...By Henry George for TDPel Media.
In recent years, microplastics have become a growing concern as they accumulate in the world’s oceans and pose a potential threat to marine life.
One study conducted by researchers at the Alfred Wegener Institute in Germany has found that microplastics can harm the algae Melosira arctica, which is an essential component of the Arctic marine food web.
The Impact of Small Particle Size
The smaller a particle is, the more organisms it can penetrate.
Microplastics can break down so small that they enter individual cells of either the algae or the zooplankton that feed on them.
The researchers are not yet able to say if all that microplastic is harming Melosira arctica.
But laboratory research has found that plastic particles can be toxic for other forms of algae.
For instance, in experiments with very high doses of microplastics, small microplastics damaged and entered algal cells, leading to stress responses such as damage of chloroplasts and inhibition of photosynthesis, according to Bergmann.
Blocking Sunlight and Interfering with Photosynthesis
If enough plastic gathers on the algae, it could obstruct sunlight from reaching the cells, further interfering with photosynthesis and growth.
This could be why scientists are also discovering large amounts of plastic particles in Arctic Ocean sediments.
“This study really does contribute to a growing body of research that shows that these microscopic organisms and these microscopic plastics can compound and become a really macroscopic problem,” says Anja Brandon, Associate Director of US plastics policy at the Ocean Conservancy.
The Impact on the Marine Food Web
Algae in the Arctic, and phytoplankton throughout the marine environment, make up the fundamental backbone of the marine food web.
But the proliferation of plastic could devastate that web.
As summer temperatures rise and the Arctic’s sea ice deteriorates, more and more algae clumps can break free and sink, carrying those microplastics with them into new ecosystems.
The sinking algae is a kind of “conveyor belt” of food to benthic creatures like sea cucumbers and brittle stars.
Food Dilution and Chemical Contamination
In this sensitive ecosystem, nourishment is relatively scarce compared to, say, in a tropical reef.
If a sea cucumber is already making do with limited amounts of food trickling down from the surface, it would be bad to load that food with inedible plastic.
This is known as “food dilution” and has been shown to be a problem for other small animals, which fill up on microplastics while reducing their appetite for actual food.
Jagged plastic particles can also cause severe scarring of the gut, as was recently shown in seabirds with a new disease known as plasticosis.
Furthermore, plastic polymers are made using at least 10,000 chemicals, a quarter of which scientists consider to be of concern.
Conclusion
The research conducted on the potential harmful effects of microplastics on Arctic algae highlights the critical role that microscopic organisms play in the marine food web.
It also underscores the need for concerted efforts to reduce the amount of plastic waste that ends up in the oceans.
While the full extent of the damage caused by microplastics remains to be seen, it is clear that the problem is a complex and multifaceted one that requires immediate attention.
