In one sentence, describe what the following article is about:

If there are some swimmers close by, move away from them. Even if they don't see you do your business, they may feel the sudden warmth and become suspicious. Move to the left or right, instead of deeper into the ocean. Do not go so far away that you can no longer see or hear other people. You want to be within sight and hearing/shouting distance, in case something happens. Lots of fish and other sea animals live there. Some of them could harm you, while others could be harmed by you. The further away you go from other people, the more likely you are to come across some sea critters. Stay clear any marine life, including other fish, sharks, and jellyfish. You may hurt them, or they may hurt you. While urinating in the ocean can be beneficial to the marine plants, it can be harmful to coral reefs. Urine helps marine plants grow—including algae. This can result in algae growing out of control on a coral reef and blocking out the sunlight it needs. This could suffocate and kill the coral reef. Try to keep a distance of at least 100 feet (30.48 meters) from these places. Both piers and jetties tend to be surrounded by rip currents, which are very dangerous. Rip currents are very strong ocean currents. They flow away from the shore. The last thing you'd want is to get caught in one.

Summary:
Make sure that there are no people close to you. Stay away from clumps of seaweed and other marine plants. Keep an eye out for other marine animals. Avoid coral reefs. Stay away from piers and jetties.