The donation rate among Mount Fuji hikers from the north rim dropped after the introduction of the mandatory fee.

Hikers climbing Japan’s highest mountain are asked to volunteer money to protect the environment, maintain public toilets and set up first aid stations. The recommended amount is set at 1000 yen or more than $6 per person.

During this year’s climbing season, the percentage of hikers who donated on the Yamanashi Prefecture side was 53.1 percent. This was a 22.5 percentage point decrease from the previous year, the second lowest figure since the system began in 2014.

The prefecture has implemented a 2,000 yen fee for Mount Fuji hikers this year, to be used for safety measures, including limiting the number of climbers.

Yamanashi officials say hikers may be reluctant to donate above the mandatory fee. Authorities say they will work on the integration of the two systems.