Past knowledge of the order Gorgonacea in Hawaii is based almost
exclusively on the collections of the United States Fish Commission steamer Albatross
in 1902, which contain 52 species. Recent efforts to investigate the ecology of
precious coral have produced a new collection based on 183 dredge hauls and 10
dives with a submersible. This program is collectively referred to as the Sango
Expedition. Of 59 species of gorgonians obtained by the Sango Expedition, 13 are
considered to be new species and 28 new geographic records, bringing the total
number of species considered to be present in Hawaii to 93 species.
In contrast to the high diversity of gorgonians in the West Indies and the Indo-West-Pacific, the faunal list in Hawaii must still be considered depauperate. This is
especially true in shallow water <75 m), where only one species is known. Although climatic deterioration during the Pleistocene could account for the scarcity
of gorgonians in shallow water at the present time, this factor is unlikely to have
affected deeper species. Furthermore, one would expect to find a modern complement
of an ancestral faun a in shallow water if it had existed, as is true in the case of
reef corals. The paucity of gorgonians in Hawaii may be due to isolation, which
appears to have been a particularly effective barrier in shallow water. It is suggested
that the only accessible route to Hawaii for gorgonians has been in deep water
where, in the past, there were numerous stepping stones that may have aided dispersal.
Moreover, chemical and physical gradients in deep water are relatively low.
Why more deepwater species have not migrated into shallow water in Hawaii may
be a reflection of their stenotypic character
