This week at Macquarie Island: 3 November 2017

Since the start of spring, thousands of southern elephant seals (Mirounga leonina) have taken up temporary residence on many of Macquarie Island’s beaches to breed. Elephant seals are the largest of all seal species — males can weigh over 3000kg. They are called elephant seals due to the size and large ‘trunk’ or proboscis (nose) of the mature males.

Large dominant males (known as beachmasters) arrived first to secure parts of beaches as their territory. Throughout September and October, pregnant females returned to the beaches they were born on, gathering in groups called harems to have their pups. Pups are fed for about three weeks, rapidly increasing in size from about 40kg to 120kg.

There is a lot of commotion on the beaches as the beachmasters battle for the control of harems, females raucously bicker with their neighbours, and scavenging skua and giant petrels are constantly on the lookout for a meal. Some harems can be very crowded — over 500 females were counted in the biggest one this year.

The commotion will now gradually diminish as the black furry pups quickly transform into plump sleepy weaners and their mothers go back to sea to forage and recover.

Andrea Turbett — Ranger In Charge

Exciting times at Macca this week with the very unexpected arrival of an iceberg!

First sighted off the station west coast shortly after 7 pm on Wednesday 31 October by our BoM Senior Observer Matt Westbury, the iceberg ('Mattberg’ as Matt has named it) is estimated by Antarctic Division glaciologists to be a few hundred metres long.

For many on station, it was their first time seeing an iceberg, so a very exciting discovery! 

After reviewing satellite imagery, our scientific colleagues from the Antarctic Climate and Ecosystems Cooperative Research Centre (ACE CRC) have indicated there aren’t any further bergs in the immediate area and that it may be the ‘Mattberg’ is the biggest and others have broken off and melted already.

With Macca lying some 1800-kilometres away from the Antarctic, it is quite uncommon for icebergs to be this far north; 2009 was the last time icebergs were sighted near Macquarie Island.

As of Thursday, we are seeing pieces of Mattberg wash ashore on our west coast beach, with Mattberg likely to continue to melt and break-up as it moves north.

A big thanks to station communications technician Tom, mechanic Lionel, and building services supervisor Dave whose excellent photography skills ensured we captured some great images of the Mattberg!