In an alarming discovery, marine biologists have said that they are able to confirm the existence of “dead zones” in the open ocean for the first time.
Dead zones are areas of the ocean, or deep water, where the water is so lacking in dissolved oxygen that marine creatures cannot survive in that area.
Dead zones are normally found along densely inhabited coastal areas, many of the “dead zones” are located off the eastern and southern coasts of the United States or the Baltic Sea. Most of these coastal dead zones are caused by the run-off of fertilizer into the ocean or other man-made pollution that trigger massive build of algae.
The combined German and Canadian researchers discovered the first deep ocean dead zones less than 100 kilometers from the Cape Verde archipelago, which is in the Atlantic Ocean just off West Africa. The dead zones were found to be in huge whirlpools which are moving along the Atlantic.
The researchers confirmed that the slowly moving whirlpools could trigger an enormous fall of in fish and other marine life in the area. This could potentially lead to an economic collapse among Western African countries.
“It is not unlikely that an open-ocean dead zone will hit the Cape Verde islands at some point,” said Dr. Johannes Karstensen of the GEOMAR Helmholtz Centre for Ocean Research Kiel. Dr. Kartensen was also the lead author of the study published in the scientific journal, Biogeosciences.
Dr. Karstensen explained that the dead zones are located inside ocean whirlpools or spinning cylinders of ocean and has a size of 150 kilometers across and several hundred meters deep. Weather.com said the reasoning for this was that the whirlpools were formed when a current along the West African coast became unstable and was pushed slowly westward by the Earth’s rotation.
Dr. Karstensen said oxygen concentrations in the dead zone are as much as “20 times lower than the previously recorded minimums in the North Atlantic.” This dramatic fall off means that these areas have become almost entirely uninhabitable to all marine life other than a few microorganisms.
Coastal dead zones are formed when bacteria consume the oxygen as they eat dead algae sinking towards the sea floor. Dr Karstensen said the deep ocean zones appear to be operating in a similar manner.
The alarming discovery of the first open ocean dead zone is increasing concerns that warming oceans might trigger an increase in the more than 400 known dead zones worldwide. The reason this matters is that a still enormous amount of the world economy and food production is based on fishing. If, and potentially when, the amount of dead zones increases there could be a massive destabilising effect worldwide.
Another worrying sign is that the size and number of marine dead zones have grown explosively over the past half-century. This can only truly be attributed to humans considering the explosion of population and the increase in the use of pesticides which are running off into the ocean causing these catastrophic changes to the world’s oceans. Hopefully something can be done before this problem becomes irreversible but the only current change which could be made is a change in the use of fertilizer, and that appears unlikely.