimes 
PC, other Polycarbonate Water jugs, sunglasses, DVDs Not usually 
Plastic TypeFull NameCodeExamplesRecyclable?
PETE Polyethylene terephthalate Soda bottles Yes 
HDPE High density polyethylene Milk jugs, shampoo bottles, yogurt containers Yes 
PVC Polyvinyl chloride Clear food packaging, candy wrappers, some bottles Sometimes 
LDPE Low density polyethylene Squeezable bottles, shopping bags Yes 
PP Polypropylene Caps, straws, some bottles Yes 
PS Polystyrene Disposable plates and cups, CD cases Sometimes 
PC, other Polycarbonate Water jugs, sunglasses, DVDs Not usually 
Table 3.

Toxic compounds in or associated with plastics: their uses and effects.

Toxic CompoundUseEffect(s)Plastic Type(s)Concentration
Bisphenol A (BPA) Plasticizer, can liner Mimics estrogen PVC, PC 43–483 mg/kg in PVC food wrappersa (López-Cervantes & Paseiro-Losada, 2003
Phthalates Plasticizer, artificial fragrances Interferes with testosterone, sperm motility PS, PVC 0.5–30.8 mg/kg in food wrappersb (Castle et al., 1988
Persistent organic pollutants (POPs) Pesticides, flame retardants, etc. Possible neurological and reproductive damage All plastics  
Dioxins Produced in manufacture of PVC, during waste incineration Carcinogen, interferes with testosterone All plastics  
Nonylphenol Antistatic, antifog, surfactant (in detergents) Mimics estrogen PVC 10–3300 μg/gc (Inoue et al., 2001
Polyaromatic hydrocarbons (PAHs) Produced when fossil fuels are burned Developmental and reproductive toxicity All plastics  
Polychlorinated biphenyls (PCBs) Electronics manufacture Interferes with thyroid function All plastics  
Styrene monomer Structure of polystyrene Forms DNA adducts PS <0.001–0.071 mg/kgd (Tawfik & Huyghebaert, 1998
Toxic CompoundUseEffect(s)Plastic Type(s)Concentration
Bisphenol A (BPA) Plasticizer, can liner Mimics estrogen PVC, PC 43–483 mg/kg in PVC food wrappersa (López-Cervantes & Paseiro-Losada, 2003
Phthalates Plasticizer, artificial fragrances Interferes with testosterone, sperm motility PS, PVC 0.5–30.8 mg/kg in food wrappersb (Castle et al., 1988
Persistent organic pollutants (POPs) Pesticides, flame retardants, etc. Possible neurological and reproductive damage All plastics  
Dioxins Produced in manufacture of PVC, during waste incineration Carcinogen, interferes with testosterone All plastics  
Nonylphenol Antistatic, antifog, surfactant (in detergents) Mimics estrogen PVC 10–3300 μg/gc (Inoue et al., 2001
Polyaromatic hydrocarbons (PAHs) Produced when fossil fuels are burned Developmental and reproductive toxicity All plastics  
Polychlorinated biphenyls (PCBs) Electronics manufacture Interferes with thyroid function All plastics  
Styrene monomer Structure of polystyrene Forms DNA adducts PS <0.001–0.071 mg/kgd (Tawfik & Huyghebaert, 1998
a

Total amount detected in food wrappers

b

Amount leached into various food products (i.e., candy bars, sandwiches).

c

Total amount migrated from PVC food wrap to various food products.

d

Amount leached into beverages from styrene cups (more styrene leached into beverages with higher fat content).

Figure 3.

Sample data sheet for Lesson 2, which shows how to record data and add comments about contaminants found in plastics collected.

Figure 3.

Sample data sheet for Lesson 2, which shows how to record data and add comments about contaminants found in plastics collected.

Lesson 3: Putting Science into Action

Lesson 3 requires students to combine new knowledge of marine debris and plastic pollution with concepts from civics and government classes. Students formulate and justify legislation on the basis of their scientific knowledge, reinforcing the importance of science to society.

  • Give students the "Making a Bill" worksheet found on the CAMEOS website. The introduction describes how science influences policy and the actions a bill can mandate, such as pollutant monitoring.

  • Have students go to the Library of Congress website (http://thomas.loc.gov/bss/111search.html) to search for environmental terms related to this topic (e.g., plastic, pollution, conservation). This process will introduce students to the content and format of environmental bills. If you do not have computer access at school, example bills are available for printing on the CAMEOS website.

  • Students will write a formal bill that includes a title, list of sponsors, background information, proposed action, and potential funding methods.

  • Good bills should incorporate knowledge from the marine debris lessons and be creative. Once bills are complete, have each group outline their bill and present it to the class for debate, discussion, and possibly a vote.

Websites with Supplemental Materials & Information

Lesson materials on the CAMEOS website: http://bml.ucdavis.edu/education/cameos/resources/ecotoxicology/

Oikonos Ocean Stewardship's website contains additional ocean education activities and resources not covered in this article: http://www.oikonos.org/projects/oceanstewardship.htm

Acknowledgments

This material is produced in conjunction with the Bodega Marine Laboratory, University of California Davis, NSF GK-12 CAMEOS program. The National Science Foundation (grant no. 0841297) supported this work. Development of marine debris and watershed activities by Oikonos Ecosystem Knowledge were supported initially by the California Coast Commission with support from Jennifer Stock of the Cordell Bank National Marine Sanctuary followed by support from the City of Benicia Water Education Program. Additional contributions were made in partnership with ACES Signals of Spring, Hawaii Pacific University, U.S. Fish and Wildlife, and Richardson Bay Audubon. Additionally, the authors thank CAMEOS principal investigators Susan Williams and Vic Chow; along with Michelle Chow, Ocean Discovery!, and the participating teachers and students.

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