ADVENTURE CAVE DESTRUCTION THROUGH MANAGEMENT - SOME HARD FACTS
ABSTRACT
An analysis of visitor sheet data for Giants Cave (WI 21-22) in the Leeuwin-Naturaliste National Park in the southwest of Western Australia is presented. This data is correlated with data gathered during a 5 day on-site visitor survey and similar survey conducted in 1982.
The factors that have contributed to the considerable damage occurring in Giants Cave are discussed. The lack of action by the management authority in respect to cave degradation throughout the Park is examined with respect to the ultimate carrying capacity of the cave.
Giants Cave management is compared with the exploitive management of the Great Cave in the Niah National Park in Sarawak where "visitor" numbers are relatively low but "residential" numbers are high. The exploitation of the swiftlets nesting in the cave is examined.
INTRODUCTION
Giants Cave - some background information
The caves of the southwest of Western Australia are formed in a very friable limestone, aeolian calcarenite. White (1985) outlines the caving potential of calcarenite in Australia and suggests that the cave potential is high. The Leeuwin-Naturaliste ridge contains about 310 numbered karst features and caves.
Giants Cave (WI 21-22) is located in the Leeuwin- Naturaliste National Park in the southwest corner of Western Australia. The cave has been known since the early 1900s when the Government surveyor, Marmaduke Terry, located the cave's entrances.
Giants Cave has 4 entrances, two vertical solution pipes of 50 metres depth and two "walk-in" entrances. The main entrance doline (WI-21) is located about 30 metres from a major sealed road, Caves Rd, which traverses the length of the National Park from Yallingup in the north to Augusta in the south.
Large chambers are the major feature of the cave, which is 575 metres long and 83 metres deep. The largest chamber in the cave is 75 metres long, 45 metres wide and 18 m high. However, besides the chambers, it also does contain a significant quantity of small delicate speleothems. Larger speleothems are not as frequent but several areas do contain massive stalagmites and flowstones.
Several staircases were placed in the cave during the 1920s when adventure caving commenced in Giants Cave. Visitors were brought mainly from Perth, some 300 kilometres north and, with the assistance of a guide, these hardy folk were shown the delights of caving by lamp and an occasional magnesium flare.
Today all of these stairways have been replaced or repaired by the current manager, the Department of Conservation and Land Management (CALM).
The Great Cave at Niah - some background information
The Great Cave is located in the Niah National Park some 96km west of the city of Miri in northern Sarawak. The 3,102 hectare park is dominated by the 394m high limestone massif whose summit is called Gunung Subis. The Great Cave occurs within a small (about 1 km long) massif at the northern end of the main massif. The cave has been declared a historical monument.
The Sarawak Museum began archaeological work in the cave in 1954. The West Mouth of the cave is one of the most important archaeological cave sites ever found in Southeast Asia. It is unusual and important because of the wide range of stone tools found in the cave. Also at a depth of 96 inches fragments of a skull were found. These have been reconstructed and dated at about 39,000 years. The skull is the earliest definite representative of Homo sapiens so far found in Southeast Asia.
Other important features of the cave are its wide variety of cave fauna. Several species of swiftlet and bats inhabit the cave. The bat guano is collected and sold as fertiliser and the two species of swiftlets produce a birds nest from their saliva, which is edible. This nest is a delicacy and hence fetches high prices in Southeast Asia.
An information centre is provided for visitors to the cave at the National Park headquarters. This details the work undertaken by the Sarawak Museum as well as providing information on cave morphology and details on the cave's extensive fauna.
GIANTS CAVE VISITATION DATA
The First Results - 1978
The first visitor books were placed in Giants Cave by Hart (1980). These results were published in a development and management plan for Giants and Golgotha Caves (Webb, 1982). This original data was collected over a 10 month period, March to December 1978.
Using simple weekly averaging, an estimate for January and February 1978 was obtained and an annual estimate of 786 visitors determined. No correction was performed for those visitors who did not record themselves in the visitors book. At this time no estimate of how many visitors registered in the visitors book was available.
An On-Site Visitor Survey - 1982
For the two weeks from 9 January to 24 January a visitor survey was conducted by the author. This on-site survey recorded visitor information and all visitors agreed to answer a questionnaire of eight questions.
Visitor Book Survey - 1988
A visitor registration box containing several sheets of loose leaf paper was established by CALM in 1987. The requested information on the data sheets was Date, Name or Vehicle Registration, Number of Persons and Town of Origin. The sheets of paper were collected and replaced with blanks by the caves ranger, Rob Klok. The interval of replacement was determined by the ranger. In some cases this interval was too long and visitors could not register due to lack of paper. Several long periods were not recorded (see Appendix 1) and estimation of visitor numbers was necessary. The known highest visitation period, the Easter holiday break, was also not recorded and hence was estimated.
The visitor registration detail was kindly supplied to the author in photocopy format by Rob Klok of CALM.
Further data was obtained from the trip book for the Western Australian Speleological Group Inc. (WASG). This book is held at the nearby WASG hut and is completed by WASG members and visitors caving from this location. This data was available for 1988.
This data was analysed in the following ways:
(a) Sum the actual recorded number of visitors:
The data sheets were summed by date. Some dates occurred on several
sheets and may have been incorrectly recorded however no attempt was made
to determine errors. Two or three large group recordings (e.g. 50)
were thought to be invalid as they were recorded
against individuals' names. One recording of 51 is known to
be invalid as it occurred during the on-site visitor survey discussed
below. In this instance the data sheet appears to be a 51 but was
actually two recordings, one of 1 and one of 5. Figure 1 summarises the
actual data recorded from 1978 to 1988.
(b) Total the number of large groups visiting the cave:
The number of large groups visiting the cave is thought to be having
a dramatic impact on the cave and hence the visitor numbers
attributable to large groups was determined.
A group of 12 or bigger was counted as a large group.
This figure accounted for 27% of all visitors recorded. Such a high percentage clearly indicates the impact that such groups are having.
c) Compare speleological group visitation with previous rates:
The data from the WASG trip book indicated that only 109 WASG members
visited Giants during 1988. The graph in Figure 2 clearly
indicates that the level of WASG visitation
has fallen dramatically from some 20% of visitors
to 2% of visitors.
(d) Averaging weekend and weekday daily rates:
The data for all weekend and weekdays was averaged for the year.
This produced results of 17 visitors on week days and 25 visitors on weekend
days. The value of 25 for weekend days was thought to be significantly
low due to the number of weekend day figures that were not recorded.
As a result an artificial value of 40 was assigned to weekend days.
This value is thought to be a conservative one. Note that the standard
deviation on the weekend figure is 22.
(e) Averaging recorded data with daily averages:
The original data was then processed against the daily averages.
The average daily value was then substituted for the actual value if it
was zero or less than twelve. This new set of data which can be called
the averaged recorded data is thought to be a closer approximation to the
visitors who would have been recorded if the visitor data sheets had been
available for the entire 12 month period.
An On-site Visitor Survey - 1988
Appendix 2 contains the results of an on-site visitor survey conducted at Giants Cave between 26th and 30th December 1988.
Besides recording the highest figures ever recorded at the cave it was the first opportunity to ascertain the proportion of visitors that do not register.
This factor has always been the greatest source of error in estimating visitor numbers from visitor books. Hence this was the major purpose for conducting the survey. All visitors to the cave were not approached until after they had visited the cave. In this way it was possible to accurately determine how many visitors registered in the visitor book
In several cases visiting parties recorded themselves multiple times. For example in one party of eight a parent recorded the party number correctly before entering the cave, then two children in the party re-recorded the same party, once each. Hence for one party of eight, 24 visitors are estimated from the data sheets.
Figures 1 & 2
This type of error produced the very high visitor numbers recorded on days 1, 4 and 5 of the survey. Hence the very high recording rate. This rate is not indicative of all visitors registering, as indicated by the very low 24% on day 2, but rather this is a multiple recording error.
The Bottom Line
The 1988 on-site visitor survey provided, for the first time, a figure on which to base an extrapolation of actual visitor book data. The average percentage of visitors who recorded themselves in the visitors book was 67%. This is thought to be a very high recording rate which is due mainly to the multiple recording error mentioned above.
However using the average of 67% the total number of visitors to the cave is estimated at 17,000 per annum. Using the worst case figure of only 67% then the number would be 18,000 visitors per annum.
Using all of the data so far collected at Giants Cave based on the current visitor growth rate and a recording rate of 67%, it is estimated that 45,000 visitors per annum will be visiting Giants Cave by the year 1998. These figures are illustrated in Figure 3.
The Current Situation
At present Giants Cave along with the many other adventure and wild caves in the National Park, awaits the release of the Leeuwin-Naturaliste National Park Plan of Management. The draft plan was released in November of 1987 but at the time of writing the final plan had not been released.
Without a directing or controlling body to plan the management of the caves in the National Park all actions over the last 5 years have been of the ad hoc variety. For example Giants Cave desperately required a larger car park. However instead of trying to reduce visitor numbers by providing a relatively small car park, a large car park, able to handle 12 to 15 vehicles and 1 or 2 buses, was constructed. The previous car park could only handle 5 vehicles before overflowing.
Figure 3
This car park was constructed in close proximity to the cave entrance (about 20m from the doline) The surface material was a white crushed limestone and as the car park was built on a slope to the main bitumen road, rain has washed a great deal of material onto the bitumen. The white material spilling onto the main road attracts many of the cave's visitors. A sign just off the road also encourages visitors to enter. Furthermore the car park now has several water erosion ruts that will require attention in the near future.
These management decisions are the result of great pressure being placed on a resource and the rangers in the field. In general the rangers have achieved amazing results given that they have been hampered by the lack of a management plan or cave management knowledge in higher management positions. Considering the number of national parks and reserves in Western Australia containing caves and karst features, CALM is sadly lacking in cave management expertise.
The Management Plan's Strategy
The draft management plan outlined a "strategy" that will be adopted with respect to cave management when the plan is released. This "strategy" has as its basis the following loosely connected parts:
- A Cave Management Committee (CMC) should be formed to provide CALM
with the necessary expertise to provide cave management in the Leeuwin-Naturaliste
National Park. The proposed CMC should be responsible for:
- Making recommendations to CALM regarding levels of access and use, including locked caves.
- Administering ethical questions regarding cave use.
- Preparing management plans for subsurface management of caves as required.
- Formalising links between CALM management and speleological groups.
- A permit system for visitors to adventure and wild caves should be implemented (this is almost certain to be altered in the final plan to cover only wild caves).
- Giants Cave and Calgardup Cave should be regarded as adventure caves and become priority areas for surface management.
- Monitoring of water levels should be undertaken.
- Catchment management should have a high priority.
- CALM regulations should be altered to attempt to protect caves.
All of these items are very important management issues. However the plan does not come to grips with the major cave management problem.
PEOPLE! The strategy does not address the dramatically increasing pressure on the caves of the Leeuwin-Naturaliste National Park caused by rapidly rising visitor numbers.
The park will see well over 250,000 visitors in 1989. A visitor survey conducted by CALM in 1987 did not survey any adventure cave sites but their survey did conclude that the major reason people visited the park was to undertake water-based activities (about 50% of all visitors).
Surfing at 13.8% of the total sample was the most popular activity, while caving rated 3.8%. However a vital question that was missing from the questionnaire was "What is your second favourite activity? The reason this question is so vital is that if the surf is bad, where do the surfies go? One answer which would rank highly would be caving. A significant number of vehicles with surfboards on or in them visited the cave during both on-site surveys.
Other popular activities in the park were camping (8.0%) and sightseeing (11.2%). Both of these activities would also provide extra visitor numbers to the casual caving occurring at Giants Cave.
Can a cave have a carrying capacity?
The term 'carrying capacity' has been discussed by several authors with respect to caves. "Caves, Cows and Carrying Capacity" was the title of a paper presented to the National Cave Management symposium in the USA in 1975 by Thomas Aley. Aley's title says it all. The term 'carrying capacity' correctly refers to the ability of a renewable resource to sustain use at a level that will not destroy the very resource being used.
This concept ensures that cows or sheep eat all of the renewable resource, the grass, without damaging the non-renewable resource, the soil.
Another point of view was expressed by E. Hamilton-Smith (1980) when he examined the topic "Caves as Commons". An example of a modern 'common' is a National Park. They are open to all without limit. The visitor numbers to parks continues to rise but the park does not get bigger - it cannot expand to accommodate the increase in visitor numbers.
Treating caves as commons, which is clearly happening in the case of Giants Cave, can only have one ultimate result - the destruction of the cave.
In his paper E. Hamilton-Smith draws the following conclusion:
"Now, within the normal time-scale, virtually everything within a cave is non-renewable, and so any destruction at all is permanent and cumulative. In other words the carrying capacity of a cave is zero.
If we dismiss the concept of a cave having a carrying capacity or that we can treat it as a 'common', how then can caves be managed to ensure their conservation for longer than the short term future?
The Sacrificial Cave
The Leeuwin-Naturaliste National Park contains some 360 speleological features. Of those 15 are accessible to and visited by the average park visitor. Of those 5 are classified as Adventure Caves. Of those Giants Cave and Calgardup Cave SHOULD be classified as the Sacrificial Caves. These caves have suffered extensive damage since the 1920s and now management is providing their location to all who ask "Where can I go caving in the park?"
Is the sacrificial lamb necessary? Will it provide the solution to the ever increasing visitor numbers or will it lead to increasing pressures on other less visited caves?
Whilst conducting the 1988 on-site survey discussed above, the question most frequently asked of the surveyor was "where are some other caves like this that we can visit?".
The sacrificial lamb is really a ram sowing the seeds of adventure in all who examine its fleece.
A significant proportion of Giants Cave visitors are excited by their caving experience and want more. With a little effort they will find the other 14 easily accessible caves and the visitor numbers to those caves will increase dramatically. This process is already occurring with caves previously classified as 'wild' caves now being heavily used as adventure caves.
What to do without Rams, Cows, or Commons?
Other authors such as Seabrook (1972) and Reider (1977) examined some of the ways to quantify the cave resource. Seabrook even devised a formula for the coefficient of destruction (Cd) of a cave.
If we attempt to quantify the cave resource by the methods of Seabrook or Reider, it is necessary to dissect the cave into the parts considered "worthy of conserving", such as cave fauna, minerals, speleothems etc. In doing so we lose the overall essence of the cave experience after which its visitors strive.
Caves do not have carrying capacities. They should not be treated as commons and they certainly should not be allowed to be held up waiting for their throats to be cut.
CALM have been extremely tardy in producing the management plan for the Leeuwin-Naturaliste National Park. This procrastination, consultation and compromise with the many parties affected by the plan has caused a great deal of damage to many of the features within the park they are trying to conserve. It is time to bite the bullet and act! Release the plan and act on its recommendations, before it is time to start the next one.
Individual cave management plans are necessary as well as an area cave management strategy. In the case of the Leeuwin-Naturaliste National Park unless effective on the ground cave management designed to reduce visitor numbers is put in place almost immediately the projected figures in Figure 3 for Giants Cave in 1998 will be duplicated in many of the other adventure and wild caves of the Park.
An immediate step to reduce visitor numbers is to introduce the proposed permit system and place an upper limit on the size of parties visiting caves. Note that large groups account for 30% of all visitors (Figure 2) in 1988 and 1987. The 1988 figures are thought to be artificially low because in 1987 the majority of the groups were advising the Ranger of their intention to conduct a trip whereas in 1988 many leaders conducted trips without informing the Ranger.
The Great Cave and Giants Cave Comparison
A comparison between Giants Cave and the Great Cave of Niah is introduced to the discussion here because of the similar management strategies being applied to both caves.
The adventure cave visitation rates at the Great Cave are not documented. However during a recent visit to the cave by the author about 60 visitors were observed in the cave during a three hour visit.
Then there are the bird nest collectors. During my visit approximately 150 persons were observed in the cave, or travelling to or from the cave, to collect nests. The collection of birds' nests is a dangerous occupation, six collectors died in 1987. The 'scrappers', as they are called, climb a 30-40 metre high wooden pole to the roof of the cave and then build platforms from which they use a bamboo pole (about 12 metres long) fitted with a scraper on the end, together with a candle to light their job, to scrape the birds nests from the roof. A second person collects the fallen birds nests from the cave floor.
This collection process is only meant to occur twice a year, in January and June. My local guide informed me that because there were so many "illegal" collectors (the National Parks office licenses collectors), collecting occurred every day of the year!
The cave is also home to a number of species of bat. The collection of guano occurs daily in the cave. The process has now reached the point where collectors are collecting fresh guano as it is produced by the bats. This is clearly having an impact on the extensive ecosystem that lives on the bat and bird guano.
The exploitation of the Great Caves cannot be sustained at current levels. Unless intervention occurs by the National Parks and Wildlife Service the renewable resources within the cave will be lost. Already severe degradation of the cave has occurred due to a very high visitation rate. A Great Cave Management Plan is vital if the fauna of this cave are to survive.
By comparison Giants Cave does not have an extensive ecosystem. However it is under similar visitor pressure. The visitors to both caves are trampling the cave to destruction.
This is occurring in both cases due to the lack of responsible management at a high level. Politics is destroying caves. Policies to reduce visitation rates and hence exploitation of the caves are not being put in place because they will be unpopular with the "exploiters" of the cave. Government authorities have to take the bit between their teeth and introduce policies that reduce visitor numbers and restrict movement within caves. Without these policies adventure caves will be destroyed.
The Future of Adventure Caving
Adventure caving is an adventure for those who participate. Who will ever forget their first visit to a wild or adventure cave? It is an experience you keep for the rest of your life.
BUT WHAT ABOUT THE CAVE?!
Is it necessary for us to destroy the adventure experience we are trying to give by encouraging the entire population to visit caves? Sensitive planning is vital if adventure caving is to survive into the next decade.
As the managers of adventure caves it is your task, not to try, but to ENSURE that the types of caves discussed here are managed to allow continued visitation without destroying the cave.
REFERENCES
Aley, T. (1976) Caves, Cows and Carrying Capacity. Proceedings National Cave Management Symposium. 70-71. Albuquerque, N.M., Speleobooks
Hamilton-Smith, E. (1980) Caves as Commons. Proc. 13th Biennial Conf. Aust. Speleo. Fed. Melbourne. 24-28
Seabrook, J. (1970) A Quantitative Approach to Cave Conservation. Proc. 8th Biennial Conf. Aust. Speleo. Fed. Tasmania. 61-62
Webb, R. (1982) Development and Management Plan for Giants and Gologotha Caves. Augusta Margaret River Tourist Bureau
White, S. (1985) Caving Potential of Australian Aeolian Calcarenite. Helictite 23(2), 56-58