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Marine conservation

# Sink or swim

Can an ambitious plan to protect unique marine habitats in the open ocean turn the tide of destruction? Henry Nicholls plunges in.

Peering through the thick glass windows of their submersible, the ocean scientists were greeted by a sight no one on Earth had ever seen before. In front of them, smoking towers of deep-sea hydrothermal vents teemed improbably with creatures, including giant tube worms and yellow mussels. As the crew of the research vessel Alvin stared in wonder, it probably didn't occur to them that this newly discovered biodiversity at the bottom of the ocean might one day need to be protected from people. But that was 1977, and it is now time for a reassessment.

Conservation biologists generally agree that unique habitats in the open sea such as hydrothermal vents, seamounts and cold-water reefs require urgent protection. Fishing, pollution and commercial traffic in international waters — known in treaties as the ‘high seas’ — have increased to such an extent that ecosystems once deemed out of human reach are feeling the effects.

Two years ago, delegates at the World Summit on Sustainable Development in Johannesburg, South Africa, agreed to establish by 2012 a network of marine reserves representing all major habitats, both within and beyond national jurisdiction. In February, this target was incorporated into the Convention on Biological Diversity, which has so far been ratified by 188 countries. Conservation biologists are pushing for the first marine parks to be in place by 2008.

But a number of obstacles stand in the way. Uncertainty about which habitats to protect, opposition from the fishing industry, legal loopholes and the challenges of enforcing marine reserves far from land are making the targets hard to meet. Nor has there been any agreement on how, or by whom, the reserves would be run. Such hurdles are likely to dominate discussions of ocean protection at the World Conservation Congress in Bangkok, Thailand, over 17–25 November.

Much of the biodiversity in the high seas has come to light only in the past three decades. As well as hydrothermal vents, there are deep-ocean trenches, crevices that plunge to more than 10 kilometres below sea level and play host to deep-sea molluscs and scavenging crabs. Dotting the ocean floor are thousands of seamounts, extinct submarine volcanoes, each of which harbours a unique ecosystem. And some of the most abundant life in the ocean is found on cold-water reefs, delicate coral systems that grow in chilly, nutrient-rich waters.

In a bind: fishing nets can be lethal to marine mammals like this sperm whale. Credit: A. ROMERO/V&W/IMAGEQUESTMARINE.COM

Despite decades of exploration, the species count continues to grow — each marine survey nets a menagerie of new life forms. One, conducted earlier this year by the Norwegian-led MAR-ECO expedition along the deep-sea ridges in the mid-Atlantic, turned up a new species of anglerfish and a new squid with an unusually small head and tiny eyes.

Even the open ocean — once assumed to be the marine equivalent of a desert, visited only by migrating animals such as tuna, turtles and whales — harbours a wealth of microscopic biodiversity. Last year, a single cupful of the Sargasso Sea near Bermuda was found to contain at least 1,800 new microbial species bearing more than one million previously unknown genes1.

The biodiversity of the high seas is indeterminate but it's immense

“The biodiversity of the high seas is indeterminate, but it's immense,” says Graeme Kelleher, who heads the high-seas task force for the World Commission on Protected Areas, the body that is coordinating protection efforts for the high-seas. Kelleher reckons that there are enough new discoveries each year to increase the estimate of biodiversity in the sea nearly tenfold. “It's not only the last great ecological frontier, but also probably the world's richest biodiversity frontier,” he says.

But the high-seas habitats that are home to these organisms are being damaged. One of the main culprits is deep-sea bottom trawling, a widespread fishing practice that involves dragging weighted nets across the tops of seamounts, some 500 to 2,000 metres below the surface. This reduces cold-water coral reefs to rubble and decimates populations on seamounts.

In the zone

So far, marine protection has largely been limited to habitats near the coast. There are about 4,000 marine reserves within the 370-kilometre Exclusive Economic Zones (EEZs) of coastal nations, where activities such as shipping, fishing and recreational boating are restricted. In such reserves, a given country's jurisdiction provides a legal framework for protection and enforcement. Yet taken together, these reserves account for less than 0.5% of the ocean's surface. To date, there is still not a single protected area in the high seas.

Part of the difficulty is that these international waters are traditionally as open and free as the Wild West once was. That principle was made explicit in 1958 in the Convention on the High Seas, which preserved the right of all nations to exploit high-seas resources. This was superseded in 1982 by the UN Convention on the Law of the Sea, which established the conservation of marine resources as a duty of nations in principle. But without specific protection schemes, such as catch limitation, the agreement has done little to curb the intensive use of the ocean.

Although the Johannesburg meeting and the Convention on Biological Diversity set 2012 as the target date for establishing high-seas marine parks, neither specified the number of areas or the expanse of ocean they should cover. Instead, the agreements called for reserves that are “representative” of all major marine habitats. This has left governments and conservation groups arguing over what the 2012 target actually means and what steps are needed to meet it.

Some guidance came from the World Parks Congress, which met last year in Durban, South Africa. There, conservation biologists agreed that at least five high-seas marine parks must be in place by 2008 if the 2012 target is to be met. Several possible sites (see graphic) have been identified that could be protected by extending existing marine laws, says Kristina Gjerde, high-seas policy adviser to the World Conservation Union's marine programme.

Park life: marine conservationists say protection is needed for sites such as these, which exemplify a range of habitats and deep-sea organisms. Credit: F. GRANER/NATUREPL;D. SHALE; B. MURTON/SOC/SPL; P. BATSON/IMAGEQUESTMARINE; CSIRO; J. FREUND/NATUREPL; M. YOUNGBLUTH

The legal backbone could come, for example, from the United Nations Fish Stocks Agreement, which came into force in 2001 and aims to reduce the exploitation of ‘straddling’ fish — those that cross between the high seas and EEZs — and highly migratory species such as tuna. But this is only a partial solution, as several key fishing states have yet to ratify the agreement. Furthermore, it does not contain provisions for protecting local concentrations of biodiversity that are neither straddling nor migratory, such as those living on seamounts. And in any case, fishing vessels can dodge such laws simply by registering in a country that has not signed up to them.

The right angle

Efforts to close these legal loopholes are under way, but diplomatic hurdles remain. At an informal meeting to discuss ocean issues in June, a proposal for the UN General Assembly to consider the legal framework necessary for marine parks to become a reality was thwarted by opposition from several countries, including big fishing nations such as Japan, South Korea and Iceland, says Gjerde. But if the World Conservation Union throws its weight behind the proposals for high-seas protection at the forthcoming Bangkok meeting, the chances are that the General Assembly will address the issue this year or next, she says.

Seeking a stopgap until marine parks can be established, an umbrella group of conservation organizations called the Deep Sea Conservation Coalition is pressuring the UN to declare a moratorium on bottom trawling. On 7 October, Costa Rica formally proposed incorporating such a moratorium into the fisheries and oceans resolutions that the General Assembly passes each year. A decision is expected on 16 November.

Deeply damaged: fishing vessels out to catch deep-sea fish such as pollack can cause serious damage to seamounts with their trawls (above). Credit: N. FORBES/CORBIS

The fishing industry is expected to fight such measures. It argues that current practices are sustainable, and that further restrictions would only harm the economies of countries that depend heavily on fishing.

Yet two-thirds of fisheries are already being fished to the fullest sustainable extent or beyond, according to UN data. And conservationists argue that fisheries actually benefit from restrictions in the long run, because marine reserves improve fish stocks both within and beyond protected areas.

Off St Lucia in the Caribbean, for instance, catches of reef fish near protected areas almost doubled within five years, says Callum Roberts, a marine conservationist at the University of York, UK2. Clam fisheries in Fiji are also improving because of nearby protected areas3. “Fijian villagers now report seeing clams that are larger than they've seen for three generations,” Roberts says. Industrial fisheries may also benefit. For example, in 1994 a quarter of the Georges Bank near the New England coast was put off-limits to scallop dredging and trawling. Compared with the fished area, the protected area now contains about ten times as many full-sized scallops4.

Such benefits suggest that the costs of creating marine reserves could be offset in the long term by reducing subsidies to fishing fleets as catch numbers rise. A survey of reserves by Roberts and his colleagues suggests that a network protecting 20–30% of the ocean would cost between US$5 billion and US$19 billion to run5. Today, subsidies to the fishing industry range between $15 billion and$30 billion, Roberts estimates.

But even if a legal framework can be put in place by 2012, the fisheries brought on board and funding found, there is still the problem of how to police protected areas on the high seas.

Great scheme

Technology may provide part of the answer. On Australia's Great Barrier Reef — widely recognized as a model marine protected area — all boats must be equipped with satellite navigation systems and transmitters. These devices tell skippers which of six different zones they are sailing through and hence what activities are permitted. They simultaneously transmit to park authorities the precise location of the vessel.

The system has performed well, even under duress, says Kelleher. At the beginning of July, the ‘no-take zone’ — where all fishing is prohibited — expanded from less than 5% to a third of the protected area with no significant problems. But there is little doubt that such a system would be much harder to operate on the high seas, not least because a larger area much farther from shore would have to be patrolled to spot any vessels that were not fitted with transmitters.

With so many complicating factors, few are willing to make a firm prediction on whether the 2012 target can be met. Daniel Pauly, a leading fisheries biologist and director of the Fisheries Centre at the University of British Columbia in Vancouver, Canada, says that the biggest factor is likely to be how much pressure conservation groups can exert on the UN and on individual nations. “It will depend on political will,” he says.

## References

1. Venter, J. C. et al. Science 304, 66–74 (2004).

2. Roberts, C. M., Bohnsack, J. A., Gell, F., Hawkins, J. P. & Goodridge, R. Science 294, 1920–1923 (2001).

3. Gell, F. R. & Roberts, C. M. Trends Ecol. Evol. 18, 448–455 (2003).

4. Murawski, S. A. et al. Bull. Mar. Sci. 66, 775–798 (2000).

5. Balmford, A., Gravestock, P., Hockley, N., McClean, C. J. & Roberts, C. M. Proc. Natl Acad. Sci. USA 101, 9694–9697 (2004).

## Author information

### Author notes

1. #### Henry Nicholls is a freelance writer based in London.

• Henry Nicholls
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Nicholls, H. Sink or swim. Nature 432, 12–14 (2004). https://doi.org/10.1038/432012a

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• DOI: https://doi.org/10.1038/432012a

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