Murder under the Microscope 2014 Online Tasks
Secondary Quiz 3 Macquarie Island
Macquaire Island
Half way between Tasmania and Antarctica in the Southern Ocean, the rugged windswept
Macquarie Island is a success story in the eradication of feral animals. Rabbits, rats and mice caused
erosion, destroyed vegetation and disrupted the breeding of many species of bird. The eradication
process was both painstaking and expensive. First they had to determine that the program would
not impact on the elephant seals, fur seals, sea lions, penguins and other birdlife such as albatross
that use the island for breeding. The albatross can soar for 1000km a day with little effort in search
of food, but return annually to where they hatched to breed. They form lifelong pair-bonds. The
rabbits were brought to the island by sealers about one hundred and fifty years ago. Since then the
rabbits invaded most parts of this cold rugged island, eroding the soils with their burrows and
building up to a population of about 100 000. Workers initially reduced the populations by dropping
baits using helicopters. After the feral populations were in decline, they followed up with three years
of scouring the island with specially trained dogs that were able to detect any remnant individuals.
They assumed that any feral pest that survived on the inaccessible cliffs would by then have
ventured into the path of the dogs and their handlers. Even the survival of one breeding pair would
have been considered a failure.
Not always has Macquarie Island been a conservation area. It was discovered by Europeans in 1810
by a sealer from Sydney. The fur seal population was decimated in 10 years with 120 000 seals being
killed in the first eighteen months of sealing. The elephant seals were the next to be exploited. By
the 1840’s they had moved on from the elephant seals who had been harvested for their oil-rich
blubber until they, too were depleted. Next the king penguins were an easy target, even if not quite
so useful for oil production. They finally demonstrated their adaptability by targeting the royal
penguins on another part of the island.
The fact that today 850 000 breeding pairs of royal penguins breed on the island is a testament to
the resilience of the species and that conservation measures that commenced in the 1960’s were
not too late.
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Murder under the Microscope 2014 Online Tasks
In 1997 Macquarie Island received World Heritage listing. Part of the reason for this listing is its
unique geology, being the result of the junction of two tectonic plates and the uplift of an undersea
ridge that exposes rocks from deep crust and upper mantle that can be seen in this pristine form
nowhere else on the Earth’s surface. The ridge broached the ocean surface about 600 000 years ago
and is still uplifting. The uplift has been likened to toothpaste being squeezed out of tube. Pillow
basalt formations that result from lava extruded into the ocean, basalt flows and dyke extrusions
help comprise this rugged island. Earthquakes are frequent and can be severe. This is the nearest
Australia gets to tectonic plate boundaries.
Watch resource: Macquarie Island 7.30 program 4.25 minutes
http://www.abc.net.au/7.30/content/2014/s3983044.htm
Read/ research in greater depth from http://www.antarctica.gov.au/living-andworking/stations/macquarie-island
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