The economy is one part of the world that relies heavily on the ocean. The fishing industry provides money for many families and without it, a huge population could fall into poverty without a providing job.
As shown by the facts, humans are heavily dependent on the ocean and its resources. With the current ocean pollution and harvesting at its current rate, many species that we rely on for food may become scarce. If that happened populations who rely on the ocean for their food will struggle to feed themselves, causing who cities to starve.
The ocean pollution on the bottom threatens marine life the most. Many species homes, like coral reefs, for example, are dying, leaving them without their source of food and shelter from larger prey. If marine life were to start going to extinction it would set off a chain reaction that effects humans and animals that rely on it for their food source.
The ocean plays a huge role on the global climate, but that ability is hindered due to excessive air pollution. Humans are releasing more and more carbon dioxide into the air, lots of which ends up being absorbed by the ocean. This causes the ocean to both increase in temperature and acidity. Because the climate is very regulated by the ocean the warming of the ocean in turn warms the who climate, hence global warming. The increasing acidity due to the absorption of carbon dioxide also heavily threaten most shelled organisms, which puts the food chain in danger.