WRI Publications Feed: Water Quality: Eutrophication and Hypoxia

Eutrophication: Policies, Action, and Strategies to Address Nutrient Pollution

Maggie Barron — Mon, 21 Sep 2009 14:58:51 -0400

Nutrient overenrichment of freshwater and coastal ecosystems—or eutrophication—is a rapidly growing environmental crisis. Worldwide, the number of coastal areas impacted by eutrophication stands at over 500. In coastal areas, occurrences of dead zones, which are caused by eutrophic conditions, have increased from 10 documented cases in 1960 to 405 documented cases in 2008. In addition, many of the world’s freshwater lakes, streams, and reservoirs suffer from eutrophication; in the United States, eutrophication is considered the primary cause of freshwater impairment.

In order to reverse eutrophication trends and mitigate nutrient losses to aquatic ecosystems, policymakers should:

Implement research and monitoring programs to characterize the effects of eutrophication, collect water quality data, and inform adaptive management strategies. Information is a key element in the development of robust strategies to reduce eutrophication.
Raise awareness of eutrophication. Eutrophication and its effects are not well understood by the public or policymakers. Public awareness campaigns, school environmental education programs, and targeted outreach and technical assistance are all important components of raising the profile of eutrophication within communities and building a foundation and support for effective actions to reduce nutrient losses and eutrophication.
Implement regulations to mitigate nutrient losses, such as standards, technology requirements, or pollution caps for various sectors.
Create fiscal and economic incentives to encourage nutrient reducing actions using taxes and fees, subsidies, or environmental markets.
Preserve and restore natural ecosystems that capture and cycle nutrients.
Establish strong, engaged, and coordinated institutions to address eutrophication. Effective institutions to implement and enforce policies are important to the success of any eutrophication strategy, especially where multiple jurisdictions are involved.
Capitalize on environmental synergies when designing comprehensive policies to address eutrophication. Many policies and activities associated with reducing nutrient pollution have synergies with other environmental problems such as climate change, smog, and acid rain. Policies selected and implemented should seek to maximize environmental benefits.

Additional Links

This policy note is third in a series. Click below to read the other two:

Eutrophication: Sources and Drivers of Nutrient Pollution

Tim Herzog — Tue, 30 Jun 2009 00:00:00 -0400

Nutrient over-enrichment of freshwater and coastal ecosystems, or eutrophication, is a rapidly growing environmental crisis. Worldwide, the number of coastal areas impacted by eutrophication stands at over 500. In coastal areas, occurrences of dead zones, which are caused by eutrophic conditions, have increased from 10 documented cases in 1960 to 405 documented cases in 2008. In addition, many of the world’s freshwater lakes, streams, and reservoirs suffer from eutrophication; in the United States, eutrophication is thought to be the primary cause of freshwater impairment. Many of our largest freshwater lakes are entrophic, including Lake Erie (United States), Lake Victoria (Tanzania/Uganda/Kenya), and Tai Lake (China).

The increase in eutrophication is the result of human activities. Major sources of nutrients to freshwater and coastal ecosystems include wastewater, agriculture, and atmospheric deposition of nitrogen from burning fossil fuels. The drivers of eutrophication are expected to increase for the foreseeable future. Specifically:

World population will continue to grow, reaching an estimated 9.2 billion by 2050, which will increase pressures on the productive capacity of agriculture and industry.
Intensive agriculture and land use conversion—for crops, livestock, and aquaculture—will increase, especially in the developing world. In addition to population growth, intensifi cation is driven by changing dietary patterns. For example, over the period from 2002 to 2030, global meat consumption is expected to increase by 54 percent.
Energy consumption is expected to grow 50 percent from 2005 to 2030. Fossil fuels, which release nitrogen oxides (NOx) into the environment when burned, will continue to be the dominant fuel source in this century.

As a result of these increasing global trends in population growth, energy use, and agricultural production, we expect that coastal and freshwater systems impacted by eutrophication and hypoxia will continue to increase, especially in the developing world.

Eutrophication and Hypoxia in Coastal Areas: A Global Assessment of the State of Knowledge

Mindy Selman — Sat, 01 Mar 2008 00:00:00 -0500

Eutrophication – the overenrichment of waters by nutrients – threatens and degrades many coastal ecosystems around the world. The two most acute symptoms of eutrophication are hypoxia (or oxygen depletion) and harmful algal blooms, which among other things can destroy aquatic life in affected areas.

Of the 415 areas around the world identified as experiencing some form of eutrophication, 169 are hypoxic and only 13 systems are classified as “systems in recovery.”

Mapping and research into the extent of eutrophication and its threats to human health and ecosystem services are improving, but there is still insufficient information in many regions of the world to establish the actual extent of eutrophication or identify the sources of nutrients. To develop effective policies to mitigate eutrophication, more information is required on the extent of eutrophication, the sources of nutrients, and the impact of eutrophication on ecosystems.

Recommendations

To improve knowledge of where eutrophication is occurring and its impacts, environmental agencies or coastal authorities worldwide need to proactively assess and monitor water quality, specifically those variables commonly linked to eutrophication such as nutrient levels and dissolved oxygen. In addition, internationally accepted methods and definitions for assessing and classifying eutrophic coastal waters—including proxies for eutrophication—need to be developed.

In Asia, Africa, and Latin America, environmental agencies or coastal authorities should:

Undertake systematic and routine assessments of coastal areas, particularly those exhibiting symptoms of eutrophication.
Develop transparent and public reporting procedures for tracking the occurrence of eutrophication and hypoxia, as well as monitoring their impact on ecosystem health.
Develop and adopt decision-support tools – such as nutrient budgets and water quality models – that can facilitate the development of appropriate local and regional responses to eutrophication.

In the United States, Europe, and Australia, environmental agencies or coastal authorities should:

Continue coastal zone assessments.
Ensure that eutrophication assessment methodologies are being consistently applied.
Enhance existing decision-support tools and develop tools for those areas where none currently exist.