The oceans and human health.

For millennia, the oceans have been perceived by mankind as a producer of essential protein, a vital transportation artery, a source of great danger (from storms, hurricanes, typhoons, tsunamis, and venomous and predatory animals) and the greatest mystery on the planet, inspiring untold realms of poetry and prose. The oceans are the world's most important sources of biological activity, water, biodiversity, and biomass production. They supply food, oxygen, and other natural products critical for human existence, and interactions between the oceans and atmosphere shape our climate and weather. Today, we recognize the oceans for all these attributes and also for their marvelous, incredible, and almost infinite diversity of life forms and life processes, as well as the extraordinary potential for many of those life forms, biological and physical processes, and other resources to be harnessed for human welfare. We are just beginning to understand the numerous and complex ways in which humans can affect the oceans, and the oceans, in turn, can affect human health, including the discovery of new pharmaceuticals to fight human illnesses.

Although not truly an island, the United States is bordered on all sides by seas, and the lands immediately adjacent to the coast annually contribute over $1 trillion to the U.S. economy. In addition, our coastal waters provide invaluable waste processing and other ecologic services for free. Approximately 25% of the country's land area lies within coastal counties, which provide homes and workplaces for > 50% of our population. In addition, ocean-based tourism is the fastest growing component of the coastal economy, with hundreds of millions of Americans and international guests visiting our coasts annually. Not surprisingly, coastal population densities are several times higher than in the rest of the nation, and coastal sprawl is consuming land at [greater than or equal to] 3 times the rate of population growth. These trends are projected to continue and may accelerate, resulting in permanent alterations to a large portion of the coastal landscape and potentially serious impacts on marine ecosystems and public health.

Estuaries--those places where freshwater rivers meet and mix with the saltwater of the ocean--are dynamic environments renowned for their ecologic complexity, biological productivity, and seafood harvests and for the critical nursery habitat they provide for many ecologically and economically important species. Linking the land to the sea, the shallow tidal creeks and embayments along the shores of larger estuaries are the first zone of impact for many of the chemical and microbial pollutants washed or released into estuaries. As nurseries for the early and generally most sensitive life-history stages of many species of fish and invertebrates, these areas may provide early warnings of ensuing harm to the environment and to humans. In addition, the continental shelf and even the open ocean show increasing evidence of human-derived pollutants, such as occurrences of pathogens and persistent organic pollutants in offshore marine mammals.

Estuarine and coastal processes are increasingly being affected by humans, with consequent impacts on coastal ecosystems and the humans who live, work, and play there. Principal sources of pollution are urban and agricultural runoff, municipal sewage discharges, atmospheric deposition of airborne pollutants, and industrial wastewater. Other causes of degradation include shoreline modification, overfishing, introduction of invasive species, and high-density recreational use. Increasing incidences of beach closures, fish and shellfish consumption advisories, harmful algal blooms, and occurrence of toxic chemicals and pathogenic microorganisms in coastal waters, sediments, and biota are indicative of the extent of the problem. Changes in marine ecosystems due to global warming and other stressors also pose increased threats to human health from microbial agents transmitted via water, food, or other vectors, or which may be harbored in animal reservoirs.

The safety and economic risks of extreme weather events, climate change, and rising sea levels to those who live on or visit our coasts are reasonably well known. However, while cases of human illness linked directly or indirectly to stressed estuarine and coastal environments are being documented with increasing frequency, the risks to human health from continued and expanded impairment of coastal and ocean environments remain very poorly understood. Globally, nontraumatic human illnesses documented in relation to coastal processes typically are associated with a) consumption of pathogen-contaminated or chemically contaminated seafood; b) spread of human pathogens (e.g., cholera) via the release of poorly treated or untreated sewage into coastal waters; c) exposure to toxins from harmful algae; and d) effects of weather and climate on the rates and means of transmission and severity of infectious diseases. Other associations are more elusive, probably because we have not looked in the right places using the right technologies. Existing national and regional monitoring and assessment programs have focused on the measurement of persistent chemicals, particularly in deeper estuarine sediments. Much more attention should be paid to assessing known or potential human pathogens and contaminants and emerging contaminants of concern such as newly registered pesticides, pharmaceuticals, and fire retardants in shallow estuarine and marine waters, coastal retention ponds, continental shelf environments, and the open ocean.

New approaches and collaborations are required if we are to understand and resolve the large-scale environmental and public health problems facing the United States' predominantly coastal population. As the U.S. Commission on Ocean Policy (2004) stated in its preliminary report, "Significant investment must be put into developing a coordinated national research effort to better understand the links between the oceans and human health...." The interdisciplinary Oceans and Human Health (OHH) initiatives now being undertaken by the National Oceanic and Atmospheric Administration and jointly by the National Science Foundation and National Institute of Environmental Health Sciences provide the first steps toward a coordinated effort to transcend traditional disciplines and boundaries and focus a broad array of scientific intellect on developing regional and national solutions to environmental and public health issues of increasing complexity involving cumulative impacts from multiple stressors. Deriving such solutions will require a sustained and concentrated effort of scientific talent from multiple disciplines and institutions, development of new technologies and new understanding of ecosystem dynamics, and effective transfer of critical information to natural resource and public health managers and to the public at large. These new OHH initiatives should help the nation build a foundation for forecasting environmental and human health risks across estuarine habitats, watersheds, and coastal and ocean regions and an enhanced capacity to design and implement future estuarine monitoring and assessment programs that will include early warning indicators of threats to public, organism, and ecosystem health. Ultimately, we believe the OHH initiatives will help the United States better address three key questions the public frequently asks about virtually every estuary and coastal area: a) Are the fish and shellfish safe to eat? b) Is it safe to swim in the water? c) If not, what can we do to make them safe?

REFERENCES

U.S. Commission on Ocean Policy. 2004. Preliminary Report of the U.S. Commission on Ocean Policy. Governors' Draft. Washington, DC:U.S. Commission on Ocean Policy.

Paul A. Sandifer

NOAA National Centers for Coastal Ocean Science

Charleston, South Carolina 

A. Frederick Holland

NOAA National Centers for Coastal Ocean Science

Charleston, South Carolina

E-mail: [e-mail]

Teri K. Rowles

NOAA National Marine Fisheries Service 

Office of Protected Resources

Silver Spring, Maryland 

Geoffrey I. Scott

NOAA National Centers for Coastal Ocean Science

Charleston, South Carolina

Paul A. Sandifer is senior scientist for the National Oceanic & Atmospheric Administration's (NOAA's) National Centers for Coastal Ocean Science. He is a member of the U.S. Commission on Ocean Policy, has published extensively in aquaculture and marine biology, and serves on graduate faculties of the College of Charleston and the Medical University of South Carolina.

A. Frederick Holland directs NOAA's Hollings Marine Laboratory, a cooperative enterprise involving NOAA, the National Institute of Standards and Technology, the South Carolina Department of Natural Resources, the College of Charleston, and the Medical University of South Carolina. His research focuses on impacts of anthropogenic activities on shallow tidal creek ecosystems and relationships between tidal creek environmental quality and human health.

Teri K. Rowles was a faculty member at Virginia Maryland Regional College of Veterinary Medicine and the University of Tennessee before moving to NOAA's National Marine Fisheries Service in 1995. At NOAA, she coordinates the Marine Mammal Health and Stranding Response Program and works on the impacts of diseases on marine protected species and on zoonotic diseases from marine organisms. She is currently on detail at the Hollings Marine Laboratory.

Geoffrey I. Scott is the director of NOAA's Center for Coastal Environmental Health and Biomolecular Research. His primary research areas include environmental toxicology and physiological ecology, and he holds faculty appointments at the University of South Carolina, the Medical University of South Carolina, and the College of Charleston.