... in 1998, NASA satellite data showed that the antarctic ozone hole was the largest on record, covering 27 million square kilometers; researchers in 1997 found that increased ultraviolet light coming through the hole damages the DNA of icefish, an antarctic fish lacking hemoglobin; ozone depletion earlier was shown to harm one-celled ... — The 2000 CIA World Factbook • United States. Central Intelligence Agency. Read full book for free!