Threats to environmentally sensitive areas from peri-urban expansion in Mauritius

Abstract

Rapid population growth and economic change on the tropical islands of Mauritius have led to one of the highest rates of urban build-out in the world. Pressure on many of the island's natural features and resources increasingly risks further degradation to the environmental services that they provide to the country. Fourteen types of marine and terrestrial environmentally sensitive areas (ESAs) are critical to the nation's sustainable development. Twelve of these ESA types are currently at risk of degradation, owing to their spatial proximity to built-up areas (BUAs) and current use designation. There was a bimodal distribution in proximity; eight of the 12 ESA types analysed had an area-weighted modal peak < 500 m from the nearest BUA, and four ESAs had a modal peak 2–3 km from the nearest BUA. Six coastal and marine ESAs had limited protection from urban expansion and over-use. The Mauritian experience reflects trends that are emerging across many tropical developing countries, where the bulk of future global growth in urban area is expected to occur. The approach detailed in this case study is replicable and may be useful in assessing degradation risk as a result of urban expansion in other island countries. (Résumé d'auteur

The movement ecology of the Mauritian flying fox (Pteropus niger): a long-term study using solar-powered GSM/GPS tags

“…Pteropus niger, along with other Pteropus species, is tree-roosting and thus dependent on vegetation cover [44]. Although 25% of Mauritius is covered by forest fragments, only about 5% of the land cover consists of native forest, of which only a third has > 50% native canopy cover [26, 45]. Given that P. niger uses forest extensively for roosting, and that it is a key disperser of the seeds of native tree species that form the forest canopy [20], conservation of the bats will promote the dispersal of canopy trees, whose growth will in turn provide suitable roosting sites for the bats.…”

“…In the present study the longest distance covered during one night by P. niger was over 92 km for a male and nearly 80 km for a female. Because Mauritius is a small island of only 1865 km 2 with native forest cover of less than 100 km 2 , or 5% of the land area [17, 45, 54], bats are able to move across the island and between the forest fragments within one night. Therefore, Mauritius has no physical boundaries that impede the bats for tracking food resources or finding a mate, and the whole island is the potential home range of individual bats .…”

Assessing temporal couplings in social&#8211;ecological island systems: historical deforestation and soil loss on Mauritius (Indian Ocean)

“…Regarding urban areas, approximately 5.5-9% of the present-day land area is occupied by manmade structures such as buildings, roads, etc. (Nigel et al 2014, Hammond et al 2015. Because the growth of urban areas throughout history is not accurately known, these areas are not included in the analysis, the only exception being the city of Port Louis.…”

“…During the 1970s and 1980s, the Mauritian economy underwent major structural changes, with a rapid phase of industrialization, diversifying into two major activities, textiles and tourism (Ramessur 2002). With the diversification of the economy, vegetated areas on Mauritius have been converted to other land uses, mainly for urban developments like roads, hotels, and housing (Hammond et al 2015). These economic changes were accompanied by rapid population growth (Fig.…”

Seawater ingestion by the Mauritius flying fox

“…828 m maximum elevation) is a 7.8-million-year old volcanic island with moist-to-wet tropical climate, located around 900 km east of Madagascar in the Indian Ocean. Anthropogenic impacts started shortly before human colonisation in 1638, which itself led to the island becoming one of the most ecologically devastated worldwide (Cheke & Hume, 2008;Florens, 2013;Hammond et al, 2015).…”