As imperative as it may sound: we must stop throwing plastic in the oceans – it is hurting the baby oysters.
Everybody likes them. They are known for their aphrodisiac effects. They are a culinary delicacy and considered a staple of fine dining establishments. They have many health benefits. They help plants grow. That’s right – the oysters. Now, mankind is making the lives of these little shellfish a hell on earth via its polluting ways.
A recent study has revealed that micro-plastics which are found in cosmetic products are adversely affecting the reproductive lives of oysters – from the movement of their sperm to the growth of their babies. The study was published in the journal Proceedings of the National Academy of Sciences.
The experts conducted their experiment in a laboratory setting using Pacific oysters, a species native to the Asian Pacific coast, but now introduced and cultivated throughout much of the rest of the world. In the lab, the researchers exposed adult oysters to two different sizes of microplastics: 2 micrometers and 6 micrometers. These are on the small side for microplastics – a micrometer is just one thousandth of a millimeter.
First of all, the researchers discovered that while the oysters ingested both sizes of microplastics, they consumed far more of the larger ones – possibly because these microplastics were closer to the size of the plankton that the oysters are typically most efficient at filtering.
Secondly, the researchers came to the conclusion that there is a physiological response coming from the oysters, in regards to ingesting the microplastics. The most obvious effect was on the animals’ reproduction. Oysters that were exposed to microplastics produced fewer and smaller egg cells and slower sperm. Exposed oysters also produced fewer larvae — about 41 percent fewer, in fact — and their offspring tended to grow more slowly.
Another theory shows that the microplastics somehow had a negative effect on the oysters’ endocrine function — essentially, the production of hormones that regulate all kinds of body processes, including sexual function and reproduction. The researchers observed that certain genetic information in charge of regulating hormones was expressed differently in exposed oysters, suggesting that endocrine disruption may have been a factor.
The history of the effects of these micro-plastics goes way back in the past decade, when capturing the experts’ special attention over the unique threats they pose to marine life. The fact that they are so tiny makes them easy to accidentally ingest, particularly for filter feeders such as clams, mussels, sea cucumbers and many marine worms, who feed by straining tiny organisms out of the water.
It is not that micro-plastics are harmful that is the sad news. This was already known. Even more depressing is what these toxic materials do to future generations of marine animals.
All in all, this paper highlights just one more problem in an already long list of ways that plastic in the ocean is harming ocean life and disrupting marine ecology. Experts advise us to take it as an ‘early warning system‘ about these dangerous effects and to try ourselves to be the change we would like to see in the world.
Image Source: cloudfront.net.