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Misconceptions about the ocean can lead people to the wrong conclusions about conservation, climate change, and marine life. There are quite a few widely accepted ideas about the ocean that are not accurate. Here are the facts behind some common ocean myths. How many do you know?

1. Garbage patches are floating islands of trash.


You may have heard about garbage patches and envisioned floating landfills. In fact, tiny microplastics make up the majority of the debris in garbage patches (by quantity). The currents in certain areas of the ocean form a sort of whirlpool, pulling in microplastics as well as larger debris like derelict fishing nets. Rather than floating, debris is spread from the surface to the seafloor and scattered over huge areas of the ocean. The currents are constantly shifting and moving debris around. This makes cleaning up garbage patches a very difficult task. NOAA’s Marine Debris Program focuses on marine debris prevention as well as removal on shorelines and in coastal areas.

2. Sharks hunt humans and are dangerous killers.


Sharks are depicted in movies as ruthless man-eaters, hunting humans for sport or revenge. In reality, humans are not part of any shark’s natural diet. There are over 500 species of sharks, but the majority are not a threat to us. Unprovoked interactions with humans are extremely rare. In fact, a world without sharks is a much bigger threat. Removing apex predators like large sharks from marine ecosystems has negative impacts throughout the food web, including on the fish and shellfish that we eat. NOAA’s Marine Fisheries Service works to ensure healthy shark populations in U.S. waters, and to protect endangered shark species.

3. Sea level is rising because of melting icebergs.


When you add an ice cube to your glass, the water level goes up. But when that ice cube melts, there’s no additional change in the water level. The same process applies to sea level rise. Glaciers hold ice on land. When they start to melt and break apart, that ice enters the marine environment. Land-based ice can melt and enter the ocean as liquid water, or large chunks can break away in the form of icebergs. When these icebergs enter the water, sea level rises. Increased melting of land-based ice is one of the major causes of global sea level rise. But once the ice is floating in the water, the sea level does not change again when it melts.

4. Whales spray water out of their blowholes.


The famous image of a spout of water rising as a whale surfaces leads many to believe whales are expelling water into the air. But whales don’t have water in their lungs. Blowholes work like nostrils; the spray is just them exhaling air. Then what makes the spray? Some of it may be water on the top of the whale’s head when it surfaces, and some is mucus, just like when you blow your nose. But the rest of the spray is actually water vapor. The air inside a whale’s lungs is much warmer than the air outside. When this warm air is expelled, it immediately condenses into water vapor.

5. If you live inland, your choices don’t affect the ocean.


Living far from the coast might make the effects of pollution, marine debris, and climate change less apparent. But, debris and pollution can enter the ocean from far inland via rivers and streams. In fact, the most common type of marine debris is cigarette butts. Water that flows into storm drains can also carry debris and chemical pollutants directly to the ocean.

The good news is that you can also have a positive effect on the ocean no matter where you live! You can stop debris from entering the ocean by organizing local river cleanups, reducing your use of single-use plastics, and always properly disposing of trash. Handling chemicals properly, including motor oil, household cleaners, pesticides, and fertilizers, prevents harmful urban runoff. Choosing sustainable seafood helps maintain balanced marine ecosystems. And anything you do to reduce your carbon footprint helps counteract the harmful effects of climate change. It doesn’t matter where you live, you can help our ocean.

Story appears courtesy of the National Ocean Service, National Oceanic and Atmospheric Administration (NOAA), U.S. Department of Commerce.