Warning: Declaration of AVH_Walker_Category_Checklist::walk($elements, $max_depth) should be compatible with Walker::walk($elements, $max_depth, ...$args) in /home/tasman92/public_html/wp-content/plugins/extended-categories-widget/4.2/class/avh-ec.widgets.php on line 0 Author: Nick Fitzgerald | Tasmanian Geographic
Nick is a writer, photographer, adventurer and ecologist who makes frequent forays into Tasmania's many wild and interesting places. His botanical proclivities have led him back to study at the University of Tasmania where he is undertaking research into the ecology of sub-Antarctic Macquarie Island.
Photographs of Tasmania often show the thick emerald greens, the blanketing moss, and the ancient green trees. But fire-singed landscapes are also part of the natural scenery. You could think of Tasmania’s natural vegetation as careening between the unburnt Southern Hemisphere rainforests and the fire-loving Australian bush. And as traumatising as the recent fires were, it helps to remember that blackened landscapes of charred trees have been part of the Tasmanian landscape for millions of years. Fires are also a conscious and careful part of human land management over many thousands of years.
For photographers, the changes have brought in a new, inkier colour palette, and an opportunity to see the forest develop after a major disturbance. If you’re keen on seeing the changes yourself, the best way to do it is to travel up to the Hartz Mountains National Park west of Geeveston. Let’s take a closer look…
The fagus turned early in Autumn 2015. King Billy pines and pencil pines produced masses of seed in the 2014-15 summer. So it seems, according to anecdotal observations. Is this unusual? Is it important?
People frequently remark on the timing of natural events and the apparent links to seasonal weather, particularly when things seem unusual. However without long-term data it is impossible to determine ongoing trends from natural variability.
The timing of events such as bird migrations and the flowering of plants is often closely linked to climate. Historical records of phenology (the study of the timing of periodic phenomena in the life cycles of plants and animals) over decades or centuries have proven useful for reconstructing changes in seasons in the Northern Hemisphere. Unfortunately, Australia has a very poor record of historical phenology.
ClimateWatch (link: http://climatewatch.org.au) is an Australia-wide initiative involving dozens of marine and terrestrial species including plants, birds, frogs, mammals and invertebrates. Around 80 of these target species occur in Tasmania. The species have been specifically chosen by scientists to bridge the information gap and better understand how climate change is affecting our natural environment.
Many Tasmanians keep a close eye on the ‘turning’ of the deciduous beech or fagus (link: http://climatewatch.org.au/species/plants/fagus-or-deciduous-beech) (Nothofagus gunnii) in Autumn. As Australia’s only winter deciduous woody plant, it will be interesting to see if the timing of seasonal events such as bud burst and leaves changing colour is shifting, as has been observed in many Northern Hemisphere deciduous trees. If even a small proportion of the thousands of photos of fagus taken every year were added to the ClimateWatch database, with date and location, ecologists could answer these questions.
‘Nature’s Notebook’ collates citizen science phenology records in the USA (www.usanpn.org). A similar program in the UK launched over 15 years ago has recorded over 2 million observations (www.naturescalendar.org.uk).
Most long-term records for plant phenology from the Northern Hemisphere are consistent with observed recent climate change; that is an earlier arrival of Spring (typically 2-5 days earlier per decade) and a slight delay in Autumn events such as colouring and leaf drop of deciduous trees. The consequent lengthening of the growing season is likely to change the stability and functioning of ecosystems, particularly when combined with other climate-driven phenomena such as migration of species and changes in rainfall and snowmelt patterns.
Trends are not consistent across species, and even within a species observed changes in phenology may vary between sites, so it is necessary to collate a large number of observations over a long time to get a good picture of phenology. That’s where the citizen science comes in. Get involved and add your records to these ongoing projects.
In April 2015 I travelled to Macquarie Island on the Aurora Australis, the research vessel named after the atmospheric phenomenon. Auroras occur when solar winds interact with the Earth’s magnetic field and are most common around the equinoxes. Auroras were seen on several nights during the two week science and resupply mission to Tasmania’s subantarctic outpost, 1500 km south-east of Hobart.
On our second night on the island we reached a small ‘googie – field hut field hut late in the afternoon, shortly before the cold southerly airflow brought a rapid dusting of snow down to sea level. A couple of hours later, after dark, the clouds cleared and the air was unusually still. The sky was filled with swirling white beams and shimmering curtains of otherworldly neon green. Having previously only seen a couple of faint auroras in Tasmania I was unprepared for the intensity and dynamism of this display.
Auroras are most often seen in polar regions because they occur in an ellipse around the magnetic poles of the Earth. At mid-latitudes, such as in Tasmania (40-42°S), the Aurora Australis is therefore seen in the southern sky. But at higher latitudes such as Macquarie Island (54°S) you can be south of the aurora, depending on how far north it happens to extend. So it was strange to see the ‘Southern Lights’ in the northern sky! At Brothers Point on the east coast of the island a large beam extended overhead from behind Mount Tulloch to the west to near the eastern horizon over the ocean. It frequently played across the northern sky over Sandy Bay, but was not visible in the south.
At its brightest it was similar to the light of a full moon, illuminating the fresh snow in an eerie way. After an hour or so of watching the aurora ebb and flow another snow squall approached from the south and it was over. All of these images are 30 second exposures so they are slightly more blurred and more colourful than what is visible to the eye.
Images by Alison Painter, Dallas Stott, Geraldina Dijkstra, Jonathan Esling, Leoni Williams, Nic Fitzgerald, Paul Fleming, Theresa Ockenden, Dave Reynolds, and Nick Dobinson
We mere mortals have marvelled at Mother Nature since time immemorial: sunsets and sunrises, lightning, hail storms, eclipses, aurorae, rainbows… and even snowbows for that matter. Nature’s art has inspired painters, poets, lovers, and the forlorn, and provided us all with a means of feeling a connection to something so much bigger than ourselves. This connection – this attraction to nature – transcends cultural boundaries, political paradigms, and the passage of time.
And it was has been on full, electric blue display across southern Tasmania.
Our story begins with a handful of aurora photographers, who were out on their regular Friday night aurora hunt. The skies were clear, the moonlight was dim, and the weather mild; unfortunately the aurora failed to develop. As they were heading home, they noticed a strange yet illuminating glow coming from waves lapping in the distance. The tide was too far out to get a closer look, yet curiosity had taken hold and a plan was made to return the next night on the hunt for the glowing stuff. And the rest, as the saying goes, is history.
Photos were posted, the story went viral, media frenzied, young and old flocked to the beach, people flew in from the mainland to see … In the blink of an eye – or really, in a flash of light – Noctiluca became a household word and Tasmania became a bucket-list destination.
The phenomenon of bioluminescence – or sea sparkles – is caused by organisms that make their own light with a chemical reaction inside their body. In this case, the organism is a tiny dinoflagellate called Noctiluca scintillans, Latin for “sparkling night light”. Dinoflagellates are a type of phytoplankton (phyto = plant, plankton = drifter); however, they aren’t true plants, rather, they are microscopic single-celled algae. They are like seaweed, but much smaller. Rather than make their own energy like a plant does, they consume organic matter floating around them, including other single-called organisms like plankton and even fish eggs.
Many types of dinoflagellates are bioluminescent, and may produce different colours of light. Noctiluca flashes or glitters with brilliant neon blue. Singly, each individual emits a tiny speck of light, but en masse, they can light up a beach with an eerie other-worldly glow. Their bioluminescence are usually be observed in three different ways: a dull glowing band along the shore that defines the edge of the concentration, brilliant flashes when disturbed such as by crashing waves or dancing enthusiasts, and gentle twinkling where individual Noctiluca cells have been washed up on the sand.
So bright is their light, in fact, that during World War II, the Japanese dried dinoflagellates into powder and issued envelopes of it to their troops. At night on the front line, the soldiers would pour a bit of powder into their hand, spit on it, and rub it between their palms, giving them enough light to read their maps by without giving away their location.
So what has triggered Tasmania’s recent sea sparkling? The present bloom had been building for a few weeks following rains that washed nutrients into the water; dog poo on the sidewalk and Seasol in Grandma’s garden act like fertilizer for algae when storm runoff gets into the sea. The bloom came to light when the winds blew it into accessible locations, and this extreme bioluminescence event has now been reported across Southeast Tasmania from Kingston, Howden, Battery Point, Howrah, Lauderdale, Eaglehawk Neck, and many points in between. Protected areas, surf beaches … you name it, people are seeing Sea Sparkles there. Many of the most incredible photos were taken at South Arm near the neck, where the northerly breeze blew the Noctiluca into Ralph’s Bay and concentrated them against the shore at the bottom of the bay. The neon blue waves were plainly visible to passing traffic.
This influx into such easily accessible areas has provided a unique opportunity for people to interact with nature in a completely unexpected and thrilling way. A hand dipped in the water comes out glowing an electric blue. A handful of sand thrown over the water produces a spray of sparkles … and then an explosion of light. Sand poured through the hands looks like molten blue light. Footprints at the water’s edge flash then twinkle. A dog splashing in it creates a light show that defies description.
While the spectacular unretouched photos made their way across the world’s headlines and mainlanders booked flights to come see this natural wonder, there is another, more sinister side of this species that is just as surprising as its sparkle: it is a pest. And a bad one at that.
The sad truth is that Noctiluca is one of the world’s most unwanted species. It was first reported in Tasmanian waters in 1994. It is not native here. Its invasive progress has been tracked and studied by researchers at the University of Tasmania, and the story is not a good one. It has spread to more or less every nook and cranny of the Tasmanian coastline, and has recently penetrated the Southern Ocean, expanding ever southward. Periodically when the conditions are right, it blooms into superabundances, the sorts of numbers that are generally only met with in astronomy. Billions. Trillions. Numbers that don’t even have names. In these sorts of numbers, Noctiluca is a killer. As the cells die, they burst and release their ammonia-rich contents into the surrounding water. The water becomes toxic and de-oxygenated. Globally, Noctiluca has more fish kills notched onto its belt than just about any other species. Having said that, it is a sight worth seeing as well as a spectacular reminder for us all to explore the world around us. You never know what amazing things you may find.
It is not difficult to imagine the Lake Judd Glacier descending from the heights of Mount Anne during the Pleistocene, carving a sinuous trough as it went. The result is one of Tasmania’s best examples of a glacial landscape.
Lake Judd is just over three kilometres long and with a dogleg shape such that the increasingly dramatic cliffs and arêtes are gradually revealed as one paddles up the lake into the shadow of the cirque. To the west and north are five hundred metre high cliffs of ragged dolerite columns on Mount Eliza and Frances Bluff.
Native conifers including king billy pine are prominent features of the forest here, indicating a cool wet climate with long-term absence of fire. Eucalyptus forest is confined to the terminal moraine. Small beaches of quartzite sand occur in a few places, with aquatic plants in the shallows.
The only easy approach to Judd is from the south where the Anne River drains the lake, spilling over the terminal moraine of accumulated glacial material. But you can always make it more difficult by carrying an inflatable boat on a 30ºC day! It seemed like a good idea for an unusual weekend trip and so after 2.5 hours slogging though scrub and buttongrass and mud we clambered over the moraine and wasted no time cooling off in the lake.