Ecosystem Approaches to Oceans and Human Health

Oceans and Human Health

Oceans and humans are inextricably linked: our activities on land, sea, and in the air impact the health of the oceans and the health of the oceans impacts us. Oceans can threaten or benefit human health just as humans can threaten or benefit ocean health. Despite this critical linkage, very little is known about the relationships between oceans and human health. Scientists are working with natural resource and human health managers to understand, predict, and reduce both direct and indirect effects of the oceans on human health. They use an ecosystem-based approach that includes studies of:
  • infectious microorganisms,
  • toxin-producing algae,
  • shellfish,
  • fish,
  • marine mammals,
    as well as important environmental factors, including
  • climate variability and change.

Direct Effects

The oceans harbor disease-causing organisms and other harmful agents (such as toxic chemicals and marine biotoxins) that can impact human (and marine) life. Most human illnesses associated with oceans and coastal areas derive from the:
  • consumption of seafood contaminated with pathogens, biotoxins or toxic chemicals,
  • exposure to a variety of harmful pathogens through direct contact with ocean waters, and
  • exposure to toxins from harmful algae.
Human activities (such as sewage/wastewater disposal, nutrient runoff from agriculture and other land uses, coastal development with associated habitat destruction and even the transfer of organisms via ballast water) can trigger or exacerbate human health risks associated with the oceans. In addition to the direct effects of human activities, natural environmental processes can also contribute to these risks. For example, various marine processes can affect the distribution and proliferation of disease-causing organisms through estuarine, coastal and ocean basin circulation; tidal fluctuations and seasonal temperature shifts. Climate and weather systems can also cause marine biotoxins, toxic chemicals and pathogens to accumulate in certain areas or spread, through:


Indirect Effects

Oceans also indirectly impact human health and can provide important clues as to current and potential human health risks. Scientists are investigating the impacts of pathogens, biotoxins, and toxic chemicals on the health of sentinel species (indicator organisms), like fish and marine mammals. By understanding the impacts of these harmful agents on the health of sentinel species, we can better understand what is happening or what could happen to humans. Through this research, for example, we will be able to develop human risk models to inform management actions, such as a model that better links consumption of contaminated seafood with human disease.

Ocean Benefits for Human Health

The oceans benefit human health by providing a valuable global food source, providing protein and other important compounds (e.g. omega three fatty acids) from fish and shellfish. They also provide a source of employment, relaxation and inspiration. Millions of people live near the coasts and millions more visit and participate in marine-related recreation each year.

The oceans give us a wide variety of marine compounds, including:
  • new biochemicals for the development of pharmaceuticals and healthcare products
  • agrichemicals for crop protection, and
  • bioremediation agents for environmental protection.

The search for novel biochemicals is complemented by examining the adaptations of marine organisms to harmful and aggressive environments resulting in the production of biotoxins and venoms, antifoulants, signalling agents, and other molecular defences. Understanding the biochemical functioning of these agents has wide potential for the rational discovery of new and useful marine products. In addition, the development of new molecular platform technologies will provide bio-innovative methods for environmental analysis of water quality, for genotypic characterisation of natural biodiversity, and for disease or pest diagnostics necessary to evaluate the sustainability of marine natural resources. Aquaculture may ensure the sustainable production of marine species needed for production of biochemicals.