The explosive growth of the human population, our unsustainable use of resources and generation of wastes, and the increasing inequity within and among nations are resulting in profound changes to the oceans. A more enlightened understanding of these changes and their possible consequences is needed. It is time to move beyond the outdated assumptions that the oceans have unlimited potential to provide food and assimilate wastes. Though the oceans are rich beyond imagining that potential will die unless we act now through conservation through actions, instead of reactions.

The plants, animals and microbes at and below the surface are wondrously diverse, exotic and marvelous. They represent phenomenal diversity - diversity of body plans, diversity of ways of making a living, diversity of sensory structures, diversity of life histories, diversity of ecological interactions, diversity of chemicals and diversity of genetic material. We are only beginning to discover this richness.

The descriptions 'salty' and 'wet' hardly do justice to the broad range of habitats which make up the ocean realm - from the more familiar coral reefs, kelp forests, sandy beaches, bays and estuaries; to the more exotic open oceans, continental shelves, abyssal plains, deep sea canyons, sea mounts, hot and cold vents, ice shelves - and more.

People have relied for millennia on the useful goods produced by marine ecosystems. Food, shells, medicines, chemicals - and now genes – are extracted, used, bartered and sold around the world. These 'ecosystem goods' have been the prime focus of the economic value and 'usefulness' of marine ecosystems. Kelp forests, mangroves and coral reefs provide homes for rich assemblages of coastal organisms and protect shores from erosion by waves. Oysters in bays filter water; mangroves and salt marshes detoxify pollutants and collect sediment, which could otherwise smother animals and plants downstream. These services are the product of the functioning of the ecosystem, the result of the characteristics of species, interactions among them and interactions between the organisms and chemical environment. Together with ecosystem goods, these ecosystem services provide the marine component of the life support systems of planet Earth.

Both are being threatened as genetic diversity is diminished, populations are fragmented, species are lost and ecosystems disrupted. Loss of species, fewer individuals of critical species, changes in their spatial configuration, size or strength of interaction with other species can all contribute to changes in the functioning of the system.

The causes of these changes are multiple and complex. They include overfishing, chemical pollution, habitat degradation, and the introduction of exotic species. Climate change and increases of UV-B radiation as a result of stratospheric ozone depletion pose additional hazards. Most waters are affected by many of these stresses, some by all of them. Ecosystems in trouble- there are clear signals from around the planet that these activities are resulting in serious problems.

The demise of many of the world's fisheries has received widespread attention but the declines of non-commercial species of seaweeds, shellfish and fishes gleaned from shores around the world for local use are equally serious. Unexpected, dramatic mass mortalities of many marine species have been reported - ranging from marine mammal die-offs and fish kills to mass mortalities of sea urchins, abalone, seagrasses and others. Water quality is seriously impaired in coastal regions: in many places this represents a critical hazard to human health. Increases in rubbish, especially plastics, are obvious to almost everyone who frequents the shore. There have been many reports of increases in the frequency, intensity and spatial extent of harmful algal blooms such as red tides; with consequences ranging from human health hazards such as paralytic shellfish poisoning to aquacultural die-offs and increased mortality of fishes and marine mammals. The symptoms vary from place to place. Some are well documented, others less so. The actual causal factors are often ambiguous. Nonetheless, on the whole, the picture is one of marine ecosystems in trouble, especially in nearshore waters.

The vast majority of people on Earth live within 80 miles of the coast. Nearshore habitats bear the brunt of both land-based and sea-based activities: tourism, recreation, fishing, mariculture, domestic and industrial waste disposal, military activities, and the transportation, mining and energy industries. As a result, bays, estuaries, enclosed seas and coral reefs provide ample evidence of a plethora of problems. Many of these systems, especially coral reefs, estuaries, kelp forests and rocky shores are among the most productive systems on Earth; coastal waters produce 75 per cent of the world's fish catch. A higher priority must be put on ensuring their sustainability.

A crisis of unprecedented complexity

The old adage 'dilution is the solution to pollution' captures the historical attitudes toward oceans as vast, bountiful and infinitely resilient. The many problems occurring around the world suggest this is grossly misplaced. We are learning that the oceans, especially coastal areas, are under increasing and serious threat from multiple sources. We do not yet know the full extent of the problems, but marine scientists are in strong agreement that we are faced with a crisis of unprecedented complexity, proportions and consequences. The magnitude, kind and rate of change are startling. Making predictions about the likely outcomes of different possible management or policy options is extremely difficult. This uncertainty, coupled with incomplete baseline information about many systems, presents enormous challenges.

The future undoubtedly holds surprises. Decisions by society about land-use practices which affect the oceans and about uses of marine biota and habitats will be at their most powerful if they are informed by the best possible scientific understanding. In some cases, we have sufficient information to manage our activities more wisely, i.e., with significantly less impact - but though known, this information is often not used or communicated. In other cases, information urgently needs to be obtained by research and adaptive management.

New mechanisms are needed to disseminate scientific knowledge more efficiently and effectively and to utilize it more appropriately. Humans depend upon the life-support systems provided by the oceans. A sustainable biosphere requires a living ocean. It is time for a substantially different approach to thinking about and managing both the land-based and sea-based activities that currently threaten our oceans. The seas can no longer be a marginal issue.

Ocean Fast Facts:

*Oil spills account for only about five percent of the oil entering the oceans. The Coast Guard estimates that for United States waters sewage treatment plants discharge twice as much oil each year as tanker spills.

*Each year industrial, household cleaning, gardening, and automotive products pollute water. About 65,000 chemicals are used commercially in the United States today, with about 1,000 new ones added each year. Only about 300 have been extensively tested for toxicity.

*It is estimated that medical waste that washed up onto Long Island and New Jersey beaches in the summer of 1988 cost as much as $3 billion in lost revenue from tourism and recreation. *The most frequently found item in beach cleanups is pieces of plastic. The next four items are plastic foam, plastic utensils, pieces of glass and cigarette butts.

*One half of the U.S. population lives in the coastal zone.

*One in every six jobs is marine-related.

*One third of the U.S. Gross National Product is produced in the coastal zone.

How You Can Help

*LEARN all you can. Read, surf the web and experience the ocean directly.

*Be a SMART SHOPPER. Ask grocery stores and restaurants about the source of seafood.

*CONSERVE water. Be careful when washing your car or watering your lawn.

*REDUCE household pollutants. Cut down and properly dispose of herbicides, peticides and cleaning products.

*REDUCE waste. Dispose of trash properly. Where possible, recycle, re-use, compost.

*REDUCE automobile pollution. Use fuel efficient vehicles or carpol. Recycle moter oil and repair oil and air conditioning leaks.

*PROTECT ocean wildlife. Don't dispose of fishing lines, nets, or plastic items in or near the water.

*BE CONSIDERATE of sealife habitats. Don't bother sea birds, mammals, and turles or their nesting grounds. Support marine protected areas.

*GET INVOLVED. Take part in a beach cleanup or other ocean-related activities.

*CARE! PASS ON YOUR KNOWLEDGE!