As our understanding of deep-sea coral communities and ecosystems has increased, so has our appreciation of their value. Intrinsically valuable as biodiversity hot-spots, deep-sea coral ecosystems are important from a conservation perspective and provide homes for a vast range of marine species. Deep-sea corals may function in ways very similar to their tropical coral reef ecosystem counterparts, providing enhanced feeding opportunities for marine species, hiding places from predators, nursery areas for juveniles, fish spawning sites, and attachment substrate for sedentary invertebrates. [a,b,c]
Structure-forming deep-sea corals are ecologically important, forming the basis of biologically diverse fish and invertebrate communities. For example, the stony coral, Lophelia pertusa, forms large reef-like structures. In the northeast Atlantic, these structures can stretch for tens of kilometers and reach up to 35 m high with levels of diversity that approach those of shallow-water tropical reefs. Deep-sea corals may also serve as habitat and reproductive grounds for certain commercially important fisheries species, thus drawing the commercial fishing industry to these fragile areas. In Alaska, for example, studies have revealed rockfish, shrimp, crabs, and other invertebrates are associated with deep-sea coral habitat.[d] Deep-sea coral and sponge areas have been identified as essential fish habitat off Alaska, the US West Coast, and the Southeast US. Additionally, a number of deep-sea corals are also of commercial importance to the jewelry industry, in particular, black, pink, and red corals.
The high biodiversity associated with deep-sea coral communities has shown potential value for commercially important fishes as they rely on deep-sea coral habitat for protection from predators and for enhanced feeding opportunities. Furthermore, deep-sea corals may provide significant opportunities for advancing pharmaceutical and medicinal applications. For example, several deep water sponges—often associated with deep-sea coral communities—have unusual qualities that may potentially aid in the development of drugs for cancer, heart disease, and other medical treatments.
Finally, deep-sea corals may also serve as important indicators of past climate. Living deep-sea corals have been dated to be more than 4,000 years old, and dead corals forming deep banks have been radiocarbon-dated to be more than 40,000 years old. Stable isotopes incorporated in their skeletons can give clues to past temperatures and analyses of their skeletal microchemistry allow researchers to reconstruct past oceanic conditions [e, f, g].