These pictures of bioluminescence in the Gippsland Lakes in my gallery have proven quite popular, so it seems time to provide a story to accompany them. But this is not a short story, rather a convoluted one of fires and floods, of microscopic algae and the inspiring, remarkable and surprising beauty of nature.
The story begins with alpine bushfires in Victoria, which started on 1st December 2006 when over 70 fires were started by a band of thunderstorms and lightning strikes which moved across the state. This was an early start to the fire season following an extremely dry autumn and several years of drought conditions before that. The fires were in remote, rugged alpine areas, which combined with bone dry forest fuels to make them very hard to control. The fires burnt for 69 days, merging to become the ‘Great Divide Complex’ and ultimately covering an area of well over a million hectares.
Smoke from the Great Divide Complex fire spreading over south-east Australia [MODIS image via emknowledge.org.au]
These fires burnt a vast area of the catchment for the Gippsland Lakes, a chain of large inland lakes in eastern Victoria. The fires affected the upper reaches of all the major rivers feeding into the Gippsland Lakes including the Latrobe, Thomson, Avon, Mitchell, Nicholson and Tambo Rivers. Such a large and in places severe fire through the catchment areas was always going to have an impact on the lakes themselves but a lot would depend on the intensity of rain events that followed the fires. In the end, it was not any ordinary rainfall event that arrived that winter. A deep east coast low pressure system dumped more than 100mm of rain over many locations across Gippsland on 27th June 2007. The result was a 1 in a 100 year flood in the days and weeks that followed.
The effect of the torrential rain over the over the vast area of recently burnt alpine forest was to wash ash and soil rich in nitrogen and other nutrients into the Gippsland Lakes. Counter intuitively, the rain and floods also increased salinity in the Lakes as the higher water level facilitated greater mixing with seawater at Lakes Entrance.
Floodwaters over Glenmaggie Weir [ABC Australia]
The fires and floods immediately led to concern about the impact on the health of the Gippsland Lakes, particularly whether it would lead to an outbreak of blue-green algae. Sure enough, the following summer, as the water in the lakes warmed up, the water across most of the Gippsland Lakes took on a disconcerting green tinge.
Synechococcus in the Gippsland Lakes
But this was not the blue-green algae that had appeared in the lakes before. Early analysis identified the cause of the green tinge as an algal outbreak of Synechococcus. While naturally present at low concentrations in seawater, this bacterium species had not been identified in the lakes before, so there was uncertainty about how it would develop and how long it would last. Although the health concerns were mild, public warnings were put out for the Gippsland Lakes in January 2008 which recommended against swimming in the lakes. This caused considerable disruption to many, including Camp Cooinda, the organisation I volunteer with that runs canoeing camps for young people on the Gippsland Lakes. Tourism across the Gippsland Lakes was affected throughout the rest of the summer (although most people there ignored the warnings anyway).
While the Synechococcus levels moderated in the cooler months of 2008, there was concern that it would return in force the following summer once the water warmed up again. Local authorities were conducting extensive sampling and testing but the experts were not able to make confident forecasts of what would happen. The growth of algae in the lakes is affected by a number of factors, including the availability of nitrogen, phosphorous and other nutrients in the water as well as the temperature and salinity of the water. Growth of Synechococcus was favoured by higher nitrogen and salinity levels while the classic blue-green algae (which are actually bacteria) required lower salinity levels and higher phosphorous levels.
As summer took hold at the end of 2008, what happened surprised everyone – a new species called Noctiluca scintillans began to prosper, by feeding on the Synechococcus. In contrast to the widespread bright green of the Synechococcus, Noctiluca Scintillans was visible during the day as localised murky red patches, often building up on sections of shoreline facing the wind during the day. At night though, Noctiluca scintillans produced a remarkable form of bioluminescence (popularly but incorrectly referred to as ‘phosphorescence’) – the water glowing brightly wherever there was movement – in the waves breaking on the shore, in ripples in the water and wherever people played in the water. Wikipedia has this explanation for some forms of bioluminescence, including for these 'Dinoflagellates':
Bioluminescence is used as a lure to attract prey by several deep sea fish such as the anglerfish. A dangling appendage that extends from the head of the fish attracts small animals to within striking distance of the fish. Some fish, however, use a non-bioluminescent lure. The cookiecutter shark uses bioluminescence for camouflage, but a small patch on its underbelly remains dark and appears as a small fish to large predatory fish like tuna and mackerel swimming beneath it. When these fish try to consume the "small fish", they are bitten by the shark, which gouges out small circular "cookie cutter" shaped chunks of flesh from its hosts. Dinoflagellates have an interesting twist on this mechanism. When a predator of plankton is sensed through motion in the water, the dinoflagellate luminesces. This in turn attracts even larger predators which will consume the would-be predator of the dinoflagellate.
Now I have been spending most of my summers for the last sixteen years paddling around the Gippsland Lakes with Camp Cooinda and I have seen luminescence in the lakes several times before, but never remotely as bright as it was in the summer of 2008/09. Luckily, Noctiluca scintillans was not a health threat, and I wasn’t program directing the camps at Cooinda that summer, so I had plenty of time late in the evenings to take photos of the remarkable luminescence. On the first night, it was actually a group of leaders playing in the water that created some of the most memorable photos – Laura, Kieran, Marty and Joel amongst others. I was using a Canon 20D Digital SLR with the Canon 10-22mm lens and wide open at f3.5 and ISO1600.
In the first image above, one of the leaders stood still while the others splashed water behind them. In the second image they stood still with their eyes and mouth closed while they were vigorously splashed with water for the full 30 seconds of the exposure – it was hilarious to watch as well as producing a bizarre image. The photography was highly addictive and I spent many late nights waiting for the moon to set, capturing as many images as I could, trying different lenses and exposures. I spent one memorable evening trying to photograph the luminescence in gentle waves lapping at Cooinda’s front beach. I kept bringing the camera closer to the water to get the best result.
Eventually I threw caution to the wind and stuck the tripod down where the waves washed over the legs. At one point, I placed a torch on the beach to provide something for the camera to auto-focus on but when I jumped up to retrieve the torch, my leg got caught in the timer release cable and knocked the tripod and camera into the water (it’s salt water too!). I muttered some swear words and plucked the camera and tripod up out of the water and rushed to give it a rinse in fresh water. Luckily the camera did not get very wet and I was back taking photos a few minutes later - the things I do for a great photo!
On another night when the water was calm, I had to create the waves myself, so I started throwing sand and pebbles into the water in front of the camera. This time I was able to put my fast 50mm f1.4 lens into action, capturing the ripples and splashes with short exposures of just a few seconds.
As the moon headed towards full at the end of camp one and through the start of the second camp, it was hard to capture good images. But later in the second camp, the moon receded from the early evening sky and the opportunities were there again. The image below actually shows the luminescence in the water on the front beach at Cooinda with the light of the moon rising over the Lakes in the east. This was the last evening I had photographing this event.
During the remainder of 2009, the Gippsland Lakes returned to better health, with the water looking cleaner and clearer than we have seen it for several years. The life cycle of the algae appears to have exhausted the nutrient supply from the sequence of fires and floods that started in late 2006. Bio-luminescence will be visible in the lakes again but it may be a lifetime before it matches this vivid outburst of December 2008 and January 2009. A search online produces few images of bioluminescence (or phosphorescence as most people refer to it) so I can only speculate that this event was rare on a broader scale, not just for the Gippsland Lakes. You can see some of the details for these images and more in my Gallery which have proven very popular. If only I could order it all up again!
UPDATE February 2013: There are more recent images of the Bioluminescence from January 2013 here. You can also learn how I take night sky images like this in my eBook 'Shooting Stars', which will teach you how to take photos of the moon and stars with just your DSLR and a tripod. Better still, get $5 off with discount code SSBLUE today.