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World’s Oceans in Trouble
Duke Marine Lab Represents a Critical Component of the Nicholas School’s Mission at a Time of Rapid Global Change

by William H. Schlesinger

On family vacations when I was growing up, I would stand with my father by the water’s edge on Cape Cod and marvel at the vastness of the ocean. One could hardly imagine that it could be polluted or that the bountiful daily catch of fish that was landed at Chatham could be diminished. Today, I know differently, and the sight I see is not pretty. Within the past year the Pew Oceans Commission and the U.S. Commission on Ocean Policy have both reported that the world’s oceans are in trouble. We are just waking up to the huge human impact on the 70 percent of the Earth’s surface that is covered by salt water.

   Many species of fish have levels of mercury that are considered unsafe for human consumption. The high concentrations in today’s fish are not natural. Studies of the mercury content in pelagic birds, taken from museum specimens and modern collections, show a consistent increase with time. Other human-derived pollutants, such as polycyclic chlorinated hydrocarbons, are found in the penguins of the Southern Ocean—far from any obvious local source of application.

  The direct catch of the most desirable fish, particularly large predatory species, has reduced many populations to 10 percent of their pre-exploitation levels, often removing the largest individuals that are the most important breeding stock. The area of trawling, which in many cases denudes the bottom sediments of the sea, is estimated to be 150 times the area of tropical deforestation each year. We are alarmed by deforestation, but when was the last time you heard anyone talk about trawling?

  Our perturbation of the oceans goes even to their physical properties, in which we now see an alarming “freshening” of the surface waters of the North Atlantic that threatens to slow or stop the northward flow of the Gulf Stream, with dramatic feedbacks to global climate. No, the script will not read like the popular movie The Day After Tomorrow, but the fact that a single species, Homo sapiens, can have this effect upon the seas should give us all a moment’s pause. The consistent northward flow of the Gulf Stream has mediated the climate of Europe and North America throughout the recorded history of human society. Do we dare disrupt it?

  The oceans do a great service to society by taking up a large portion of the carbon dioxide that we emit to the atmosphere from fossil fuel combustion. Recently, however, it is clear that this uptake of carbon dioxide causes increased acidity in ocean waters, threatening to dissolve coral reefs throughout the world.

  As a terrestrial species, we tend to overlook the human impact on the marine environment—it is difficult to see and expensive to study. Like the atmosphere, most of the oceans are an unregulated global commons, which are subject to exploitation without much oversight from the world community of nations. How are we to manage a sustainable population of the bluefin tuna when it spends but a few months in the U.S. territorial waters and the remainder of its time migrating to the Mediterranean Sea? Who will watch pelagic long-line fishermen to ensure that their bycatch of endangered sea turtles is minimized?

  The Duke Marine Lab and our faculty who study marine science and policy form an essential component of the Nicholas School. Its graduates populate the halls of all the important regulatory agencies of our government. International outreach in its Global Fellows Program, supported with generous grants from a variety of foundations, allows foreign students to attend an intensive summer program in Beaufort and to disseminate knowledge in their home countries. More than 60 fellows from 36 countries have attended since 1998.

  Over the years I have come to notice that no undergraduate who has attended the Marine Lab for a semester reports anything less than “it was the best experience I had at Duke.” With year-round programs for undergraduate, masters professional and doctoral students, the Lab focuses its attention on marine conservation biology and biological oceanography—of both coastal and bluewater habitats. Research in the Nicholas School has improved the design of fishing nets to minimize unintended catch, elucidated the processes of shoreline erosion and beach management, and offered new ways to reduce marine fouling without contaminating coastal waters.

   In addition to its faculty, any marine lab must have boats, flowing seawater, marine technicians, and a host of specialized equipment to study its large, unique environment. This is expensive to maintain, and periodically some colleagues question the wisdom of this investment. In return, I argue that the Marine Lab is a critical and unique component of the Nicholas School and its mission to understand and address the most pressing environmental problems of the world. To forsake the marine environment in a time of rapid global change would leave a huge fraction of the Earth’s biosphere at the mercy of human ignorance and without a plan for sustainable management.

Schlesinger is dean of the Nicholas School and James B. Duke Professor of Biogeochemistry