The price of success: integrative long‐term study reveals ecotourism impacts on a flagship species at a UNESCO site

Abstract

Disturbance of wildlife by ecotourism has become a major concern in the last decades. In the Mediterranean, sea‐based tourism and related recreational activities are increasing rapidly, especially within marine protected areas (MPAs) hosting emblematic biodiversity. We investigated the impact of ecotourism in the Scandola MPA (UNESCO World Heritage Site, Corsica island), on the population of a conservation flagship, the Osprey Pandion haliaetus. Over the 37‐year study period, tourists flow increased sharply. Osprey breeding performance initially increased, but then dropped for pairs nesting within the MPA compared to those breeding elsewhere in Corsica. We examined several hypotheses that could explain such reduction in breeding performance. Recent osprey breeding failures in the MPA are not caused by food scarcity. Using underwater fish surveys, we showed that fish consumed by ospreys were more numerous within the MPA. Focal observation at nests revealed that the overall number of boat passages within 250 m of osprey nests were three times higher inside the MPA compared to a control area. Elevated boat traffic significantly modified osprey time‐budgets, by decreasing prey provisioning rate by males, and increasing time spent alarming and flying off the nest in females. This caused stress, and corticosterone levels in chick feathers were three times higher in high‐traffic areas compared to places with lower touristic flow in Corsica, the Balearic Islands and Italy. Overall, our integrative, long‐term study demonstrates the negative impact of sea‐based ecotourism on the Corsican osprey population. This stresses the worldwide importance of rigorously implementing sustainable ecotourism, within well‐enforced MPAs.

Long‐term study highlights the conundrum of nature‐based tourism in marine protected areas

“…Given the relatively advanced economies of the region, these countries would have the capacity to invest in practices that enhance sustainable tourism. This study by Monti et al (2018) provides further justification for this, by highlighting these negative effects on one of Europe's most iconic raptors, the osprey. Given the perilous status of this species elsewhere in the region, these findings should certainly be viewed as the warning signal that something needs to be done.…”

“…The findings of Monti et al (2018) provide justification for concerns about the sustainability of tourism in the UNESCO listed Scandola MPA. Despite confirming adequate prey resource availability for ospreys in the MPA, relative to outside the MPA, the species' breeding performance is in decline.…”

“…These responses reduced the ospreys' ability to provide resources for their offspring, where fledging and overall breeding success were both significantly reduced inside the MPA (where the bulk of tourism occurs) relative to outside the MPA. Finally, Monti et al, (2018) provide evidence that the flushing of adult ospreys from nests at sites with high boat traffic is likely increasing the stress responses in the chicks left unattended in the nests. Chick feather samples from areas of high boat traffic exhibited higher levels of the stress hormone corticosterone compared to those from elsewhere in Corsica.…”

“…In this study, Monti et al (2018) have explored a specific case of this much broader issue, using a multifaceted approach illustrating the negative effects tourism can have on resident ospreys Pandion haliaetus. They focus on the island of Corsica, France, which lies in the Mediterranean Basin Biodiversity Hotspot (CEPF 2018).…”

“…Despite confirming adequate prey resource availability for ospreys in the MPA, relative to outside the MPA, the species' breeding performance is in decline. By monitoring the ospreys' behaviour and employing physiological tests assessing stress levels, Monti et al, (2018) found that disturbance by tourist boats is more than likely to blame for this decline. The authors observed significantly higher rates of alarm behaviour and associated disturbance events at sites with increased tourism-related boat traffic.…”