Plastic ingestion is one of the biggest threats to marine life today, and when these plastics reach the oceans, they break down into small pieces that are easily confused by food for animals. Ingestion may cause asphyxiation, internal injury, malnutrition, and may even lead to death. This time, accidental ingestion is not a problem at all.
Researchers at Duke University have found that in the case of corals, an ingestion of micro-plastics may occur for another reason, that is, they “like” the taste. As plastics can release hundreds of chemical compounds in their bodies as well as not surrounding environment, it is thought to be something for which corals have a special appetite. Especially for some of the substances contained in the electrical components, however, scientists still cannot tell which.
Thus, the biological effects of the set of chemical compounds for corals, are still unknown, there are some already known as estrogens and environmental androgens, hormones that affect the determination of sex.
For this study, researchers collected corals off the coast of North Carolina, USA, etc., were placed in a saltwater tank. At the time of feeding, they dropped pieces of plastic and sand of the same size near the polyps (cylindrical sac-shaped structures that form the body of the coral) and at the upper end where a mouth is found.
For the first test, we use different types of micro plastics and clean sand grains. When he recognized the grains of sand, the mouth of the polyps closed. “We have found that corals have eaten all kinds of plastic materials they have and practically ignored the sand”, said researcher Austin S. Allen in a university statement. “This suggests that the plastic itself contains something that makes it tasteful”.
The coral has no eyes, which means that it is a food for human life. Essentially, you should first try to decide if it is food and if you will ingest it. So, the coral ate 80% of the plastic offered, but ate sand only once in 10 trials, which means they can perceive as the difference between the two.
Already in the second test, they divided the corals into separate feed chambers, and each group was offered the same amount of plastic “food” for a period of 30 minutes. But some groups received only pure and clean microplastic particles, which is a bacterial microfilter, which masks the “taste” of plastic.
This time the researchers found that corals ate both types of plastic but preferred the pure type by a margin of three to one because new materials have a higher chemical charge than you are in advanced stages of degradation. In addition, about 8% of ingested plastic was retained in the digestive systems of corals for 24 hours or more.
Researchers hope these findings will encourage more research to explore the role that “taste” plays in plastic and why marine organisms ingest these micro-plastics, thus looking for ways to get around this problem.