Marine reserves can help restore world fisheries

Posted: 14 November 2008

Speaking at the launch of the 2008 World Resources Report earlier this week, WRI President Jonathan Lash warned that the loss of coastal ecosystem services combined with rising seas due to climate change mean that the 500 million people who depend on the sea for their livelihoods and as the main source of protein in their diets, are increasingly at risk.

"The climate is changing at a much accelerated pace, faster than previous models suggested," said Lash. "And at the same time the state of ocean and coastal ecosystems is undermining their capacity to produce necessary services. There are now 500 coastal areas around the world suffering from hypoxia, a lack of oxygen , due to the influx of huge quantities of wastes from land-based activities."

In this report, Lester Brown, President of the Earth Policy Institute, sets out the case for a global system of marine reserves which could go far to restore and preserve the world's disappearing fish stocks.

Rising populations and increasing affluence in the developing world driving the demand for fish. (Photo by I. de Borhegyi courtesy UN Food and Agriculture Organization)
Rising populations and increasing affluence in the developing world driving the demand for fish. (Photo by I. de Borhegyi courtesy UN Food and Agriculture Organization)
Rising populations and increasing affluence in the developing world driving the demand for fish. (Photo by I. de Borhegyi courtesy UN Food and Agriculture Organization)
After World War II, accelerating population growth and steadily rising incomes drove the demand for seafood upward at a record pace. At the same time, advances in fishing technologies, including huge refrigerated processing ships that enabled trawlers to exploit distant oceans, enabled fishers to respond to the growing world demand.

In response, the oceanic fish catch climbed from 19 million tons in 1950 to its historic high of 93 million tons in 1997. This fivefold growth -more than double that of population - raised the wild seafood supply per person worldwide from 7 kilograms (15.4 pounds) in 1950 to a peak of 17 kilograms in 1988. Since then, it has fallen to 14 kilograms.

As population grows and as modern food marketing systems give more people access to these products, seafood consumption is growing. Indeed, the human appetite for seafood is outgrowing the sustainable yield of oceanic fisheries. Today 75 per cent of fisheries are being fished at or beyond their sustainable capacity. As a result, many are in decline and some have collapsed.

While oceanic fisheries face numerous threats, it is overfishing that directly threatens their survival. Oceanic harvests expanded as new technologies evolved, ranging from sonar for tracking schools of fish to vast driftnets that are collectively long enough to circle the earth many times over. Indeed, a 2003 landmark study published in Nature concluded that 90 per cent of the large fish in the oceans had disappeared over the last 50 years, as a result of this expansion.

Collapsing fisheries

Fisheries are collapsing throughout the world. The 500-year-old cod fishery of Canada failed in the early 1990s, putting some 40,000 fishers and fish processors out of work. Fisheries off the coast of New England soon followed. And in Europe, cod fisheries are in decline, approaching a free fall. Like the Canadian cod fishery, the European ones may have been depleted to the point of no return. Countries that fail to meet nature's deadlines for halting overfishing face fishery decline and collapse.

Frozen Tunas
Frozen Tunas
Frozen Tunas to be auctioned at the Tsukiji fish market, Tokyo. Photo © WWF-Canon/Michel GUNTHER
Atlantic stocks of the heavily fished bluefin tuna - a large specimen of which, headed for Tokyo's sushi restaurants, can bring in $100,000 - have been cut by a staggering 94 per cent. It will take years for such long-lived species to recover, even if fishing were to stop altogether.

The US Chesapeake Bay, which yielded more than 35 million pounds of oysters per year a half-century ago, now produces scarcely 1 million pounds per year. A deadly combination of overharvesting, pollutants, oyster disease, and siltation from soil erosion is responsible.

Even among countries accustomed to working together, such as those in the European Union (EU), the challenge of negotiating catch limits at sustainable levels can be difficult. In April 1997, after prolonged negotiations, agreement was reached in Brussels to reduce the fishing capacity of EU fleets by up to 30 per cent for endangered species and overfished stocks. The EU had finally reached agreement on reducing the catch but these and subsequent cuts have not been sufficient to arrest the decline of the region's fisheries.

African coasts

When some fisheries collapse, it puts more pressure on those that remain. Local shortages quickly become global shortages. With restrictions on the catch in overfished EU waters, the heavily subsidized EU fishing fleet has turned to the west coast of Africa, buying licenses to fish off the coasts of Cape Verde, Guinea-Bissau, Mauritania, Morocco, and Senegal.

They are competing there with fleets from China, Japan, Russia, South Korea, and Taiwan. For impoverished countries like Mauritania and Guinea-Bissau, income from fishing licenses can account for up to half of government revenue. Unfortunately for the Africans, their fisheries too are collapsing.

Diseased star coral
Diseased star coral
A colony of mountainous star coral (Montastrea faveolata) with black band disease. This colony is about 300 years old and lost about one-third of its tissue in a few weeks. The ruler is 154 cm (six inches). Photo © Andy Bruckner/NOAA Fisheries
Overfishing is not the only threat to the world's seafood supply. Some 90 per cent of fish residing in the ocean rely on coastal wetlands, mangrove swamps, or rivers as spawning areas. Well over half of the mangrove forests in tropical and subtropical countries have been lost. The disappearance of coastal wetlands in industrial countries is even greater. In Italy, whose coastal wetlands are the nurseries for many Mediterranean fisheries, the loss is a whopping 95 per cent.

Damage to coral reefs from higher ocean temperatures and ocean acidification caused by higher atmospheric carbon dioxide levels, as well as damage from pollution and sedimentation, are threatening these breeding grounds for fish in tropical and subtropical waters. Between 2000 and 2004, the worldwide share of destroyed reefs, those that had lost 90 per cent of live corals, expanded from 11 per cent to 20 per cent. Some 24 per cent of the remaining reefs are at risk of imminent collapse, with another 26 per cent facing significant loss in the next few decades, due to mounting human pressures. As the reefs deteriorate, so do the fisheries that depend on them.

Dead zones

Pollution is taking a devastating toll, illustrated by the dead zones created by nutrient runoff from fertilizer and from sewage discharge. In the United States, the Mississippi River carries nutrients from the Corn Belt and sewage from cities along its route into the Gulf of Mexico. The nutrient surge creates huge algal blooms that then die and decompose, consuming the free oxygen in the water, leading to the death of fish. This creates a dead zone each summer in the Gulf that can reach the size of New Jersey. Worldwide, there are now more than 200 dead zones in oceans and seas, "deserts" where there are no fishing trawlers because there are no fish.

For decades governments have tried to save specific fisheries by restricting the catch of individual species. Sometimes this worked; sometimes it failed and fisheries collapsed. In recent years, support for another approach - the creation of marine reserves or marine parks - has been gaining momentum. These reserves, where fishing is restricted, serve as natural hatcheries, helping to repopulate the surrounding area.

Red tides are an increasing threat to Pacific coastlines. Photo: Canadian Ministry for Fisheries and Oceans
Red tides are an increasing threat to Pacific coastlines. Photo: Canadian Ministry for Fisheries and Oceans
Red tides are an increasing threat to Pacific coastlines.© Canadian Ministry for Fisheries and Oceans
In 2002, at the World Summit on Sustainable Development in Johannesburg, coastal nations pledged to create national networks of marine parks, which together could constitute a global network of such parks. At the World Parks Congress in Durban in 2003, delegates recommended protecting 20-30 per cent of each marine habitat from fishing. This would be up from 0.6 per cent of the oceans that are currently included in marine reserves of widely varying size.

A UK team of scientists led by Dr. Andrew Balmford of Cambridge University's Conservation Science Group analyzed the costs of operating marine reserves on a large scale, and concluded that managing reserves that covered 30 per cent of the world's oceans would cost $12-14 billion a year. At stake in the creation of a global network of marine reserves is the protection and possible increase of an annual oceanic fish catch worth $70-80 billion, as well as the creation of 1 million new jobs.

Other measures

A 2001 statement signed by 161 leading marine scientists called for urgent action to create the global network of marine reserves. The signatories noted how quickly sea life improves once the reserves are established. Within a year or two of establishing a marine reserve, population densities increased 91 per cent, average fish size went up 31 per cent, and species diversity rose 20 per cent.

While the creation of marine reserves is clearly the overriding priority in the long-standing effort to protect marine ecosystems, other measures are also required. One is to reduce the nutrient flows from fertilizer runoff and untreated sewage that create the world's 200 or so dead zones.

In the end, governments need to eliminate fishery subsidies. There are now so many fishing trawlers that their catch potential is nearly double any yield the oceans can sustain. Restoring fisheries by spending $12-14 billion on managing a network of marine reserves is far less than the $22 billion in harmful subsidies that governments dole out today to fishers to empty our oceans.

To see a summary of the 2008 World Resources Report click here

Lester Brown's article is adapted from Chapter 5, "Natural Systems Under Stress," and Chapter 8, "Restoring the Earth," in Lester R. Brown, Plan B 3.0: Mobilizing to Save Civilization (New York: W.W. Norton & Company, 2008), available for free downloading and purchase at www.earthpolicy.org