Effects of COVID-19 pandemic restrictions on coral reef fishes at eco-tourism sites in Bora-Bora, French Polynesia

Abstract

The COVID-19 pandemic led to a global lockdown in mid-2020, leading to a rapid decline in international travel and tourism. In French Polynesia, marine-based tourism activities ceased in March 2020 with the suspension of international flights (i.e., 45 days - between 20th March and 04^th May 2020), slowly restarting between May-July as domestic and international visitors returned. The impacts of this rapid change in human activity at reef tourism sites on associated reef fishes was examined at Bora-Bora Island through underwater surveys of five control and nine eco-tourism sites. Our results showed that fish density significantly increased from March to May (i.e., the overall density of fishes increased by 143% and harvested species by 215%), but returned to pre-lockdown levels by August 2020. At the usually busy eco-tourism sites, fish diversity, notably of piscivores, omnivores, and benthic feeders, was higher in the absence of tourists. The impact observed is almost certainly related to short term changes in fish behavior, as any density fluctuations at the population level are unlikely to have happened over such a short time frame. Overall, these findings highlight the influence of human activities on fish communities and underline the need for further research to evaluate the environmental impacts of eco-tourism.

Keywords: COVID-19; Coral reef; Eco-tourism sites; Fishes; Future management; Human activities.

Fig. 1

Map of Bora-Bora with the location of the 14 surveyed sites. Black rectangles represent control sites and white circles represent eco-tourism sites. BR: barrier reef, FR: fringing reef. Hōā is a small open channel between the reef and the ocean. Dark grey represents land areas, light grey represents reef areas.

Fig. 2

Box plots of the total density (number of fish per m²) of all fish species (top) and of harvested species (bottom) calculated at barrier reefs (A, D), at fringing reefs (B, E) and at the hōā (C, F). Control sites are in blue, eco-tourism sites are in red. Boxes represent the first and third quartiles, thick horizontal bars are the median (second quartile), whiskers correspond to the distribution range (min-max) and circles are all the observations. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)

Fig. 3

Box plots of the total species richness (number of species per m²) of all fish species (top) and of harvested species (bottom) calculated at barrier reefs (A, D), at fringing reefs (B, E) and at hōā (C, F). Control sites are in blue, eco-tourism sites are in red. Boxes represent the first and third quartiles, thick horizontal bars are the median (second quartile), whiskers correspond to the distribution range (min-max) and circles are all the observations. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)

Fig. 4

Non-metric multidimensional scaling (NMDS) plot of the similarity of fish assemblages calculated from the Bray–Curtis distances on the total number of fish of each species recorded in the eco-tourism sites.

Fig. 5

Box plots of the total density (number of fish per m²) of each trophic guild in the eco-tourism sites. Boxes represent the first and third quartiles, thick horizontal bars are the median (second quartile), whiskers correspond to the distribution range (min-max) and circles are all the observations.