Microplastics and Their Effect on the Ocean Ecosystem

By: Haasini Sanisetty 

What are Microplastics? 

The presence of small plastic fragments in the ocean was first reported in the 1970s but the phrase microplastics wasn’t coined until 2004 when it was used in a newspaper to describe the small plastic particles only micrometers in diameter. Later on there became two different subsections of microplastics, primary and secondary. Primary microplastics are introduced into the environment through cosmetic products and manufacturing processes. The microplastics used in cosmetics are known as microbeads and they are tiny pieces of plastics commonly made of polyethylene terephthalate or other substances. Secondary plastics result from the degradation of bigger plastics. This often happens because the plastic is exposed to sunlight, wind, water, and other abrasions. Plastic waste on the beach or near the ocean is even more prone to this because it absorbs more UV rays from the excessive amount of sunlight. 

What is Their Effect on Marine Life? 

Microplastics can be found anywhere, from the air to water. One of the main concerns about microplastics is their presence in the ocean and other bodies of water. Because microplastics are used in many cosmetics like face wash and toothpaste, they get flushed down our drains often. Because of their microscopic size, microplastics don’t get filtered out at water filtration plants and concurrently get flushed out into bigger bodies of water, which could face a threat to the organisms living there. Statistics show that 10 percent of waste plastic gets deposited in the ocean through some method, and this can account for 60 to 80 percent of ocean pollution. The microplastics don’t only come from cosmetics, they can also come from secondary sources. Some of these places of origin include natural forces and tourism on beaches. Because plastic degrades faster on beaches due to the low specific heat and high heat it’s one of the main sources of microplastic flow into the ocean. Plastic can also be directly thrown or lost in the ocean through ship waste and fishing. 

In the year 2018, microplastics had been found in 114 marine organisms, and the number had grown since then. Due to their size microplastics can easily infiltrate animal systems and cause damage by building up in the tissue. One of the main side effects of microplastic exposure is the inhibition of growth and maturation in fish. Polyethylene is a popular ingredient in microplastics and it can lower food consumption and consequently decrease growth in some species. The plastics can build up in the digestive tracts of the organisms and decrease food capacity and energy levels. Since fish are such an important staple in many aquatic ecosystems, it could affect other organisms even if they don’t directly consume the plastics. 

Sources: 

https://iopscience.iop.org/article/10.1088/1755-1315/631/1/012006/pdf#:~:text=Marine%20micro plastics%20will%20affect%20many,oxidative%20damage%20and%20abnormal%20behavior.

https://www.britannica.com/technology/microplastic 

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7268196/#:~:text=2.2.-,Microplastic,a%20few%2 0microns%20in%20diameter. 

https://pubs.acs.org/doi/10.1021/acsenvironau.1c00016