BLACK WATER DIVING Royal Text by Gary Myors Tasmania Photos by Karen Gowlette-Holmes Tasmania’s Southwest National Park and World Heritage Area is the land that time forgot, and most of the civilized world has never heard of Bathurst Harbour. It is the home of the world’s oldest living plant, Kings Holly (Lomatatia tasmanica) discovered in 1934 by the late Deny King, an environ- mentalist and local legend who lived in the area most of his adult life earn- ing his living mining tin. On the banks of the Old River, bushwalkers able to penetrate the closely guarded secret Yellow Polyps, Parazoanthus Arial view of Bathurst location can admire a 10,500-year-old Huon Pine Tree. From the bird hide near the Melaleuca airstrip, you can watch the mating dance of a pair of orange bellied parrots, a species which breeds only in this region and has been saved from extinction by volunteers and the Tasmanian Parks and Wildlife Service. Apart from the rare flora and fauna, the landscape is as rugged and spectacu- lar as any wilderness on earth. Bathurst, Tazmania 81 X-RAY MAG : 7 : 2005 EDITORIAL FEATURES TRAVEL NEWS EQUIPMENT BOOKS SCIENCE & ECOLOGY EDUCATION PROFILES PORTFOLIO CLASSIFIED features Biscuit star, Tosia australis Tasmania deepwater (100m +) are found in much place where the unique southern part in delaying our departure from shallower water due to the low light lev- Australian shelf-break species can be Hobart for the best part of two days. els. seen and studied in safe diving depths. Flying conditions can change within In the Bathurst Channel, this phenom- minutes of locating the isolated airstrip enon is enhanced due to Breaksea The first expedition adding unnecessary cost by returning to Island in the mouth of the Channel shel- On our first expedition in 2002 for a Hobart. tering the Channel from wave action, so smaller Japanese television company, This expedition was different from that the seafloor in the Channel is not we spent ten days diving and filming in many points of view: bigger budget, only dark, it is also relatively calm—mim- almost perfect conditions. All equipment smaller crew, and most importantly, icking conditions on the “shelf-break”, and personal were flown into the departing Hobart aboard the vessel we the edge of the continental shelf and remote Melaleuca airstrip. Seven were to use for the duration of the stay upper slope in depths of 80-200m, and Cessna flights transported the team of in Bathurst Harbour. The abalone mother the marine life we find living in the eight Japanese, two Eaglehawk Dive ship ODALISQUE was our chosen live Bathurst Channel is typical “shelf-break” Centre staff and the two Southern aboard. She is a modern 18-metre alu- species. The Bathurst Channel/Harbour Explorer crew. It was a logistical drudge minum vessel able to accommodate 12 area is unique in a world context, a with the weather playing a significant passengers and crew in comfort, a large But having set the scene in this remote Area. The TWHA covers 20 percent of the corner of Tasmania’s world heritage Island State and encompasses a greater area, we were not here for any of the breadth of natural and cultural values above. We were on a mission for Japan- than any other World Heritage Area on ese television, filming a documentary Earth, according to the Tasmanian about the impact of the tannin-stained Department Primary Industries Water and freshwater layer on the marine life the Environment (DPIWE). The waterways that exists below it in Bathurst Harbour. were formed as the sea level rose after Eaglehawk Dive Centre has conducted the last ice age flooding the river valleys two successful underwater filming expe- with seawater, and the huge volume of ditions into this unique location. Both of black, tannin-stained freshwater flowing these expeditions were adventures that from the numerous rivers forming a dark most mere mortals only dream about. freshwater layer over the top of the sea- This story is of our most recent expedition water. The freshwater layer, usually 2-6m with the Japanese national public broad- thick, is so dark from the tannin that little caster NHK / Science and Environment light penetrates it. Below the tannin layer, Division. the seawater is very clear but dark even on the sunniest of days, the light levels The Territory are so low that you cannot see without Port Davey and Bathurst Harbour makes dive torches. This gives rise to a rare phe- up a large and ecologically significant nomenon called “deep water emer- part of the Tasmanian World Heritage gence”, where species usually found in Basket star, Conocladus australis 82 X-RAY MAG : 7 : 2005 EDITORIAL FEATURES TRAVEL NEWS EQUIPMENT BOOKS SCIENCE & ECOLOGY EDUCATION PROFILES PORTFOLIO CLASSIFIED features Tasmania back deck with cradles for 15ft and 17ft alu- stow everything and to sail from Hobart at the first day when Tomita, the cameraman, nearly minum dinghies, and two holds that kept our appointed time. We had advised the film drowned his digital beta-cam camera while equipment and extra provisions below deck crew that we might have to wait in traveling at dangerous speed in the dinghy in out of the weather. Recherché Bay if the weather on the south pursuit of a shot. Despite the conditions, Tom The expected duration of twenty days in coast was as bad as forecasted by the still managed to shoot some useable footage the wilderness required extensive and careful Bureau of Meteorology. It was a little lumpy before the journey westward continued. planning. To cater for five Japanese, two rounding Whale Head, but the vessel handled After a journey of about eight-hours from marine biologists, myself as dive guide and it well, and only a couple of the film crew Hobart that included the stop at Maatsuyker the ODALISQUE’s crew of three (skipper, took to their bunks. Island, we entered beautiful Spain Bay near deckhand and cook) in a remote region that We made a brief stop at Maatsuyker Island the entrance to the Bathurst Channel an hour can only be reached by sea or light aircraft to film the huge colony of between 1000-1500 before sunset and anchored for the night. and is subject to extremes in weather, we had Australian fur seals at The Needles on the Our chef, Johnno, knocked up a first class to be very well organized. We even took a south side of the majestic rock that is home to meal, and we were in bed reasonably early ABOVE: Detail view of a sea pen, Sarcoptilus grandis washing machine. While the Japanese were a couple of volunteers who look after the her- expectating an early start and a busy first day TOP LEFT: Garden of sea pens with seastar over-equipped not knowing the isolation of itage-listed light house and buildings. in Bathurst Harbour. the location, we managed to find a place to The whole expedition nearly finished on that Karen Gowlett-Holmes, one of Eaglehawk 83 X-RAY MAG : 7 : 2005 EDITORIAL FEATURES TRAVEL NEWS EQUIPMENT BOOKS SCIENCE & ECOLOGY EDUCATION PROFILES PORTFOLIO CLASSIFIED features Tasmania LEFT TO RIGHT: Botrylloides leachii; Bryozoa Adeonellopsis; Nudibranchs Dermatobranchus BELOW: Bramble coral community Dive Centre’s marine biologists, and I the next three or four days but this failed conditions were generally appalling, but searched for subjects to study or photo- were acting as guides for this expedi- to impress the film crew as the tannin we were here to dive, and dive we did! graph. tion. Karen had done a number of sci- wasn’t dark enough, wasn’t thick I moved away from them to seek out entific research field trips to the area enough and the animals were too few Diving in tannin my own creatures, and as I headed with CSIRO prior to our last filming expe- or too uncooperative. Having seen the Dropping over the side of the dinghy down the slope into the dark, I was dition the previous year. I had worked in finish documentary from the previous into the dark tannin layer can be rather amazed to see the scene behind me the area on several occasions during expedition they were under pressure to daunting for those who have never only grew smaller rather than disap- my ten years as an abalone diver. So, produce a superior product. It was diffi- experienced it before. Karen was first peared. Visibility horizontally was at we were well acquainted with the diffi- cult for them to cope with lack of tan- away while I geared up the two least 30 metres, but the red surface culties of extended diving in such a nin, and at times, the mood among the Japanese divers and over the side they glow faded away to black above me remote location. film crew became quite explosive. went with me following minutes later. as I reached a depth of 12 metres. The But then the rain came, and came As I descended through the tannin, all slope leveled out and sea pens The Bathurst Channel and kept coming for the next ten days. sound had ceased except for that of (Sarcoptilus grandis) started appearing The Bathurst Channel has several heavi- This created another set of problems, my exhalation bubbles. Visibility seemed on the silty bottom. ly wooded islands that offer shallow but it also gave the film crew a great absolutely zero then at about three water diving in beds of sea whips as example of how this bizarre ecosystem metres. I saw red lights below and shallow as 4m depth—these are usually originates.