The Marine Conservation Institute puts it this way:
"People need air to breathe, water to drink, food to eat, new medicines, a climate we can live in, beauty, inspiration and recreation. We need to know we belong to something bigger than ourselves. We want a better future for those we care about. Because the oceans are the largest ecosystems on Earth, they are the Earth’s largest life support systems. To survive and prosper, we all need healthy oceans. Oceans generate half of the oxygen people breathe. At any given moment, more than 97% of the world’s water resides in oceans. Oceans provide a sixth of the animal protein people eat. They’re the most promising source of new medicines to combat cancer, pain and bacterial diseases. Living oceans absorb carbon dioxide from the atmosphere and reduce the impact of climate change."
Of course, if cuteness has any effect on you, this video of an orphaned sea otter pup being taken in and cared for by the incredible staff at the Shedd Aquarium might motivate you to consider that by protecting our oceans -- and doing our part to reduce the amount of plastic waste we throw into them -- we're in turn protecting the incredible (and heart-meltingly cute) creatures whose lives depend on it. Enjoy.