There’s a new health craze on Macquarie Island. Forget boring old rice milk. Put the soy milk away. Consider the health benefits of Macquarie Island Invertebrate Milk ©.
Invertebrate ‘milk’ comes to you across many kilometres of feldmark, tussock, cabbage, herbfield and grassland and from all over the island. The sweat and tears spent, the pain and suffering experienced by dedicated porters add complexity and depth of flavour to the product.
We ‘milk’ the invertebrates using specially designed funnels, called tulgrens or berlese funnels. Surfer-come-chippy extraordinaire Joe, fashioned up some hooks along the ceiling of the biology lab, so that the funnels can hang in a warm, dry place whilst we continue laboratory work underneath them.
Litter is collected from 24 sites across the island by myself the resident invertebrate hunter, at a volume of one litre per one square metre in replicates of three, and taken back to the laboratory on station, with the assistance of any unsuspecting field parties I might encounter on my way back up-island.
On station, litter is placed into the top of the berlese funnel, whilst a jar of ethanol is attached to the bottom of the catch piece. As the litter dries and warms the worms, springtails, spiders, snails, beetles, mites and other creatures crawl downwards to try to escape, falling unsuspectingly into the ethanol below. The method is very effective at capturing everything in the litter. The funnels have stirred a few comments from station locals, Doctor Helen referring to them eloquently as Melissa’s ‘Hanging Gardens’ and reminding Sparkie Benny perhaps wistfully of ‘Udders’. What do you think dear reader?
Litter sampling is just one method of sampling invertebrates that I am employing as part of my PhD project — investigating ecosystem recovery on Macquarie Island after the successful rodent and rabbit eradication project. I began sampling last summer and will continue through to 2017.
The aim is to measure ecosystem change over time through macro-invertebrate surveys, a keystone group in terrestrial sub-Antarctic ecosystems. Changing macro-invertebrate community assemblages are assessed by sampling at 24 sites, 10 of which are historical sampling sites, in five different vegetation communities across the island using a range of techniques including vegetation beating, sweeping, pitfall trapping, litter collection and 20 minute counts.
The results of this project, a collaboration between the University of Queensland’s Environmental Decisions Group and Tasmania’s Department of Primary Industries, Parks, Water and the Environment, will give an indication of ecosystem recovery since the removal of pest vertebrates, detect ranges of non-native invertebrates and potentially provide a framework for a cost-effective and efficient method to monitor the Macquarie Island ecosystem as a whole.
AND… I get to fantasise that I am continuing exploration work in the Antarctic region in the footsteps of the great explorers; discovering fascinating, weird and wonderful creatures every day. It can’t be denied some of these invertebrates are pretty cute!