Enduring Vigil

AT 8:46 P.M. ON A SATURDAY NIGHT LAST DECEMBER, Tully Rohrer received an SOS from a machine. It came as text messages on his cell phone and indicated that one of the ocean-monitoring buoys he had helped to deploy off the Oregon and Washington coast a few months earlier had come loose from its mooring.

The faculty research assistant in the Oregon State University College of Earth, Ocean, and Atmospheric Sciences (CEOAS) knew that seas had been high the previous week. At times, waves exceeded 30 feet. But the buoys had been designed to withstand this kind of battering, so he wasn’t worried. He had gone for a bike ride with his fiancée and had just finished dinner when the messages started arriving.

Five other members of Oregon State’s Ocean Observatories Initiative (OOI) team — Ed Dever, Chris Wingard, Walt Waldorf, Jon Fram and Craig Risien — had received the same messages as Rohrer. In a rapid-fire email exchange, they shared ideas about what had happened and where the buoy was headed. “We notified the Coast Guard so they would add it to their updates to mariners. And we started looking for ships that could help us recover it,” says Rohrer.

Jumping into a boat and going out to rescue the wayward buoy wasn’t a practical option. Although the top was only 5 feet above the water, the buoy was equipped with flashing lights and radar reflectors and painted bright yellow. It wouldn’t be hard to locate. But seas were still high, and it was loose on the Pacific where waves and fog swallow ships and where currents head north this time of year. Normally secured to the seafloor by hardware strong enough to lift a small car, it carried a state-of-the art package of computers and communications equipment.

Over the next few days, the buoy continued to send regular text messages, noting its latitude, longitude and distance from home. The previous October, the team had left it moored to an anchor platform in water nearly 2,000-feet deep about 35 miles due west of Grays Harbor. When it crossed into Canadian waters, the researchers notified that country’s Coast Guard.

It was the first time one of the buoys in the recently completed network known appropriately as the Endurance Array had come loose. Developed jointly at the Woods Hole Oceanographic Institution (WHOI) and Oregon State, these floating sentinels are designed to withstand hurricane-force winds and crashing waves.

Complementing a fleet of a dozen gliders and a 900-kilometer (575-mile) network of underwater monitoring stations known as the Cabled Array (the first to cross an active subduction zone), the buoys send steady streams of data back to shore with measurements of water chemistry, temperature, plankton, weather, wave heights and other ocean features.

Paired with devices that descend from the surface to the seafloor and back again like small elevators, they illuminate roiling currents and the nutrient-rich upwelling waters that feed the coastal ocean’s bounty of fish and fowl.

As part of a Pacific Ocean monitoring system managed by Oregon State and the University of Washington, they stand a constant vigil for science. Mooring positions located north and south of the Columbia River enable the Endurance Array to capture the river’s influence on the coastal ecosystem.

But machines malfunction, run into logs and other flotsam and are subject to the opportunistic behavior of ocean creatures large and small. Sharks have left teeth marks on underwater gliders in the Atlantic. Even barnacles can create problems. When the thumbnail-sized crustaceans glom onto the slick sides of gliders, the winged instruments have been known to be thrown off course. All it takes is the gentle force of barnacles opening their shells and waving their frond-like appendages in the water.

To recover an off-course glider or a wayward buoy, scientists may charter fishing boats or other research vessels. On rare occasions, a glider might end up accidentally in fishing nets. In one memorable case, a recreational fisherman snagged an Oregon State glider and then returned the device to the water, but not before taking out a green waterproof marker and writing “Go Ducks” on the side.

Last December, Rohrer and his team tracked the northward-drifting buoy to the waters just west of Tofino on Vancouver Island. A University of Washington oceanography class happened to be nearby on the UW’s research vessel, the R/V Thomas G. Thompson. “We sent them information about the buoy’s location and its lifting points (handles on the buoy for safely lifting the 8,000-pound instrument), and they were kind enough to recover it for us,” says Rohrer. “Walt drove a truck up to Seattle to pick it up.”

Machine Shop Oceanography

You can’t see the ocean from the Ocean Observing Center in Corvallis. Located a few miles south of downtown on Highway 99, the nondescript industrial facility appears more machine shop than window on the sea. But this is a state-of-the-art facility where a team of a dozen or so scientists, mechanical and electrical technicians and software programmers maintain the buoys and gliders of the Endurance Array. Researchers here actually do have a window on the ocean, a kaleidoscope made up of the multifaceted data that stream 24/7 from the machines at sea.

“We deploy and recover the buoys twice a year,” says Ed Dever, professor in CEOAS and project manager for the array. “We go out in the spring, take out the buoys that we put out in the fall and deploy a new set. And we do the same thing in the fall. The whole season is based on these two deployments and recoveries.”

When the machines come back from spending six months at sea, they need to be scrubbed and disassembled. Instruments are sent off to be repaired or recalibrated. Then the process happens in reverse. Structural members must be repainted or recoated with antifouling compound. Once reassembled, the gleaming towers of sensors, wind and solar generators and battery packs are tested before being trucked over the Coast Range to Newport where they are loaded on ships for deployment.

At sea, nothing happens without a plan. “We plan for everything and try to plan for the unknown as well,” says Rohrer. “Our lives may depend on it.” Whether the crew is deploying or recovering a buoy, every piece of equipment has its place on deck, and every task runs step-by-step. Safety is paramount.

To take a 10,000-pound buoy (hardware plus a 6- to 8-inch layer of barnacles and seaweed) out of the ocean requires a deft hand at the helm, a trained team on deck and well-tested lifting gear. “Our crew is really good at this,” Rohrer adds. “When we go out, we put our winch on the deck and fill up a giant water bag at one-and-a-half times the load it will ever see. We make sure it won’t break. You put a lot of faith in every little piece of equipment. It’s old seamanship.”

A moment of truth comes early as the ship approaches a buoy. A technician sends an acoustic signal to the seafloor to release the buoy from its anchor. This usually works, but if the anchor platform has been covered with silt by ocean currents, the mooring line may not release. Then all bets are off. Plan B may include inspection by a remotely operated vehicle. Another tactic: Tie the anchor to the ship and gently rock the vessel to free it from the sediment. Even “fluidizing” the mud around the anchor with a commercial rig designed to recover crab pots has been tried successfully.

When the mooring is released, the ship maneuvers close to the buoy, and a member of the team reaches over the side with a titanium hook on the end of a carbon-fiber pole. “The hook is basically a carabiner (a metal loop used to secure mountain climbers to safety lines) on steroids,” says Rohrer, who enjoys climbing at places like Oregon’s popular Smith Rock when he’s not at sea.

Once clipped to the buoy, a line is run through an A-frame on the rear of the ship to a winch. As the mooring line comes onboard, the ship must be moved without endangering any of the instruments trailing like crab traps below the buoy in the water.

With everything onboard, the scrubbing begins. Barnacles — both gooseneck and the harder-to-remove acorn species — and kelp must be removed before they dry out. “It takes a lot of elbow grease, a lot of people working together to keep morale up,” says Rohrer. “It’s sensitive, valuable gear. You can’t just sandblast or pressure wash it. You clean up as much as you can on ship. It becomes gross pretty quickly if you don’t.”

International Waters

The Northwest’s ocean monitoring system doesn’t stand on its own. It’s part of the National Science Foundation’s Ocean Observatories Initiative (OOI), which was more than 20 years in the planning and maintains seven locations in the Pacific and North and South Atlantic oceans.

These places are exceptionally sensitive to currents, climate and geology. For the first time, the OOI gives scientists a round-the-clock view of what they could previously glimpse only occasionally from ships or satellites when the weather cooperated.

The local network is designed to study an overarching question: How will a highly productive coastal ocean evolve under a changing climate? The answers will shed light on similar regions of the world’s oceans and affect the Northwest’s rich fishing, seafood and tourism industries, not to mention the spectacular diversity of Oregon’s coastal waters. After arriving at the Ocean Observing Center and routed elsewhere, OOI data are made available to the scientific community and to the public.

Success comes down to the crews of technicians and scientists who face the same wild forces that mariners have struggled with for centuries. As for the buoy that escaped last winter, analysis continues into what went wrong. “It was either fatigue from so many big-sea days in a row or it’s possible that it was struck by a log or something during the storm. There was wood embedded in the tower,” says Rohrer.

In May, the Endurance team recovered the rest of the components of the broken mooring. Over the summer, they will examine the evidence to pinpoint the cause of the failure. The buoy will be reconditioned and sent back to its post. It’s all part of the dance that oceanographers do to unlock the secrets of the sea.