March 3, 2004 – Although elkhorn and staghorn corals were first declared candidate species in 1991, it wasn't until the Center filed a petition 13 years later that the ball got rolling to grant federal protection. This listing petition also included the fused-staghorn coral.
March 18, 2005 – Responding to the Center's petition, the National Marine Fisheries Service concluded that existing measures for protecting corals were ineffective in curbing dramatic losses to the species and proposed to place both elkhorn and staghorn corals on the list of threatened species under the Endangered Species Act. The agency determined that fused-staghorn coral was a hybrid and ineligible for listing.
May 4, 2006 – Elkhorn and staghorn corals were officially listed as threatened species, becoming the first species listed due to their vulnerability to global warming.
February 6, 2008 – The Fisheries Service proposed designation of critical habitat for elkhorn and staghorn corals. The move was brought about by an agreement settling a Center lawsuit concerning the government's lack of action to protect coral habitat.
October 28, 2008 – The Fisheries Service passed a rule prohibiting all activities that kill or harm elkhorn or staghorn corals, including removing or damaging them; harming, polluting, or contaminating their habitat; and engaging in boating activities that harm or break the corals.
November 25, 2008 – The Fisheries Service announced it would designate almost 3,000 square miles of reef area off the coasts of Florida, Puerto Rico, and the U.S. Virgin islands as critical habitat for the elkhorn and staghorn corals. However, the Fisheries Service created a giant loophole that allows the rule to disregard the primary threats to the corals: ocean acidification and elevated seawater temperatures caused by global warming.
November 26, 2008 – The Center filed a notice of intent to sue the Bush administration over its illegal exclusion of ocean acidification and global warming — the two main threats to the corals — in the critical habitat rule announced the previous day.
January 30, 2012 – The Center filed a lawsuit in federal district court seeking greater protections from fishing for the elkhorn and staghorn corals.
November 30, 2012 – The federal government proposed that 66 species of coral should be newly protected under the Endangered Species Act, 12 as “endangered” and 54 as “threatened.” This included a change of status from "threatened" to "endangered" for staghorn and elkhorn corals.
January 23, 2013 – The Center filed a lawsuit against the Fisheries Service for failing to develop a recovery plan for elkhorn and staghorn corals.