The 8th of June 2009 marked the first World Oceans Day as designated by the United Nations General Assembly earlier this year. This awareness-raising Day comes at a crucial moment for marine biologists and conservationists who have long recognized the role that the ocean plays in our society and the challenges we face in maintaining the ocean’s capacity to regulate the global climate and ecosystems, and provide sustainable livelihoods.

Our oceans are crucial to life on Earth. We can trace our cells back to the oceans through the saltiness of our tears, and our blood. Our heritage, our future is linked to the oceans, thus the health of the oceans is our responsibility.

The world’s oceans cover over two-thirds of the Earth’s surface and contain over ninety per cent of the world’s biomass. This blue planet of ours is both fragile and resilient. The ocean serves as a reservoir, store and transmitter of heat and water vapor; it regulates the Earth’s climate and weather. The ocean plays a critical role in the global carbon cycle, absorbing some of the carbon dioxide that we humans emit. It provides over fifteen per cent of the protein needed by almost half of the world’s population. For many developing countries, fish provide fifty per cent of dietary protein. Thus, healthy fisheries are critical to the food security of millions of people. Fisheries also provide employment and economic opportunities, and help to sustain coastal communities.

Though global trends related to the world’s marine fish stocks appear stable over the last ten to fifteen years, these statistics only consider stability relative to overall trends of stocks, ignoring the individual trends of certain keystone species. Large predator species that act as critical regulators of ecosystems – tuna, sharks and others – have been greatly overfished. Scientists report that many such stocks have declined by 90 per cent from historic levels. Bluefin tuna will essentially disappear from the Mediterranean in a few years if current rates of fishing are not immediately reduced. In other areas, the taking of large numbers of small prey fish is altering ecosystems. Large schools of menhaden together with oysters used to filter all of the water in the Chesapeake Bay every few days, but this no longer happens.

It is our responsibility, to the oceans, to ourselves and to our children, to manage fisheries well.  Under the United Nations Convention on the Law of the Sea, States have accepted an obligation to protect and preserve the marine environment. States have an obligation to conserve and manage living resources in such a way that they are protected from over exploitation.

We must move quickly to better manage fisheries if we are to have fish to eat tomorrow and if we hope to continue to rely on critical ecosystem services that the world’s oceans provide to us and to other species. This is our responsibility.

The time for change is now. It will soon be too late to save the ocean and revitalize its fish stocks to a level that is sustainable. We need to reduce fishing capacity and reduce harmful subsidies. We need to implement ecosystem-based management whereby all species and activities are managed as a whole. We need to protect the marine environment through the broadened use of marine protected areas including marine reserves or no-take zones. Marine reserves will provide a refuge where fish can reproduce, thus ensuring healthier ecosystems and better harvests for future generations. We need to implement a process that includes an assessment of the cumulative impacts of human activities on the world’s oceans. We need to better understand the science that drives nature through more accurate and more transparent collection of fishing data. An Assessment of Assessments is welcomed under the United Nations to report globally on the state of the marine environment, building on existing regional assessments, as this would undoubtedly provide an important mechanism to better manage our oceans.

Fishing is a human activity and it supports human life. We must look at methods that ensure communities in developing countries will continue to have access to protein from the world’s oceans. We need to build capacity in developing countries, by providing tools and training to better monitor, control, survey and enforce fisheries management laws and regulations in areas subject to their national jurisdiction and by adopting a good agreement on port-state measures to better enforce fisheries management.

We must work to reach the goals agreed at the World Summit on Sustainable Development in Johannesburg to create an effective globally managed system of marine and coastal protected areas by 2012 and to maintain or restore stocks to levels that can produce sustainable yields by 2015.

Changes in water temperature, ocean chemistry and ocean currents have resulted from the build-up of greenhouse gases in the atmosphere. These changes are causing shifts in the availability and the quality of fish, thus potentially destabilizing the lives of fishers and coastal communities, many already vulnerable through poverty and rural underdevelopment. As carbon is absorbed by ocean waters, those waters are becoming more acidic, thus threatening the stability and well-being of organisms that depend on calcium to build structures, including corals and shellfish.

Seventy science academies around the world recently released an Inter-Academy Panel on Ocean Acidification statement in which they confirmed that the acidification of the world’s oceans, like climate change, is a direct consequence of increasing atmospheric carbon dioxide concentrations and that deep reductions in carbon dioxide emissions are the only solution. However, ocean acidification does not appear as a subject on the agenda of the current United Nations Framework Convention on Climate Change (UNFCCC) talks.

The oceans are now more acidic than they have been for 800,000 years. The statement calls for reductions of global carbon dioxide emissions by at least fifty per cent by 2050, with further sharp cuts thereafter. The scientific leaders note the urgent need to act to reduce other stressors, including overfishing and pollution, on marine ecosystems in order to increase resilience to ocean acidification.

It is not just the change in ocean chemistry that threatens the welfare of ocean ecosytems and coastal communities. The thermal mass of the oceans will expand as temperatures rise and land-based ice melts. In Alaska, shrinkage of winter sea ice cover has allowed storms to erode coastlines, forcing some vulnerable communities to move. Sea-level rise threatens mangroves, which filter water, provide shelter and protect coastal communities. Sea-level rise threatens the very existence of low-lying island states.

We have a duty to our oceans, to ourselves, to our children and to other species with whom we share our planet to restore our oceans to health. We must act responsibly to reach agreement this year in Copenhagen to sharply reduce our greenhouse gas emissions. As consumers, we are a powerful force that can demand change. We must call on regional fisheries management bodies to reduce fishing efforts to a level that is sustainable. We must act now.