Studying the mysterious plastisphere at sea

Transcription

1 Studying the mysterious plastisphere at sea By Los Angeles Times, adapted by Newsela staff on Word Count 611 Sea Education Association's brigantine Robert C. Seamans sails 10 miles offshore from Point Loma in San Diego to conduct research into a new ecosystem known as the plastisphere, which refers to the effect discarded plastic is having on the oceans, on Sept. 14, Photo: Bob Chamberlin/Los Angeles Times/MCT OFF THE COAST OF SAN DIEGO Science student Elizabeth Lopez moved the huge steel claw slowly. Carefully, she lowered it over the side of a 134-foot sailboat. Her plan was to catch something mysterious: bits of what scientists are calling the plastisphere. We are only now beginning to understand the plastisphere. It is a sort of human-created ocean ecosystem. An ecosystem is what scientists call a place where different living things interact. It starts with bits of broken-down plastic no bigger than grains of salt. Bacteria grow on those tiny pieces of debris, or trash. Bacteria are a kind of microbe. Any living thing so small it can't be seen without a microscope is a microbe. Then single-celled animals feed on the bacteria. Next, larger predators feed on them. We ve created a new man-made ecosystem of plastic debris, said Lopez. This article is available at 5 reading levels at 1

2 Made From Thrown-Out Plastic The plastisphere has been growing for 60 years. It was created by all the plastic stuff people throw out. That trash gets swept into the sea. It's made up of bits of everything from flip-flops to toys and toothbrushes. When the debris washes into the ocean, it breaks down into bits. Tiny creatures called organisms then start to grow on these bits. Some of these tiny creatures are disease-causing bacteria. They are hitching longdistance rides on all the floating junk. Scientists also worry about something else: Creatures in the plastisphere are completely breaking down chunks of plastic. That allows dangerous chemicals to spread through the ocean. This is an issue of great concern, said scientist Tracy Mincer. Plastic Bits In Their Guts Every year about 245 million tons of plastic is produced. In the ocean, plastic waste gathers in huge garbage patches. The plastic bits may remain for centuries. Scientists know a lot about the harm caused by larger pieces of plastic. Fish, birds and other animals sometimes swallow such pieces. They can choke or starve to death. But what about the tiny pieces that make up the plastisphere? Scientists are only now beginning to understand the damage they are causing. Scientist Miriam Goldstein has studied the Great Pacific Garbage Patch. This huge area of plastic debris lies between Hawaii and California. Goldstein and fellow scientist Deb Goodwin looked at barnacles living in the patch. Onethird of them had plastic bits in their guts. But that is only a small part of the problem. Crabs eat barnacles. And crabs in turn are eaten by other animals. This means that the plastic that barnacles eat is spreading through the food web. It may be reaching all the way to people. Fish that swallow plastic debris cause damage to their livers. And not only the plastic itself is dangerous. The poisonous chemicals the plastic has absorbed are dangerous as well. Many Kinds Of Bacteria Other scientists look at the problem from another angle. They study the bacteria and other microbes that live on plastic debris in the ocean. This article is available at 5 reading levels at 2

3 It turns out there are many kinds of bacteria living on plastic. And some can cause cholera and other illnesses. Such bacteria could be traveling long distances. But it doesn't end with those bacteria. Other bacteria feed on their waste products. And predators feed on all of them. Each one of these plastic bits is a circle of life," Mincer said. "One microbe s waste is another microbe s dinner. And some microbes may simply be "waiting to be eaten by fish." This would allow them to travel into a whole new ecosystem. Scientist Drew Talley is very concerned. It would be a crime," he says, not to find out what plastic is doing "to the oceans and to humans. This article is available at 5 reading levels at 3

4 Quiz 1 According to the article, what is a plastisphere? a human-created ocean ecosystem a place where barnacles break down plastic a place where all the plastic is collected in the oceans a place in the ocean where harmful chemicals are released into the ocean 2 According to the article, plastic in the ocean harms all of the following EXCEPT: fish birds sea creatures reptiles 3 Which of the following sentences summarizes the main idea of the article? This means that the plastic that barnacles eat is spreading through the food web. Scientists are only now beginning to understand the damage they are causing. The poisonous chemicals the plastic has absorbed are dangerous as well. And some microbes may simply be "waiting to be eaten by fish." 4 Select the paragraph from the first part of the article that shows how the plastisphere starts. This article is available at 5 reading levels at 4

5 Answer Key 1 According to the article, what is a plastisphere? a human-created ocean ecosystem a place where barnacles break down plastic a place where all the plastic is collected in the oceans a place in the ocean where harmful chemicals are released into the ocean 2 According to the article, plastic in the ocean harms all of the following EXCEPT: fish birds sea creatures reptiles 3 Which of the following sentences summarizes the main idea of the article? This means that the plastic that barnacles eat is spreading through the food web. Scientists are only now beginning to understand the damage they are causing. The poisonous chemicals the plastic has absorbed are dangerous as well. And some microbes may simply be "waiting to be eaten by fish." 4 Select the paragraph from the first part of the article that shows how the plastisphere starts. Paragraph 2: It starts with bits of broken-down plastic no bigger than grains of salt. Bacteria grow on those tiny pieces of debris, or trash. Bacteria are a kind of microbe. Any living thing so small it can't be seen without a microscope is a microbe. This article is available at 5 reading levels at 5