1994 Arctic Ocean Section
dividual bears compare with those of bears found nearer to the continental
Mother and cub
prior to capture.
shelves. To meet our goals we planned to capture as many polar bears as possi-
ble and to determine, using genetic and morphological methods, their degree
of affinity with animals from known populations.
The increased use this century of environmentally persistent chlorinated
hydrocarbon (CHC) compounds in industrial and agricultural practices has
led to global contamination of the world's ecosystems. Although human popu-
lation densities and industrial activity are low in Arctic regions, CHCs
released in more southerly latitudes are advected north through a variety of
physical processes and eventually reach the Arctic Ocean and its fauna. These
compounds are lipid soluble and tend to become sequestered in the energy
storage tissues of exposed organisms. At each successive stage in a food web,
CHCs become more concentrated in the tissues of the animals, a process called
bioaccumulation. Polar bears are at the top of the relatively long Arctic marine
food web, so their contaminant loads are relatively high and reflect an integra-
tion of the entire marine environment. Polar bears can be considered an "early
warning" species reflecting global changes in the Arctic. Consequently a second
goal on the voyage was to collect tissue samples from live-caught polar bears
for monitoring the extent of organochlorine contamination in the remotest
parts of the Arctic marine environment.
A watch for marine mammals was conducted from the bridges of both vessels.
The sea ice was scanned in a narrow band no more than a few kilometers wide
along the track of the ships' path. When helicopters forayed out from the