Microplastics in Lake Champlain Angelo Sinisgalli

To begin with, we have all seen plastic pollution either on the ground or in the water that consists of larger pieces. However these large pieces of plastic are just the beginning of a much bigger problem that plagues many bodies of water ranging from streams to oceans. These larger plastic pieces are easy to pick up on their own but they break down into much smaller pieces called microplastics due to weathering and other natural processes. These smaller plastics pose a threat to organisms in both aquatic and terrestrial ecosystems.

Microplastics originate from larger plastics that are broken down. These larger plastics have a few main sources which I will explain here. One of the main sources are synthetic textiles such as clothes, these clothes can lose fibers while washing which make their way into the watershed and pollute the water. Exterior plastics such as plastic paints, siding, furniture or other products are another main source of plastic pollution due to the breakdown from natural processes. Another main source is household plastic waste which we are all familiar with. Sometimes these waste plastics do not make it to the recycling or garbage centers and are discarded into the natural world where there are broken down. Cigarette butts and wet wipes are main sources of plastic pollution. This due to the plastics inside the butt and wipes themselves, there are many cigarette butts being discarded into the water and onto the ground around Lake Champlain. More main sources of plastic pollution include but are not limited to tea bags, tire weathering, wastewater, and laundry pods. (Plastic Action Center)

With knowing some of the main sources of plastic pollution let’s discuss how these larger plastics are turned into microplastics. There are several ways in which these plastics turn into microplastics as well as there are multiple different types of microplastics themselves. One of these ways is solar radiation in which the plastics are exposed to ultraviolet radiation which freaks down the plastics into different molecules therefore splitting the plastic into thousands of pieces. (Recykal) Another way in which plastics break down is through mechanical weathering in which natural processes such as wave action or other actions that physically breakdown the plastics into smaller pieces, microplastics. Microplastics can also travel through wastewater treatment plants as there are not filters small enough to catch these plastics. Another way that these microplastics are formed is when synthetic textiles are washed. The physical action of washing the clothes seperates fibers into smaller individual pieces in which are washed away with the wastewater from the washing machine. There are also separate types of plastics that are formed due to the breakdown of macro plastics. These different types of plastics have categories such as fibers, foams, fragments, and pellets. They are differentiated due to the shape and composition.

The goal of my independent study under Dr. Garneau is to determine microplastic counts in the organisms of Lake Champlain. In this study I believe that we will find mainly fibers in the fish of Lake Champlain. In order to do this study I had to take a series of steps to in order proper lab safety and precaution when working with the chemicals. To begin with, I had measured the fishes length and overall weight before I had dissected it.

After I had done those I moved on to the dissection of the the fish where I had removed the stomach, esophagus, and the intestines. I had then separated the individual organs into their own weigh boats which I had then used to weigh them individually.

After the weighing process was completed, I put the the organs in individual beakers in order to dissolve them for later examination. I had put four molar KOH into the beakers and stirred them for an hour. I then added other chemicals to help dissolve the organs further so I am left with the micro plastics.

After the dissolving process I had ran each beaker through a stack of sieves varying in size, 1mm, 355 micrometer, and 125 micrometer. I had rinsed what was caught in the sieves into Petri dishes labeled correlating to the size of each sieve.

For some reson my video did not capture the beginningbut I had poured the mixture through the different sized sieves to seperate the particulates. This is done to help examine the microplastics after this process under a micrscope.

Now we had used the microscope to examine what was in the Petri dishes and count all of the microplastics that we find. Here are some of the pictures that I had taken of microplastics in the samples. Notice that the ruler is in centimeters and how small these fibers really are.

What I found is that I had only fibers in the samples and no other microplastics were present. This indicates that the fish of Lake Champlain are ingesting fibers into their bodies in which they cannot dissolve. This had surprised me although I had believed that this is what I would find.

Dr. Garneau and I have also planned to use Nile Red staining to help visualize the plastics more. This is done by taking the plastics and dipping them into the Nile Red stain and covering them with aluminum foil for a set amount of time. At that point you bring the samples under the microscope and shine ultraviolet light on them to illuminate them much more clearly. Dr. Garneau had done this portion of the study and had created a video for you to better understand the process. Hopefully NIle Red can be used in the future to help scientist find microplastics in their samples.