Achim Steiner is U.N. Under-Secretary General and Executive Director, U.N. Environment Program (UNEP). Here he expresses his opinion on environmental protection of the oceans.
(CNN) -- The epic voyage of Plastiki is bringing into sharp focus the inordinate environmental and economic impact that humanity is having on the oceans and seas.
While the focus is solid waste, and especially plastic marine litter, the expedition also underlines the myriad of other, sometimes invisible, factors that are accelerating the degradation and decline of fisheries to coastal ecosystems, such as mangroves and sea grasses.
Unless urgent action is taken, commercial fish stocks may have disappeared in a matter of decades, along with the livelihoods of millions of often poor people, who depend on fish for food and jobs. And unless urgent steps are taken, ecological infrastructure such as mangroves may soon be lost and with them natural coastal defenses, water purification systems and fish nurseries.
Instead of mining the world's marine environment and running it down as a result of pollution and mismanagement, humanity needs to re-commit and re-engage on the challenge of healthy seas and oceans.
How can this be achieved?
First, sound science is absolutely central: it provides governments with the reality of how the marine environment is faring and the kinds of choices that need to be made. Science can also be empowering: it can validate positive actions that are catalyzing improvements that can stage a recovery of one of the world's most important natural and economically-significant assets.
State of the Marine Environment-Positive and Negative Trends UNEP, through its Global Program of Action for the Protection of the Marine Environment from Land-Based Sources (GPA), spotlights how some persistent problems are indeed improving.
Its latest "State of the Marine Environment" report found that oil and oily wastes being discharged or spilled have been reduced by 40 percent since the mid 1980s. Oil spills linked with tankers accidents are also down by 75 percent; from tanker operations they have fallen by 95 per cent and oil from city and industrial discharges has dropped by 90 per cent.
Improvements have also occurred in terms of radioactive substances, in large part linked with the prohibition in the early 1990s of the dumping of low-level radioactive wastes at sea under the London Convention.
In terms of so called persistent organic pollutants long lived and toxic chemicals used, or once used, in industries such as power generation transformers to agriculture the picture is mixed. For example in the Baltic Sea there has been a 50 percent reduction in pollution loads, especially of the notorious pesticide DDT and other pesticides are generally falling too in of eastern and western South America. Levels of several key persistent organic pollutants are also dropping in the North East Atlantic.
All in all, the decision by many countries to ban many of these chemicals has borne positive fruit.
However, more action is needed is places like the Caspian Sea; South East Asia and the Pacific; East Asia and the Indian Ocean where pesticides are either heavily used or produced.
There is also emerging concern that, as a result of climate change, the problem without national and international action, may intensify rather than recede. There is evidence that toxic chemicals like DDT and their break-down products -- stored in glaciers and at the poles -- may be being discharged back into rivers and seas, as the ice melts.
Heavy Metals to Waste Water: Big and Emerging Challenges
These are some of the high points, cases where concerted national and international action is making a difference. But other sobering facts abound. Heavy metals, including the neuro-toxin mercury, remain a challenge, not least because they can travel around the world in the seas and the jet stream.
In the Arctic, there are areas where concentrations of mercury in beluga whales and ringed seals are between two and four times higher than 25 years ago.
These are marine animals upon which many indigenous peoples rely on for food. In the seas of East Asia, rising amounts of electronic waste disposed of on land -- which can contain up to 1,000 different materials including heavy metals -- is an increasing problem as it leaks from landfills into rivers and the sea. As many as nine million batteries are dumped annually in this region alone.
In respect to mercury, measures are being drawn up to reduce the threat. Governments have now agreed to establish an international treaty to tackle mercury and negotiations are underway.
But a great deal more needs to be done by governments and by industry in respect to other heavy metals, including federating take-back schemes for end-of-life products such as mobile phones and the rapid establishment of more re-use and recycling especially in developing economies.
Many of these metals have economic value which should be captured in smart market mechanisms that favor recovery rather than dumping.
Meanwhile, the levels of soils and sediments swilling down rivers into coastal waters is in many areas further cause for concern and linked with deforestation and changes in land use due to agriculture and urbanization.
In South Asia, an estimated 1.6 billion tones of sediment is now entering the Indian Ocean and in the seas of East Asia, the levels of silt draining into river basins are three to eight times the global average. In the Wider Caribbean, sediment loads are estimated to be one gigaton or 12 percent of the global level with loss of forests the main trigger.
Excessive sediments can choke coral reefs and smother other coastal ecosystems such as seagrasses. Dam building, for example, can have the diametrically opposite effect.
The building of the Aswan Dam in Egypt has led to close to 100 percent of the soils and sediments that once ran down the Nile being trapped. Erosion has thus occurred at the mouth of the river which is being linked in part with a decline in the sardine catch of 95 percent.
Perhaps the most serious challenge is the level of wastewater, and especially raw sewage, which is being discharged into coastal waters. To mark World Water Day in March this year, UNEP and partners launched the report "Sick Water?"
It estimated that around 2 million tons of wastes are passed into sewage systems every day: this may be producing well over two billion tons of polluted water daily, 365 days a year, right into our freshwaters and oceans.
The consequences are profound.
Waste water, a cocktail of human and animal wastes; agricultural fertilizers and other chemicals, is in part linked to a rise in deoxygenated, dead zones. These zones, which can be permanent, persistent or temporary, form when high levels of nutrients like nitrogen and phosphorous trigger algal blooms, which in turn such oxygen out of seawater. The result is areas where little if any life can survive.
The number of dead zones in coastal waters has doubled every decade since 1960 with the problem mainly in developed economies but spreading to the developing world as economies there grow.
Fisheries: A Major Unresolved Challenge
Finally, over-fishing: Lord Stern, the British economist, has called climate change the biggest market failure of all time.
Well, fisheries must run a close second.
According to UNEP's Global Environment Outlook-4, three-quarters of marine fisheries are exploited up to, or beyond, their maximum capacity.
Today's industrial-scale fleets, deploying giant nets, are going further and farther in pursuit of fish stocks yet often finding less and less to catch. The struggle to better manage fish stocks to match science with sensible quotas; to deploy more sustainable fishing technology to reduce bycatch and leave young fish to grow -- was brought into sharp relief at the meeting of the Convention on the International Trade in Endangered Species (CITES) in Doha, Qatar earlier in the year.
Despite sound scientific evidence that stocks of the western Atlantic Blue Fin tuna are in serious trouble -- down to 80 percent of their former size -- governments failed to agree on tough conservation and trade measures.
This fish stock like so many, could now be heading for collapse and the consequences could be irreversible.
When the explorer Cabot arrived off Canada's Newfoundland some 300 years ago, stocks of cod were so plentiful they slowed down his sailing ships, and crews could catch fish simply by lowering buckets overboard. Not any more. By 1992, overfishing had forced the closure of this once highly productive fishery, and despite all efforts the Grand Banks fishing grounds have never recovered.
Over fishing of sharks in the Caribbean has triggered a rise in octopus and a drastic drop in spiny lobster and scallops -- two major sources of revenue for neighboring coastal communities.
Turning the tide and making a more intelligent economic case
How should the world respond to this reckless tide of pollution, habitat destruction and overexploitation?
Firstly, governments need to look at science as an ally rather than as a provocation. Industry should view science-based recommendations and conservation-led measures not as a restriction but as an opportunity to re-tune their operations, boost competitive practices and a path towards guaranteeing profitability over short term gains.
Bringing the latest economics into the political and business equations could be key. One contribution to 2010, the International Year of Biodiversity, is The Economics of Ecosystems and Biodiversity (TEEB).
The initiative, hosted by UNEP and funded by among others the European Commission, Norway, Germany and the United Kingdom, will publish its landmark report just before the meeting of the Convention on Biological Diversity in October.
However, some key facts and figures are already emerging which if taken up by governments could shift the balance away from damage and destruction and in favor of more intelligent management.
Take shrimp farms for example. TEEB cites one study from Thailand. Subsidized shrimp farms can generate returns of around $1,220 per hectare by clearing coastal mangrove forests. But this does not take into account the losses to local communities totaling over $12,000 a hectare linked with losses due to reduced availability of wood and non-wood forest products; fisheries and coastal protection services.
Nor does the profit to the commercial operators take into account the costs of rehabilitating the exhausted and abandoned sites after five years of exploitation -- estimated at over $9,000 a hectare.
Coral reefs, increasingly under threat from coastal developments, pollution, destructive activities such as cyanide and dynamite fishing and now climate change, are generating close to $190,000 per hectare in terms of coastal defenses and other areas of "natural hazard management".
In terms of diving and other tourism revenues, the annual services generated by coral reefs equate to perhaps $1 million a year. Genetic materials -- for example, pharmaceuticals -- up to $57,000 per hectare and fisheries just under $4,000 per hectare per year. Many fishing folk fear that establishing a comprehensive network of Marine Protected Area or marine parks could damage their livelihoods.
TEEB makes a different economic case. Its experts argue that such areas, involving a 20 percent closure of global fishing grounds, would result in losses to the industry of an estimated $270 million annually. However, it argues that such a network could sustain fisheries worth $80 to $100 billion a year; assist in conserving an estimated 27 million related jobs, while generating one million new ones while protecting the food supply of one billion people.
New kinds of international markets and funding mechanisms also need exploring. A recent study -- Blue Carbon-- by UNEP; the UN Educational, Scientific and Cultural Organization; the UN's Food and Agricultural Organization and IUCN, estimates that mangroves, seagrasses and salt marshes could be absorbing up to half the world's transport emissions.
Governments are moving to pay countries to maintain tropical forests, precisely because of the links between deforestation and climate change. Why not marine ecosystems too?
In terms of wastewater, it is estimated that if all the nutrients could be re-used and recycled, it could supply all the fertilizer farmers need, and perhaps at a fraction of the cost, while generating new businesses and jobs in recycling and re-use. Similar arguments could be made for all the wastes -- including plastics -- that end up in the seas and oceans, if smart policies and creative market mechanisms can be deployed to tip the balance in favor of waste as a resource rather than as a problem.
Healthy, well managed oceans are going to be key to whether six billion people rising to over nine billion, will be able to survive let alone thrive over the coming decades especially in a climate-constrained world.
If society can begin turning the tide in 2010, then Plastiki will have assisted in not only raising awareness about marine litter as it sails from San Francisco to Sydney. But the ship, David de Rothschild and his courageous crew will have helped charter a fundamental and decisive new course: one that sees the seas and oceans as an extraordinary resource which we damage and degrade at our peril.
Human beings evolved from the oceans, it is high time we evolved a different attitude to the place from where we came. Getting rid of rubbish and pollution by pouring it into the sea may line the pockets of some, but it will ultimately impoverish the many.