A lonely gray boat bobbed like a cork in the Chesapeake Bay where its brackish waters converge with the Choptank River on Maryland’s Eastern Shore. On deck, four men reluctantly set aside their last-minute preparations and posed together for a photograph.
The day had finally arrived. “I started proposing this 20 years ago, and I’m not the first,” said Doug Wilson, a longtime oceanographer with the National Oceanic and Atmospheric Administration and now a consultant to the agency. “People were proposing this 20 years before that.”
Moments later, Wilson and a fellow crew member unceremoniously heaved a yellow buoy into the Bay’s gentle swells, launching a new era for monitoring the pulse of America’s largest estuary.
With its splashdown on that late April morning, the buoy became the first to operate under a new effort to vastly expand how scientists track “dead zones.” A partnership involving three federal agencies — NOAA, the U.S. Environmental Protection Agency and U.S. Geological Survey — aims to distribute 10 monitoring stations around the Bay and in a select number of tidal rivers by the end of 2025.
The main objective for the network is to give Bay scientists a clearer understanding of where and when low-oxygen conditions occur. These are often called “dead zones” because they are practically devoid of life; any living thing that can’t flee fast enough eventually suffocates.
While naturally occurring, the events are worsened by pollution. Farms and suburban landscapes across the Chesapeake’s 64,000-square-mile watershed leak excess nutrients — nitrogen and phosphorus — into the Bay. There, they feed algae blooms. When those blooms die off, they consume dissolved oxygen, leaving blobs of “dead” water in their wake.
Bringing dead zones to heel has been the primary goal of the 40-year campaign to restore the Chesapeake Bay. Billions of state and federal dollars have been spent on the problem. But many questions about the performance of these measures remain unanswered, experts say, at least partly because real-world sampling of the Bay’s dissolved oxygen levels has been sparse.
“For large parts of the Bay, we just don’t have the ability to look at the oxygen,” said Tom Parham, head of the Maryland Department of Natural Resources’ Tidewater Ecosystem Assessment Program.
What is known about the Bay’s dead zones mostly derives from a handful of sources.
The Chesapeake Bay Program, the federal and multi-state partnership that drives the restoration, has maintained a boat-based monitoring program since 1984. The cruises visit 49 locations per month — twice per month from June to August during peak dead zone season. Researchers test oxygen levels every few feet in depth throughout the water column.
The main drawback from that method is that the samples represent a fleeting moment in time, experts say. If water quality turns up bad in a single monthly sample, it paints the entire month as bad. But research shows that oxygen concentrations can shift at a particular location within little more than a moment’s notice.
Another major monitoring effort consists of a network of seven floating stations that began operating in 2007. The Chesapeake Bay Interpretive Buoy System (CBIBS) is popular with scientists and fishing folks alike because it transmits fresh data to the web and mobile apps every six minutes. Its primary downside is that the sensors only detect water quality at the surface, leaving lower depths unmeasured.
DNR’s Parham, who isn’t directly involved in the new project, said that the new program is poised to become the most advanced system yet. It will send sampling data almost in real time and include points from the surface to the bottom of the Bay.
“This monitoring will help us get a better handle on what our living resources are actually experiencing and being able to tie that back to our nutrient– and sediment-reduction goals,” Parham said.
A better assessment of dissolved oxygen would be welcome on several fronts. Scientists say it could help improve forecasting the annual dead zone in the Chesapeake’s deep channel. It also could give fishery managers a better idea of how much suitable underwater habitat is available to commercially important species, such as striped bass, blue crabs and menhaden.
Wilson, who founded the CBIBS program during his days at NOAA, said that technological advancements helped turn his dream into a reality. The first generation of buoys in the 2000s were expensive and bulky, towering about 14 feet above the water’s surface. They could only be lifted with a boat-mounted crane.
Developed by Wilson’s company, Caribbean Wind LLC, and Seattle-based Soundnine Inc., the current versions are far cheaper and smaller — about the size of an exercise medicine ball. Each is expected to cost about $5,000. Its sensors are attached every 6 feet to a wire strung between the buoy at the surface and an anchor at the bottom.
In addition to monitoring dissolved oxygen, the stations will gather data on several other parameters, including salinity, temperature and water pressure. The team’s goal is to make the data available to the public in real time within a few months of its launch.
A panel of Bay Program experts is selecting the buoy locations. The main difficulty is placing them where the water is deep enough to experience low-oxygen conditions but not where shipping traffic is likely to occur, said Jay Lazar, a NOAA scientist working on the project. The Coast Guard must approve each location.
Lazar hopes to get three deployed by the end of this month. Besides the Choptank location, the initial buoys are targeted for an area west of Hoopers Island on Maryland’s Eastern Shore and at the mouth of the Potomac River.
Back at the marina in the quiet village of Oxford, Wilson killed time on the boat, waiting for the sign that the newly installed buoy was up and running. The sensors collect measurements every 10 minutes, but the data is only transmitted once per hour. An email would automatically land in his inbox when that happened.
At the exact moment it was expected — 50 minutes past the hour — the message arrived, overflowing with numbers and decimals.
“It’s working,” Wilson said in a near whisper to Lazar.
Relief spread across Lazar’s face. “We don’t have to go back out today,” he said.
This article was originally published on BayJournal.com and is republished with permission.