In my search for plastic debris, in order to compare FL's
east coast content to that of the west coast, I had originally planned on
including the following sources:
plastic pieces, pellets, and microbeads. However, it turns out that detecting
microbeads in a sample requires lots of time and patience, of which, as most of
you college students can probably relate, time I do not have.
Attempts made in search of microbeads:
1. I visited our lab with three 2-quart sediment samples and
had planned to inspect one scoopula of sediment at a time under a Southern
Micro Instrument light microscope. Looking at sand under a microscope is
fascinating, however, after a little over an hour and only 12 scoops, which
barely made a dent in one of my 2-quart jars, I realized this method was very
time consuming, as well as ineffective because it was like looking for a needle
in a haystack.
2. Dr. Woodall's husband had the great idea to mix portions
of my sample with water in order to get the less dense plastic to separate from
the sediment, which worked well with the easily visible pieces I had found in
my samples. However, without knowing if my sample contained microbeads, how
could I know if this method would work for said beads?
The microbead quest continues:
The next day, I brought three different facial/body scrubs
that each contained plastic microbeads to lab in order to create a sample
containing microbeads and test method two described above. Confusingly enough,
the visible, very colorful, beads in my scrubs kept on sinking to the bottom
and mixing with the sediment, turns out those are wax beads! While trying to
fish out some of the visible beads with a scoopula, I noticed extremely tiny
particles on the scoopula itself, which after examining them under a microscope
turned out to be the microbeads.
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| Smashed wax bead (right) |
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| Microbead (left) vs. wax bead (right) |
Based on the time required to find a microbead in a sample
of sediment, I've decided to put this source of plastic on the backburner and
for the rest of the semester will be focusing on the quantifiable plastic
debris I come across at each beach...stay posted for my alarming discoveries at
Melbourne and Ft Pierce
Ahhhhh....this process they call "science"--so dynamic! Just when you think you have a handle on it--it demands change! Welcome to the real world :-)
ReplyDeleteCould you sieve the microbeads from the larger particles? I'm thinking, take Paul's idea one step further. Assuming that the microbeads are less dense than sediments, Could you 'pan' the sand like gold? Rinsing the beads into another container. The beads look pretty small compared to the dime...
ReplyDeleteAlso great idea, which I tried after Dr. Woodall suggested it(she even brought a cheesecloth). After attempting to separate the microbeads from the sediment I sieved the liquid into a 70µm sieve which ended up containing lots of different types of particles; I looked at those particles under the microscope and it turned into another needle in a haystack search). Granted, this process would be less time consuming then the very first process I attempted, but still too time-consuming for 10 plus 2-quart size samples. If I were to dry my samples in the oven first, then sieve them, I would probably still end up with the smallest pore size sieve containing several different types of particles, and looking through those is the time-consuming part. Since I put this on the backburner, If I have time towards the end of the semester I will take the time to find microbeads, otherwise I will be doing that for my own purposes after the semester.
DeleteCorrection: It was a 75µm sieve.
Delete