Dead zones in the oceans have quadrupled in size since 1950 – a dramatic surge that has been linked to the animal agriculture industry by scientists.
A new study published in the journal Science found that areas devoid of oxygen in open ocean have soared in the past 50 years, with the number of very low oxygen sites near coasts having multiplied tenfold.
Scientists are warning that this could lead to mass extinction in the long run, as sea creatures cannot survive in these zones – and could also negatively impact the hundreds of millions of people who depend on the sea.
The new study represents the most comprehensive view yet of ocean oxygen depletion, and was published by scientists from GO2NE (Global Ocean Oxygen Network), a United Nations working group which investigates the impact of oxygen loss from the oceans.
Climate change and pollution are main drivers for the large-scale deoxygenation of the oceans.
An expert argued that ”unchecked pollution from industrial agriculture’ in particular has led to the shocking findings.
Lucia von Reusner, campaign director of campaign group Mighty Earth, which recently exposed a link between the dead zone in the Gulf of Mexico and large scale meat production, said: “These findings are no surprise, and further confirm that the unchecked pollution from industrial agriculture has reached crisis levels and requires immediate action.”
Pollution from meat producers
She adds: “These dead zones will continue to expand unless the major meat companies that dominate our global agricultural system start cleaning up their supply chains to keep pollution out of our waters.
“Companies like Tyson Foods are driving the demand for vast quantities of unsustainably-produced corn and soy [animal feed] that are leaking the bulk of the nutrient pollution into our waterways, in addition to the manure that is often dumped on fields where it then washes off into surrounding waterways.”
Denise Breitburg, at the Smithsonian Environmental Research Center in the US and who lead the analysis, explained the grim situation that Earth is facing.
“Oxygen is fundamental to life in the oceans. The decline in ocean oxygen ranks among the most serious effects of human activities on the Earth’s environment.
“Major extinction events in Earth’s history have been associated with warm climates and oxygen-deficient oceans.”
Breitburg highlights: “Under the current trajectory that is where we would be headed. But the consequences to humans of staying on that trajectory are so dire that it is hard to imagine we would go quite that far down that path.”
She goes on to say that it’s ‘a problem we can solve’: “Halting climate change requires a global effort, but even local actions can help with nutrient-driven oxygen decline.”
She pointed to recoveries in Chesapeake Bay in the US and the Thames river in the UK, where better farm and sewage practices led to dead zones disappearing.
But Prof. Robert Diaz at the Virginia Institute of Marine Science, who reviewed the new study, believes: “Right now, the increasing expansion of coastal dead zones and decline in open ocean oxygen are not priority problems for governments around the world.
“Unfortunately, it will take severe and persistent mortality of fisheries for the seriousness of low oxygen to be realised.”