Pyle 2019

scientific chapter |


Pyle RL


The nearly 1000 islands, islets, atolls, and reefs of Fiji are located in the southwestern tropical Pacific Ocean, east of Vanuatu and New Caledonia, and west of Samoa and Tonga. The Fiji islands include a rich variety of habitats and consistently clear, calm, and warm offshore waters. Shallow coral reefs in Fiji have been subject to a great deal of research, but research on mesophotic coral ecosystems (MCEs) has been limited primarily to fishes. A series of expeditions from 2001 to 2010 using mixed-gas, closed-circuit rebreathers resulted in the discovery of many new species. Data downloaded from the Global Biodiversity Information Facility (GBIF) reveal a clear pattern of under sampling on MCEs for all taxonomic groups. Patterns of diversity and species richness among fishes are similar to those for reef fishes in general. A series of controlled rotenone stations at depths of 0–120 m at one particular site suggest that fish diversity on MCEs may approximate that of shallow reefs and that as many as 30% of the total ichthyofauna may consist of undescribed (and undiscovered) species. Very little is known about the ecology of MCEs in Fiji. Fijian MCEs face the same general threats as adjacent shallow reefs, in addition to global-scale threats facing reefs worldwide (i.e., climate change, ocean acidification, and overfishing of food fishes). The geographic location, variety of habitats, excellent diving conditions, and logistical infrastructure suggest that Fiji is an excellent location to conduct additional MCE research in the Pacific.