Worms and Flowers

Toxic Algae Blooms Fueled by Fertilizer

Posted in Environment by Lzyjo on December 25, 2008

Every year between August and October cyanobacteria bloom, forming masses of brilliantly-colored blue-green flowers. There is fossil evidence that Cyanobacteria existed more than 2,000 million years ago. Before the Proterozoic Eon, cyanobacteria were the primary producers of nitrogen, capable of fixing the valuable nutrient from the atmosphere and more importantly, producing oxygen as a by-product, which caused an explosion of life on earth. Cyanobacteria have formed symbiotic relationships with many species. The bacteria is found in the roots of cycads, in rice paddies, and even in the fur of sloths. Cyanobacteria have made life on earth possible, but the blooms of some species produce toxins that are harmful to the nervous system, liver, and skin.

People and cyanobacteria have coexisted practically since the beginning of time. Only recently have things spun out of control. Excessive algae blooms, which smother aquatic life, have become a global problem, from Alaska’s Bering Sea to the Tasman Sea, surrounding New Zealand and Australia. Because of cyanobacteria’s ability to fix nutrients, synthetic fertilizers, particularly phosphorus, cause the cyanobacteria take over, choking-out other vegetation, which is left to die and be decomposed by bacteria. These bacteria require oxygen and quickly use up all the dissolved oxygen that is available. A healthy aquatic ecosystem retains 80% dissolved oxygen at all times. When available oxygen drops below 30%, it is termed hypoxic or anoxic, fish, crabs, and anything that is living, dies. In the U.S., many areas are effected, there are dead zones off of the Mid-Atlantic Coast, Gulf of Mexico, and Pacific North-West. Florida’s St. Johns Rivers has been dubbed the Green Monster due to the algae blooms which have overrun the river. These dead zones cannot support aquatic life and have caused great economic damage to the lucrative fishing industry.

If we think back to a basic idea we learned in elementary school, about the continental divide. All water East of the Continental divide drains into the Atlantic and the Gulf and all water West of the continental divide goes into the Pacific. If this is true, than all fertilizer applied to each side of the continent will go into one or the other, that is, if it is not used by the plants it is applied to and allowed to leach away from the farmer’s field and into the water supply.

The EPA’s own documents agree that it must implement a numeric value for permissible levels of nutrients in water. Current regulations rely on a narrative paragraph, which states that nutrients should not be found in the water, but it does not give a numeric value and is therefore unenforceable.

Because cyanobacteria is found virtually everywhere, in fresh water, salt water, and land, there is an extremely high risk that surface drink water sources will become contaminated. The toxins are known to cause tumors, skin irritation, respiratory irritation, and other health complaints in residents who were exposed to the toxins in their water. A condition known as Baby Blue Syndrome is caused when infants, who have not been breast-fed, consume water containing toxins from cyanobacteria. In the anaerobic conditions of a newborn child’s stomach, the toxins produce changes in the blood that prevent the hemoglobin from carrying oxygen, thus suffocating the child from the inside-out.

Recently, there have been scares about manure and bagged soil contamination, which have revealed that historically, civilizations used dung as a fuel source, rather than a fertilizer. So what makes the ideal fertilizer? The cells of everything are made of carbon, and carbon balance is an important part of making compost, yet commercial fertilizers only include the nutrients N-P-K, plus what-ever filler adds up to 100, if the four numbers are added together. Good quality soil looks like black gold; moist, crumbly, full of organic material, and carbon. An NPR article, about global warming and farming shows that carbon dioxide is released when carbon rich soil is tilled, gradually depleting the soil quality and exhausting significant amounts of Carbon Dioxide into the atmosphere. By using cover crops that are retilled into the soil and composting carbon-rich corn stalks and garden waste, carbon and nitrogen are stored in the soil to enrich next year’s crops.