Q1_Winter_2017_AlertDiver

WINTER 2017

DIVE SLATE

DEEP STUDY

STUDYING DEEP REEFS

AND DEEP DIVERS

By Payal S. Razdan, MPH, EMT

NOAA rebreather diver

Brian Hauk photographically

documents benthic algae

and coral.

apahānaumokuākea Marine National

Monument (PMNM) in the

Northwestern Hawaiian Islands is the

largest marine conservation area in the

United States and one of the largest

in the world. Its atolls, islands, reefs,

pinnacles and surrounding habitats make up one of the

last expansive wild places on Earth.

Until recently, coral reef research has focused on

the shallowest one-third of reef habitat, leaving deeper

regions mostly unexplored. As a result, many species

have remained unidentified or even undiscovered. But

as coral reefs continue to be threatened, supporting

habitat and species diversity is increasingly critical. The

National Oceanic and Atmospheric Administration

(NOAA) recognizes that extensive exploration of

these reef systems is integral to understanding the

contributions of Hawaii

’

s reefs to overall global

biodiversity. Scuba diving operations are a necessary

element of this exploration, but the long-term

physiological impacts of these deep dive exposures are

not completely understood. Divers must rely on dive

computers, mathematical models and decompression

algorithms that have undergone only limited testing on

humans. As a result, significant gaps in knowledge exist.

Studying the biodiversity of the Hawaiian archipelago

using scuba has given scientists a unique opportunity

to monitor the physiological impacts of deep dives

and thus expand our knowledge of diving science,

particularly decompression risk.

THE DIVERS AND EQUIPMENT

The deeper regions are of particular interest because of

the potential protection and support they provide for

shallow reef systems during and following environmental

disturbances.

Mesophotic (

meso

meaning middle,

photic

meaning light) coral ecosystems, found in tropical and

subtropical regions from about 100 feet to 500 feet,

are extensions of shallower coral environments. Reef-

building corals in Hawaii have been recorded as deep

as 500 feet. These reefs had never been explored prior

to the commissioning of the NOAA ship

Hi’ialakai

which has conducted mesophotic research cruises for

six years now.

While remotely operated vehicles (ROVs) and

submersibles can be used at these depths, they have