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Plastics

“Like diamonds, plastics are forever.”

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The Nature of the Problem

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The Nature of the Problem

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Mismanaged Plastic Waste

Waste management is an issue generally – with increasing populations, we have increasing amounts of garbage. Now with single use items as a norm, this makes management even more difficult. Jambeck et al 2015 looked at 192 coastal countries to estimate the mass of mismanaged plastic waste (MMT) in 2010.
Explain the graph and colors – gray countries were not looked at.
They calculate that 275 million metric tons (MT) of plastic waste was generated in 192 coastal countries in 2010, with 4.8 to 12.7 million MT entering the ocean. Population size and the quality of waste management systems largely determine which countries contribute the greatest mass of uncaptured waste available to become plastic marine debris. Without waste management infrastructure improvements, the cumulative quantity of plastic waste available to enter the ocean from land is predicted to increase by an order of magnitude by 2025.

Photo source: https://www.unep.org/interactives/beat-plastic-pollution/

Data from “Plastic waste inputs from land into the ocean” by Jenna Jambeck and others, published in Science (2015)

Paper: https://static1.squarespace.com/static/5abe4d6c70e8026873259030/t/5c8d3dc34e17b66697b7184e/1552760270616/Science-2015-Jambeck-768-71__2_.pdf

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How does plastic enter the ocean?

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What kind of items can the students identify in these photos? Fishing gear, laundry jugs, cans, bottles, plastic bags (can resemble a jellyfish – devastating for sea turtles and other animals that feed on jellyfish!), ropes, etc.
Explain how these different types of everyday items can end up in the ocean
What about microplastics? Very small plastic fragments (< 5mm)
Explain that much of the plastic in the ocean is small because it’s being broke down or starts out small.
Microplastics form when plastic trash in the ocean breaks down from the sun’s rays and the motion of ocean waves. These small flecks of plastic are harmful to marine organisms and ecosystems. Microplastics can be carried hundreds or thousands of miles away from the source by ocean currents, making it difficult to track and remove them.

Photo sources:

Polluted beach: http://blog.geogarage.com/2015/10/we-can-solve-ocean-plastic-problem.html

Floating plastic bag: http://www.factorydirectpromos.com/blog/how-much-plastic-is-really-in-our-oceans

Plastic oceans: http://www.seaturtlecamp.com/one-plastic-buffet-please/

Microplastics in sieve: https://www.nasa.gov/feature/esnt2021/scientists-use-nasa-satellite-data-to-track-ocean-microplastics-from-space/

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Microplastics

Explain primary and secondary microplastics
Primary: manufactured products used in facial cleansers, toothpaste, etc. Microplastics in cosmetics and toothpaste were banned in the U.S. by 2018.
Plastic resin pellets are also considered primary and consist of small disk- or cylinder-shaped granules with a short diameter of a few millimeters. Manufacturing sites re-melt and mold these pellets to develop new products.

Do those look like anything that could be found naturally in the ocean environment? Maybe fish eggs?

Secondary: pieces of plastic that have broken off larger plastic objects. Top right image.

Photo sources:

Plastic resin pellets: http://qianmiaonuo.en.made-in-china.com/productimage/jSuJnQTcqgWl-2f1j00ISZEQtTJZFon/China-Virgin-LDPE-Granules-LDPE-Plastic-Raw-Material.html

Microplastics on beach: https://www.unep.org/news-and-stories/story/inside-clean-seas-campaign-against-microplastics

Toothpaste: https://www.nst.com.my/opinion/letters/2019/07/508838/microplastics-threat-marine-ecosystem-and-human-health

Cosmetics: https://www.greenpeace.org/international/story/7638/microbeads-how-did-companies-respond/

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“Great Pacific Garbage Patch”

In the central North Pacific, plastic outweighs surface zooplankton 6 to 1!

Garbage patches are large areas of the ocean where litter, fishing gear, and other debris - known as marine debris - collects. They are formed by rotating ocean currents called “gyres.” You can think of them as big whirlpools that pull objects in. The gyres pull debris into one location, often the gyre’s center, forming “patches.”
The most famous of these patches is often called the “Great Pacific Garbage Patch.” It is located in the North Pacific Gyre (between Hawaii and California). “Patch” is a misleading nickname, causing many to believe that these are islands of trash. Instead, the debris is spread across the surface of the water and from the surface all the way to the ocean floor.
Point out the colors in the jar – these are tiny plastic pieces and outweigh zooplankton by a factor of 6 to 1.

Photo sources:

https://marinedebris.noaa.gov/movement/great-pacific-garbage-patch

http://discovermagazine.com/2008/jul/10-the-worlds-largest-dump

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5 Gyres

Plastic Pollution in the World's Oceans - 5 Gyres

http://worldminded.com/the-5-gyres-institute/

https://wastewatchers.wordpress.com/tag/5-gyres/

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What are some impacts of plastic pollution?

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Ask the students to brainstorm about why plastic is a problem.

Show them these reasons.

Marine debris can hurt the economy by keeping tourists away from beaches, competing with active fishing gear, and reducing commercial catches.
Entanglement of wildlife in marine debris is a global problem that affects hundreds of species, including marine mammals, sea turtles, birds, and fish. When animals are caught in marine debris it can be difficult to swim and feed, cut into their bodies, and potentially lead to death.
Eating plastic may lead to loss of nutrition, internal injury, intestinal blockage, starvation, and even death.
When a net settles on a reef, it continues to move around with the motion of the ocean, causing the net to become tangled around the corals. Coral reefs are often damaged through fragmentation, abrasion, and smothering by nets.
The Marine Pollution Bulletin published a study estimating ocean plastic creates losses of $2.5 T (trillions) every year as a result of damage to fisheries, tourism, and shipping.
Human-made debris takes far longer to break down than natural debris, meaning the species that attach themselves to our trash can travel further and for longer periods of time than ever before. This could allow non-native and potentially invasive species to reach places they would not have normally reached.

Photo sources:

Polluted beach: http://blog.geogarage.com/2015/10/we-can-solve-ocean-plastic-problem.html

Entangled seal: https://www.sealsitters.org/dangerous_waters/marine_debris.html

Turtle and plastic bag: https://www.cawrecycles.org/recycling-news/turtlebags

Coral Entanglement: https://www.scientificamerican.com/article/ghost-gear-haunts-the-oceans-in-a-growing-threat/

Ship Rudder: https://www.clearbluesea.org/ocean-plastics/

Plastic bottles and hitchhikers: https://sites.uw.edu/bevanseries/2018/03/06/a-hitchhikers-guide-to-the-ocean/

Crab:

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Vibrio

Kingdom: Bacteria

Rod shaped
Flagella
Motile
Can be pathogens, which can make humans and animals very sick
They occur naturally in estuarine and marine waters worldwide
Temperature and salinity dependent

Thrive in warm temperatures and high salinity

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The Scientific Method

The scientific method is used in all sciences—including chemistry, physics, geology, and psychology.

Scientists in these fields ask different questions and perform different tests. However, they use the same core approach to find answers that are logical and supported by evidence.

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Project Hypothesis

If plastics remain in the marine environment for long periods of time, then plastics may be a vector for bacteria and human pathogens

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Project Study Area

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Chesapeake Bay

Elizabeth and Lafayette Rivers

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Project Methods

Biofilm

Biofilm removed

CHROMagar

Colony Forming Unit (CFU)

Project title: Plastics and Microplastics as vectors for bacteria and human pathogens

Explain the experiment:

We set up two experiments on a local dock in the Lafayette River to examine Vibrio spp. colonization over time. We hung different plastic types from a floating dock and sampled the biofilms on each over time. We looked at days 1, 2, 4, 8, and 16. Biofilms were scraped off a section of the plastics (2cm by 1cm = 2cm2) and then filtered onto CHROMagar, a selective growth medium for Vibrio bacteria. Colonies were counted after ~24 hours. Colonies counted can be recorded as CFU or colony forming units. CFUs are then normalized to the size of the area scraped (2cm2). Water samples were taken in tandem to compare with plastic colonization over time.

Colonies grow different colors based on specific enzymes produced from different species of Vibrio bacteria and can be counted after ~24 hours. Point out the colors in the top right image.

Define colony, colony forming units (CFU), chromagar.

A bacterial colony is what you call a group of bacteria derived from the same mother cell. This means that a single mother cell reproduces to make a group of genetically identical cells, and this group of cells form a mass, which is known as a bacterial colony. In the laboratory setting, this refers to a bacterial mass that you can view on a nutrient agar plate.
A colony-forming unit (CFU, cfu, Cfu) is a unit used in microbiology. It estimates the number of bacteria or fungal cells in a sample which are viable, able to multiply.
CHROMagar is a specific media used for the detection and isolation of V. parahaemolyticus, V. vulnificus, and V. cholerae.

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Classroom Activity Overview

Students will count colonies on plates for two substrates and water in replicates (3) and over time (Days 1, 2, 4, 8, & 16).

The substrates are polypropylene and low‐density polyethylene
Total plates to be counted = 39
Counts will be recorded and then graphed
CFUs for plastics will need to be corrected for:

Area (plastics; 2cm²) – units CFU/cm²
Volume (water; 2ml) – units: CFU/ml

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Graphing Overview

A variable is something that can change depending on conditions or information

Independent Variable – input or cause (time)
Dependent Variable – dependent on the independent variable of time (bacterial growth)

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Example

Variables: Water Temperature and Time

Which is the independent variable?
Which is the dependent variable?

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Questions?