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Why Phytoplankton is so Important

Updated: Nov 28, 2022

By Vicki Patterson

Phytoplankton are some of Earth's most critical organisms and so it is vital study and understand them. They generate about half the atmosphere's oxygen, as much per year as all land plants. Phytoplankton also form the base of virtually every ocean food web.

These microscopic creatures not only contribute at least 50 percent of all oxygen to our atmosphere, they do so by capturing about 37 billion metric tons of CO2, an estimated 40 percent of all CO2 produced. To put things in perspective, calculating that this is equivalent to the amount of CO2 captured by 1.70 trillion trees—four Amazon forests’ worth—or 70 times the amount absorbed by all the trees in the US Redwood National and State Parks each year. More phytoplankton means more carbon capture.

Climate change is shifting not only the intensity of phytoplankton blooms, but their composition. Harmful algal blooms (also known as red tides) are expected to increase as the oceans warm.

Biotoxins released from the blooms can cause large-scale die-offs of fish and shellfish, with knock-on effects to coastal economies.

HABs may be linked to 'overfeeding.' This occurs when nutrients (mainly phosphorus, nitrogen, and carbon) from sources such as lawns and farmlands flow downriver to the sea and build up at a rate that 'overfeeds' the algae that exist normally in the environment.

Excess nitrogen from the fertilizers can cause eutrophication in the ocean, which can lead to harmful algae blooms or hypoxia — reduced levels of oxygen that create conditions in which organisms can’t survive.

How Does Fertilizer Affect The Environment?

When the excess nutrients from all the fertilizer we use runs off into our waterways, they cause algae blooms sometimes big enough to make waterways impassable. When the algae die, they sink to the bottom and decompose in a process that removes oxygen from the water.

Run-off from farmers or neighborhood gardeners using non organic nitrogen rich and potassium rich fertilizers leads to little algal growth and organisms cannot get the oxygen they need. Farmers and gardeners using phosphorous rich fertilizer are also detrimental to wetland marine life because their run-off causes the overgrowth of algae blooms.

Organic gardening is so vital in keeping our oceans alive!

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