
Guess What Oysters Are Eating?
Microplastics are everywhere, including our oceans, polar circles and mountain tops and even in areas that look pristine. As a result, tiny pieces of plastic are ending up in our food chain. Many scientists believe that eating microplastics is not only harmful to animals but it is also harmful to humans.
Due to their small size, microplastics can be ingested by ocean filter feeders. The purpose of this study was to determine if microplastics are being ingested by oysters living on the BC coast. Microplastics found in oysters reflect what’s floating in the ocean around them. Learning about how microplastics get into our food chain can help us solve this huge pollution problem.
I collected six – 3 year old oysters from an oyster farm on the BC coast. The oysters were removed from their shell, measured and weighed. Each oyster was dissolved in a solution of potassium hydroxide and filtered through a 20um filter. The filter paper was then viewed under a microscope 100-400x magnification to see if there were any microplastics.
I found microplastics in all 6 oysters. 75% of the microplastics found were microfibres, 14% were plastic fragments, 8% were films and 3% looked like black tar. Most of the fibres were blue or black in colour which could be from the breakdown of fishing nets or rope. Another source of the fibres could be synthetic clothing. The transparent films and irregular fragments could be from the breakdown of larger pieces of ocean plastic. The black tar could be from the breakdown of tires or tar. An average of 6 microplastics was found in each oyster.
It is well known that our oceans are full of plastics. Now we also know that microplastics are even ending up in our shellfish!
This project would not have been possible without the help of many people. I would like to thank Mr. Scott for taking me to his oyster farm and teaching me about oysters. I learned about their life cycle and how they are grown. I would also like to thank my parents and my teacher for answering questions, lending me equipment, and proofreading my work.