Christian McDonald knew in high school that he wanted to work in the marine science area when he grew up. He was on the swim team, and started diving when he was 15. He studied Marine Biology at the University of California at Santa Cruz, became involved in scientific diving, and later taught the subject there. While at Santa Cruz, his diving skills got him to Alaska for five months. He helped in a study of sea otter ecology in the underwater kelp forests that stretch along the Pacific coast from Baja California to the Aleutians.
Sea otters eat urchins, and urchins eat kelp.
The sea otter population was decimated in the last century, but now they are gradually returning. Christian first came to Antarctica in 1997 to help in a study of pollution around McMurdo Station. Although in recent years efforts have been made to reduce pollution at the base, in earlier times people were not as concerned about the Antarctic environment. Particularly worrisome are hydrocarbon and heavy metal pollution in Winter Quarter's Bay. Christian placed samples with known pollutant levels on the bottom, and retrieved them later to find out what organisms could tolerate what levels of pollution.