Marine Debris: Fishing for Microplastics in Your Home
There has been a growing of public awareness of plastics found in the ocean environment. Plastics are found at the top and within the water column, in ocean floor sediments, and within beach material. This activity will demonstrate the ease of movement of plastics from your home directly into the ocean environment. Students will explore the typical products which contain plastics and learn how to calculate the concentration of plastics found in a chosen personal care product.
In this activity, the students will:
- use a global environmental topic to apply scientific skills to include research, investigation, quantification, and modeling/predication;
- use the scientific method to answer questions concerning a global environmental topic;
- learn laboratory methods to apply gravimetric analyses for materials being explored;
- present their data both in written-and oral-format in order to communicate results;
- apply the concept of sustainability through group investigations of human behaviors that have unintended consequences to the environment.
In addition, students will:
- be able to define the problems associated with microplastics in the ocean;
- be able to uncover factors causing the environmental problem and relevant concepts to perform an analysis of the problem;
- be able to define the systems that dictate the presence of microplastics in the ocean;
- demonstrate their understanding through completion of homework assignments, classroom discussions, laboratory activities, and formal reports.
Context for Use
This activity was created for introduction to science/environmental science students with little science training to demonstrate pathways of pollutants into the environment. I have used it to demonstrate scientific thought, exploration, and analysis of current plastic quantification practices.
This activity has also been used in 3rd-year environmental science oceanography and environmental topics at the university level and for summer science camp for middle-school children. It is appropriate for non-majors with little background in science. Skills needed for the activity include algebraic manipulations, and precision in the laboratory. It works well with groups of 2 or 3, depending on equipment availability
Adaptability: The activity can be adapted for many learning groups. Older students can complete easily on their own with minimal supervision. Younger students may need to complete each step all together in small groups. It also could be used as a discussion topic in environmental ethics, environmental law, and environmental topics classes.
In my teaching of the activity, I allot 1 hour for discussion, 1 hour for outside investigation, 3 hours in lab, 1 hour follow-up discussion, all of which can serve as an optional spring-board for further investigations.
Description and Teaching Materials
Locating marine debris, specifically plastics, is not a novel topic. Walks on beaches, cruises on ships, and strolls along docks reveal the presence of plastics in water bodies and along their borders. What isn't seen clear;y is the presence of these plastics on a much smaller level, specifically microplastics.
The pathways of microplastics into the environment are from two main sources; these include the breakdown of macroplastics or entry into the environment already in the form of microplastics. The full range of impacts of microplastics on ecosystems is not yet known. What is known is that macroplastics could potentially kill megafauna in three ways; these include clogging their guts, creating false-cessation, and POSSIBLY transferring pollutants adsorbed to the plastic. More and more lower-trophic organisms are found to have small pieces of plastic in their digestive systems. Researchers are presently exploring the effects of plastic-presence in smaller organisms such as fish, worms, bivalves, and ctenophores.
This activity reveals how easily microplastics can be released into the environment through use of personal care products. No waste water treatment plant in the world can prevent these particles from being deposited in waterways and ultimately into ocean ecosystems.
Small plastic bits, or microplastics, are found in personal care products. The manufacturers use plastics as abrasives for two main reasons: 1. they are cost effective; and 2. the physical properties (size, hardness, color, shape, etc.) can be defined. I have found, during plastic discussions and lessons, that several consumers are unaware that plastics are the "microbeads", "scrubbers", and "exfoliants." In the past, these ingredients included such materials as ground shells and pumice. Though these ingredients are still used in some products, more and more mainstream products include the plastic substitutes.
Plastics are a tangible pollutant for most observers. The mention of pollutants in the environment is most often not seen and can potentially be reasoned away by explanations of potential natural occurrences. The presence of plastics in the environment has only one link: humans. Seeing plastics on either a macroscopic- or microscopic-scale illustrates the impact of humans on the environment. One concept of sustainability is clearly demonstrated here. An ideal of sustainability is leaving the smallest impact on a region possible after use. The presence of plastics in water bodies, from urban to remote locations, is growing and is not sustainable. Current research is trying to determine how long plastics remain in the environment, how much plastics are in the environment, what the impact of plastics is in the environment, and what the pathways are for plastics to enter environmental systems.
To understand the problem, students will be asked to research what the marine debris problem is and report on their findings. To set-up the lab, students will then explore their own medicine cabinets to find personal care products with plastics impregnated in those products. Students will group this data together to list the types and amounts each product possesses. The lab simply extracts microplastic directly from the product and is quantified. The follow-up to this activity is to determine, with algebraic modeling, how much plastic material is potentially in the environment. The goal would be to predict trends of material found in the environment over the period of 3, 5, and 10 years. If interested, an awareness campaign could be created using the data collected in the lab.
A laboratory assignment is attached. This includes teachers' notes and the student handout.
Teaching Notes and Tips
The activity will be preceded with a research project for students to collect data from their households. This information will be tracked using tables and graphs.
The laboratory will include pre-lab questions, activity questions, and post-lab questions. The pre-lab questions can be answered and reviewed during the activity. Activity question and post-lab questions will be included in a formal lab report.
A follow-up research option can be used to understand the problem. A reflective paper can synthesize the activity results and implications for the environment.
A final group poster or oral presentation can be used to assess understanding and reveal conclusions.
References and Resources
Andray, A.L. 2011. Microplastics in the marine environment. Marine Pollution Bulletin, 62(8), 761-767.
Bry, D. 2011. Thing Not as Big as Was Originally Claimed. The Awl. http://www.theawl.com/2011/01/thing-not-as-big-as-was-originally-claimed
Doyle, M.J., W. Watson, N.M. Bowlin, and S.B. Sheavly. 2011. Plastic particles in coastal pelagic ecosystems of the Northeast Pacific ocean. Marine Environmental Research, 71(1), 41-52.
Fendall L., Sewell M. A. 2009. Contributing to marine pollution by washing your face: Microplastics in facial cleansers. Marine Pollution Bulletin. 58(8), 1225-1228.
Graham, E.R. and J.T. Thompson. 2009. Deposit-and suspension-feeding sea cucumbers (Echinodermata) ingest plastic fragments. Journal of Experimental Biology and Ecology, 368(1), 22-29.
Hirai, H. et al. 2011. Organic micropollutants in marine plastics debris from the open ocean and remote and urban beaches, Marine Pollution Bulletin, 62(8), 1683-1692.
Moore, J. M. 2008. Synthetic polymers in the marine environment: a rapidly increasing, long-term threat. Environmental Research, 108(2), 131-139.
NOAA Marine Debris Program. http://marinedebris.noaa.gov/
O-Brien, T. and R.C. Thompson. 2010. Degradation of plastic carrier bags in the marine environment. Marine Pollution Bulletin, 60(12), 2279-2283.
van Franeker, J.A., et al. 2011, Monitoring plastic ingestion by the north fulmar Fularus glacialis in the North Sea, Environmental Pollution.