SOME MANAGEMENT ISSUES IN THE NATIONAL PARKS AND RESERVES OF SOUTHWEST TASMANIA
Karst areas are widespread in Tasmania's Southwest National Park (SWNP) and Franklin-Lower Gordon Wild Rivers National Park (FLGWR NP), both of which form part of the Tasmanian World Heritage Area (WHA). Karst is also widespread in the multiple-use Southwest Conservation Area (SWCA) that surrounds the WHA. These karsts include the deepest and longest caves in Australia; landforms and landform associations of considerable scientific interest; caves with archaeological remains that document the lifestyle of the most southerly outpost of humanity on earth during the last ice age; caves of considerable biological interest, and surface landscapes of great importance to the tourist industry. In this paper I wish to briefly address some of the management problems that have arisen.
The Mt Anne Area
The small but spectacular Mt Anne massif consists in part of extensive deposits of dolomite. The NE ridge of Mt Anne is characterised by impressive surface karst topography. It contains Australia's longest continuous shaft, Kellars Cellar, and Australia deepest cave, Anne-A-Kananda. The dolomite continues eastwards into the valley of the Weld River where the caves include an archaeological site of Pleistocene age, and an impressive natural arch through which the Weld River flows. The dolomite relief exceeds 600m and, hence, this area has the greatest cave depth potential of any in Australia. It is therefore of considerable importance to cavers. It is also important for its geomorphology, as there is a close association between karst and cave development and the glaciers that eroded the spectacular landscape. At the foot of the NE ridge lies Lake Timk, a glacial lake contained in a cirque. Lake Timk has a large catchment but no surface outlet. It drains instead into solution channels in its bed and the drainage from it breaches underground a major surface drainage divide. Some ancient shafts close to the margin of the NE ridge appear to have been partly shorn away by eroding glaciers. The location of some of the caves, and the sediments within them, suggest they may have been formed by meltwaters flowing within and close to glacier margins. Large moraines and other glacial deposits east of the lake document the history of the glaciation, and hence the evolution of the karst.
This area is also important to archaeologists. The most southerly known archaeological site of Pleistocene age on earth lies in the Weld Valley. And the area is important also to botanists for its alpine flora and its rainforests, and to bushwalkers for its spectacular scenery.
The karst management issues that have arisen in this area relate largely to the arbitrary boundaries by which the park is defined. Much that is of value extends beyond the boundaries of the SWNP into areas that are potentially available to industrial development, such that the integrity of the area in the park is reduced and many scientific sites of value are unprotected. For instance, Anne-A-Kananda, most of the karst drainage from Lake Timk, the moraines and the archaeological site all lie outside the arbitrary boundary (Kiernan 1984). Each of these places forms part of a set of features, and the value of that set will be reduced by more than the value of any individual piece that is lost.
An additional problem in this area is the vulnerability to damage of the alpine flora in the vicinity of the caves. Pandani Shelf, at the SW end of the karst ridge, is greatly valued for its botanical assets, including cushion plant bolster communities of great beauty that were strikingly depicted by the photography of the late Olegas Truchanas. Some of those areas that grace the pages of his memorial volume have now been damaged through trampling, largely by cavers. For instance, despite their efforts to avoid some of the more sensitive boggy areas in selecting a walking route between their campsite and the caves, there are suggestions that a recent two week long trip to the area by cavers has done more damage than the bushwalking impact of the last decade or more (Anon 1987).
The boundary problem can only be solved by rationalisation; the trampling problem is likely to demand formalised tracks that will transform the character of Pandani Ridge.
Bubs Hill
The Bubs Hill karst consists of an outcrop of limestone a few square kilometres in extent, located beside the Lyell Highway in Western Tasmania (Kiernan 1977). It has attracted little attention from cavers due to its distance from the main population centres and the closer proximity of places like Mole Creek, Ida Bay and Junee-Florentine. But Bubs Hill was one of eight karst areas included in a recent survey of the cave fauna of SW Tasmania, and it proved to be a place of considerable faunal diversity and potential interest.
This karst area lies astride the boundary of the FLGWR NP. The caves that contain the fauna lie outside the park in an area that was formerly part of the Southwest Conservation Area but which was excised and vested in the Hydro Electric Commission (HEC) in 1982 to facilitate access to proposed damsites on the upper Franklin River.
Two aspects of this situation warrant comment. Firstly, the part of the karst revoked from the Conservation Area in 1982 was never reinstated as Conservation Area after the High Court decision that blocked construction of the dams and is not part of the SWNP or World Heritage Area. In April 1987 an arrangement was finalised whereby the NPWS has leased the excised area from the HEC. This has the effect of giving the Bubs Hill karst and its fauna a measure of protection superior to that which it previously enjoyed, since the legal implications of the Service leasing land make such land effectively a State Reserve. But unfortunately the problem does not end there. A small stream sinks just outside boundaries of the national park and the leased reserve close to a small limestone quarry operated by the Department of Main Roads (DMR). Although the quarry has not been used for some years, an artificial entrance to a cave that contains the stream has previously been opened in the quarry face.
Where the water goes is not yet known, but the cave most rich in fauna is a likely candidate. The DMR is also planning road improvements in the area. So the possibility exists that we could end up with greatly improved protection of the cave fauna outside the WHA boundary due to the new lease agreement, but it could be rendered meaningless by developmental activities in the catchment. An ironic twist indeed!
Wilderness Karst
In Tasmania we are fortunate in still possessing large areas of remote landscape in a pristine condition that warrants description as wilderness. To the extent that attempts are made to define what wilderness is at all, vigorous criteria are applied. We are still able to have reasonably high expectations as to what wilderness is in Tasmania, and those feelings and expectations are strongly held. Wilderness is, above all, a blank and distant spot on a map, a romantic coupling of mystery and remoteness. It is a commodity that can be diminished by excessive knowledge as much as by excessive development or excessive use. For my own part, I have long held that the only thing which can destroy wilderness faster than a bulldozer is a map. This is of some relevance to cave and karst management in some parts of southwest Tasmania. Some years ago Brian Collin, who spearheaded the exploration and mapping that revealed Exit Cave as Australia's longest cave, remarked to me in a reflective moment that he now sometimes felt that he should burn the map, to let others have the same pleasure of exploration and discovery. It was a suggestion likely to arouse strong responses from cavers who feel that their documentation of caves is a positive contribution, or from planners and managers consumed by an axiomatic passion for resource inventories as a foundation for their work. In most cases documentation is valuable and necessary, but to what extent is it really necessary or desirable in little-visited wilderness areas, or might it be a negative thing sometimes?
Some Tasmanian cavers have made a conscious decision not to document some areas, to string out the finite resource of true exploration and discovery and to extend it into the future. Inventories are deliberately not being compiled for wilderness karsts in some areas of southwest Tasmania.
The Prehistoric Caves of the Gordon-Franklin area
Where potential development or visitor pressures are on the horizon there is obviously a strong case for inventory and study, as exemplified in the case of the Lower Franklin caves where the inventory process revealed the presence of archaeologically-rich caves of world significance (Middleton 1979, Kiernan et al 1983). One of the principal problems that now arises for the management of these caves is the unusual coupling of the remote location with the considerable visitor traffic rafting down the Franklin River. Fortunately only one site is well known, but that site is Kutikina (formerly Fraser) Cave, the richest among them. It is impossible to police against souveniring, impromptu digs, careless trampling or possible wanton vandalism from distant Strahan. And the vindictive burning and felling of a majestic old Huon Pine near Warner's Landing on the Lower Gordon in response to the decision to halt the dam stands starkly in the memory of all those concerned for the future of the caves.
But to station a ranger on site would be expensive and involve an unacceptable intrusion on the character of the area.
A further problem is posed by land tenure. The area nominated for World Heritage Area status by the Tasmanian State Government in 1981 included all of the FLGWR NP. However, when a later state government wished to undertake hydro-electric development works in the area, the State Reserve and Conservation Area status of those parts of the park in which most of the karst occurs was revoked and vested in the Hydro Electric Commission so that construction and flooding could proceed. This involved all or almost all the Franklin, Gordon - Sprent and Olga Karsts. In the case of that part of the Franklin Karst that contains the archaeological sites, the revocation was not to become effective until 1990, to allow management of the sites by the NPWS to continue until the dams were filled. Because all these areas were still part of the World Heritage Area the High Court of Australia ruled that construction of the dams could not proceed. However, protective provisions of the National Parks and Wildlife Act no longer applied to most of the karst, and the NPWS was therefore unable to fulfil any management role.
Those revocations still stand. Hence, the most important karst areas in the region remain outside the boundaries of the Franklin-Lower Gordon Wild Rivers National Park which will, after 1990, contain neither the lower Franklin river nor much of the Lower Gordon. Leasing by the NPWS of that area vested in the HEC has recently been finalised. It will afford temporary protection to areas where 'permanent' protection previously existed. It will extend temporary protection to one or two other areas such as the Nicholls Range Karst, and some important non-karst sites such as the Gordon Splits, once reputed to be a tunnel but in reality a 100m deep gorge only 4-5m wide through which Tasmania's largest river runs.
However, the area of greatest archaeological value is not included in the lease because it was never vested in the HEC. Moreover it will still lose its State Reserve and Conservation Area status in 1990. Kutikina, Deena Reena and the other caves and karst features will then be afforded no protection under the National Parks and Wildlife Act, though souveniring of artefacts would still be prohibited in theory by the general provisions of the Aboriginal Relicts Act 1975. This latter legislation, incidentally, still remains the sole protection for Balawinnie Cave in the nearby lower Maxwell Valley, a place which is at least a candidate for being the oldest prehistoric art site in the world. A further problem that must be of concern is that a lack of academic discipline has meant that the full results of the 1981 Kutikina excavation have not yet been published. It is highly unhelpful that this information remains unavailable when the future of the area remains uncertain.
A metal walkway, interpretation panel and plea for cooperation has been installed in Kutikina. In order to safeguard the other archaeological sites their precise location is not being disclosed to the general public. The lease for the previously revoked area, which will probably be called the Franklin-Lower Gordon Leased Reserve, was signed in April 1986. Access to some of the more robust caves along the Franklin may be encouraged in an effort to minimise the pressure on the sites that are more sensitive.
The Lower Gordon
The Lower Gordon karst consists of a long but fairly narrow belt of limestone that has been little explored by cavers (Kiernan 1979). However, cruises up the limestone valley of the Lower Gordon are the keystone of the tourist industry of western Tasmania, and the lifeblood of the town of Strahan. The cruises have operated for decades and take visitors through tranquil waters where river-sculpted limestone cliffs and outcrops alternate with overhanging Huon pines, myrtles, sassafras, celery top and other native species of the verdant temperate rainforest. It is the shop window of the World Heritage Area.
The dams debate increased public interest in the area and visitor pressures upon it. As a result, two 200 passenger vessels now traverse the river at speeds of up to 25-30 knots, sometimes 2-3 times per day, and a 100 passenger jet boat takes visitors a little further for a view of the dam-site and the Franklin River. Since that advent of high speed tourist vessels in 1983 extensive areas of river bank have collapsed from undercutting and buffeting by boat wakes. Where toe support has been eroded away from the slope deposits that cloak steep limestone hillsides, land slips that extend progressively upslope have developed. Increasingly the river has become lined by fallen timber, landslips and dying trees. Since 1983 very many kilometres of previously stable riverbank has either collapsed or been destablised. Once the banks are broken, some of them recede rapidly - up to 2m of backwearing in a single year has been documented on some narrow levee banks. Any rehabilitation will be extremely difficult and must also involve protection measures.
Speed limits have been introduced for the cruise boats but are difficult to enforce and if applied too widely may extend the duration of the cruises to an extent that is unacceptable to the politically influential tourism operators who transport the visitors to Strahan. In addition, different vessels travelling at the same speed produce wakes of different size due to differences in hull design. Studies are being undertaken on the erosive affects of boat wakes of different heights and their relationship to bank erosion. It seems that once the banks are broken, even very small wakes are sufficient to erode them. Engineering solutions on the riverbanks may be investigated but will be expensive and intrusive. Although the river forms part of the World Heritage Area the Australian Government, once so concerned about the prospect of dams damaging the area, hasn't been seen since the High Court headlines faded. Maybe we need to find a tourist cave close to the mouth of the river to provide an alternative attraction that will make it easier to limit the cruises.
Conclusions
In summary then, a number of karst management problems exist in the parks and reserves of southwest Tasmania. They stem from a variety of causes including poor definition of land parcels, inadequate resource inventories, excessive resource inventories, competing demands for the karst terrain, and the commercial pressures that surround mass tourism. The solutions are usually complex and not always satisfactory. Fortunately, a happier story awaits outside the boundaries of Tasmania's parks and reserves, but that is the subject of another paper.
References
ANON (1987) Camping Impact on Alpine Environment, Tasmanian Conservationist, Feb-Mar 1987:14-15
KIERNAN, K (1977) Caves at Bubs Hill, Southern Caver 9(2)
KIERNAN, K (1979) Limestone and dolomite in and adjacent to the Franklin and Lower Gordon Rivers, Southwest Tasmania: An Inventory and Nomenclature. J. Syd. Speleol. Soc. 23:189-204
KIERNAN, K (1984) Landuse in Karst Areas: Forestry Operations and the Mole Creek Caves. Australian Heritage Commission, Canberra, 320pp
KIERNAN, K, JONES, R and RANSON, D (1983) New Evidence from Fraser Cave for Glacial age man in southwest Tasmania, Nature 301: 28-36
MIDDLETON, G (1979) Wilderness Caves of the Gordon-Franklin River System. Centre for Environmental Studies Occas. Pap.11. Univ. of Tasmania