More than 70% of the Earth’s surface is covered in water. About 97% of it exists in our oceans.

But the oceans aren't just full of aquatic creatures and colorful coral that comprise the perfect snorkel scenery. Major problems lurk on top of, and especially beneath the surface — problems that need our attention. That's why we need World Oceans Day.

Led by The Ocean Project, World Oceans Day is celebrated June 8 with the goal of drawing attention to the factors that threaten the health of our seas and our planet overall.

Our oceans are a major player in the environmental health of our world — after all, they generate much of the oxygen we breathe while absorbing a vast chunk of the carbon dioxide emissions from our power plants and cars. It's about time we gave them the attention they deserve.

These seven threats to oceans need our attention and consideration on World Oceans Day — and every day.

1. We dump 19 billion pounds of plastics into the ocean every year.

Beach goers and sailers aren't just finding sea glass and swirling shells in the sand anymore. They're finding plastic, and lots of it. Plastic pollution is one of the main focus areas of World Oceans Day this year, but there are plenty of other types of pollution threatening our shining seas, such as pesticides, detergents and oils from marine shipping.

Gyres of marine debris, like the Great Pacific Garbage Patch, are composed of microscopic pieces of plastic, chemical sludge and other types of pollution. These debris collection areas can span for hundreds of thousands of miles in our oceans, and they're growing larger with time. It's estimated we dump 19 billion pounds of plastics into the ocean every year.

Some ways you can make a difference include cutting unnecessary plastic out of your routine, recycling the plastics you do use and cleaning up your local beaches. Plus, there's a major case for supporting pesticide-free farming, natural detergents and advocating for more responsible ocean travel and transport policies.

2. Sea levels are set to rise by at least 3.3 feet during this century alone.

What 5 feet, 12 feet and 25 feet of sea level change would look like for New York City.

Seas are rising at an increasing rate, even if you don’t notice a yearly change at your favorite beach. Oceans are rising about 3 millimeters per year — that may not seem like a big deal, but those tiny millimeters add up. By 2100, it’s expected that sea levels will have risen by an average of 39 inches compared to where they were at in the early 1990s. And that reality is going to cost us an estimated $1 trillion by the end of this century.

Already, storm surges in cities like New York and Washington, D.C. are affecting more homes and businesses than they used to because of the relatively small amount of sea level rise seen to date, and parts of Miami have been regularly flooding even on sunny days.

Rising sea levels are a direct result of our warming climate. Melting glaciers and ice caps are the biggest contributor now, but rising sea temperatures (more on that later) are causing an expansion in the volume of waters in our oceans, too.

So, what can you do about all this? Truthfully, we can't entirely curb this trend. Our oceans will keep rising in the near future, there's no changing that — but we can slow the rate that they do, and stabilize things before they get too high. Cutting our greenhouse gas emissions can help the situation, but we are already at a dire point.

Scientists have said that if emissions are not dramatically cut in the next one to two decades, it may be too late to stop some of the worst impacts of global warming, including the inundation of low-lying island states from sea level rise.

However, the scope of the challenge shouldn't discourage you from doing your part to enact even a slight change. Using water efficiently and reducing your carbon footprint are all things to consider.

See also: Rising Seas Swallow 8 Cities in These Climate Change GIFs

3. Sea surface temperatures rose 0.18 degrees Fahrenheit over the last century.

That's actually a huge change. Increasing sea surface temperatures may seem appealing to any beach lover — who doesn't want a nice, warm ocean to swim in? — warmer seas mean more powerful tropical cyclones, including hurricanes and typhoons. Over the last century, sea temperatures have risen about 0.18 degrees Fahrenheit.

Even the slightest change in sea temperature can throw off the entire aquatic ecosystem, spurring a mad dash to cooler waters. Science shows this is already occurring in many areas. Once-excluded bacteria and other sea critters can suddenly thrive in environments they weren't meant to live in, which disrupts native aquatic life.

The fix? Those pesky greenhouse gases I mentioned earlier really need to go. If you aren't paying attention to your carbon footprint, start. For good measure, you can plant a tree to take in even a tiny bit of that CO2. For extra-good measure, be sure to factor in a political candidate's views on the climate when you go into the voting booth.

4. More than 60% of fish stocks are now considered overfished.

Decades of overfishing, bluefin tuna populations barely hold on at 4% of their original size. http://t.co/wpuic63gdG pic.twitter.com/si7fMJIBev — Racing Extinction (@Extinction_OPS) June 1, 2015

Entire populations of fish are being wiped out due to overfishing. When too many fish are removed too quickly from our oceans, ecosystems can have trouble recovering from the loss. The result is an less healthy underwater community left with only low-trophic level species that are less commercially valuable. While seafood is pleasing to your tastebuds, it's important to enjoy responsibly and support efforts to regulate overfishing.

More than 60% of global fish stocks are overfished, meaning that fishing is putting their species in danger. That's not only bad for the environment; it's bad for the job market.

About 40,000 jobs were lost when one species of cod was overfished in 1992. In 2003, that same species of cod was officially listed as an endangered species in Canada.

Some scientists claim that, at the rate we're going, we will effectively be out of fish by 2050. An easy way to support healthy ocean life is learning which fish and shellfish are most responsible to eat. For example, you should avoid favorites like Atlantic cod and bluefin tuna. Both of these are overfished, and bluefin tuna may be gone within the next few decades.

5. More than 90% of all marine predators have already been removed from their habitats.

When major declines in the shark population off the coast of North Carolina occurred in the early 2000s, it caused the collapse of a century-old scallop fishery. Predator sharks were removed from the local ecosystem, causing their prey, the cownose ray, to be left alone. These rays demolished the scallop population, their main food source, which was the backbone of the local economy. Disturbing the natural balance of this underwater environment caused a ripple effect that extended far beyond the sea.

More than 90% of top predators, including sharks, tuna and swordfish, have already been lost due to overfishing and habitat destruction. Without the ability to replace predators, their prey thrive — which isn't a good thing.

We need to reduce our impact on the ocean, but we also need to leave the ocean to be largely responsible for regulating itself. Take this as a friendly reminder to advocate for sustainable ocean policies, including responsible fishing and anti-pollution efforts to keep everything under the sea happy and healthy. Let's try to keep the food web intact. Buying fish from local fishing communities can often be more sustainable the buying fish at large supermarket chains, where much of the seafood is flown in.

6. In 2005, 50% of Caribbean coral reefs were damaged due to coral bleaching.

What is coral bleaching? Check out this infographic from our friends at @noaaocean: http://t.co/w4uiGfQgsk pic.twitter.com/viW3XC1EhE — Rock The Ocean (@RockTheOcean) May 19, 2015

Because of pollution and extreme temperatures due to climate change, coral is becoming bleach-white in our oceans. While it may look cool to have pristine coral on the ocean floor, healthy coral is essential for overall sea well-being — and healthy coral looks colorful and is crawling with essential algae. Yet, when pollution and warming seas pass certain thresholds, coral suffers. And when coral suffers, so does the 25% of marine life that calls coral reefs home.

Bleached coral isn't dead, but it is extremely stressed. However, stressed coral can die more easily, which is exactly what happened in the Caribbean in 2005 when the U.S. lost 50% of coral reefs in one year alone. To help abate coral bleaching, be friendlier to the ocean by reducing your carbon footprint.

7. More than 30% of all our carbon dioxide emissions end up in the sea.

Ocean acidification refers to the gradual decrease of pH in the Earth’s oceans, which is caused by carbon dioxide being dissolved in the ocean. A big source of all that CO2 floating around? Humans. Every time you start your car, you're releasing carbon dioxide into the atmosphere — and the U.S. alone is responsible for 16% of carbon dioxide emissions for the whole globe. More than 30% of all carbon dioxide produced globally ends up in our oceans, which is causing some major problems.

Carbon dioxide from the Earth's atmosphere reacts with seawater to form carbonic acid. Changes in the ocean’s seawater chemistry may have a devastating toll on aquatic life. This carbonic acid has been known to prevent healthy shell growth in some marine animals, and could possibly be causing some species of fish to have serious reproduction issues.

We need to reduce our carbon emissions, which isn't an easy task. Try to explore transportation options other than your car, like mass transit and bicycles. You should also pay more attention to your home energy usage, which can spike your carbon footprint, and choose to take more rail and bus trips than flights.

BONUS: Less than 10% of the ocean has actually been explored by humans.

Possibly the greatest threat to our oceans is how much we just don’t know about them. Less than 10% of the ocean has actually been explored by humans, making everything below the sea a relatively great mystery.

Take some time to advocate for ocean exploration, and support organizations doing work to save the oceans.