with signs of poor health more than doubled in transects with high exposure to dredging sediment plumes. Sunscreen Sunscreen can enter the ocean indirectly through wastewater systems when it is washed off and from swimmers and divers or directly if the sunscreen comes off people when in the ocean. Some 14,000 tons of sunscreen ends up in the ocean each year, with 4000 to 6000 tons entering reef areas annually. There is an estimate that 90% of snorkeling and diving tourism is concentrated on 10% of the world's coral reefs, meaning that popular reefs are especially vulnerable to sunscreen exposure. Certain formulations of sunscreen are a serious danger to coral health. The common sunscreen ingredient oxybenzone causes coral bleaching and has an impact on other marine fauna. In addition to oxybenzone, there are other sunscreen ingredients, known as chemical UV filters, that can also be harmful to corals and coral reefs and other marine life. They are: Benzophenone-1, Benzophenone-8, OD-PABA, 4-Methylbenzylidene camphor, 3-Benzylidene camphor, nano-Titanium dioxide, nano-Zinc oxide, Octinoxate, and Octocrylene. In Akumal, Mexico, visitors are warned not to use sunscreen and are kept out of some areas to prevent damage to the coral. In several other tourist destinations, authorities recommend the use of sunscreens prepared with the naturally occurring chemicals titanium dioxide or zinc oxide, or suggest the use of clothing rather than chemicals to screen the skin from the sun. The city of Miami Beach, Florida rejected calls for a ban on sunscreen in 2019 due to lack of evidence In 2020, Palau enacted a ban on sunscreen and skincare products containing 10 chemicals including oxybenzone. The US state of Hawaii enacted a similar ban which comes into effect in 2021. Care should be taken to protect both the marine environment and your skin, as sun exposure causes 90% of premature aging and could cause skin cancer, and it is possible to do both. Climate change Rising sea levels due to climate change requires coral to grow to stay close enough to the surface to continue photosynthesis. Also, water temperature changes or disease of the coral can induce coral bleaching, as happened during the 1998 and 2004 El Niño years, in which sea surface temperatures rose well above normal, bleaching and killing many reefs. Bleaching may be caused by different triggers, including high sea surface temperature (SST), pollution, or other diseases. SST coupled with high irradiance (light intensity),