MIDTERM INDIVIDUAL [ HIEP TON] October 21, 2015
Individual Exercise #1 [20 points total]
Consider the poster of RPM 5
“Microplastic Contamination in the San Francisco Bay”
1) What is a microplastic? (2 points)
Comparing the size classes of plastic pollution level, microplastics are size
0.33 - 1.00 [small microplastic] and 1.01 – 4.75 [large microplastic] in mm.
Or in short, microplastic is abundance and weight of floating plastics size
less than 5mm.
2) Name 5 key sources of microplastic pollution (3 points)
Microbeads
Foamed
Fragments
Fibers
Nurdles
3) Which waste water treatment plant has the largest amount of
particles/gallon? (3 points)
SFO (Sanitary plant): 0.05 Particles/Gallon
4) Which waste water treatment plant discharges the largest amount of
particles/day? (3 points)
San Jose – Santa Clara
5) What is the most common microplastic detected in waste water
treatment effluent samples and where is it likely derived from? (2 points)
Page 1 of 5
MIDTERM INDIVIDUAL [ HIEP TON] October 21, 2015
Fiber - from washing synthetic clothing
6) What is the most common microplastic in surface water and where is it
most likely derived from? (2 points)
Fragments – microbeads in personal care products.
7) What is the relationship of microplastics and cosmetics? (3 points)
Cosmetics are personal care products, which include the micrpplastics.
8) Research the California ban on the use of microplastics, when does it
go into effect? (2 points)
Title: AB 1699
Information: Escaping from sewage plants, there are 100 products of
microbeads can possibly wind up in rivers, lakes, and oceans. These toxic
product can be eaten by fish then those fish can be eaten by human.
Effect Date: approved a ban on the sale microbeads starting in 2019
Violation: fine $2,500 per day
Page 2 of 5
MIDTERM INDIVIDUAL [ HIEP TON] October 21, 2015
Individual Exercise #2: of the article: “Plastic Pollution in the World’s Oceans:
More then 5 Trillion Plastic Weighing over 250,000 Tons Afloat at Sea”. Answer
the following questions [20 points total]
1) Explain the net tow sample collection and visual survey protocol in
your own words (4 points)
Net Tow Sample Collection
Conducting from neuston nets at the sea surface, through using dissecting
microscope, new tows separate manually and sort plastic from natural
debris into three size classes using stacked Tyler.
Visual Survey Protocol
South Pacific, North Pacific, South Atlantic, Indian Ocean, and around
Australia; the ocean surface was observed within set period. Large debris
items were noted as well as calculating the area surveyed through the
initial and ending position.
2) What particle size class gave the highest count (4 points)?
1.01 – 4.75 mm
3) What particle size class gave the highest density (4 points)?
> 200 mm
4) Why is it so surprising that there is as much plastic in the oceans of the
Southern Hemisphere compared to the oceans of the Northern
Hemisphere? (4 points)
Based on important sources of plastic pollution in the Southern Hemisphere
had not been accounted for, as well as the disproportionality of the losses
Page 3 of 5
MIDTERM INDIVIDUAL [ HIEP TON] October 21, 2015
from the sea surface, seashores, sinking, and degradation. The Southern
Hemisphere has as much plastic in the oceans compared to the oceans of
the Northern Hemisphere.
5) How does the plastic from the sizes that you collected break down into
microplastics? (4 points)
The UV degradation from the Sun can break down the bonds in the big
structure into smaller ones. Also the biodegradation and ingestion by
organisms, such as those plastic are eaten by birds, animals will decay in
the stomachs process.
Page 4 of 5
MIDTERM INDIVIDUAL [ HIEP TON] October 21, 2015
Individual Exercise #3 [10 points]
Write a paragraph summarizing how plastic affect marine food web.
As animals cannot distinguish and filter the food sources they take in,
plastic pollution is surely causing a changing in the food chain in general
and the marine food web specifically. Plastic material is indestructible,
hence, as small fish eat their food that has been plastic polluted, the
amount of plastic will be remain in their bodies even though the
biodegrading still processes in a very extremely slow rate. Therefore, the
bigger fish after eating the small fish, their stomachs now contain the small
fish, which has plastic in it. Considering second, third, forth and so on
consumer according to the food chain pyramid, they will continuously and
consecutively get effect from the plastic as the food web will be
contaminated by the plastic pollution. Yet, if bringing the health condition
to account for, some fish might be pushed to extinction deal to the plastic
pollution and living condition.
Page 5 of 5