How do you pick a path through the foam and waves of the sea and enter its depths? Here in Byron Bay, you can swim beyond the surf and snorkel the hidden wreck of Tassie III, old jetty posts and rocky reefs such as Middle Reef.
Further and deeper, at Julian Rocks you can dive down into the likes of the Cod Hole and Hugo’s Trench. Beyond is a shelf that extends for kilometres. The sunlight shines right through the water to its physical limit, which is the same as the depth to the seabed (about 200 m). Further on, all is midnight black, the seabed plunging into canyons and caldera. This cold, dark, high-pressure zone is 90 per cent of the global ocean. Here, submersibles and remote cameras are now retrieving images of life never before seen. Telling the tales of such exploration will be Justin Marshall, deep-ocean researcher at University of Queensland. He’s a guest at this year’s final event of the Byron Bay 2nd Annual Science Film and Talk Fest on November 16.
Marshall is also fascinated with the sensory systems used by fish and other marine creatures. Recently he won several awards for underwater devices that he designed which ‘see’ the underwater world the way marine life does – with receptors for up to a dozen different colours plus ultraviolet light. All these are outside of the range of humans, whose vision is based on only three colours (red, blue and green).
To see some of this for yourself, you can use a ‘blue light’ dive light such as the one produced by Charlie Mazel’s research company Nightsea. Shine the weak light at underwater rocks and many types of marine life blaze with fluorescent colours. Many different corals show up, as well as their young, which are less than a single millimetre in diameter. The blue light reveals these magic sights by day as well as night. A small torch-sized blue-light device is useful for looking inside small aquariums and through microscopes.
What makes that glow? Some marine creatures incorporate glowing bacteria into their own cells. Many others produce it for themselves from inside their cells. An enzyme interacts with one of four types of light-emitting substrates. This is chemical bioluminescence and is dependent on the moods and activities of the organisms themselves. There is still another process by which a fluorescent protein lights up when excited by different wavelengths of light. These are greens and reds that show up under blue lights or ultraviolet lamps.
What do all the glowing colours mean? Photobiology is a young science and there are many hints. Colours protect corals from certain rays of sunlight. Colours attract prey or mask predators. Colours reveal moods or camouflage bodies. The many-splendoured senses of organisms which understand so much more are being coaxed for other details by neurobiologists such as Marshall.
Another neurobiologist, the late Francisco Varela, also advocated that we humans use ‘first-person science’ and ask ourselves. For example, he would point to how we use colour and landmarks to get ourselves from place to place. This is what we, embodied minds, do as we include our environment to help us think. To further illustrate this, he translated a poem by Anotonio Machado which says in part we ‘lay down a path in walking’. This could also be true as we swim deep over our heads, primates watching the internal colours of the global sea.
Join Professor Marshall (http://web.qbi.uq.edu.au/ecovis/justin.htm), Libby Hepburn (www.alcw.org.au) and Karl Goodsell (www.positivechangeformarinelife.org) at the final session of Byron Bay 2nd Annual Science Film & Talk Fest on November 16 at 6pm, SCU room, Byron Bay Community Centre. Admission is free and includes ‘duckumentary’ Duck! Live video link at the festival is managed by Lightforce Training Academy.