People across the globe on Saturday gathered to clean up beaches and celebrate the importance of oceans in honor of World Oceans Day.

More than 1,000 events have been scheduled.

Many people attended beach cleanups or information sessions, while others made art installations and attended ocean-themed exhibitions.

The oceans cover about 70% of the Earth's surface and provide 70% of the oxygen we breathe.

The giant swathes of water also absorb around a third of all man-made CO2, and 90% of the excess heat created by those emissions goes into the sea.

Read more: Plastic pollution: Do beach cleanups really make a difference?

Artists Gepetta and Salvabarche in Milan made an installation to raise awareness for sustainable fishing

Problematic plastic

Among the problems the ocean is facing, plastic pollution is one of the biggest.

According to the United Nations, 13,000,000 tonnes of plastic find their way into the ocean every year, which kills 100,000 marine animals annually.

Most plastics in the ocean are expected to remain intact for decades or even centuries after use, but those that erode end up as microplastics, which are then consumed by fish and end up in the global food chain, the UN said.

Read more: Plastic waste and its environmental impact

Next oceans report 'fairly grim'

The UN Intergovernmental Panel on Climate Change, which released a landmark report in October 2018 warning of the effects of global temperature rises, is due to publish its latest assessment on the state of oceans in September.

"The IPCC report will be fairly grim," Lisa Speer, director of the international oceans program at the Natural Resources Defence Council, told French news agency AFP.

The last IPCC assessment, in 2014, predicted that sea levels could rise as much as one meter (3.3 feet) by the end of the century.

But newer studies using more varied scenario planning have said that current warming trends could see the ocean rise as much as two meters by 2100.

Dan Laffoley from the International Union for the Conservation of Nature said there were four main threats facing the world's oceans: surface warming, ocean heating, deoxygenation and acidification.

"We scientists are taken aback by the scale, depth and speed of the change," he said.

Fish have feelings too Fish do have feelings Fish were long believed to be unfeeling, dead-eyed animals. But now scientists are discovering the intrinsic social life of fish. They grieve, engage in cooperative hunting and some have very weird sex lives. Take an underwater journey to learn more about the greatly misunderstood and underappreciated fish.

Fish have feelings too Bodyguards Fish have each other’s back. The rabbit fish even go out for lunch together: While one of them feasts on the algae found on deep-water reefs, the other is on the look out for predators. Then they switch. Scientists call this virtuous behavior. The rabbit fish make sacrifices for another by waiting their turn.

Fish have feelings too The fearful fish It was long believed that fish cannot feel fear because they’re missing the part of the brain where other animals and humans process it. But scientists have now shown that fish do feel fear, pain and stress. It is still a contested issue among researchers, though. Fish welfare lobbyists say the new findings are an inconvenient truth as it means we would need to rethink our fishing practices.

Fish have feelings too Red lips are made for kissing Those lush lips look like they are made for smooching! One fish species goes even further and uses their mouths to procreate. The female drinks the male's sperm which passes rapidly through the intestinal systems and fertilizes the eggs. It’s a pretty weird sex practice not often observed in the animal kingdom. But the red-lipped batfish pictured here actually procreates the traditional way.

Fish have feelings too Full house The world-famous clown fish are very social creatures: They share their anemone homes with other fish. The venomous anemones offers life-saving protection to the little fish, as they are immune to its sting. As a result, it often gets a bit tight in their cozy homes.

Fish have feelings too Hunting pals The mean-looking grouper cooperates with the moray eel while hunting. The grouper initiates the hunt by shaking its head at the eel. The eel then follows it to the prey hiding in a hole and enters the hide-out. It's a 50/50 chance whether the eel corners and eats the prey or it escapes out of the hole into the grouper's mouth. This kind of team effort is extremely unusual in the animal kingdom. Author: Katharina Wecker



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