Showing posts with label laysan albatross. Show all posts
Showing posts with label laysan albatross. Show all posts

Monday, 23 April 2012

Old Paint is Killing Rare Birds: Cleaning Up Toxic Lead on Midway Atoll

There is a piece of Midway's past that is haunting today's albatross. Amid the crumbling buildings built by the Commercial Pacific Cable Company at the turn of the last century nest many thousands of Laysan albatross and burrowing Bonin Petrels. But they nest in soil that has been contaminated by decades of lead-based paint, and the exposure causes a neurological disorder called "droopwing" in which the chicks are unable to lift their wings.

This disorder means certain death for the birds. Every year, thousands of the Laysan albatross chicks die from droopwing, and even if they manage to fledge and fly off, the levels of lead in their bodies likely cause an early death later on.
The Environment News Service reported two years ago that 70 of the old buildings "have been responsible for the deaths of as many as 130,000 Laysan albatross chicks since jurisdiction of Midway was transferred from the Navy to the Department of the Interior in 1996" and that as many as 10,000 chicks a year die from disorders and illness caused from ingesting the lead paint chips.
This is an incredible loss, especially since the Laysan albatross is a threatened species and about 70% of the world's population nests on Midway Atoll.
The same article states, "[S]cientists and managers from the U.S. Geological Survey and the U.S. Fish and Wildlife Service, concluded that by 2060, there may be 190,000 fewer albatrosses due to lead poisoning. By contrast, removing lead-based paint now could increase the albatross population by up to 360,000 by 2060."
Those numbers are convincing, and that's why a reported $20 million budget as been provided to clean up the lead problem, and the massive project has gotten started.

Wednesday, 1 February 2012

Land of the rising Sunfish

New observations of Sunfish behaviour have revealed an intriguing symbiotic relationship with Laysan Albatross.


When Japanese researchers in the western North Pacific observed a school of Sunfish appearing to actively follow Laysan Albatrosses resting on the sea, they were soon to discover that this behaviour was mutually beneficial. The juvenile Sunfish, measuring about 40 cm across, were heavily infested with a parasitic worm-like copepod Pennella, a kind of crustacean, which held somewhat of an attraction for the birds. It soon became apparent that the albatrosses were feeding on the worms, as one was photographed doing just this.


The observers suggest that this cleaning behaviour may be frequent in the lifestyle of Sunfish, as the fish seem to actively seek out the birds, which then relieve them of their parasitic. the Sunfish school numbered about 57 individuals and were swimming right at the surface, exhibiting no defensive or evasive behaviour. The feeding actions of one Laysan Albatross soon attracted more, including a black-footed Albatross too. Some of the Sunfish appeared to present themselves by swimming sideways next to the birds, the better to show their parasites.

On a pelagic birding trip, Sunfish are often one of the major non-avian attractions a they swim on or near the surface, and it had been suggested that this behaviour might be due in some respect to their parasitic load. It would now appear that this might actually attract seabirds to remove the parasites. sunfish have also been noted to have associations with Sooty Shearwaters for possibly the same reason, and are attended by cleaner fish species.


Sunfish is the largest marine bony fish species, growing up to 2.7 m in length and weighing up to 2.3 tonnes. Laysan Albatross is a wide-ranging seabird in the North Pacific, with an estimated global population of over 1,180,000, though it is classed as Near Threatened by BirdLife International due to historical declines, but there are also signs that there has been a recent range expansion.


Reference
Abe, T, Sekiguchi, K, Onishi, H, Muramatsu, K and Kamito, T. 2012. Observations on a school of ocean sunfish and evidence for a symbiotic cleaning association with albatrosses. Marine Biology DOI 10.1007/s00227-011-1873-6

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