This decline was due to a variety of factors, including disease, algae growth, climate change, ocean acidification, and human activity.

During bleaching events, or long-term periods of increased turbidity, Elkhorn coral can obtain nourishment from alternative food sources through filter feeding.

Zooxanthellae meet their nutritional requirements using photosynthesis, a process that converts carbon dioxide and water into sugars and oxygen.

Elkhorn coral provide habitat for these algae and, in turn, receive an abundant source of oxygen, enabling them to grow quickly.

By concentrating their predation activities at night, Elkhorn coral expend less energy catching large amounts of prey.

Like all animals, Elkhorn coral requires oxygen to survive, most of which they obtain through special, photosynthetic algae living in their tissues called zooxanthellae.

[7] Characteristically found in shallow, turbulent water ranging from 1 to 5 meters, Elkhorn coral thrive best in high-energy zones where wave action is frequent.

As previously mentioned, Elkhorn coral does best in environments that are shallow and experience high energy changes, which aid in the reproductive process.

Their interwoven lattice-like branches create a variety of habitats varying in topography, which in turn, support diverse fish populations.

Their thick branches absorb the energy of storm waves, in turn, dissipating the force that crashes into beach shorelines.

[10] With less force, beachfront properties experience less damage, reducing the financial demand needed to restore the homes and livelihoods of many.

For example, the Fortuna Reefer Vessel grounding site showed no measurable growth over the last ten years due to stress.

[11] The Elkhorn coral reproduction cycle occurs once per year, after a full moon in the late summer, during the months of either July, August, or September.

During storms, strong waves, or ship disturbances, fragments of coral break off and are transported to other areas where new colonies can begin.

Present locations of the Elkhorn coral include the southern coasts of Florida and the northern regions of the Gulf of Mexico.

A longitudinal study done from 2005-2015 shows that the Elkhorn coral population had a proportional decline of 0.4-0.7 times in colony density across the entirety of its occupied range.

These factors include the necessity for additional tools to assess future population changes, sexual reproduction, and environmental disturbances.

As mentioned, the species faces many threats, which include but are not limited to disease, temperature-induced bleaching, and physical damage from hurricanes.

The BRT determined that Elkhorn coral was not at risk for extinction, but could become so in the foreseeable future because its population sizes were low and the severity of threats was predicted to increase.

The persisting population decline was potentially attributable to several increasing threats such as ocean acidification and levels of thermal stress.

Many people argued that there had been significant advances in active restoration projects, and they feared that listing this coral as endangered would possibly disrupt and discourage the ongoing conservation efforts.

As mentioned, Elkhorn coral have special algae called zooxanthellae, living on their tissues, which provide many benefits.

[citation needed] In addition, climate change increases the severity and prevalence of storms, which can decimate Elkhorn coral populations.

Most of the existing regulation was intended to protect corals against physical impacts incurred through fishing gear, anchoring, and vessel grounding.

Given that the range of the Elkhorn coral extends along the coasts of several different countries, the inconsistency in policy presented an issue.

The NMFS published a recovery plan in March 2015, which clearly outlined the conservation goals and efforts for Elkhorn coral.

Most of the ongoing restoration projects for Elkhorn coral involve the creation of protected areas, which are intended to promote reproduction and growth by minimizing some of the threats to the species.

On November 26, 2008, the NMFS issued a final rule, effective December 26, 2008, which designated 2,959 square miles (7,664 sq km) as critical habitat for Elkhorn coral.

[6] In 2009, the United States government enacted the American Recovery and Reinvestment Act, which provided funding for coral conservation through the National Oceanic and Atmospheric Administration (NOAA) department.

This failure is in part due to the time and energy-intensive procedures that were previously required to rehabilitate Elkhorn coral reefs.