WRI Stories Feed: Eutrophication and Hypoxia

Can Nutrient Trading Shrink the Gulf of Mexico's Dead Zone?

Michelle Perez — Wed, 17 Apr 2013 10:30:46 -0400

The Gulf of Mexico has the largest dead zone in the United States and the second-largest in the world. Dead zones form when excessive amounts of nitrogen and…

Extreme Weather: A Mixed Bag for Dead Zones

Mindy Selman — Wed, 10 Oct 2012 14:56:58 -0400

This post was co-authored with Bob Diaz, a WRI partner and professor at the Virginia Institute of Marine Science.

This year’s…

Tools to Improve Water Quality

Cy Jones — Wed, 29 Aug 2012 09:54:19 -0400

This post is part of a series on World Water Week, an annual event designed to draw attention to and discuss global water issues….

How Food Production Impacts Water Quality

Mindy Selman — Thu, 23 Aug 2012 12:46:00 -0400

This post is part of a series on World Water Week, an annual event designed to draw attention to and discuss global water issues….

Eco-Compensation in China: Opportunities for Payments for Watershed Services

Erin Gray — Tue, 15 May 2012 17:50:32 -0400

Water supply and availability could be the most pressing problem restricting China’s economic growth in the next 10-15 years, according to a new report by the…

New Fact Sheet Helps Chesapeake Bay States Design Nutrient Trading Programs

Evan Branosky — Fri, 15 Jul 2011 03:52:56 -0400

2011 will be an important year for the Chesapeake Bay, not only because scientists are predicting an unusually bad “dead zone” this summer….

World Water Day: How Cities Cause “Dead Zones”

Mindy Selman — Mon, 21 Mar 2011 14:54:03 -0400

WRI identifies 13 new eutrophic areas around the world.

World Water Day this year focuses on “Water for Cities,” but what about water from cities? Urban runoff is one of the biggest threats to water quality around the world, with serious impacts on economies and people. However, it’s a problem that most cities are only starting to address.

Nutrient Pollution and Urban Runoff

Eutrophication occurs when water bodies are polluted with nutrients (for example, chemicals from fertilizer and sewage) that wash into surface waters from farms and urban areas that can cause oxygen depletion, fish kills, and ecosystem collapse. These are often called “dead zones” – because of the impact on fish and other sea life.

These issues can be especially problematic in urban areas. When it rains, nutrient pollution from lawns, pet waste, and vehicle exhaust washes into nearby waterways. This sewage (sometimes treated, sometimes not) is often discharged into nearby bodies of water.

Eutrophic Areas Around the World

In January, the World Resources Institute (WRI) and the Virginia Institute of Marine Science (VIMS) identified 534 low-oxygen “dead zones” and an additional 228 sites worldwide exhibiting signs of marine eutrophication. Thanks to responses from readers, WRI has since discovered 13 additional sites that are already eutrophic and in danger of becoming dead zones, bringing the total number of coastal areas around the world known to be suffering from nutrient pollution to 775.

Explore our Interactive Map of Eutrophication & Hypoxia

Some of the newly recorded sites have symptoms caused by urban runoff:

Halifax, Canada: Due to the growth of urban populations, Halifax Harbour and Bedford Basin receive high concentrations of urban waste that are high in nitrogen, phosphorus and other organic matter. Compounding the problem, municipal sewage is entering Bedford Basin from neighboring Bedford and Sackville, and a recent failure of the Halifax treatment plant resulted in high levels of fecal coliform pollution in the Inner Harbor. As a result, people can no longer safely swim or fish in certain areas. As the urban area around Halifax has grown since with 1960s, there have been more severe symptoms of eutrophication, including phytoplankton blooms and fish-kills.
Algeciras, Spain: The nearby Palmones River Estuary is located in a small area with a high population and a mixture of agricultural, urban and industrial land. Symptoms of eutrophication in the estuary have been observed since the early 1990’s, caused by high phosphorous concentrations from urban runoff, organic sewage from nearby towns, and waste from both a paper mill and nearby industrial park. Recent reports indicate the system is highly eutrophic and already many shellfish species have been diminished or depleted.

Development in the City of Algeciras exerts tremendous pressure on the bay. Photo credit: Wikimedia/Falconaumanni

In addition to sea water, fresh water sources often suffer eutrophication. In some extreme cases, local rivers and lakes can become so polluted by urban runoff that they are unsuitable for drinking water or even industrial uses. One striking example of this is Tai Lake in China, where urban runoff, combined with sewage and industrial discharge, led to a massive toxic blue-green algae bloom in May 2007. The bloom rendered the water in the lake too polluted for human, agricultural or industrial uses, and residents were forced to import water from other locations.

States and Cities Taking Action

Some regions are starting to take steps to reduce urban runoff and address wastewater issues:

In New Jersey, in an effort to reduce the nutrient load to Barnegat Bay, a bill was recently passed that will limit the nutrient content of lawn fertilizers in the state.
In Maryland, a June 2000 bill imposed strict standards for enhanced nutrient removal on all major wastewater treatment plants, in an effort to control pollution entering the Chesapeake Bay.
Around the Great Lakes, where eutrophication is a growing problem, New York, Michigan and other surrounding states have enacted phosphorus bans for detergents.
Some cities, like Portland, OR, have begun to manage urban runoff through the use of “green infrastructure” such as forest lands, rooftop gardens, rain gardens, wetlands, ponds and trees planted along stream banks to intercept runoff and cycle nutrients before it can reach surface waters.

WRI has also released the full data set (Excel, 975 Kb) available for 775 eutrophic sites worldwide. We hope that by making this data set widely available, we can help advance the critically important research and policy discussions to address the problems associated with eutrophication.

Obama Administration Releases New Strategy to Clean Up Chesapeake Bay

Evan Branosky — Fri, 14 May 2010 09:33:54 -0400

The federal commitment to develop and support environmental markets could have national significance.

The most apparent challenge to restoring the Chesapeake Bay involves a balance between the competing needs of ecosystems and humans. Kingman and Heritage Islands Park, a tract of 50-forested acres along the Anacostia River in the District of Columbia, appeared to balance those needs pretty well on Wednesday morning. Great blue herons fed within walking distance of Metro’s Orange Line as the Chairperson of the White House Council on Environmental Quality, Administrator of the Environmental Protection Agency (EPA), Secretary of Agriculture, and other senior officials unveiled President Obama’s new Bay clean-up strategy.

The Strategy for Protecting and Restoring the Chesapeake Bay Watershed kicks-off the most comprehensive Bay restoration effort ever, and it does it in part though unprecedented support for environmental markets.

A New Federal Strategy for Bay Cleanup

The Bay is in bad shape, with just 12 percent of its waters having met Clean Water Act standards for dissolved oxygen between 2007 and 2009. Partially for this reason, President Obama issued an Executive Order on May 12, 2009 that required EPA and the departments of Agriculture, Commerce, Defense, Homeland Security, Interior, and Transportation to launch a new restoration effort based on collaborative action. The guiding strategy has four priorities: restoring clean water, recovering habitat, sustaining fish and wildlife, and conserving land and increasing public access.

The priorities will be achieved, in part, through four cross-cutting strategies, one of which is the development of environmental markets.

Environmental Markets and Nutrient Trading

The emphasis on environmental markets was welcome news for me and my colleagues on the Water Quality Team at WRI. Our team has worked on nutrient trading, a type of environmental market, for over ten years. With nutrient trading, regulated point sources, such as wastewater treatment plants, can comply with Clean Water Act regulations at the lowest possible cost.

Nutrient pollution has been a huge problem for the Chesapeake Bay in recent decades. When nutrients such as nitrogen and phosphorus (from sources like wastewater treatment plants, farms, and cement surfaces) run off into the Bay, they can cause algal blooms and hurt water quality.

Pollution controls can be expensive, which is where nutrient trading can provide a welcome solution. EPA policy shows how entities such as wastewater treatment plants that face high costs to reduce their nutrient discharge could purchase reductions from other sources in the form of “credits.” Farms, for example, can often reduce their runoff at a lower cost than wastewater treatment plants, so they can be a source of credits. The flexibility of market exchanges also lets new wastewater treatment plants and stormwater programs expand as more people demand the services they provide. Credit purchases reduce the impacts of additional discharges on water quality.

WRI works with states to develop nutrient trading guidance and regulations. We are also building support for linking those programs into a bay-wide trading program by forecasting the financial benefits of producing and acquiring nutrient credits from the agriculture, wastewater, stormwater, and additional sectors. Our most recent analysis found that a representative 200-acre farm in Virginia could realize $8,200 per year from participating in a bay-wide nutrient trading market under a modeled scenario.

A Template for Environmental Markets Nationwide

The strategy requires the Department of Agriculture to lead an “Environmental Markets Team” of seven agencies and the EPA. The Team will establish infrastructure for environmental markets in the Bay watershed, which includes developing tools that measure ecosystem benefits from land management practices; establishing “baseline” requirements that a farmer would need to meet before participating in a market; and establishing a platform for registering, reporting, and tracking practices to generate credits; among other tasks.

The federal commitment to develop and support environmental markets could have national significance. The strategy notes that:

Successful environmental markets in the Bay watershed might be used as a template for environmental markets nationwide.

Nutrient trading markets, of which 23 exist in various stages of development throughout the United States, could be used to achieve cost-effective reductions in nutrient pollution in other regions beyond the Chesapeake Bay watershed. WRI, for example, is evaluating the potential for markets to reduce the nitrogen and phosphorous pollution in the Gulf of Mexico (which each year suffers from a nutrient-induced “dead zone” the size of Massachusetts).

The federal effort will have the greatest impact if it involves as many stakeholders as possible. The Team should consult throughout the process—and not just at the end through public comment—with: a) the state environment agencies that ultimately decide whether or not credits count toward complying with discharge limits, b) the buyers and sellers in the markets that will provide real-world insight into the most cost-effective market designs, c) the finance community that will leverage market exchanges to achieve maximum savings, and d) the non-governmental organizations who can share their experience in market-development and analysis.

If stakeholders beyond the federal government are included during the development phase, the resulting bay-wide trading program is more likely to become the cost-effective policy mechanism we all are hoping for to help restore the Bay. In addition, it will serve as a model for impaired water bodies throughout the United States.

NEWS RELEASE: Suite of Policies Could Clean Up Polluted Waters

Jessica Forres — Thu, 17 Dec 2009 12:16:38 -0500

Lawmakers should consider a suite of policies to reduce harmful algal blooms and dead zones caused by eutrophication–the over-enrichment of nitrogen and phosphorous in freshwater and coastal ecosystems.

“Eutrophication is like climate change,” said Mindy Selman, lead author of a new report released by the World Resources Institute (WRI). “It’s caused by human activity, there is no single solution and addressing it will require a number of approaches.”

Eutrophication: Policies, Actions, and Strategies to Address Nutrient Pollution, the last report in a three-part series, identifies and highlights local, state and regional tactics to address nutrient and phosphorus pollution. Findings from the report suggest that lawmakers maximize outcomes by focusing on policies with numerous environmental benefits.

For example, while regulating nutrient discharge from wastewater treatment plants helps mitigate eutrophication, WRI’s research reveals that this approach has few environmental co-benefits, and could even result in significant environmental tradeoffs.

In addition, many of the technologies to remove nutrients from wastewater use a significant amount of energy. Depending on the energy source, this could lead to additional emissions of nitrous oxide (NOx), a pollutant that not only contributes to eutrophication when re-deposited on land and in water, but also contributes to smog and acid rain. Currently, atmospheric deposition accounts for 30 percent of the nitrogen pollution found in the Chesapeake Bay.

Some of the nitrogen that is scrubbed from wastewater might also be released as nitrous oxide (N2O) gas, which is a greenhouse gas with a warming potential that is nearly 300 times greater than that of carbon dioxide (CO2).

“Because there are so many pathways, sources, and drivers of nutrient pollution, the policies that address eutrophication cannot be limited to traditional environmental regulations,” said Selman.

Policies encouraging energy conservation, energy efficiency and development of alternative energy resources have multiple environmental and public health benefits. Such policies would reduce the burning of fossil fuels—- a significant source of carbon dioxide, NOx and nutrient pollution in aquatic ecosystems.

Another approach which promotes considerable environmental synergies is agricultural policy that provides incentives to farmers who reduce nutrient pollution. For instance, growing vegetative buffer strips on farms not only prevents organic and chemical fertilizer from running off into the water, but can also improve wildlife habitats, reduce soil erosion, and sequester carbon.

Supporting research and development of new technologies should also be considered by politicians, WRI’s report concludes. In Florida and California, algal turf scrubber systems are being used to remove nitrogen and phosphorous in freshwater. The algae can then be harvested and used for cattle feed or biofuel production.

“Nearly 500 coastal areas around the country already suffer from dead zones and without decisive action by policymakers the number is expected to rise in the foreseeable future,” said Selman.”Lawmakers should carefully consider policies that maximize environmental returns.”

This report follows Eutrophication: Sources and Drivers of Nutrient Pollution. The first report, Eutrophication and Hypoxia in coastal Areas, is a survey of where coastal eutrophication is occurring worldwide.

Protecting Waterways from a Deadly Problem

Mindy Selman — Thu, 17 Dec 2009 12:12:58 -0500

Nutrient pollution emerges as one of the greatest threats to water quality.

In the Chesapeake Bay, large schools of jellyfish scare away swimmers. In the Gulf of Mexico, a 3,000 square mile “dead zone” threatens a multi-billion dollar fishing industry. In Qindao, Beijing Olympics officials had to scoop large masses of green algae out of the water before sailing races could take place. These are all effects of eutrophication—pollution caused when nitrogen, phosphorus and other nutrients enter the water in massive amounts. And it’s a problem with which people in both the developed and developing world are becoming frighteningly familiar.

What is eutrophication?

While “nutrients” are usually seen as a good thing, eutrophication is really a matter of “too much of a good thing.” Nutrients entering waterways can come from a variety of sources, such as chemical fertilizers, vehicle emissions, treated wastewater, manure, and septic systems.

Over the past fifty years, eutrophication has increasingly become one of the greatest risks to our water quality. A new set of WRI policy notes provide a global assessment of areas at risk, a description of eutrophication sources and drivers, and a review of policies, actions, and strategies to address this deadly problem.

When too many of these nutrients run off into waterways, they upset the natural balance of aquatic ecosystems. Too many nutrients act like too much fertilizer – the nutrients feed booming algae populations, which can overrun waterways, block sunlight, and sap the water of its oxygen, creating hypoxic or “dead” zones, fish kills, and ecosystem collapse. Today, over 500 coastal areas are suffering from eutrophication, and 405 of those experience hypoxia, where oxygen levels in the water dip so low that they cannot sustain life.

Nutrient pollution is devastating to communities that depend on ecosystem services like tourism, recreation, and fisheries. For people living alongside eutrophic water, the decaying smell and the toxins released by the algae can irritate eyes, throats, and skin. Recently, Wisconsin state officials had to advise residents near algae-covered lakes across the state to close their windows, avoid walking near the shorelines, and to keep pets away too, as several dogs had died from drinking the water. “It is like living in the sewer for three weeks,” said one resident. “You gag. You cannot go outside. We have pictures of squirrels that are dead underneath the scum and fish that are dead…It has gotten out of control.”

What are the sources and drivers of nutrient pollution?

Most of these chemicals come from agricultural, urban, and industrial sources, and from the burning of fossil fuels. Over-applied synthetic fertilizers run off agricultural fields and leach into groundwater, and animal waste from concentrated livestock operations and fish farms (aquaculture) also find their way into water systems. Municipal wastewater treatment plants, industrial wastewater discharges, septic tanks, raw sewage, and storm runoff are other contributors. Pollutants can also enter waterways through the air. When fossil fuels are burned, they release nitrogen oxides (NOx) into the air which can then redeposit into the water.

The world’s growing population and economy are increasing the demand for food, land, energy, and natural resources, ultimately leading to greater agricultural production, more sewage, an use of fossil fuels. These activities in turn lead to the destruction of “nutrient sinks” like forests and wetlands that traditionally filter excess nutrients out of waterways. The rapid increase in meat consumption is one example – in China, meat production rose by 127 percent between 1990 and 2002, but fewer than 10 percent of an estimated 14,000 intensive livestock operations have installed pollution controls.

In the United States and European Union, the primary sources of nutrient pollution are typically agricultural sources, while in Asia and Africa the primary source is often urban wastewater. Developing countries have a problem with “point sources” of nutrient pollution: pipes or other outlets that discharge chemicals and sewage. North America treats 90 percent of its sewage, but Asia treats only 35 percent, Latin America and the Caribbean 14 percent, and Africa less than one percent.¹

What can be done?

Designing an effective response to eutrophication is a challenge. Pollutant sources are often miles away from the areas they affect, and many different players can share the same watershed. For example, the Chesapeake Bay watershed covers parts of six states, and the Mississippi River watershed includes 31 different states. Preventing nutrient runoff in Corn Belt state can help address the recurring dead zone in the Gulf of Mexico, over one thousand miles away. This fall, a task force dedicated to restoring ecosystems in the Gulf actually met in Iowa.

Despite the geographic challenges, the good news is that these areas can recover. Boston Harbor and the Mersey Estuary in the UK are both showing improved water quality because of better industrial and wastewater controls. The Black Seaonce had recurring hypoxic areas, but has slowly moved into a state of recovery with the reduction of fertilizer use. And New York City still gets its drinking water from the largest unfiltered water supply in the U.S., in the Catskills Mountains, since officials realized it would be cheaper to protect the watershed ecosystem than to pay to purify the water. Today, there is more sensitive land in conservation, better sewage treatment, and more sustainable forestry and farming practices in the area.

In developing countries, basic sewage treatment and improved governance can help immensely. Point sources (pipes and waste outlets) are typically the most controllable sources of nutrient pollution. Strong governance is the greater challenge. Without strong institutional authority, adequate funding, and properly trained personnel to enforce the rules already on the books, there’s only so much that good regulations and policies can achieve.

Policymakers in developed countries must look broadly at agricultural, energy, land use, and public health policies to address the diverse sources of nutrient pollution and design policies to mitigate them. Policies cannot be limited to traditional command-control approaches such as regulatory standards, nor can they focus on one single sector.

Eutrophication, like climate change, is a big picture issue. Its causes stem from our very way of life. We know the policies that would help, but the challenge is in implementation. In the end, it’s really about sustainable lifestyles.

For more information, see the full policy notes:

Part 1: Eutrophication and Hypoxia in Coastal Areas: A Global Assessment of the State of Knowledge
Part 2: Eutrophication: Sources and Drivers of Nutrient Pollution
Part 3: Eutrophication: Policies, Action, and Strategies to Address Nutrient Pollution

Martinelli, L.A. 2003. “Element interactions as influenced by human intervention.” In J.M. Melillo, C.B. Field, and B. Moldan, eds. Element Interactions: Rapid Assessment Project of SCOPE. Washington, DC: Island Press. As cited in Howarth, R. and K. Ramakrishna. “Chapter 9: Nutrient Management.” In K. Chopra, R. Leemans, P. Kumar, and H. Simons, eds. 2005. Millennium Ecosystem Assessment (MA). Washington, DC: Island Press. ↩