The Revitalization of Monterey Bay

sea otter

Monterey Bay is well-known for its sea otter population. (Photo credit: worldswildlifewonders/Shutterstock)

It wasn’t all that long ago that the Monterey Bay was a gloopy mess and one of the most polluted places on the Pacific Coast. Today it is considered to be one of the most productive marine ecosystems on the planet. What changed? How did a once-neglected and degraded region become one of the most revered and studied ecosystems on Earth? [Read more…]

The Great Pacific Garbage Patch

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In 1997, Charles Moore had just finished a sailing race in Hawai’i and decided to take a different route traveling back to California than most sailors do. He sailed through a region that is sometimes known as “the doldrums” due to the region’s light winds. More scientifically, the area is called the North Pacific Subtropical Gyre (NPSG). A gyre is an area of circulating currents that is usually very calm at its center. Moore sailed through the eastern region of the NPSG. He might have expected some slow travel though the area, but what he didn’t expect was to be surrounded by pieces of plastic floating in the water. His discovery of what is now known as “The Great Pacific Garbage Patch” led Moore to dedicate his life to educating people about the role all of us play in literally trashing the oceans.

Moore isn’t the only person interested in The Great Pacific Garbage Patch. Since its discovery, scientists around the world have taken notice. This region has few big mammals or predatory fish, but it is rich in phytoplankton and zooplankton. It also contains what amounts to millions of pounds of trash, most of it plastic. To make matters worse, there is more than one patch. The Great Pacific Garbage Patch is made up of both the Western Pacific Garbage Patch, located between Hawai’i and California and another, the Eastern Pacific Garbage Patch, located between Japan and Hawai’i. Running between the two patches is a thin, 6,000 mile current called the Subtropical Convergence Zone. This zone acts like an interstate highway, carrying trash along the current to the two gyres that make up the eastern and western garbage patches.  The Subtropical Convergence Zone, unlike the garbage patches, is rich in many types of sea life. In addition, there is also a garbage patch in the Atlantic Ocean. In fact, there are five or six major gyres in the world’s oceans, so it is likely that there are even more garbage patches out there.

Where is all this garbage coming from? Some comes from the fishing industry. Abandoned fishing nets are dangerous to sea life and are estimated to make up about 10 percent of the trash in the oceans. Somewhere around another 10 percent is from the shipping industry. Accidents at sea cause entire shipping containers full of goods to be overturned into the ocean. The world’s military ships and recreational boaters are to blame for a percentage of the garbage too. But much of the trash comes from land. The 2011 tsunami in Japan has added to the ocean debris. Beachgoers that leave behind trash and belongings in the sand also are to blame. And all of the plastic that we use, from laundry detergent bottles and toothbrushes to grocery sacks, typically gets tossed into a landfill. Winds blow and carry trash into streams and rivers, or blow out of garbage trucks and eventually blow offshore. It can take six years for trash from the west coast of the United States to make it to the Western Pacific Garbage Patch. It takes about a year for trash from Asia to reach the Eastern Pacific Garbage Patch. Regardless of the time at sea, plastic does not disintegrate. Microbes, which are responsible for biodegrading most materials, do not consider plastic as food. Plastic does, however, photodegrade. That means it breaks down in the sunlight. Most non-plastic trash will settle down to the ocean floor. Plastic, however, floats and is carried along the currents, exposed to the sun all the while.

Because the plastic breaks down in ever-smaller pieces, by the time it reaches the Great Pacific Garbage Patch, most of it is no longer identifiable. The garbage patches cannot even be seen from aerial photos, because the pieces are so small and many float below the surface of the ocean. This aspect also makes cleaning up the patches almost impossible. The currents change with the seasons, making even the size and shape of the garbage patches hard to measure and their locations tough to pinpoint. Scooping up the plastic with nets would also remove at least as many plankton as plastic pieces from the ocean, and plankton are the foundation of the marine food chain. In fact, seabirds such as albatrosses often think the plastic is plankton or other food, and they feed it to their chicks. Many thousands of albatross chicks are killed every year by ingesting large amounts of the tiny pieces of plastic. The plastics can also contain hazardous toxins from the colorants and plasticizers used to produce them. They also absorb toxins already in the ocean, concentrating them and introducing them to our food supply when we eat fish that has eaten plastic. Science has many questions yet to answer about the Great Pacific Garbage Patch and other marine garbage patches, but everyone is clear on one point. Plastics do not belong in our oceans.

Questions:

1. Any attempt to clean up the Great Pacific Garbage Patch would be extremely costly and almost impossible. Also, no country wants to be solely responsible for the task since the trash is not within the boundary of any nation. What actions can every person take to prevent more trash from making it to the ocean, even if they do not live by a coast?

2. There have been claims that the Great Pacific Garbage Patch is larger than the United States, while other researchers claim that the actual trash accumulation is closer to 1 percent the size of Texas. What are factors that make the garbage patch so hard to measure?

3. Scientists studying the Atlantic Garbage Patch were surprised at research findings that it has not increased in size since the mid-1980s. What are factors that might explain it has remained the same size for the past 30 years?  What are possible factors in their research methods that might make these results inaccurate?

4. Another effect of having tiny bits of plastic floating on and near the ocean’s surface is that it blocks out the sunlight for the phytoplankton, possibly threatening their populations and lowering the amount of global oxygen available. What could be the effects of a significant decrease in phytoplankton on marine food chains? Use specific examples in your answer.

5. Before the plastics break down into tiny pieces, they still cause many hazards to sea life. What hazards might trash such as plastic bags and soda rings cause to sea turtles, seals, and other sea life?

6. Some scientists feel that the claims by other researchers about the Great Pacific Garbage Patch are exaggerated. What would be the possible danger to exaggerating findings to the public in order to get their attention?

More to Explore

Why is the world’s largest landfill in the Pacific Ocean?
Demystifying the “Great Pacific Garbage Patch”

The World’s Largest Dump: The Great Pacific Garbage Patch
Drowning in Plastic: The Great Pacific Garbage Patch is Twice the Size of France
What is the Great Pacific Ocean Garbage Patch?

Society and the Environment: Ocean Currents

rubber duckie

A shipment of rubber ducks lost at sea helped scientists study ocean current movements.

Ocean currents are important in transporting heat, water, nutrients, pollutants, and organisms around the world. Even though they are important, ocean currents have been hard to study. Scientists used to drop labeled bottles in the oceans in different places and then recorded where they were picked up. Now, oceanographers attach transmitters to drifters. These transmitters send their position to satellites overhead, providing scientists with information that is helpful in a variety of ways, from protecting endangered species to making important decisions with far-reaching effects.

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