LC Australia Program 2011: Of Wind and Waves

By Jared Delahaye

Even having spent the majority of our time thus far traversing the beautiful coastline of this island continent, there was something about rising slowly to the clear sunshine on Straddie this Sunday that felt even more exotic than usual. I think much of this came from our accommodation's location right on a long, sandy beach. The sun was a welcomed newcomer compared to the overcast skies of Saturday; a second and more prevalent weather guest was the wind. As appropriate as I found the slightly gloomy weather in the marshes the previous day, the sun and gusts figured in just as perfectly.

We set out on a daylong excursion to explore Straddie firsthand with our lecturer from Saturday: Shane. With the previous day's lecture fresh in our heads, he was able to guide us through many facets of the island's ecology with ease. The morning started with a stroll down to the water where Shane pointed out a thin strip of wetland forest just before the sand started. The most prominent figure here was the paperbark tree with its thin, peeling bark that made the name choice obvious. The bark does serve a practical purpose because the many layers of bark provide resistance to fire. On the beach we observed sparse vegetation on the exposed bluff due to direct exposure to wind and the salt that comes with it. This was made all the clearer as we scrambled up some rocks to a more lush and diverse area of plants sheltered from the harsh winds by the boulders. As we bounded down the far side of the bluff to a second beach, I was puzzled after seeing what I thought were a few upturned frog legs buried in the sand, but approaching a small pond it all became clear. The pond was teeming with what must have been thousands of tiny tadpoles, but not just any tadpoles: cane toad tadpoles. Australia is a country known for many things: kangaroos, the outback, barbies, Crocodile Dundee. But it's also home to numerous examples of invasive species introductions gone awry. One of the more ridiculous of these examples is the cane toad, which was originally brought to the country in the hopes of eradicating the cane beetle, a pest in its own right. I cannot imagine the number of scientists who must have been fired once it was discovered through introduction that the little buggers prefer just about every other possible food choice over the cane beetle. Aside from the large litter size which we saw, the toads have persisted problematically due in part to poison glands, which make them troublesome to potential native predators. Getting back to the cane toad leg cemetery, Shane explained that some of the local birds have learned to flip over the toads before enjoying their meal, which allows them to eat around the poison; sweet!

Our next stop was a large eroding sand dune that rose high above our heads with channels and ridges of multicolored sand all around. The main artists in this natural work of art are wind and rain. Most interesting were numerous tiny sand spires that donned the surfaces of much of the elevated sand. These structures are created by small rocks (visible in the photo below) that protect the sand beneath it from rain that washes away all the sand around the rock over time. It is this same type of process that created, on a much larger and longer timescale, Lamington Plateau, which we will be visiting next month.

Soon after, we found ourselves battling the wind as we traced the shape of Straddie via the headlands. Standing on the rocks above the crashing waves with the wind and salty spray in my face, I felt truly overpowered by nature. The buildup of the land, occurring over many years, with the headlands providing a bookend for sand to compact against, was overtly clear. Continuing our ocean side walk we saw two cool tricks of nature in quick succession. The first was a cove of sea foam which formed at the end of a long channel of ocean water cutting into the cliffs. I know most people have seen foam form in the ocean before so I would go so far as to classify this as sea whipped cream. It was so thick that it was hard to tell there was water underneath and periodically a gust of wind would pick up some of the foam and float it past our heads. It's simple in principle; (much like whipping cream) the seawater and organic material get mixed and aerated so much so that they form a bubbly foam. The next trick the island had in store was a whale rock. This rock, sitting amongst the waves, had been eroded in such a way that when water bashed against it just right, ocean water, accompanied by a whoosh, would spray from a hole. As far as impressions of whales breathing through their blowholes, it was spot on.

Following a lunch break, we drove to an area of inland forest that had undergone a planned burn 6 months earlier. It was easy to spot where the fire had been by looking at the surrounding trees and shrubs. Shane showed us different examples of how the plants deal with fire. It is often thought that most of the trees are dependent on fire but it is probably safer to say that they are nearly all take advantage of it. Some of them release seeds after a fire to get a jump start on growing in newly open space while others sprout leaves at spots where their bark burns. We went further up the road to see a second forest that had also been affected by a much larger fire, but much longer ago (15-20 years). The differences between the two burned forests were stark. Where the first forest had open space and plenty of bushes, the second forest was much more crowded and dominated by two main tree species, both tall and thin.

From there, we drove up to a higher area of the island. This landscape was dominated by dry heath plants, distinguishable by their small, tough leaves and short stature. The sand here was also different, being completely white as opposed to the yellows, reds, and browns seen in the lower dunes. The color is a result of the sand being completely leeched of all nutrients and is a target for mining as the white sand is used to make glass and solar panels.

Our afternoon wound down with a visit to a large lake where many of us took the opportunity to swim and look for the tallest thing to jump off of, in this case a tree. Finally, we drove down to the beach. Walking along the sand, with the waves crashing softly and the sun coming down, its rays shimmering almost religiously through the clouds, I was struck by a full range of emotions.

The following morning I felt it was all too soon to be packing up our things to leave Straddie. I took the time to sit on the pristine beach one last time before loading into the van for the ferry trip back. After a failed attempt to look for koalas back on the mainland, everybody parted ways downtown for a much deserved afternoon off. For me this entailed a haircut, a trip to a nearby skatepark and burritos with my host family. Despite having to leave Straddie behind, there was no better place to return to than the house where Dick and I are staying, complete with a cute dog, an adorable toddler, a smart tween and our caring, hilarious hosts.