The bird at risk is the ivory gull. The ivory gull (Pagophila eburnea) is a small gull (17 inches tall) which breeds in the high Arctic. In non-breeding seasons the bird can be found in Greenland, Canada, and Eurasia. Unusually for a gull, the bird has a totally white plumage.
There are around 20,000 birds in existence. The species is said, by the International Union for Conservation of Nature, to be in rapid decline and the status is “threatened.”
As well as habitat loss and risk from predators, the ivory gull has a new threat: mercury poisoning. New research, based on a review of museum specimens, indicates high mercury levels in the gulls. The analysis spanned the time period from 1877 to 2007. Here the increase in mercury levels was over fifty times, with the greatest rises occurring over the past thirty years.
The finding with the gulls is consistent with rising mercury levels in other Arctic birds, fish and mammals. The source of the mercury probably relates to atmospheric pollution. The gull is a good indicator of mercury levels due to the absorption of the toxin into its feathers. The direct concern with the gulls is that, in time, this will affect the bird’s reproduction.
Lead researcher Dr Alex Bond told the BBC: “We figure in the next 50 to 70 years, we’re going to see deleterious effects such as reduced reproduction and an inability to forage or find a mate or raise a chick every year.”
A number of nations have pledged to reduce levels of mercury pollution. In 2013, 94 countries signed the Minamata Convention on Mercury, which is a global treaty to protect human health and the environment from the adverse effects of mercury. Provisions include a banning new mercury mines, phasing-out of existing mines, control measures on air emissions, and the international regulation of gold mining.
The research was performed by scientists working at the University of Saskatchewan, Canada. The findings have been reported to the journal Proceedings of the Royal Society of London B- Biological Sciences. The paper is called “Rapidly increasing methyl mercury in endangered ivory gull (Pagophila eburnea) feathers over a 130 year record.”