NCCOS’s Puzzle Piece in Solving the Oceans/Health Continuum
Ask a group of NCCOS ocean scientists why they do what they do, and chances are the word “health” will figure prominently in their answers.
But is it public health as generally understood? Or ocean health, as in the “ecological health of the oceans” that professionals worry about?
The answer is both. Both human and ocean health. And that’s the way it should be.
NCCOS—the National Centers for Coastal Ocean Science—is far from alone within the Department of Commerce and its National Oceanic and Atmospheric Administration, NOAA, in having public health as part of its portfolio. But within NOAA and the National Ocean Service, NCCOS’s commitment to its public health responsibilities runs deep.
“Just as we affect the health of our oceans, so too do the oceans affect our health,” says Dr. Gary C. Matlock, director of NCCOS. “As we increase our exposure to the oceans and the bounty they have to offer, we increase the chances that the physical, chemical and biological aspects of oceans will adversely affect us.”
“Our choice to reside, work and play along the ocean’s shores brings potential calamity on us as we change the very nature of the ecosystem we so cherish,” Matlock cautions. “Those changes can make us more vulnerable to physical hazards, like floods, storm surges, high winds, and tsunamis. And our harvesting of the coasts’ bounties of biological resources, oil and gas, and other resources can alter the very biodiversity, composition and processes of the ocean ecosystems that attract us to the coasts in the first place.”
The Oceans/Health Continuum
With their unique specialties and areas of expertise, the five NCCOS research centers work collaboratively in their sampling activities and research aimed at improving ocean and human health. And the challenges have never been greater.
For centuries, the oceans’ carrying capacity to meet human needs had seemed limitless.
“As we know today, this is not true,” says the National Oceans Commission’s “Ocean Blueprint for the 21st Century.” It’s now generally accepted as something of a quaint notion that the oceans are “too big” to be affected by us mere humans. In recent decades, scientists have come to better appreciate that human activities contributing to pollution, resource extraction, climate change, and overfishing can affect the health of the oceans.
Excessive human releases of nutrients and pollution into the ocean, and a subtle, yet measurable rise in ocean surface temperatures, says the Oceans Commission’s report, are causing an increase in pathogens, primarily bacteria and viruses.
Human exposure to harmful bacteria and viruses in the oceans can result from eating contaminated seafood (especially raw seafood), and from coming in direct contact with sea water. Per capita seafood consumption in the US has been rising—increasing the risk of public health problems from contaminated seafood.
Professional fishers and prudent recreational anglers avoid exposing open wounds when handling fish, particularly those showing visible signs of disease. In the 1990s, widespread outbreaks of fish lesions in Chesapeake Bay and Pamlico Sound regions, initially linked to the dinoflagellate Pfiesteria piscicida, raised widespread concern over the safety of seafood and recreational waters. Neurological problems and a variety of other complaints were reported by some who had come in contact with infected fish. These concerns caused many people to avoid eating seafood and avoid contact with the water.
Just this past year, a new study by NCCOS scientists, published in the peer reviewed journal Applied and Environmental Microbiology, provided strong evidence that a water mold known as Aphanomyces invadans is responsible for these seasonal outbreaks. For this study, scientists developed two new tests or “assays” to detect the presence of A. invadans water mold. They applied them first in the laboratory, and then in the field. “Assays developed in this study now make it possible to screen the large number of environmental samples needed to identify alternative hosts and sources of A. invadans infections,” said NCCOS scientist Wayne Litaker.
In another promising area of research, NCCOS scientists are looking into concentrations of pharmaceuticals found in the nation’s waters. Taken as directed, pharmaceuticals are helping Americans have longer and better lives, but little is known about the possible impacts of pharmaceuticals on aquatic life and on humans who may subsequently eat it in the form of seafood. An important first step involves documenting which compounds are present and in what concentrations.
With that in mind, NCCOS scientists in 2002 took water samples from the Chesapeake Bay, Biscayne Bay and the Gulf of the Farallones, focusing in particular on residues in sewage treatment plant effluent, thought to be a primary source of environmental contamination. The study tested for the presence of 24 different pharmaceuticals and related compounds, including a number of antibiotics, analgesics, fat and cholesterol regulators, and antidepressants. The highest number of compounds, 13 in all, were detected in the Chesapeake Bay. By comparison, three compounds were found in the Biscayne Bay samples and two in the Gulf of the Farallones. Toxicological studies conducted by NCCOS document levels of several classes of pharmaceuticals that cause harm to sensitive marine organism and also sublethal indicators of stress that may serve as early warning indicators.
NCCOS scientists point out that elevated levels of antibiotic resistant microbes and pharmaceuticals have been found in areas where human sewage is discharged. Also, aquaculture, which has made seafood more plentiful and affordable at supermarkets throughout the US, uses pharmaceuticals to control disease outbreaks in cultured stocks—raising the possibility of broader contamination to surrounding waters. The presence of pharmaceuticals within marine ecosystems poses significant risk to both seafood consumers and swimmers. Recent studies of bottlenose dolphins in Charleston Harbor, S.C., for instance, found that more than 50 percent of the dolphins had numerous antibiotic resistant microbes within their digestive tracts.
The studies also point to very high levels of flame retardants in dolphin blood. The scientists say the highest levels of flame retardants were measured in dolphins near sewage treatment plants within Charleston Harbor. The flame retardants, found in most modern fabrics common to carpeting, drapes, and clothing, had become a common part of the municipal waste stream.
Ocean Health Can Change Slowly…or Take a Sudden Turn
Some changes signal a need for immediate attention. NCCOS’ event response team concept combines the collective expertise and laboratory capacities of NCCOS and its research partners to solve emerging threats to human and ecosystem health.
In Washington State, for instance, an NCCOS-sponsored Harmful Algal Bloom (HAB) event response program has built such a successful early warning monitoring system for a potent neurotoxin in razor clams called domoic acid that the State took over its operation. Elsewhere, the event response team has been mobilized to investigate reports of large scale marine mammal deaths.
Observed HAB Events on the Upswing
Increased nutrient loads, says the Oceans Commission’s report, can lead to excessive growth of microscopic algae, some of which produce toxins which become concentrated in the tissues of fish and shellfish. When ingested or inhaled by humans, these concentrated toxins can present human health risks ranging from the merely annoying to the deadly.
HAB events frequently coincide with increases in nutrients in coastal waters, leading some scientists to believe there may be a causal connection. Studies have documented increases in the frequency and severity of HABs, though some scientists attribute these observed increases merely to stepped-up monitoring. While more study is needed to resolve this issue, one thing is certain: HABs occur on virtually all US coasts, in both fresh and salt water, and require prompt action to keep people from getting sick.
HABs “are a serious human health threat and are economically damaging to communities,” Navy Vice Admiral Conrad C. Lautenbacher, Jr., Ph.D., Under Secretary of Commerce for Oceans and Atmosphere and NOAA Administrator, has said. “Monitoring efforts assist states in maintaining a safe and plentiful seafood supply by allowing targeted closures.”
Severe Coastal Storm Events
Changes to coastal ecosystems persist after the winds and tides subside. But to what extent and for how long? NCCOS has focused some of its research getting answers to these questions.
In 1999, three hurricanes hit the Pamlico–Albemarle Sound area of North Carolina in rapid succession, raising concerns of large-scale disruption to fish spawning and nursery grounds. Pat Tester and her colleagues from NCCOS began preparations for field sampling as soon as the last storm had passed. Flooding and power outages were still widespread, and the situation was still chaotic in the region generally. Said Tester, looking back: “I went to the local flight school and got an instructor to take me up with a video camera to have a look at the flooded areas and the inlets. The plumes of sediment and discolored water were just boiling out of Ocracoke and Oregon Inlets.”
The resulting study reported that the threat of severe shortages of oxygen, or hypoxia, did not materialize in part because of fall’s onset of cooler temperatures. Within six to twelve months, chlorophyll patterns had returned to pre-hurricane levels.
More recently, and in the wake of Hurricanes Katrina and Rita in 2004, NCCOS joined with other federal and state partners to assess the human-health and environmental impacts on affected coastal waters. Twenty years of sampling data on contaminants from NCCOS’s National Status and Trends (NS&T) Mussel Watch field surveys provided a baseline with which to assess how post-Katrina contamination in the northern Gulf of Mexico compared with historical levels.
In one of these studies, NCCOS and its partners collected samples from sediment, water and the soft tissues of American oysters (Crassostrea virginica). Comparing chemical and biological contaminant levels against twenty years of historical data, they found concentrations of post-Katrina PCBs and PAHs (hydrocarbons) to be extremely low. On the other hand, concentrations of metals, including selenium, chromium, copper, iron, manganese and nickel were found to be extremely high compared to the 20-year record.
In addition, NCCOS scientists’ measurements of fecal coliform and Enterococcus bacteria levels in surface waters helped establish the post-storm water quality conditions after the storms, indicating that the estuarine waters were suitable for swimming and for harvesting of shellfish.
Tapping the Oceans’ Potential to Cure Human Disease
While the oceans can pose risks to human health, they also hold tremendous potential to benefit humankind through medical uses of the chemicals that marine organisms produce.
The oceans are the greatest source of biological diversity on the planet, with an abundance of life forms not yet discovered, much less explored for their potential to prevent and cure disease. Marine organisms synthesize natural chemicals for a variety of purposes to increase their chances of survival under often harsh conditions. These organisms may hold the key to solving many of humanity’s ills—curing diseases, or at the very least making them easier to bear. Marine Natural Product Chemistry research at NCCOS has already led to several discoveries of unique chemicals that may have great promise as pharmaceuticals. Marine organisms and marine-derived compounds also have a proven track record in biomedical research, allowing scientists to investigate biological processes analogous to those found in humans.
NCCOS’s health/oceans research efforts are aimed at better understanding the full-circle nature of the human health/oceans health continuum. There’s no denying that there is lots more to be done.
The National Oceans Commission, and earlier reports by the National Research Council and others, have stressed a need for a multidisciplinary and cross-agency approach to marine natural product discovery and development—one not restricted by the “very structure of the federal scientific support system.”
What’s needed, the Commission said, is a coordinated national research effort to better understand links between the oceans and human health, with research aimed at discovering new drugs and products derived from marine organisms, and at detecting and mitigating disease impacts. NCCOS’s scientific research on oceans and human health continues to be one integral part of that large and evolving puzzle.