How Many Is Too Many?

AThe idea that a place can absorb only so much use before it begins to fail was not invented by tourism planners. It was borrowed, in the 1930s, from rangeland science, where carrying capacity meant the number of cattle a pasture could feed without losing its grass. Recreation managers in the United States took up the term in the early 1960s, when visits to their national parks were doubling every decade, and it has been in circulation ever since. In its tourism form it is usually defined as the greatest number of visitors a destination can receive without unacceptable deterioration of the physical environment or of the quality of the visitor experience. Four strands are normally distinguished: physical capacity, meaning the space available; ecological capacity; the capacity of infrastructure such as water supply and sewerage; and social capacity, which concerns how crowded people feel. Sixty years of argument have turned on a single word in that definition, and the word is unacceptable.

BEcology at least offers something to count. Where walkers cross a vegetated surface, damage accumulates along a curve that is steep at the start and almost flat afterwards. In trials on the dune grasslands of the Ardova coast, researchers walked marked lanes a fixed number of times and found that the first 200 passes stripped roughly three-quarters of the plant cover, while a further 1,800 passes removed only nine percentage points more. A path that is already worn is cheap to use again; a fresh route is expensive from its first day. The management conclusion runs against instinct. Dispersing visitors across a wide area, an approach that sounds gentler, multiplies the number of surfaces sitting at the steep end of the curve, whereas concentrating them on hardened routes confines the damage to ground that has little left to lose. Dispersal is the better policy only where the purpose is to keep people away from sensitive wildlife rather than to keep feet off plants.

CSocial capacity has proved far less tractable. Wanjiru Castellanos, a tourism geographer at the Verrand Institute, spent four seasons between 2016 and 2019 interviewing 1,240 walkers as they left the coastal reserve at Cape Miroy, asking each of them how many other groups they had met and how satisfied they felt. Reported satisfaction did not fall steadily as encounters rose. It held almost level up to a point and then dropped sharply, but the location of that point varied from walker to walker. Those who had come in search of solitude reported dissatisfaction after roughly eight encounters; those who had come to watch a particular seabird colony met more than thirty and said afterwards that the presence of other people had not entered their minds. Castellanos's inference is that there is no single number waiting to be discovered. “The question has no answer,” she wrote in 2021, “until somebody states which visitors the place is being managed for.”

DThat reasoning underpins Limits of Acceptable Change, a procedure that gives up the search for a threshold figure and instead obliges managers to name indicators — bare ground, water clarity, encounters per hour — to set a limit for each, to monitor them and to act when a limit is passed. Tomás Ferreiro, an economist at the Blakemoor Centre, accepts Castellanos's survey findings without reservation and objects to what has been built on them. A procedure that specifies monitoring but not consequences, he argues, will always be settled in favour of admitting more visitors, because the pressure to admit them is immediate while evidence of harm accumulates slowly. His own instruments are blunt ones: fixed daily quotas, or prices high enough to ration demand. The evidence he cites is mixed. When the Sarnen valley began issuing 2,800 permits a day in 2017, arrivals on peak days fell by a quarter, yet visits across the whole year rose by 11 per cent as trips migrated into spring and autumn.

EResidents supply a third measure, and it agrees poorly with the other two. A model published in 1975 proposed that host communities travel through stages from enthusiasm to irritation as arrivals grow, and for two decades researchers tested it by setting complaint levels against visitor totals. The correlations were weak. Work since 2010 points instead to the ratio of visitors to residents and, above all, to changes in housing. In the harbour town of Kestrel Bay, formal objections to tourism development followed the share of dwellings converted to short-term letting far more closely than they followed arrivals: in the two years after conversions passed a fifth of the housing stock, objections tripled, while arrivals stayed flat. No town in which such conversions were later reversed has yet been studied.

FAuthorities therefore choose between two imperfect levers. Quotas hand out access by queue or lottery and are easy to explain; charges hand it out by willingness to pay. When Lake Verrand introduced a twelve-euro entry charge in 2019, total visits fell by only 6 per cent, but the make-up of the crowd changed, with day visitors from the nearest city dropping most. Critics called the charge a tax on the poor; the operators answered that the revenue paid the wardens who repaired the paths. Neither camp disputes the underlying arithmetic, and nor should they: any limit placed on a popular place will exclude somebody. That is why the notion survives six decades of failing to deliver the number it promised. Its worth lies not in the figure it yields but in forcing an authority to declare, in public and in advance, what condition it means the place to be in.