Pulley Ridge is a mesophotic coral reef system off the shores of the continental United States. The reef rests on sunken barrier islands and lies 100 miles west of the Tortugas Ecological Reserve and stretches north about 60 miles at depths ranging from 60 to 80 meters. Pulley Ridge was originally discovered in 1950 during a dredging operation conducted by an academic group from Texas. While well known to fishermen, this remarkable habitat remained undiscovered by scientists until 1999 when the U.S. Geological Survey (USGS) and graduate students from the University of South Florida happened upon it. This reef system, like other mesophotic ecosystems, is inhabited by photosynthesizing corals and algae that are adapted to low-light environments. It is habitat for numerous species of bottom fish including Epinephelus morio (red grouper) spawning area. "Although deeper-water corals form reefs in the dark of ocean depths, Pulley Ridge is the deepest photosynthetic coral reef that we know of today," said Robert Halley, former US Geological Survey marine geologist." Other reefs lie about 46 meters below sea level. Once established on the seabed, the corals help create hard bottom habitat that becomes home to a diverse community of algae and animals that includes some species that are unique to these communities, and others species that are also found in shallower reef habitats. Understanding the factors that determine where mesophotic reefs are located and distances over which species living within such environments disperse and therefore 'connect' populations are of great interest to marine scientists and resource managers alike. Despite this interest, the deep depths of such reefs hinders both their discovery and their exploration. Coral reefs struggle to survive in the world today. "In the past 10 years the world has lost 25% of the known living coral reefs". Coral reefs are particularly damaged by "…climate change, over fishing and coastal pollution". Scientists hope that through the exploration of Pulley Ridge, they can gain new insight of how reefs function in order to better preserve other reefs. The first scientific dives on Pulley Ridge In 2002, the Gulf of Mexico Fishery Management Council through NOAA's Coral Reef Conservation Grant Program funded an expedition to examine the habitat and fish fauna on Pulley Ridge. Led by Chief scientist Bob Halley (U.S. Geological Survey, St. Petersburg, FL). Other expeditions have followed, including one led by James K. Culter of the Mote Marine Laboratory in Sarasota, Florida