H/t reader squodgy:
“Could the fertiliser, pesticide and herbicide run off from intensive farming be a contribution to this?
It is known in UK that run offs cause algal blooms and fish loss in lakes, so why not the sea?”
CHICAGO (Reuters) – As much as 1 million times the normal level of methane gas has been found in some regions near the Gulf of Mexico oil spill, enough to potentially deplete oxygen and create a dead zone, U.S. scientists said on Tuesday.
– ‘Dead zones’ found in Atlantic open waters (The Watchers, May 15, 2015):
A team of German and Canadian researchers have discovered areas with extremely low levels of oxygen in the tropical North Atlantic, several hundred kilometres off the coast of West Africa. The levels measured in these ‘dead zones’, inhabitable for most marine animals, are the lowest ever recorded in Atlantic open waters. The dead zones are created in eddies, large swirling masses of water that slowly move westward. Encountering an island, they could potentially lead to mass fish kills.
Dead zones are areas of the ocean depleted of oxygen. Most marine animals, like fish and crabs, cannot live within these regions, where only certain microorganisms can survive. In addition to the environmental impact, dead zones are an economic concern for commercial fishing, with very low oxygen concentrations having been linked to reduced fish yields in the Baltic Sea and other parts of the world. Continue reading »