New Zealand's multimillion-dollar glacier tourism industry is potentially under threat by ongoing glacial retreat, according to a university researcher.
University of Canterbury Geographer Dr Heather Purdie said she has been monitoring Fox Glacier since 2005 and was increasingly concerned about the impact that climate-driven glacier retreat would have on glacier tourism and regions reliant on glacier-related products.
Steepening ice slopes, increased debris cover and an increase in rock fall hazard were just some of the challenges facing glacier tourism operators at Fox and Franz Josef, she said.
"The termini of the Fox and Franz Josef Glaciers are drawing increasingly close to their previous minimum which, coupled with thinning, indicates that retreat will continue for the near future."
Adaptation to changes associated with retreat - such as steepening ice slopes - included increasing the use of helicopters to access flatter parts of the glacier and extending access tracks up valleys.
However such solutions came at a cost, not only in monetary terms, but also in terms of increased environmental disturbance, Dr Purdie said.
Negotiation to establish acceptable degrees of adaptation would be ongoing, she said.
Scientists, policy makers, and tour operators needed to work together, sharing knowledge, ideas and experience, to find a balance between utilisation, safety, and conservation, she said.
The Intergovernmental Panel on Climate Change noted that predicted glacier shrinkage and retreat would reduce visitor numbers in tourism-dependent towns like Fox Glacier and Franz Josef.
Access and viewing points would potentially become increasingly unsatisfactory as glaciers retreated into steeper, more inaccessible terrain, Dr Purdie said.
However, despite the dramatic changes in glacier length and thickness, glacier tourism has been maintained in New Zealand and was as busy as ever.
"The introduction of boat tours instead of walking tours on Tasman Glacier means that a century on, tourists can still visit the glacier," she said.
Up to 400 tourists a day were guided to the glaciers last summer.