Coastal 'Dead Zones' Get Attention

Courtesy of Charles S. Hopkinson Jr.Brackish tidal marsh along the Plum Island estuary in northeastern Massachusetts Lessons learned decades ago resurfaced this spring when the National Research Council of the National Academies issued a report calling for a nationwide plan to combat the nitrogen and phosphorus pollution threatening U.S. coastal waters. Lesson one: Ecosystems are interdependent. Lesson two: Virtually every human being is part of the problem and can be part of the solution. "We

A. J. S. Rayl
Jun 25, 2000

Courtesy of Charles S. Hopkinson Jr.

Brackish tidal marsh along the Plum Island estuary in northeastern Massachusetts
Lessons learned decades ago resurfaced this spring when the National Research Council of the National Academies issued a report calling for a nationwide plan to combat the nitrogen and phosphorus pollution threatening U.S. coastal waters. Lesson one: Ecosystems are interdependent. Lesson two: Virtually every human being is part of the problem and can be part of the solution.

"We believe that this excess nutrient pollution is the biggest pollution problem of the coastal waters, and it is a national problem," contends Robert W. Howarth, professor of ecology and environmental biology at Cornell University. Howarth chaired the NRC committee that prepared the report "Clean Coastal Waters: Understanding and Reducing the Effects of Nutrient Pollution," which called for the formation of the National Coastal Nutrient Management Strategy. The report is available online at

Estuaries and coastal zones are among the most productive ecosystems on Earth, but these resources are in danger from eutrophication and other problems caused by excess input of nutrients from fertilizers, fossil fuel combustion, animal feedlots, and human waste. The causes and effects are site specific. But in general, excessive enrichment of rivers, lakes, and sea areas stimulates the growth of algae and bacteria. This in turn uses up the oxygen in the water, causes harmful algal blooms and red tides, and destroys sea grass, making it uninhabitable for most fish and other coastal wildlife. In essence, excess nitrogen and phosphorus sets off a chain of ecological events that initially reduces biodiversity and ultimately destroys the ecosystem.

At present, there is no national strategy. Nor are there any consistent, reliable sources of data to allow for a rigorous quantitative national assessment or any kind of routine monitoring system, which, comments Howarth, "is a little shocking if you think about it." (See also Commentary, page 4.)

Relying on a National Oceanic and Atmospheric Administration (NOAA) study that assessed 139 coastal areas during the late 1990s, the report describes 44 watersheds as severely affected. At the top of the list: the mid-Atlantic Coast and the Gulf of Mexico, where a dead zone forms every spring along the Texas and Louisiana coasts. But the problem could be worse.

"Most of the information collected in that NOAA report was through interviews with individual scientists like myself--asking 'What's the condition of your estuary?'--and not by any systematic, routine collection of levels," explains committee member Charles S. Hopkinson Jr., senior scientist at the Ecosystems Center at the Marine Biological Laboratory in Woods Hole, Mass.

In recommending that the federal government work with state and local agencies to develop the National Coastal Nutrient Management Strategy, the committee suggested a goal of reducing severely damaged coastal areas by at least 10 percent by 2010, 25 percent before 2020, and ensuring that presently healthy coastal waters stay that way.


A Slow Progression

The problem of excessive nitrogen and phosphorus hasn't happened overnight. "It's happened gradually over the last 30 to 40 years," says Howarth. Globally, human activities have more than doubled the amount of nitrogen in the environment from 1960 to 1990, according to the report. The use of synthetic fertilizers accounts for more than half that growth. Combustion of fossil fuels and animal feedlot operations are the other primary contributors. "These huge animal feedlot operations are something of a new phenomenon," he says. "We didn't have such a thing in our country 40, 50 years ago, and it's now a big part of the problem."

The nitrogen and phosphorus from all these sources seep into groundwater, rivers, and streams, eventually flowing into coastal waters, or are carried to the water systems through the atmosphere. In coastal marine ecosystems nitrogen is integral in both causing and controlling eutrophication. However, "the balance between nitrogen and phosphorus triggers good or poor water quality," notes Holly Greening, senior scientist with the Tampa Bay National Estuary Program in St. Petersburg, Fla.

Meanwhile, in lakes and other freshwater bodies, eutrophication is primarily caused by excess inputs of phosphorus, mostly from fertilizer and human waste, says Hopkinson, who has been studying the Ipswich River Basin in northeastern Massachusetts. "Historically, detergents were a huge source of phosphorus, but the [United States] has been very effective in reducing phosphorus levels in detergents."

In addition to its call for a coordinated local, state, and federal effort and the creation of routine monitoring and assessment programs, the committee recommended a number of initiatives, outlined in the following paragraphs.

Develop more effective ways to provide consistent and competent data and technical assistance to state and local coastal authorities through a federal clearinghouse and Internet database. "We found that most of the places where we were seeing improvements had a very strong local component that was usually a mixture of local environmental groups, local governments, and state programs, but they also had very close ties to the expertise and tools available through federal programs," says Greening. "You really do need both ends of the spectrum."

Exert federal leadership on issues that span multiple jurisdictions or threaten federally protected natural resources. "We know as a community that the farm practices of the upper Midwest--Iowa, Illinois, and Indiana--are severely degrading the Gulf of Mexico, transporting nutrients down the Mississippi River," points out Howarth. "That makes it a national problem, and we really need the federal government to step up to that challenge." In addition, in the big picture, there are some larger-than-watershed issues that require federal leadership, says Greening: "One is the concept that air quality can [have an impact on] water quality. This atmospheric component of nitrogen sources is a relatively new concept, but it's turning out that in many coastal areas, air quality is one of the major sources of nitrogen to the water. And air quality, of course, isn't confined to just a watershed."

Address overlaps and gaps in existing and proposed federal legislation. Because several federal agencies--NOAA, the Environmental Protection Agency, and the United States Geological Survey--already have some pertinent regulations in force, the government should ensure that programs focus effectively on meeting local needs. Also, changes from new research need to be incorporated into the Clean Water Act, the Clean Air Act, and the Coastal Zone Management Act. "For example, when the Clean Water Act was first passed in 1972 and reauthorized in the mid-1980s, we had the view that the pollution came from pipes, waste treatment plants, and discharges from industry," points out Howarth. "It is really well designed to deal with that type of pollution, but now that we're seeing a more diffuse situation, we think it ought to be strengthened to explicitly deal with this non-point source pollution."

Develop a classification scheme to provide better information on susceptibility of estuaries. "A lot of research is going to be required, because right now we just can't predict whether this estuary can handle 10 grams per meter square per year, or another could handle 100 grams per year," says Hopkinson.

Conduct periodic assessments. "One of the conclusions of the White House initiatives over the last couple of years is that there is a tremendous paucity of information to even say what the present condition of the nation's estuaries is," says Hopkinson. While the NOAA study offers something of a baseline assessment, "we need to conduct more comprehensive assessments more often," he adds, noting that the committee recommended reassessments every 10 years.

Expand and target research to improve understanding of nutrient overenrichment. "We still have a lot of questions about nutrient management and about the impact of nutrients in our coastal waters," adds Greening. "It's still a new science ... and so we need more research."

The National Coastal Nutrient Management Strategy should not be just be a voluntary set of guidelines, the NRC committee says. "We suggest explicitly that we use in the regulatory framework some mixture of voluntary compliance, but that we also have a regulatory backstop for those who might not want to work in a voluntary way," says Howarth. Though the committee did not address the costs that would be incurred or where that money would come from, the general belief, says Hopkinson, is that it will come from congressional and other federal mandates.


Courtsey of Cornell University Photography

Robert W. Howarth helped prepare a report calling for a National Coastal Nutrient Management Strategy.

Progress So Far

Many concepts set forth in the report have been implemented already on a smaller scale, in Tampa Bay and Chesapeake Bay, as well as the Rhine and Elbe watersheds in Europe.

In the late 1970s, Tampa Bay was in poor health, recalls Greening. Sheet algae covered the surface. No one even thought about fishing or swimming there, and local headlines went so far as to declare: "The Bay Is Dead." But the local community decided to change that and homed in on a common goal. "The collective goal was to restore some of our underwater grasses to levels that we observed in 1950," Greening continues. "More sea grasses would mean more fish and a cleaner- looking bay." The public outcry led in 1980 to state legislation requiring wastewater treatment plants to reduce nitrogen input significantly. "It took about five years before we started seeing some response in the water quality and 10 years before we started seeing some of our sea grasses coming back." Now the bay has been revived, and the results provide continued incentive, Greening says.

Gaining insights from areas that are still healthy is equally important. In studying the Ipswich River Basin, says Hopkinson, "we clearly see the problems extend beyond political boundaries, and so it's not a problem usually with what's going on in a single town, but what's going on in every one of the towns. Each draws water from the river for everything from drinking to watering lawns. If they continue to take it, the river will go dry. That's going to have a deleterious impact on the communities and the habitats along the river--marshlands, bottomland hardwood forests, cedar swamps--habitats that are ultimately important in maintaining high water quality."

Hopkinson and colleagues also have discovered that 80-90 percent of all the nitrogen and phosphorus that comes into the watershed stays in the watershed and never gets to the estuary. "So there's something that's going on, some processes we're trying to identify that are responsible for this retention or this loss of nitrogen or phosphorus before it gets to the coastal zone," he says. "We want to know where are these important habitats--what are the processes operating, because these are habitats that ultimately we want to protect."

On the Horizon

Measures on the horizon will either help or hinder the effort to clean up U.S. water systems, says Greening. Cleaner fuels and actions based on the Clean Air Act may help, but the increasing number of cars on highways and the trend toward larger, less fuel-efficient cars and trucks may be counteractive. "The things that can be done and the things that are done most frequently successfully are the ones that have benefits in a number of different ways, so that a little effort to one goal can achieve multiple goals," she continues.

To not do anything isn't an option: All agree that we'll begin to lose our seas and rivers. "We'll lose our desire to look at it, sail in it, to have primary contact with it, and we'll lose the food that comes from it," says Hopkinson. "Algal blooms will become the norm, and we'll see more and more toxic algal blooms. The stench coming from decomposing algae and macrophytes will be unbearable. We'll lose oxygen on a regular basis, which is going to prevent almost all higher trophic levels that humans value, like fish and shellfish ...."

This raises another critical factor to success: Achieving these goals cannot happen without the cooperation of private industry and the public. "You really need to have a very strong willingness of the people," says Greening, "and public awareness for this is absolutely critical."

The bottom line is that we're all part of the problem. "It's emissions from SUVs everywhere and all the suburban people who are having [lawn services] come into their yard and apply fertilizer whenever it looks less than the bright green golf-course color," says Hopkinson. Despite Earth Day and consistent media attention to environmental degradation, however, most people are oblivious or apathetic to their contribution to pollution. "It's going to take a raising of the perception of the public at large that there is a problem, that they're part of the problem and there is something that can be done about it. I don't know if there is any way to have a lawn that looks like a golf course without putting down massive amounts of nitrogen and phosphorus, so it might require a willingness to perceive something as being beautiful."

On May 25th, President Bill Clinton, standing on a pristine beach on Assateague Island in Maryland, announced plans to create a system of ocean preserves, similar to the 200 million acres of protected forests, wilderness, and parks on land. Clinton cited the spreading dead zone in the Gulf of Mexico and stated that the oceans deserve better protection. The oceans and coastal zones, he said, are "immensely powerful. But they are also very, very fragile. We must try to do better."

A.J.S. Rayl ( is a freelance writer in Malibu, Calif.