Bloom Blog

Insights from Michael Bloomfield, Founder and Executive Director of the Harmony Foundation

Phytoplankton Vanishing from Warming Oceans- World’s Oxygen Supply Threatened

The scientific headlines scream looming disaster as the ocean’s phytoplankton steadily populations drop.  The public yawns, who cares if phytoplankton, the microscopic plants that live in the ocean, are disappearing?  You can’t eat them.

We better care; these tiny organisms gobble up carbon dioxide and produce half the world’s oxygen—equaling that of trees and plants on land. They are the basis for life in the world’s oceans.

According to recent studies led by Dalhousie University, phytoplankton populations are in significant decline, and the implications for both marine life and life on Earth
could be immense.

According to the study, published on July 29th in Nature, the world is losing an average of one per cent of its phytoplankton each year, and the northern hemisphere has lost roughly 40 per cent since 1950.[1]

The study, which took three years to complete, is the first comprehensive survey of for the global populations of these microscopic organisms and the results are disturbing, that is if you care about life.

In order to understand the significance of this decline, we must first understand the significance of phytoplankton.

Phytoplankton is the staple upon which the entire marine food chain is built.  Phytoplankton is the main source of food for zooplankton, which in turn is the staple for many small fish and other sea creatures, which are then eaten by the bigger fish and large mammals such as seals and whales. A decline of phytoplankton harms the entire food chain, and is contributing mightily to the decline of all life in the ocean.

But the consequences of losing these microscopic beings are far greater!

The role of phytoplankton goes well beyond the marine environment.  Like terrestrial vegetation, phytoplankton photosynthesizes and in doing so consumes carbon dioxide and produces about half of the world’s oxygen supply.

The phytoplankton of the seas provide an enormous carbon sink, one essential for absorbing the huge volumes of carbon we have and increasingly release through fossil fuel consumption. As such Phytoplankton plays an enormous role in the world’s carbon cycle and therefore the stability of the global climate.

What has caused this dramatic decline?

While the exact causes are unclear, researchers of the recent study suspect that there is likely a strong correlation between the decline and rising sea temperatures. As surface water warms, it tends to form a distinct layer that does not mix well with cooler, nutrient-rich water below, depriving phytoplankton of some of the materials they need to turn CO2 and sunlight into energy.

The loss of phytoplankton therefore, seems to be part of a very troublesome feedback loop. Rising ocean temperatures are driving a decline the Earth’s natural ability to absorb carbon dioxide, which is in turn leading to a greater abundance of greenhouse gasses, which leads to warmer oceans.

More than a wake- up call this study should set off alarm bells.  Urgently we need it more research and analysis.  We can’t even begin to address this problem, this broken natural cycle, without a fuller understanding of all the factors that are driving this population decline.

As the CBC reports there have already been calls for drastic intervention and bioengineering schemes to add more nutrients to ocean water to boost phytoplankton growth.[2]

Clearly action is needed, but we should also be wary of the laws of unintended consequences— a law that when combined with hubris and human arrogance is perhaps largely responsible for getting us into this mess in the first place.

In the meantime, on our regularly scheduled program, “The small fish eat the little ones, the big fish eat the small ones, not my problem, give me some! * Well, it is our problem and I encourage you to think about it.

* (With apologies to Radiohead).




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This entry was posted on September 28, 2010 by in Commentary: Current Events.
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