Toilets: Then and Now, Part 11; Excessive Human Wastes in Coastal Waters, Page 4 of 4

(an excess of nutrients flowing from the land to the sea has created serious environmental problems)

In the 1990s marine eutrophication remains a problem of many wealthy nations

  • Countries; such as, the U.S. spend billions on fertilizer, automobiles, power plants and sewer systems, all of which feed nitrogen into the oceans.
  • In fact, the amount of nitrogen available per square kilometer of land from fertilizer application, livestock and human waste alone is currently more than 100 times greater in Europe than in much of Africa.
  • Fortunately, at least the richer nations may be able to afford high-tech remedies.
  • Sewage-treatment facilities that can eliminate nitrogen from waste water are springing up, and man-made wetlands and precision application of fertilizers may stem the flow from farms.
  • Just as people are seeing improvements in some of the worst-polluted coastal waters in the U.S. and Europe, the developing world is poised to repeat what industrial countries experienced over the past 100 years.
  • Part of the problem will come directly as a result of population growth

  • With the occupancy of the planet set to reach more than nine billion by 2050, there will be that many more mouths to feed, more fields to fertilize, more livestock to raise and more tons of human waste from toilets to dispose of.
  • Many experts predict that the release of nutritive nitrogen from fertilizer and fossilfuel combustion will double in the next twenty-five years, most of that increase occurring in the developing world.
  • The United Nations Population Fund estimates that eighty percent of the rise in global population is taking place in the urban areas of Africa, Asia, and Latin America.
  • This increase amounts to about eighty-one million more people every year, a situation akin to spawning ten cities the size of Moscow or Delhi.
  • Compounding this source of urban growth is the continuing movement of people from the countryside into cities.
  • It was city sewers that first overloaded waterways such as Narragansett Bay with human-waste nutrients from toilets, and the scenario is not likely to play out differently in the developing world.
  • Sewers there, too, will likely carry raw-toilet sewage initially, and where treatment of these sludges does occur, it will probably not remove nitrogen for many years.
  • With large stretches of coastline exposed to unprecedented levels of nitrogen, it seems inevitable that ocean waters around the world will become greener, browner and redder and that there will be more frequent periods when the bottom of the sea in vulnerable locations becomes lifeless.
  • Much of the next round of pollution will take place in the waters of the tropics, where both the corals and the fish that inhabit these delicate ecosystems are at risk.
  • Yet, it remains difficult to gauge exactly how damaging this inadvertent fertilization will ultimately prove.
  • Scientists are still far from understanding all the ways the oceans will pay for keeping human life so widespread and abundant.
—Compiled from information located in "Enriching the Sea to Death"
by Scott W. Nixon; as seen in Scientific American, 1998; pages 43-58.

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