This week at the station
This week at Macquarie Island: 22 February 2013
Macquarie Island Pest Eradication Project
The big news here at Macquarie Island is that our season is coming to an end.
The Aurora Australis is scheduled to arrive on the 3rd March and as soon as it drops anchor we will commence resupply operations – a one year supply of food, fuel, building materials and essential station supplies will arrive by helicopter or larc over approx nine days. We’ll also welcome the new wintering team who will take our place and continue the good work, monitoring for any signs of rodents and rabbits. In addition to those coming ashore for 12 months, we’ll also assist numerous scientists and operational personnel to inspect, test, research, review and report on various projects while the ship remains in the harbour. It will be a very busy busy time.
The hunters arrive back on station Saturday 24th and on this day their work in the field comes to an end.
A message to the 2012 hunters (and their dogs) - Congratulations to you all! You’ve done an awesome job, you’ve worn out many pairs of boots and clothes during your 12 months walking every inch of the island (numerous times). To be a part of the Macquarie Island Pest Eradication project, a World Heritage listed island, is rewarding and an enormous achievement. The final result of your combined efforts will have such a long lasting positive outcome for the local inhabitants (Macca’s unique fauna and flora). Well done team!!!
Macquarie Island Ranger work
As the days are counting down until the big orange ship rolls over the horizon, the rangers and albatross staff are frantically trying to complete the works program. Last week we had two very enjoyable tourist ship visits and received many comments from tourists coming off a 28 day trip to the Antarctic via South America as to how enjoyable Macca was and many stated it was a highlight of their journey. On completion of the tourist ships, Paul and the albatross researchers walked down the island counting southern giant petrel chicks to complete the island-wide census. The other task planned is to complete long term photo monitoring to assess landslips and landscape changes. Unfortunately, over the past two weeks we have had poor weather for this task with much precipitation, and the Macca favourite, low cloud and mist. With only a little over a week to go, we have two more tourist ships but will squeeze in another field trip to complete the season's work.
With an earlier than expected resupply, Anna and Jaimie the albatross researchers are working at capacity banding grey-headed, black-browed and light-mantled albatross chicks on one last down-island mission.
It is an exciting time to be on Macca.
Science at 'Macca'
After a couple of weeks in the field, Jennie and Nick have provided the following update on their botanical findings:
Azorella macquariensis dieback
Azorella dieback is continuing to be active across the island, with almost no area completely free of dieback. However, the SMAs (Special Management Area) have good populations of healthy Azorella. We have completed 80% of the Azorella photo monitoring plots.
Vegetation recovery in the absence of rabbits
The 30 year vegetation/rabbit plots and exclosure plots have all been scored and photographed. Initial impressions are that there is amazingly rapid recovery in some of the most palatable and visible species (Stilbocarpa - Macquarie cabbage, Pleurophyllum and Poa foliosa - tussock grass). The shield fern, Polystichum vestitum, is showing good recovery in the exclosures constructed to conserve a 'seed' population, as well as in scattered locations across the island. Acaena minor also appears to be more common (although this might also be because we are earlier in the season). The introduced species Poa annua forms thick lawns in places.
Huperzia australiana populations
The enthusiasm and intense scrutiny of the vegetation by the MIPEP team has resulted in several new populations of Huperzia australiana being identified on the island. Previous inspections of populations has revealed that many of the plants were unhealthy and appeared to show signs of chlorosis. However, new populations with as many as 20 individual clumps per site, have been identified and inspected. Many of these appear quite healthy. These new populations mean a significant range extension, with the most southerly population being at Lusitania Bay (previously it was in Green Gorge basin). Kelly currently holds the record of most Huperzia found and Dave holds the record for the most southerly extension of the range.
The distribution and health of Sphagnum moss has varied over the 25 years that it has been monitored. Currently, the Sphagnum moss appears to be in good health and expanding at monitoring sites. A new population ofSphagnum moss was found just north of Pyramid Peak, extending southwards the previous known range of Green Gorge basin.
The most unexpected and exciting find of our visit has been the re-location of Galium antarcticum on the northern shore of Skua Lake. We found a total of 35 individuals spread over 15 metres in the general vicinity of the original collection. The plants appeared to be in good health, with one or two flowers evident. It is possible that additional individuals may exist in the area, but snow, hail and pending hypothermia curtailed our enthusiastic searching and celebrating.
We are wondering whether the initial recovery of the ecosystem in the absence of rabbits and rodents has resulted in an expansion in numbers and distribution of some species, particularly the Galium and Huperzia.
Jennie and Nick