|For over 20 years, NOAA's Undersea Research
Program (NURP) has specialized in developing, modifying, and operating
advanced underwater technologies (e.g., SCUBA diving, submersibles,
remotely operated vehicles, etc.) to enable the Nation's scientists
to accomplish a broad spectrum of undersea research. The goal of NURP-funded
research is to support NOAA's stewardship responsibilities in the
oceans, coasts, and Great Lakes, through the application of advanced
underwater research techniques and technologies. NURP supports scientific
research that addresses NOAA's management responsibilities through
a rigorous peer-review process patterned after the National Science
SCUBA diving is an exciting and first-hand way
for scientists to study the underwater environment, and the most
effective way to perform underwater experiments that require fine-scale
measurements and a light touch. SCUBA literally stands for Self-Contained
Underwater Breathing Apparatus meaning that the diver carries all
the needed breathing equipment and gases with them, and is subject
to the water temperature, pressure, currents, and other environmental
factors present at their diving depth. In an average year, the NURP
Program through its Centers supports approximately 10,000 SCUBA
dives for scientific research.
provides scientists the equipment and technical assistance to conduct
diving missions using open circuit breathing apparatuses and, more
recently, closed circuit breathing apparatuses. The primary difference
between open circuit and closed circuit breathing apparatuses is
what happens to the exhaled gas. In open circuit diving, the diver's
breathing gas is exhaled directly into the water; where as, in closed
circuit diving, the diver's breathing apparatus recycles the diver's
exhaled breath by removing the carbon dioxide and adding oxygen
to replace the consumed oxygen. By recycling the diver's breathing
gas, closed circuit breathing apparatuses allow the diver to be
more streamlined and reduce the amount of gas tanks required.
The primary breathing gases provided by NURP include
compressed air, NITROX (gas mixtures of nitrogen and oxygen), and
TRIMIX (gas mixtures of Oxygen, Nitrogen, and Helium). NITROX is
of special interest to NOAA. In the late 1970's, NOAA pioneered
the use of nitrogen-oxygen breathing mixtures or NITROX, which allows
the diver to spend considerably more time at depth, then when breathing
compressed air. Each breathing gas has different properties and
allows the diver to dive to certain maximum depths. The NOAA Dive
Manual (4th edition, available at http://www.ntis.gov/), produced
through a collaboration between NURP and the NOAA Marine and Aviation
Operations, which operates the NOAA Dive Program, offers a comprehensive
review of diving equipment, breathing gas mixtures, safety, first
aid, marine life, and a brief history of diving.
Click here for more info
on Advanced Diving through the NOAA's Undersea Research Program.
Scientific divers that use SCUBA diving to conduct
their research do have limitations that can inhibit their productivity
underwater. Limiting factors such as, diving depth, gas mixtures
and supply, weather, and decompression obligations can have a significant
impact on the amount of time a scientist will actually have to conduct
their research underwater. Saturation diving, a technique developed
by the U.S. Navy in the 1950s, has proven to be useful to several
scientists to extend their work time. Saturation diving works on
the premise that if a diver's tissues are in equilibrium with the
surrounding water, then the decompression time will not change for
the length of time spent underwater. This "saturation"
process takes approximately 24 hours and means that the diver needs
to remain at the same depth.
The revolutionary development of undersea habitats
(also known as undersea laboratories) has made "saturation"
diving a reality for scientific divers. An undersea habitat is a
pressurized facility that provides a living space for small teams
of divers on the ocean floor that extends the depth ranges and time
at depth for the divers.
Divers can either undergo compression and decompression at depth
in the undersea habitat or in a surface chamber.
NURP provides the ability to live and work beneath
the waves in the
Aquarius undersea laboratory (right), the only undersea habitat
in the world devoted to science. The habitat, owned by NOAA and
operated by the Southeastern & Gulf of Mexico center, is located
three miles off Key Largo in 20 m (64 ft) at the base of a coral
reef within the Florida Keys National Marine Sanctuary, an ideal
site for studying the health of sensitive coastal ecosystems. The
habitat accommodates four scientists and two technicians for missions
averaging ten days. Aquarius successfully supported 80 missions
between 1993 and 2003.
the use of occupied submersibles, scientists can be physically transported
to great depths of the oceans, far beyond the physiological restrictions
of wet diving on the human body. NURP makes a variety of research
submersibles available. The Pisces IV and Pisces V (left) are operated
by the Hawaii & West Pacific regional center. Both subs carry
a pilot and two scientists. They are capable of diving to 2000 meters.
The submersible is custom equipped to accommodate a variety of mission
requirements. Standard gear includes external video and still cameras,
two hydraulic manipulator arms, a CTD profiler and color sonar.
Pisces V's mother ship is the 220 ft. RV Ka'imikai-o-Kanaloa (RV
JSL is owned and operated by the Harbor Branch
Oceanographic Institution (HBOI) and leased to NURP scientists.
With its fish bowl acrylic sphere, two scientists can make observations
and conduct experiments at 920 m (3,000 ft) while inside the Johnson-Sea-Link
The Delta submersible has nineteen viewing ports and can reach a
depth of 335 m (1,100 ft). Owned and operated by Delta Oceanographics,
the submersible is small enough to be flown by plane to research
sites around the world and versatile enough to be operated from
ships of opportunity.
The Alvin is a three-person deep submersible vehicle (DSV) with
a depth capability of 4,500 m(14,450 ft). It is owned by the U.S.
Navy, operated by the Woods Hole Oceanographic Institute (WHOI)
and funded by the National Science Foundation (NSF), National Oceanographic
and Atmospheric Administration (NOAA), and the Navy. Alvin has taken
more than 8,300 people to the deep sea on about 4,000 dives and
about 20,000 hours underwater.
|Human Occupied Submersibles (left
to right): Johnson Sea Link, Delta, Alvin
|ROVs are unmanned underwater robots that are controlled
by a pilot, via a long tether that is spooled out from the support
ship. These robots can be fitted with advanced camera, lighting, and
sampling systems allowing scientists to be virtually transported,
through real-time video transmission, to great depths of the oceans.
The advantages of ROVs include greatly extended bottom times, reduced
human risk, more affordable technology, and the ability to deploy
in harsher environments. NURP operates a number of ROVs that are deployed
from many ships of opportunity. The program provides access to a variety
of ROVs some owned by the centers, some leased. ROVs have been used
to conduct science in a wide range of environments from the tropics
to the poles.
example of an ROV used for underwater science is the Kraken (right),
owned by the center for the North Atlantic and Great Lakes at University
of Connecticut. The Kraken is a light working class vehicle with
a depth capability of 940 meters (3,000 feet). The manipulator arm
allows the pilot to reach out and gather specimens and place them
in containers for further analyses. Kraken's suction samplers collect
organisms and sediments. The video cameras on the Kraken allow for
high resolution, wide angle and close up color images illuminated
by 400 watts of HMI lighting. In addition, a low light monochrome
camera can be used to view organisms sensitive to the effects of
bright light. A digital or 35 mm film camera with a flash allows
for high resolution still photography. Paired lasers allow the scientist
to determine the size and scale of objects underwater. Finally,
a scanning sonar uses sound to view objects and organisms outside
the visible range of the lights and cameras.
Rutgers University and Woods Hole Oceanographic
Institution (WHOI) have developed a Long-term Ecosystem Observatory
(LEO-15) that sits 15 meters deep on the inner continental shelf,
six miles off the New Jersey coastline. The observatory includes
numerous sensors that continuously monitor the local environment.
An electro-fiber optic cable runs along the bottom of the ocean
to two submerged nodes. These nodes have profiling instruments that
measure temperature, salinity, and depth and are readily controlled
by scientists onshore, via the Internet. LEO's website provides
access to real-time data from in-situ sensors, transmitted via satellite.
Since it's inception, many projects have been supported with funding
from NURP, the National Science Foundation, and National Ocean Partnership
Program. LEO-15 supports a broad spectrum of research sponsored
by NURP's Mid-Atlantic Bight (MAB) research center.
Click here for more
info on Ocean Observing Systems through NOAA's Undersea Research
are the most recent class of undersea research technology. As the
name suggests, AUVs can be preprogrammed to conduct various measurements,
video surveillance, etc. Independent of the surface, battery powered,
and controlled by computers using various levels of artificial intelligence,
these vehicles are programmed to carry out various underwater survey
tasks. The Remus AUV (right) was developed by Woods Hole Oceanographic
Institution for NURP's Mid-Atlantic Bight Center to carry out wide
area continental shelf surveys.