Topic: Eutrophication and Hypoxia

Coastal Eutrophic and Hypoxic Areas of Africa

Mindy Selman — Thu, 27 Mar 2008 16:42:29 -0400

This map identifies only 20 eutrophic coastal zones in all of Africa, of which 8 have documented hypoxia and 12 are areas of concern. There are undoubtedly many more, but a lack of reliable water quality data makes it difficult to assess the true scope of eutrophication in Africa.

Coastal Eutrophic and Hypoxic Areas of Asia

Mindy Selman — Thu, 27 Mar 2008 16:39:10 -0400

This map identifies just 24 eutrophic coastal areas with documented hypoxia and 9 areas of concern within Asia. Forty-two percent of these areas are located in Japan, where monitoring of eutrophication is well advanced. In China, some hypoxic and eutrophic systems are identified at a coarse scale. For example “South China Sea” and “Bohai Sea” are represented as single points because data were not available at a finer scale. Because of large increases in intensive farming methods, industrial development, and population growth in Asia over the past 20 years, we know that eutrophication and hypoxia are greatly underrepresented in this map. Better water quality monitoring and assessment in China and throughout Asia are needed in order to understand the full extent and nature of eutrophication in Asia.

Coastal Eutrophic and Hypoxic Areas of Australia and Oceania

Mindy Selman — Thu, 27 Mar 2008 16:36:30 -0400

This map identifies 36 eutrophic coastal zones; 9 with documented hypoxia and 27 areas of concern. The majority of information on eutrophic areas in Australia is derived from a national water quality audit conducted in 2001.

Coastal Eutrophic and Hypoxic Areas of Europe

Mindy Selman — Thu, 27 Mar 2008 16:35:03 -0400

This map identifies 168 eutrophic and hypoxic coastal areas in Europe. Fifty-nine of these are documented hypoxic areas, 106 are areas of concern, and 3 are improved systems that are in recovery. Although relatively comprehensive geographically thanks to multinational surveys such as those carried out by the Commission for the Protection of the Marine Environment of the North-East Atlantic (OSPAR), coordinated eutrophication assessment is still hampered by inconsistent reporting methods between countries and sometimes inconclusive data for determining eutrophic status. It is worth noting the substantial ecological improvements made in the Black Sea, which was formerly one of the most notorious hypoxic areas but is now in recovery.

Coastal Eutrophic and Hypoxic Areas of South America

Mindy Selman — Thu, 27 Mar 2008 16:07:45 -0400

This map identifies 25 eutrophic and hypoxic zones, with 3 having documented hypoxia and 22 areas of concern. Most are found in Brazil, Chile, and Peru. This is most likely an undercount for the continent given recent increases in nutrient delivery to coastal waters related to agriculture, growing industry, fossil fuel combustion, and population growth. It is estimated that only 14 percent of wastewater, a key source of nutrients, is treated in Latin America and the Caribbean. Improved water quality monitoring and assessment is required to identify problem areas and their sources, and to develop strategies to reduce eutrophication.

Coastal Eutrophic and Hypoxic Areas of North America and the Caribbean

Mindy Selman — Thu, 27 Mar 2008 16:01:35 -0400

This map identifies 131 eutrophic and hypoxic coast zones in North America and the Caribbean. Sixty-two have documented hypoxia, 59 are areas of concern, and 10 are systems in recovery. Despite having many well-studied systems such as the Chesapeake Bay, which has 12 distinct eutrophic and hypoxic zones, water quality data in the U.S. still have room for improvement. In 2007 the U.S. National Oceanic and Atmospheric Agency’s (NOAA) National Estuarine Eutrophication Assessment program evaluated the eutrophic status of 141 estuaries, yet 30 percent lacked adequate data to make a definitive assessment. As with many less-developed regions of the world, data on eutrophication for the Caribbean is generally sparse, making this map likely an underrepresentation of the actual number of eutrophic and hypoxic areas.

World Hypoxic and Eutrophic Coastal Areas

Mindy Selman — Wed, 23 Jan 2008 13:39:00 -0500

This map identifies 415 eutrophic and hypoxic coastal systems worldwide. Of these, 169 are documented hypoxic areas, 233 are areas of concern and 13 are systems in recovery. The map is based on research conducted by WRI’s NutrientNet program and Dr. Bob Diaz at the Virginia Marine Institute.

Agriculture, growing industry, fossil fuel combustion, and population growth are together causing significant growth in areas receiving nitrogen and phosphorous endflows. Over the past 50 years, nitrogen flux has doubled and phosphorus has tripled, according to the Millennium Ecosystem Assessment. These cumulative changes are, quite literally, choking coastal waters around the world.