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Earth's life support
by Sylvia Earle, Ph.D.
CI Executive Director for Global Marine Conservation;
National Geographic Society Explorer in Residence

It is impossible to overstate the importance of the ocean. Without it, Earth would be barren--a lifeless planet much like Mars. The ocean, alive with complex ecosystems and fine-tuned over billions of years, is the cornerstone of Earth's life support system. More than 97 percent of the world's water is ocean. It drives climate and weather, shapes planetary chemistry, generates more than 70 percent of the oxygen in the atmosphere, absorbs carbon dioxide and replenishes our fresh water through clouds. As important as terrestrial systems are to life on Earth, if they were to disappear entirely, life in the sea could continue to prosper. However, if life in the ocean disappeared, or its basic chemical processes altered, the impact on the rest of the planet would be catastrophic.

While many take the Earth's life support functions for granted, we now understand that our past, present and future are directly linked to the state of the ocean. The sea is not infinitely resilient, but rather is vulnerable to what we put in and what we take out. What we do and, just as important, what we do not do in the next half century will have a major impact on the future of life in the ocean and the future of humankind.

A history of exploitation

For thousands of generations, people relied largely on wild animals and plants for sustenance. Over time, cultivation of a handful of selected species and modification of natural systems to favor certain others made possible unprecedented expansion of the human population, from a few million 10,000 years ago to more than 6 billion today. Long ago, humans moved beyond reliance on wild birds, mammals and other wildlife to satisfy the nutrition needs of a growing population. Yet the notion persists that the ocean can sustain yields close to 100 million tons of wildlife for human consumption.

The term "bushmeat" is applied to the wild animals hunted for food on land. By contrast, marine creatures caught in the wild are thought of more as commodities than wildlife. For the past half-century, humans have been exploiting these creatures at an unprecedented speed and volume. This has been made possible by new acoustic, satellite, aerial and materials technologies that have helped fishermen more effectively find, track and extract marine life. At the same time, demand has increased for seafood, fish oils and processed fish protein. Such increased demand has stripped the ocean of immense quantities of organisms. These have been taken indiscriminately by fine-meshed nets, millions of traps, miles of long lines baited with hooks every few feet, and dredges and trawls that scrape the sea floor. For highly complex and vulnerable environments, this has the same impact as leveling a rain forest with a bulldozer to capture the resident birds and frogs.

The impact of such technology over time has been staggering. The bluefin tuna is already 97 percent depleted in the North Atlantic yet commercial fishing continues. Cod has long been of vital economic interest to several Atlantic nations, but total catches throughout the North Atlantic today are 70 percent lower than levels seen through the 1960s and 70s. Overfishing of cod in the western Atlantic Ocean recently led to the closure of the George's Bank fishery off New England.

Having depleted much of the shallow water species, fishing trawls are going much deeper, targeting fish such as orange roughy, monk fish and Chilean sea bass. Many of these deep sea fish grow slowly and are typically long-lived. Orange roughy take more than two decades to mature and may be more than a century old when brought to market.

Not only targeted species but millions of tons of "bycatch" and the habitats themselves are destroyed by current fishing techniques. In 1998, the IUCN-World Conservation Union listed 100 marine species as threatened or endangered.

Our land-based activities are only making things worse. Over the decades, we have released billions of tons of noxious materials into the sea, significantly impacting the way the ocean works. More than 50 "dead zones" blight our coastal areas. Gigantic swaths of toxic algae are fueled by high levels of nitrates and phosphates in runoff from over-fertilized fields, farms and lawns. Coral reefs have declined about 30 percent in 30 years, largely because of overfishing, downstream effects of agriculture and deforestation, coastal development and global warming.

Recent protective measures have been able to save some marine mammals, like the great whales. However, they came too late to save others, such as the Stellar's sea cow and the Caribbean monk seal. Some, including the North Atlantic right whale and gray whale in the western Pacific, are barely hanging on. Fisheries management regulations have expanded significantly since the 1950s. However, political pressure to continually increase quotas, despite scientific evidence urging restraint, has negated the effectiveness of these regulations. There has been a movement to create sanctuaries, parks or preserves in the world's oceans since the mid-1970s, and a few even encompass thousands of square miles. However, only in a small percentage of these areas does wildlife receive the same protection as in terrestrial parks.

Much of the problem stems from the perception that sea creatures have little value to humankind except for those that are taken for food or products such as fertilizer. And there is a widely held view that, except for mammals (whales, dolphins, seals, dugongs, otters), marine organisms can better tolerate high levels of predation by humans than terrestrial wildlife. However, the facts don't bear this out. Swift declines in the past 50 years of once abundant and commercially exploited species provide compelling evidence that ocean life is as vulnerable to high levels of killing as land animals.

The time for action is now

We still have a chance to turn things around for the ocean. The whales, turtles and sharks are not all gone yet. Marine life can make a significant comeback if we initiate effective recovery programs and give species time to replenish. The DOE conference, held in Los Cabos, Mexico, was a critically important first step in this regard. For the first time, the world's largest environmental organizations--working with scientists, economists, the business community and international governments--met specifically to develop a comprehensive and achievable action agenda to reverse the decline in health of the world's ocean. The agenda includes several preliminary recommendations:

  • Promote a World Ocean Public Trust: Sixty percent of the world's ocean falls in international waters. These waters, largely open to uncontrolled exploitation, must be proactively managed. This marks a major reversal in thinking in ocean policy, since the ocean has always been free for anyone to exploit.

  • Expand the Global System of Marine Parks: Less than one percent of the world's ocean currently enjoys full protection. Seamounts, or mountains that rise from the ocean floor, are areas that offer refuge for a high percentage of marine life. Areas such as these are of particular concern, since many are located in unregulated international waters.

  • Accelerate Global Fisheries Reform: Poorly managed fisheries threaten marine biodiversity and ecosystems all over the world. Investments are needed to improve management, strengthen enforcement and end fisheries policies that create a "race for fish."

  • Assess Global Priorities: The conservation status of countless marine species and the health of many marine systems is unknown. A massive effort is required to more accurately assess conservation priorities in the ocean, particularly those marine species most vulnerable to extinction.

  • Create an Ocean Ethic: An urgent global communication and education campaign is needed to shatter myths about the ocean's limitless ability to withstand human neglect and abuse.

    To help turn these recommendations into reality, a donor has provided a $5 million, 5-year grant. The grant, which requires $4 million in matching funds, will allow CI and its partners to mobilize additional support and help with critical planning efforts. These are key first steps in a lengthy and challenging endeavor that seeks to do no less than save the natural systems that sustain us.

    Related Articles:
  • Conservation coalition charts course for healthy ocean
  • Gulf of California: A study in marine conservation challenge and reward
  • Q&A: Interview with CI fisheries expert, Jim Cannon
  • Ten species on the brink of extinction


© Courtesy of National Geographic Society
Sylvia A. Earle

© Roger Steene
Nudibranch in Milne Bay, Papua New Guinea.

© CI, Ernesto Bolado
Fishermen fix bottom-trawl gear in San Felipe harbor in Mexico's Gulf of California.

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