Poachers are taking species out, and tourists are bringing species in. A new study suggests that ecotourism threatens the very ecosystems that draw visitors in the first place.
Unique fauna and habitats attract visitors from around the world, but those visitors don’t always come alone. A recent study recorded the numbers of seeds that were found on visitors arriving to trailheads at Table Mountain National Park in South Africa. The goal was to assess the potential for park visitors to introduce non-native plant species, and also to investigate whether the threat was related to the specific activities of visitors in the park.
Researchers found that dog walkers were the most likely visitors to have plant seeds on their shoes and carried the most types of seeds, even though few of the dogs carried any. A little over half of hikers carried seeds on their shoes, and cyclists were the least likely offenders. Trail surveys revealed the same trend, with routes designated for dog walkers having the greatest number of invasive plant species and the most space taken up by invasives.
Overall, only around a quarter of visitors were found carrying seeds, and most were local residents. However, a significant proportion were from other parts of the country or from outside the country, demonstrating the potential for introducing non-native seeds. In fact, a hiker from England carried the highest number of seeds found and had last worn his shoes in London.
Although tourists are often implicated in degrading habitats, the topic is rarely studied and poorly understood. The current study addresses that gap and shows that opening protected areas to the public is likely to increase the introduction of invasive species. For many parks, including those in South Africa, where ecotourism accounts for around 80% of the National Parks’ revenue, limiting public access is probably not a reasonable solution.
Fortunately, the cat is out of the bag, and hopefully, park managers will plan accordingly.