And why have ocean nutrients been decreasing? And how do we stop that decrease? What is causing the dead zones?
Some have theorized that mankind, via soil conservation efforts, have interdicted the natural wind born dust clouds. This would apply to areas that are far away from a land area.
However, Brumar is also correct that algae can be fed by agricultural fertilizer run-off from rivers and literally kill an area. But these kinds of algae are not the preferred forms, such as Diatoms.
Diatoms have a hard shell, which adds the necessary weight to drag the dead algae to the ocean bottom, whereas non-shell algae will float on the surface and decay, releasing methane and depleting available oxygen. It's not the growth of the algae, but it's decay that depletes the oxygen, which is why it's so important to foster the ocean's biological pump and sequester the CO2 they've captured.
That's why it's been recommended that when OF is attempted, it should be a mixture of both Iron and Silica, which would foster the growth of Diatoms and other frustule forming algae.
Hawk |
