“We have more than doubled the amount of fines this year compared to other years,” said Sonja Wipf, the Head of Research and Monitoring at the Swiss National Park, who noted that the fines were primarily for bringing a dog into the park, leaving marked trails and disturbing wildlife with loud noise or unruly behavior, including flying drones.

Overcrowding, irresponsible behavior and parking issues were among the top challenges identified in the study, led by researchers at the University of Cambridge, that analyzed the experiences of 14 European protected areas during the coronavirus pandemic. All of the areas saw an increase in visitors from the previous year, especially during the summer.

The study identified some of the most effective responses to the year’s challenges, including public information campaigns, online education programs and careful planning of visitors’ movements.

But finding the time and money to implement those responses is another matter, especially given that, unlike in the United States, very few national parks in Europe charge visitors an entrance fee.

“I think in the early days we were simply coping,” said Sarah Fowler, the chief executive of England’s Peak District National Park, an expanse of limestone gorges and moorland plateaus within an hour’s drive of more than 16 million people. Ms. Fowler added that the park has a staff of about two dozen to cover 555 square miles. The park normally relies on a broad network of volunteers to supplement the rangers’ work, Ms. Fowler said, but this year the volunteers’ contributions were reduced to meet government requirements on Covid-19.

It was a similar story in France’s Parc National des Ecrins, home to nearly 25,000 acres of glaciers, as well as some 150 peaks that rise above 9,800 feet.

“The context is that we’ve been losing staff for the last 10 years or so,” said Pierrick Navizet, the park’s head of tourism and communications.