A modelling study published online in the journal Animal Conservation has shown how removing sources of lead-based paint on an albatross breeding island will give the population a respite while international efforts continue to reduce mortality from fisheries at sea: considered to be a harder problem to address.
A simple deterministic modelling approach was used to evaluate the impact of chick mortality from ingestion of lead-based paint on the population growth rate of Laysan Albatrosses Phoebastria immutabilis breeding on Sand Island, Midway Atoll (part of the USA's Papahanaumokuakea Marine National Monument and a nominated World Heritage Site to be considered for listing next year, click here for earlier news item). Up to 7% of the chicks on the island fail to fledge as a result of lead poisoning each year, estimated to result in a 16% reduction in population size ( some 190 000 less birds) 50 years in the future.
Myra Finkelstein, an environmental toxicologist at the University of California, Santa Cruz, who co-authored the publication, has been reported as saying she hopes that the recent findings will help spur cleanup efforts on Midway Atoll, where lead-based paint from abandoned military buildings contaminates nearby nests.
In 2003, Finkelstein identified the source of lead poisoning on Sand Island as 95 decaying buildings covered in lead-based paints. Chicks eat the paint chips that blow or fall into their nests. She also observed chicks eating peeling paint directly from the buildings. The most visible symptom of lead poisoning in chicks, called "droopwing," is an inability to lift their wings as a result of the toxic effects of lead on the nervous system. Chicks with droopwing are not able to fledge and die from starvation or complications of lead poisoning.
About half of the world's 2.5 million Laysan Albatrosses breed on Sand Island. According to the study, removal of lead paint from the island could increase the island's population by some 100 000 birds within 25 years.
See also: http://www.physorg.com/news175962474.html to view a picture of a Laysan Albatross chick with "droopwing".
Reference
Finkelstein, M.E., Doak, D.F. Nakagawa, M., Sievert, P.R. & Klavitter, J. 2009. Assessment of demographic risk factors and management priorities: impacts on juveniles substantially affect population viability of a long-lived seabird. Animal Conservation DOI: 10.1111/j.1469-1795.2009.00311.x. http://www3.interscience.wiley.com/journal/122655647/abstract.
John Cooper, ACAP Information Officer, 20 November 2009