Coral bleaching is not just due to a warming planet, but also a planet that is simultaneously being enriched with reactive nitrogen from sources like improperly treated sewage, and fertilizers. Nitrogen loading from the Florida Keys and greater Everglades ecosystem caused by humans is the primary driver of coral reef degradation in Looe Key. These coral reefs were dying off long before they were impacted by rising water temperatures. Elevated nitrogen levels cause phosphorus starvation in corals, reducing their temperature threshold for bleaching.
This full article appears on <a href="https://www.sciencedaily.com/releases/2019/07/190715164652.htm">Science Daily</a>