Thinking Downstream

Excess nutrients are entering the seas at a rapid pace, polluting our oceans, killing ocean life, and creating "dead zones." We know that we're the cause and we know how to fix it. Do we have the will to take action before it's too late?

Blue Planet Magazine, Winter 2005
Story by Carol Gardner

What's a crab jubilee? A festive 4th of July celebration? A crab feast? Actually, when the water they inhabit becomes oxygen-depleted, blue crabs scramble onto land in a desperate attempt to breathe. Watermen from Mobile Bay to the Chesapeake call this a "crab jubilee."

In the summer of 2003, a number of these events were reported along the shores of the Chesapeake. That summer, the nation's largest estuary exhibited its largest "dead zone" ever, an oxygen-starved area stretching more than 150 miles-from Baltimore to the York River in Virginia-across 40 percent of the waterway.

What caused this dead zone? People did: specifically, people allowing too much nitrogen and phosphorous to enter the Bay. When waterways receive a glut of these elements, scientists call it nutrient pollution.

But that term depersonalizes a phenomenon that is caused by people's actions: our over-use of fertilizer, inadequate waste treatment, burning of fossil fuels, and our destruction of forests and wetlands to build houses, buildings, and roads. These practices have created dead zones-areas so devoid of oxygen that nothing can survive-in our most productive bays and estuaries: the Chesapeake Bay, Puget Sound, Long Island Sound, and one in the Gulf of Mexico the size of New Jersey.

We've known for more than a decade that to tackle this problem, we must cut way back on fertilizer use, modernize our antiquated sewage treatment systems, and protect the land's natural filters such as forests and wetlands that actually capture and recycle nitrogen before it reaches the oceans. We don't lack solutions; but do we have the political will to carry them out?

How Nutrients Pollute

Nutrients like nitrogen and phosphorous are good for plants and crops. But when they reach water bodies in huge amounts, they cause algae—or phytoplankton—to bloom. As phytoplankton die they are, in turn, decomposed by bacteria, a process which consumes much, and sometimes all, the oxygen in the water, leaving none for other life. Crabs and fish—if they're lucky—can move away from these dead zones; less mobile animals—like clams, oysters, or starfish—simply suffocate.

It's not so much a question of toxicity as balance. In the proper amounts, nitrogen and phosphorous are helpful; in excess, they can be harmful-like many vitamins or medications. Phytoplankton, too, is relatively harmless until it is supplied with excess nutrients; when that happens, it can take over a waterway like a pestilence, consuming all the available oxygen and leaving none for fish, shellfish, or other aquatic creatures.

According to the United Nations Environment Programme (UNEP), hypoxia, or very low levels of oxygen, is fast becoming the oceans' number one environmental challenge for the 21st century, outstripping even overfishing. Robert Diaz, a professor at the Virginia Institute of Marine Science, co-authored UNEP's 2004 Global Environment Outlook Year Book. "The number of coastal areas reporting hypoxia doubled throughout the 1980s and '90s," says Diaz. "If the trend can't be controlled or reversed, it will be dire for our fisheries resources."

Some algae do more than use up the dissolved oxygen in water; many are toxic to fish and other marine life, and harmful to humans. In 1997, hundreds of dead and dying fish were found in Maryland's Pocomoke River, a tributary of the Chesapeake Bay. Scientists noted the presence of Pfiesteria psicicida, a type of algae that has a life stage that is toxic to fish and harmful to humans. As more fish died and several watermen became ill, officials were forced to close the Pocomoke and two other tributaries to fishing and contact. Restaurants and stores stopped selling Chesapeake Bay seafood, and the seafood industry lost nearly $50 million in just four months. Scientists from the National Centers for Coastal Ocean Science found that excess nutrients were a significant part of the problem; they fostered an abundance of the phytoplankton that Pfiesteria commonly feed upon.

Our Fascination with Fertilizer

Where do these excess nutrients come from? Here's an illustration. Go out and buy 10 bags of fertilizer. Apply two bags to your lawn and garden and then take eight bags and dump them into your local stream. That's pretty much what we are doing to the global ecosystem.

According to UNEP, around the globe, people apply 120 million tons of fertilizer every year. Yet only 20 million tons of that is retained in the food we eat; the rest-more than 83 percent-is never taken up by plants. Instead, it runs off farm fields, gardens, and lawns into streams, rivers, and ultimately, the ocean.

Nitrogen Is a Terrible Thing to Waste

It is no coincidence that our nation's largest dead zone-in the Gulf of Mexico-lies immediately downstream of its most productive agricultural land.

But must our most productive farms compromise our most productive estuary? The Gulf of Mexico provides some 40 percent of our domestic seafood-more than New England and the mid- and south-Atlantic areas combined. But its growing dead zone is cutting deeply into that productivity.

Before the 1950s, animal manure, which contains large amounts of nitrogen and phosphorous, was the fertilizer of choice for farmers. But with the invention of synthetic fertilizer, people began to tip the delicate balance of nitrogen in the global equation. Fertilizer manufacturers, of course, didn't urge farmers to use restraint when applying the product. According to the U.S. Geological Survey, nitrogen concentration in the Mississippi River-which drains into the Gulf of Mexico-has doubled since 1950, and the main culprit has been commercial fertilizers.

Over-application of fertilizer is a significant part of the problem. According to Robert Howarth, Professor of Ecology and Environmental Biology at Cornell University and a specialist in nitrogen cycling, "The average farmer could cut fertilizer use by one-third without reducing crop yields."

Even as people were manufacturing more nitrogen, livestock operations were ending up with more manure than they could use-or give away. Concentrated animal feeding operations (CAFOs)-where hundreds or thousands of animals are kept confined in large feedlots-produce huge amounts of liquid waste. Much of it is stored in open-air "lagoons," some larger than seven acres.

CAFOs aren't required to treat this waste. Instead, the liquid waste is sprayed on farm fields as fertilizer, but often at a rate faster than crops can use it. According to the U.S. Environmental Protection Agency, the amount of land needed to efficiently distribute the manure generated in a typical CAFO is 1,000 times larger than the feedlot itself.

Here's another part of the problem; while our most important law to protect our water-the Clean Water Act-regulates and controls nitrogen, phosphorous, and other pollutants from industry and municipalities, it provides a loophole for pollutants from agricultural runoff. In essence, there are no limits, guidelines, or rules asking agricultural operations to clean up after themselves.

Less Is More

Cutting back on fertilizer use can bring positive results, for farmers and waterways alike. The Black Sea once possessed one of the largest dead zones in the world. In the 1980s, this area extended some 7,700 square miles-larger than Lake Ontario. But after the collapse of the Soviet Union and regional economies, phosphorus and nitrogen use was cut in half in the region. As a result, the dead zone shrank, and in 1996 it was absent for the first time in 23 years. Despite the sharp reduction in fertilizer use, farmers found that crop yields didn't suffer.

According to Howarth, agriculture is the biggest source of excess nitrogen to the oceans, yet we have the technology to solve the problem. "Planting winter cover crops, for example, greatly reduces runoff from spring rains; switching crops, too-such as perennial grasses for corn-can help soils to retain nutrients. There are dozens of answers for agriculture."

In the United States, the American Farmland Trust has created an innovative, voluntary program that gives farmers credit for cutting back on fertilizer. Under the Nutrient Best Management Practices Endorsement, farmers who follow recommendations for fertilizer application and cut their use are guaranteed financial coverage for any crop shortfalls. So they save money on fertilizer and are insured against crop losses.

But are voluntary efforts likely to be enough? Not according to Ellen Athas, Clean Oceans Director for The Ocean Conservancy. "We can't save our most treasured estuaries unless we can effectively regulate the amount of runoff coming from farms and feedlots. Agricultural operations need clear and established limits for waste production and disposal. Even with these voluntary programs, the number of dead zones continues to grow."

Making Cities Clean Up Their Act

City-dwellers create their share of nitrogen-laden waste, too. In Washington, DC, every time it rains above a half inch, storm water from streets and lawns mixes with raw sewage from households and enters local creeks and rivers. These "Combined Sewer Overflows," or CSOs, are responsible for two and a half billion gallons of mixed rain and wastewater entering the Potomac and Anacostia Rivers and Rock Creek each year. What lies downstream? The Chesapeake Bay.

Although the Clean Water Act requires that CSOs be phased out, and that all waste is treated, many cities have applied for, and won, "exceptions."

If enforced, Clean Water Act regulations could help to solve the Chesapeake's nutrient woes. In 1985, for example, a lawsuit found the state of Massachusetts to be in violation of the Clean Water Act for sewage pollution in Boston Harbor. A federal court ordered the Massachusetts Water Resource Authority to construct new sewage treatment facilities. Between 1986 and 2000, they upgraded four main parts of the system to end the discharge of untreated and partially treated sewage to Boston Harbor. The result? Seagrasses have come back to Boston Harbor for the first time in 200 years.

But it takes money to retool and upgrade CSOs, and in recent years, the federal government hasn't been willing to help out. According to a National Resources Defense Council report, Swimming in Sewage, federal funding for wastewater infrastructure received the largest cut of any environmental program in President Bush's budget proposal for fiscal year 2005.

In some states, however, people and lawmakers are trying to clean up their act. In Pennsylvania, voters recently approved a $250 million bond issue to upgrade sewer and water systems that contribute nitrogen and phosphorous to the Chesapeake Bay. Downstream, Maryland's General Assembly recently passed a "flush tax" imposing new fees on sewage users to help pay for the $1.07 billion worth of needed improvements to the state's sewage systems.

Wetlands Matter

Before there were combined sewer overflows, treatment plants, or the Clean Water Act, there were wetlands. Marshes, swamps, vernal pools, and small streams all serve a vital function that we're just beginning to understand; they filter and transform harmful runoff before it reaches larger waterways and the oceans.

Once, wetlands were seen as unproductive land. In fact, between 1780 and 1980, half of our nation's wetland acreage was lost to filling, draining, and development.

Yet wetlands-even small headwater streams far from the oceans-provide a critical ecosystem "service." It's becoming increasingly clear that it's a service we can't do without. Headwater streams hold excess nutrients, preventing them from traveling downstream; then the bacteria and other microorganisms living on the stream bottom consume the nutrients and convert them into less harmful substances. And the smaller and shallower the stream, the more efficient it is at retaining and transforming nitrogen and phosphorous.

What does this mean for the oceans? Small streams can absorb and recycle the nutrients that are so harmful to ocean waters. Like capillaries in a human's circulatory system, small streams are vital to the functioning of the larger system; without them, the larger body dies.

Reinvigorating the Clean Water Act

The Clean Water Act contains provisions to protect wetlands. But even with regulations, we continue to lose wetlands, especially on private lands.

Now more than 30 years old, the Clean Water Act is still the best we have. Is it good enough? According to Ellen Athas, if we remove the exemption for agricultural and runoff pollution, if its municipal waste and wetlands protection provisions were strictly enforced, we could reverse nutrient pollution-in the Chesapeake, the Gulf of Mexico, and all our critically important bays and estuaries. But laws are, after all, words. It takes people to enact, implement, and enforce them. Robert Howarth agrees, "If we had decent political leadership at the national level, we could make significant progress in solving this problem."

For Love or Money

On Maryland's Eastern Shore, Chesapeake Wildlife Heritage works to persuade landowners to restore wetlands, for the benefit of both wildlife and water quality. One of their programs employs federal funds from the Conservation Reserve Enhancement Program to help restore and maintain wetlands from marginal farmland. "Marginal" refers to wet soils that don't produce very well. Andi Pupke, Chesapeake Wildlife Heritage's education and outreach director admits that it's hard work getting landowners to buy into the effort for the benefit of conservation alone. "We begin to talk about wildlife issues and then the water quality issues. But the financial incentive is usually what pushes people over the edge."

Protecting wetlands is vital to protecting our bays, estuaries, and our oceans. But, like the larger problem of nutrient pollution, it entails changing our behaviors, our laws, and our perspectives. It means thinking beyond immediate economic gains. In the end, it comes down to whether or not we care about the downstream effects of our actions, or whether, like the blue crab, we think we can simply run away.

You Can Make a Difference

Speak Out! Write your Congressperson and insist that: