The Seychelles: An Ecological Overview

The Seychelles is renowned as one of the beautiful destinations on the planet; an island paradise surrounded by mesmerizing turquoise waters. Li Zhaoxing, a former foreign minister of China described the island nation as “the true Garden of Eden.” Contributing to its immense beauty, the Seychelles possesses a unique ecology, featuring large coral reef complexes, tropical rainforests, and an exceptional assemblage of flora and fauna, including many endemic species.

The unique ecology of the Seychelles is attributed to its remarkable geological origin. Unlike many oceanic islands that formed as a result of volcanic activity, the Seychelles have a continental origin. The Seychelles are part of the Mascarene Plateau, which along with the Madagascar Plate, broke off from the Indian Plate approximately 66 million years ago. As such, the island contained an established terrestrial ecological community from its formation, unlike volcanic islands which are colonized by newly-arrived species.

The Seychelles, located approximately 1500 km east of mainland Africa, are composed of 115 islands, of which 45 have a continental origin, and are composed of granitic rock. The remainder of the islands are coral islands, which have formed due to continental uplift, or the accumulation of corals. The granitic islands, as well as two adjacent coralline islands comprise the Inner Islands, which feature 54% of the land area the Seychelles, and contain 98% of the human population. Mahé is the largest island in the archipelago, and features the capital Victoria.

A diversity of terrestrial environments exists throughout the Seychelles, which follow an elevational gradient. The coastal regions feature mangrove forests, which have an important role in limiting shoreline erosion. As these habitats accumulate sediments, they permit the successional formation of lowland forests. Upland areas contain palm forests, as well as dry scrub communities featuring limited tree cover.

These terrestrial habitats are comprised of over 270 flowering plant species, including 75 endemic plant species. The palm forests contain endemic palm species, including the coco de mer (Lodoicea maldivica), as well as representatives from five other genera. Another extraordinary endemic is the jellyfish tree, which is the sole living member of the family, Medusagynaceae. Other endemics include the carnivorous Seychelles Pitcher Plant (Nepenthes pervillei), and an orchid (Malaxis seychellarum).

The terrestrial habitats support a fascinating group of animals. The Seychelles contains twelve endemic bird species, including the Seychelles black parrot, the national bird, and the incredibly beautiful Seychelles paradise flycatcher. Some of the outer islands support some of the largest seabird colonies in the world, featuring immense breeding populations of sooty terns, fairy terns, white-tailed tropicbirds, noddies, and frigatebirds. The Aldabra giant tortoise, one of the world’s largest species of tortoise, is abundant on the island of Aldabra, and has been introduced to other islands. Other fascinating endemics include a freshwater crab, two species of bats, five species of frogs, six endemic caecilians, and the tiger chameleon.

The Seychelles also supports an incredible marine community, which features large reef complexes. These habitats support over a thousand species of fish, as well as a diversity of other marine life, such as green as hawksbill sea turtles, and a number of cetacean species.

The biodiversity of the Seychelles is recognized globally, as the island nation belongs to the West Indian Ocean Biodiversity Hotspot. It also contains two UNESCO World Heritage Sites: the Vallee de Mai Nature Reserve on the island of Praslin, which features a tropical palm forest, and the Aldabra Atoll, which features tortoises, sea turtle nesting sites, and rich terrestrial and marine communities. The Seychelles boast the highest proportion of land area under conservation protection of any nation, around 50%, and also features a number of Marine Protected Areas.

Despite large areas of the Seychelles being protected, it is not without its ecological problems. There has been considerable modification of the terrestrial environment, through land-clearing activities, and the introduction of invasive plant and animal species.

The nation is also dealing with large amounts of sea trash washing up onto the islands. Climate change represents an immense threat to the island nation, as sea level rises could threaten the long-term existence of many of the islands.

– By WorkingAbroad Blog Writer Sean Feagan

If you would like to visit this fascinating and incredible place, while helping to restore the integrity of its ecosystems, consider WorkingAbroad’s Volunteer in Seychelles program, located within the Cousin Island Nature Reserve.

All photos taken from Wikimedia Commons