"I dream of the field visits," she says. "It's a wavy boat ride to get to Broughton Island, 16 kilometres off the coast of Port Stephens. You pass several other small islands and can spot seals, dolphins and whales along the way; it's incredible. I love how remote the island feels and the natural landscapes are quite unique."
Over the past 18 months, COVID notwithstanding, Mary has visited Broughton twice, and intends making another visit during her candidature. But rather than experiencing these windswept refuges when they are teeming with migratory seabirds - mostly wedge-tailed and short-tailed shearwaters - she gets to experience them at their quietest.
"The island is covered in literally thousands of active nests during the breeding season [shearwaters burrow up to 2 metres in the ground to create a nest] and it can be difficult to walk around; you can sink into the nests very easily in the sandy soils," Mary says. "I prefer to visit in between breeding seasons, when there are the least amount of birds, to cause as little disturbance as possible."
Mary completed her coastal and environmental science studies at a small college in Florida, US, where she studied geomorphology and soil science on barrier islands. She had been researching other universities and researchers before stumbling across the Terrestrial Carbon Research Group, led by Associate Professor Brian Wilson at UNE. He was seeking a PhD student to study the impact that breeding birds have on the soils and plants of islands like Broughton, and Mary was soon sold.
"These islands are largely managed by the New South Wales National Parks and Wildlife Service (NPWS), but they have experienced a range of human influences, from Aboriginal occupation to post-European settlement," she says. "Many of the seabirds, like wedge-tailed shearwaters, are internationally protected species that migrate from South-east Asia each year. They occupy their burrows for about six months, construct a nest, mate and grow their chicks. There are more than 55,000 pairs of nesting shearwaters on Broughton Island and growing, thanks to habitat restoration efforts."
Mary's PhD is being undertaken in collaboration with NSW NPWS to investigate what nutrients the birds contribute to the island's ecosystems, via their guano, and its impact on soil dynamics, nutrient cycles and plant communities.
"Islands are terrific ecological study sites," she says. "Many of the things that happen on islands happen at a faster rate than their mainland equivalents, and have fewer external influences because they are isolated by their geography. This allows researchers to observe change in meaningful time scales, which can better inform ecological interactions both on island and mainland ecosystems."
Today, the permanent presence on Broughton includes just "a cute little hut with a few bunk beds" used by NPWS staff and occasional researchers like Mary. The few huts next door that remain of a former fisherman's colony also welcome hardy modern-day fishers.
"Staying close to the beach, you get to hear the ocean at night," Mary says. "You're working hard - the treks can be rigorous through thick vegetation on steep hills - but, to me, it feels as much an adventurous vacation as it does a field study. Australia has a bounty of ecological diversity and this work has been an incredible experience."
