The Phoenix Islands Protected Area was the first marine protected area in the world to include large areas of deep water habitat including seamounts. This is remarkable given that the deep ocean is the largest habitat on earth. Because the deep sea is mostly unexplored, protecting it also safeguards many species that have yet to be studied or even discovered. For example, both six gill and Pacific sleeper sharks have been filmed by remote camera near the islands. Little is known about these elusive deep ocean species and PIPA presents an opportunity to study them further. It also serves as an added buffer against the global changes that are happening worldwide. The Phoenix Islands are located in extremely deep ocean waters (>4,000m).
A significant feature of the marine environment of PIPA is an outstanding collection of large submerged volcanoes, presumed extinct, rising direct from the extensive deep seafloor. These underwater mountains contribute a huge diversity of marine habitat types - atoll, low reef island, submerged reef, seamount and deep seabed as well as open ocean habitats. It can also be described as an underwater ‘mountain-scape’ with the highest peaks of the volcanic mountains rising more than 5,000 meters above the adjacent seabed, the highest reaching almost to the surface, forming atolls, reef islands and, just below the surface, shallow submerged reefs. The large bathymetric range of the submerged seamount landscape provides depth-defined habitat types fully representative of the mid oceanic biota. The widely recognized local endemicity and distinctive species assemblages associated with seamounts generally, specifically demonstrable in PIPA, is evidence of on-going in situ evolution of marine ecosystems and communities of plants and animals.
At this time, we have almost no information about the biodiversity or abundance of the zooplankton in PIPA waters. The pelagic invertebrate collections and deep water ROV confirmed that PIPA waters are typical of oligotrophic ocean conditions, with low biomass in the water column, many cosmopolitan species of gelatinous plankton, and very clear waters. Given the remoteness of the Phoenix Islands, could include species that are rare or unknown elsewhere. It is likely that new knowledge of the biodiversity of these waters will be gained from deep sea sampling.
The tunas (family Scombridae) are the target of large commercial fisheries worldwide and are of special significance to Kiribati and the other Parties to the Naru Agreement (PNA) countries. Over 50% of the global supply of tuna comes from the western and central Pacific Ocean (over 2.4 million tons in 2009), and close to 40% of that comes from the EEZs of the PNA countries. The revenue obtained through licensing agreements with distant water tuna fleets are of vital importance to the economies of the PNA countries. Maintaining healthy, robust stocks of yellowfin (Thunnus albacores), bigeye (Thunnus obesus), skipjack (Katsuwonus pelamis), and albacore (Thunnus alalunga) are therefore important to Kiribati, and by extension, for PIPA.