AND THEY ALL GO BLIND
by Bruce Torrie
copy and distribute
In spring 1995 the Associated Press reported that penguin chicks were "starving to death near one of Australia's bases in the Antarctic... the penguins can't find enough krill; small shrimp like crustaceans they depend on for food" (1). In 1995 reports circulated that 10-15% of the estimated 3.3 million grey kangaroos in Australia have been "blinded from a mysterious virus" (2). Researchers are suggesting that this epidemic may be due to increased levels of ultraviolet-B radiation (UVB) turning off the kangaroos' immune system, leaving them prone to previously harmless viruses.
The Antarctic spring and summer of 1995 saw the most profound depletion of atmospheric ozone ever: a hole with a 75% depletion stretching over an area larger than the entire North American continent. The thickness of ozone and the area affected under the hole fluctuated and moved with the weather, exposing a vast area of ocean to hitherto unprecedented levels of UVB.
In the usually remote regions surrounding Antarctica legions of scientists and support staff have been struggling to evaluate the impacts of the massive dose of UVB now penetrating the tattered south polar ozone shield. One of their first observations was a personal one; the researchers skin blistered and burned despite heavy use of chemical sunscreen products.
Prior to our production and release of ozone depleting substances, the layer that protects life on Earth from harmful radiation was thickest at the poles. Scientists now think that this may be the reason for the great abundance of life present in the polar and sub-polar oceans. Indeed the primary reason for man's visitation to the polar regions prior to this new flurry to study UVB impacts was to harvest the rich abundance of fish, marine mammals and krill which flourished under the thick polar ozone shield. So what observations have the scientists made under the ozone hole, and how will this affect us in the temperate and equatorial regions of the world?Atmospheric Equilibrium and Climate
As of June, 1995 is looking to be the warmest year in recorded history. Record breaking temperatures bake the northern hemisphere. Global warming can be accelerated by the presence of the polar ozone holes, and it is now clear that UVB is dramatically damaging plankton.(3) Phytoplankton are tiny plants which float in the water column. Zooplankton are tiny animals which graze on the phytoplankton. These two tiny organisms are critical to the oceanic food supply and the phytoplankton are the main climate control center for the planet. In the Antarctic spring as the ice recedes, vast blooms of plankton feed off carbon dioxide from the air and oceans. By this process vast amounts of CO2, which is an effective "greenhouse" gas are removed by the plants, who build their bodies out of the carbon, and release the oxygen into the system, thus helping to keep CO2 levels down in the atmosphere. Research is showing that these plankton are very negatively affected by the high levels of UVB now reaching the polar and sub-polar environments.(4)
New research has identified that nano and pico plankton, extremely tiny organisms, are much more abundant than previously estimated. If we evaluate the abundance of plankton globally including these two we find that the "plankton" is 10 to 100 times as abundant in the polar and sub-polar regions as it is in the temperate and equatorial oceans. Accordingly most of the world's biomass is now, or will in the near future, be exposed to unprecedented levels of UV radiation.
Research has been published indicating that plankton communities are dramatically affected by UVB.(5). Not only is the total plankton substantially reduced but some vital types of small plankton are completely destroyed. Unfortunately these small plankton used to be the main food source for krill; small shrimp-like plankton known as copepods, which often make up 70 - 90% of the zooplankton. The krill are vulnerable in several ways. According to David Lean, a senior research scientist with Environment Canada, "The little tiny ones were obliterated when exposed to UVB... in Antarctica the baby krill can only eat cells less than 20 micrometers in size. The baby krill give rise to big krill, and they are pivotal in the whole Antarctic food chain. Without krill you don't have whales; without krill you don't have seals. It is absolutely central to the whole Antarctic food chain."(6)
Krill and other zooplankton are also disappearing from some areas of the temperate regions. Reports show an 80% drop in the population of zooplankton off the coast of Southern California and researchers attribute this drop to global warming's effect on ocean currents and circulation.(7)
So we come full circle. UVR destroys small phytoplankton in the Antarctic, contributing to global warming and a collapse in the polar and sub-polar oceanic food supply. Global warming progresses and causes a collapse of the zooplankton in the temperate and equatorial oceans, further contributing to the collapse of the oceanic food chain. Reports of starving penguins and seals circulate, but provoke no popular concern or outrage. All the while the popular and scientific press offer little analysis or call for action. It remains impossible to buy a refrigerator in North America which does not contribute to ozone depletion or global warming. Car air conditioners are thrown in free with new vehicles! In Berlin this spring at the World Climate Summit, the U.S. and Canada blocked any progress on CO2 emission reductions and the world continues to destroy the forests, the terrestrial carbon sinks, by clearcut logging.
The penguins are washing up on the beaches, the kangaroos are being shot as they blindly search for water. All these things: the oceans, the trees, the air we breath, the food we eat and the sky above us are interrelated. Take out one and they all go. Better living through chemicals? Stay Tuned!
1) Associated Press story: Times Colonist, March, 1995
2) Associated Press story: Times Colonist, Victoria, B.C. May 16,1995
3) see: Ultraviolet Radiation in Antarctica: Measurements and Biological Effects: Weiler and Penhole (eds.) Vol. 62, Antarctic Research Series, American Geophysical Union, 1994.
4) IBID., and see Environmental Effects of Ozone Depletion: 1994 Assessment, UNEP pp. 65 -93
6) Proceedings of the International Conference on Ozone Depletion and Ultraviolet Radiation: Preparing for the Impacts. Heidorn and Torrie (eds.) 1995 p 115.
7) Climate Warming and the Decline of Zoo plankton in the California Current. Roemmich and McGowan in Science vol. 267 , March 3, 1995
go to BruceTorrie.ca Main Page