2.?? Garbage Patches 25-26

Part 1: Engage

What Do We Throw Away?

Did you know human beings are the only living organisms on the planet that create unnatural waste?

Closely analyze the two images and then answer the following questions.

• What types of items do humans throw away?

• What types of materials are these items made of?

Now compare this image to the image of the landfill from the previous slide.

• What differences do you observe between the two images?

• What ideas do you have about how this garbage and debris ended up here?

The image below lists the top 10 types of waste found in the oceans around the world. Analyze the image and then answer the following questions.

• Of the top 10 waste items found in the ocean, how many are plastic?

• What ideas do you have about why these items are the most common types of debris found in the ocean?

Part 2: Explore

Garbage Patches are large areas of ocean where litter and other marine debris collect. You can think of them as large whirlpools that pull debris into one location, forming what we call "patches". In this section, you will explore the following data related the ocean circulation patterns in order to predict where garbage patches form around the world:

• Wind Patterns

• Ocean Circulation Patterns

• Ocean Gyres

• Watersheds

• Rivers

On the map you are viewing average wind speed and direction near the ocean surface during September of 2019. The direction of the arrow represents the direction of the winds, while the color of the arrow represents wind speed.

Wind Speed (Meters per second)

Where do the winds blow clockwise (to the right)?

Where do the winds blow counterclockwise (to the left)?

Which areas or regions of the ocean are garbage patches likely to form based on wind patterns?

Select from the areas highlighted on the map.

Observe the map of surface currents. Warm currents are red and cold currents are blue.

What similarities do you notice between this map and the previous map of wind patterns?

Which areas or regions of the ocean are garbage patches likely to form based on ocean currents?

Select from the areas highlighted on the map.

Part 3: Explain

Trash, packaging, and waste improperly disposed on land are washing into rivers, streams, lakes and creeks, and from there to the ocean. This is estimated to account for 80% of the marine debris in the oceans.

Rivers typically begin at mountaintops where melting snow and ice create streams, which often merge to form larger rivers. As water flows from high elevations to low elevations, it carves deep, V-shaped valleys in the mountains, transitions to wider valleys with meandering streams, and eventually reaches floodplains where it may split into channels and form deltas before draining into the ocean. A watershed, or drainage basin, is the land area that collects rainfall and snowmelt, directing it into rivers, streams, and ultimately to larger bodies of water like bays and oceans.

Consider this graphic:

What are 3 events or processes that contribute to trash entering the watershed?

So how do garbage patches form in ocean gyres? Ocean gyres circulate around large areas of calm waters. The circular motion of the gyres is what pulls marine debris in, and once it reaches the calmer waters in the center it becomes trapped. Ocean gyres essentially act as a vortex for marine debris.

Garbage patches are of concern to scientists because plastic behaves differently than natural materials like wood and metals. Plastics do not break down naturally like other materials. Instead, they only break down into smaller and smaller pieces until they become micro-plastics, never fully disintegrating.

What characteristics of ocean gyres lead to the formation of garbage patches?

What are ocean garbage patches?

What are the tiny plastic pieces in the garbage patch called?

What is the ultimate solution to the garbage patch problem?