Date: July 13, 2016
Source: Central Ornithology
Publication Office
Shorebirds breeding in Alaska are
being exposed to mercury at levels that could put their populations at risk,
according to new research from The Condor: Ornithological Applications.
Thanks to atmospheric circulation
and other factors, the mercury that we deposit into the environment tends to
accumulate in the Arctic. Mercury exposure can reduce birds' reproductive
success and sometimes even be lethal. Shorebirds may be particularly vulnerable
because they forage in aquatic environments where mercury is converted into
methylmercury, its most dangerous form. Marie Perkins of the Biodiversity
Research Institute (BRI) and her colleagues investigated the level of mercury
in Alaska's shorebirds and found that some birds breeding near Barrow, at the
state's northern end, have mercury concentrations upwards of two micrograms per
gram of blood.
"These species already face
a lot of tough new challenges, from climate change to disappearing stop-over
habitat, so throwing a neurotoxin in the mix that can reduce reproductive
success is likely to harm their populations," according to Dan Cristol of
the College of William & Mary, an expert on mercury in birds who was not
involved with the new study. "The mercury concentrations reported in this
paper are likely to reduce reproduction, but not catastrophically, based on
what we know from other species. What may be even worse, though, is that these
mercury levels probably spike when they leave the breeding grounds and start
burning their reserve fuel, making their already arduous continent-jumping
trips even harder."
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