By Daniel Cressey

Fuelled by more than $100 million from the US economic stimulus package, an unprecedented network of underwater surveillance equipment is beginning to take shape in the world's oceans.

The Ocean Observatories Initiative (OOI) is the "single greatest step forward for ocean science in the United States for half a century", says Tim Cowles of the Consortium for Ocean Leadership, a non-profit organization that manages and coordinates the OOI from its base in Washington D.C.

The initiative is part of a wider plan to build vast networks of monitoring equipment in the oceans, allowing researchers a real-time view in places that they have previously been able to visit only fleetingly.

Last month, scientists at the OceanObs'09 Conference in Venice, Italy, issued a call to significantly enhance "internationally-coordinated provision of sustained observation and information of the world ocean, as a part of the larger Earth observing effort, for public good and stewardship". The OOI represents the US National Science Foundation's contribution to this.

Stimulating science

Although the OOI has been in planning for more than a decade, recent stimulus funding of nearly $106 million from the American Recovery and Reinvestment Act (see 'Where the US stimulus money is going') has accelerated the project by about a year. "The whole Recovery Act did provide an impetus for several projects to break out into initiation or the first stage of construction -- that was certainly true for ours," says Cowles.

Total construction costs are projected to be $385 million over five and a half years, with operating costs of $30 million to $50 million a year.

Past ocean studies have tended to be short-lived and not conducted in real time, says Albert Plueddemann, an oceanographer at the Woods Hole Oceanographic Institution (WHOI) in Massachusetts. "What we want to gain is a more complete look at the ocean in space and time," he says.

To do this, three separate ocean regions will be subjected to long-term intensive monitoring.

First, the 'global scale' nodes will monitor four different high-latitude sites -- in the North Pacific, South Atlantic, southwest of Chile in the South Pacific and southeast of Greenland in the North Atlantic. Moored instruments at these locations will provide data supplemented by findings from sea gliders. "This is just a leap forward," says Robert Weller, a physical oceanographer at WHOI.

Second is the ambitious 'regional scale nodes' component that sits closer to home. In theory, this will allow researchers to simply plug in data-collection sensors to a network of power and information cables laid off the coast of Oregon on the Juan de Fuca tectonic plate in the Pacific Ocean. Up to 200 kilowatts of power and 240 gigabits per second of bandwidth should be available through 800 kilometres of cable, slated to be installed in 2011.

The network of cables will complement a Can$100-million (US$97-million) Canadian project called Neptune, which in 2007 installed similar cabling off Vancouver Island, British Columbia, at the north end of the Juan de Fuca plate.

Third, a coastal component of the OOI will see more monitoring equipment installed both off the coast of Oregon and off Cape Cod in Massachusetts. These will combine instruments carried on buoys and moorings with data gathered by ships, sea gliders and submersibles. The University of Washington in Seattle will be responsible for the cable that makes up the regional scale nodes, whereas WHOI will construct the buoys and moorings that make up the coastal component, working with Oregon State University in Corvallis and the Scripps Institution of Oceanography in La Jolla, California.

WHOI expects to get its first set of equipment -- sea gliders -- into the water off Massachusetts by summer 2012. The entire OOI system is planned to be fully operational by 2015.

Worldwide web

In addition to the initiatives in Canada and the United States, other countries are developing similar ocean-observation networks.

Japan plans to establish a real-time monitoring network in the nearby Nankai trough, called the Dense Oceanfloor Network System for Earthquakes and Tsunamis (DONET). A similar Taiwanese project, named the Marine Cable Hosted Observatory (MACHO), is being developed off the east coast of Taiwan. And Europe has the European Seas Observatory NETwork (ESONET), which stretches from Scandinavia to the Mediterranean.

Previously, ocean-observatory projects have focused on specific topics such as seismic data. The OOI, by contrast, will tackle multidisciplinary questions ranging from ocean mixing and climate change to fisheries management and whale conservation.

John Delaney, an oceanographer at the University of Washington, compares the arrival of cabled observatories on the sea floor with the advent of satellites for atmospheric sciences. "I see this as the beginning of an entire era," he says. "Sputnik was the first satellite. It wasn't the last."