If you've ever felt a little guilty about polluting the deep blue with your pale yellow, you can now flush away your concerns: The American Chemical Society has officially declared, once and for all, that urine is a safe substance in the ocean.
In a newly released video on the ACS' “Reactions” channel on YouTube (watch it here), the reason why it's fine to answer nature's call while you're swimming in a vast body of water is that “urine is made up of more than 95 percent water.” So basically, what you're excreting is pretty close to the H2O that you're floating in. The video goes on to further explain the similarities, stating that pee contains sodium and chloride ions, which are also naturally occurring in seawater. And like urine, you should never drink a tall glass of seawater.
While both are bad for human ingestion, they are delish to aquatic life. Urine combined with ocean water produces ammonium, which actually nourishes marine plants. That means every time you relieve yourself at sea, you're sorta watering the plants! This not true, however, for lakes and ponds, where smaller ecosystems are more fragile. You'll have to swim to shore to let your liquids flow in these protected areas. As for pools, which have no ecosystem, the only harm peeing in chlorine will cause is irreparable damage to your adult ego.