nutrient pollution

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Restrictions in Seaweed Agar-vate Scientists

Thursday, December 17th, 2015
Bivalves from Panama for Dermo disease study

Bivalves from Panama for Dermo disease study

by Heather Soulen

Last week Nature magazine published a news piece about how supplies of agar, a research staple in labs around the world, are dwindling. Agar is a gelatinous material from red seaweed of the genus Gelidium, and is referred to as ‘red gold’ by those within the industry. Insiders suggest that the tightening of seaweed supply is related to overharvesting, causing agar processing facilities to reduce production. Most of the world’s ‘red gold’ comes from Morocco. In the 2000s, the nation harvested 14,000 tons per year. Today, harvest limits are set at 6,000 tons per year, with only 1,200 tons available for foreign export outside the country. In typical supply and demand fashion, distributor prices are expected to skyrocket. As a result, things could get tough for scientists who use agar and agar-based materials in their research.

Agar is a scientist’s Jell-O. Just like grandma used to make Jell-O desserts with fruit artfully arranged on top or floating in suspended animation within a mold, scientists use agar the same way. Bacteria and fungi can be cultured on top of nutrient-enriched agar, tissues of organisms can be suspended within an agar-based medium and chunks of DNA can move through an agarose gel, a carbohydrate material that comes from agar. Agar and agar products are the Leathermans of the science world.

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Smithsonian Study Measures Watershed-wide Effects of Riparian Buffers on Nutrient Pollution

Wednesday, October 27th, 2010
Aerial photo of farmland and streams - with trees growing in between them.

Well-developed riparian forests outline streams and help protect stream water quality.

Most of the time, nutrients are viewed as a positive and essential part of life. However, excess amounts of a nutrient, like nitrogen, can create major ecological problems for the Chesapeake Bay and other aquatic ecosystems. Too much nitrogen leads to an abundance of microscopic plant growth in the water. When the algae die and decay, they consume the oxygen that other organisms need to thrive.

Much of the Bay’s nitrogen pollution comes from farms where rainwater carries nitrate, a form of nitrogen, from fields into streams that drain into the Bay. For years, ecologists have noted that forests and wetlands growing between croplands and streams can reduce the amount of nitrate that reaches the waterways. Scientists have measured nitrate removal by these “riparian buffers,” but only in small study areas.
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