Google Trekking in Chagos

Image: Jon Slayer of the Chagos Conservation Trust and his Google Trekker


A Google Trekker unit has accompanied the Catlin Seaview Survey team to the Chagos Archipelago. You may have already experienced imagery that has been taken by Trekker if you’ve taken a virtual walk along the base camp of Mt. Everest, or a stroll along the edge of the Grand Canyon – Trekker goes where Google’s StreetView cars can’t go and is responsible for capturing some of the most unique imagery in all of StreetView.


While the Catlin Seaview Survey divers collect data underwater, the Trekker is working above the surface. These picturesque islands are best described as "classic tropical"; the sapphire and cerulean waters are purer than any waters the team have ever seen, juxtaposed with bright white sands and sprawling palms in greens of lime, avocado, and emerald. The imagery that the Trekker is capturing is sure to be almost as special as what we’re seeing beneath the surface!


Google Trekker was first brought to Chagos two years ago by Jon Slayer of the Chagos Conservation Trust who’s work, funded by the Darwin Initiative, is endeavouring to restore native species to these islands. 



A short history of ecosystem modification in Chagos

These islands were completely undisturbed until the Portuguese stumbled across them in the 16th century. Ecosystem modification was well underway by the 1700’s when the islands became a stop for spice traders en route to the East Indies, rats were introduced and many of the natural Indian Ocean hardwood trees were cleared to make room for coconut plantations, chiefly for the harvest of “copra” or dried coconut meat. If an ecosystem is modified, it will generally be pushed into an alternative stable state which has implications for an entire ecosystem where everything is connected. Today, with fewer hardwoods, there are less seabirds nesting in the trees. On islands with introduced rats, there are even fewer birds, as many species of seabird, such as wedge tailed shearwaters, nest on the ground. These islands are thought to have been important birding areas in the past, and with this coconut monoculture and invasive rats, human activity has put these birds at risk.



Restoring Vanche Marine – A Pilot Study

A pilot study has begun on the island of Vache Marine, translated from French to mean ‘Sea Cow’, which was surveyed by both teams just a few days ago. Here, the rats have been eradicated, and an area of coconut palms has been cleared and the ground spread instead with hardwood seeds. At six months on, we cannot say for certain whether all the rats are officially gone, but positive effects can be seen in the form of a unique trophic cascade; where natural hard wood forests bring more nesting seabirds, and more nesting seabirds bring more nutrients in the form of droppings, where rain washes the natural fertilisers into the ocean, attracting, ultimately, manta rays.



Trekking the Islands

The islands are trekked day in and day out by Jon Slayer himself, where on this trip alone he has set foot on more than 25% of the individual islands. Each evening Jon regales us with tales of his travels, reporting on the curious coconut and ghost crabs he startles into the rock pools, and where the free-swimming moray eels slither by on the hunt for an easy dinner. Although we are arguably in some of the most isolated islands in the world, he reports on finding masses of marine debris, ranging from perfectly intact light bulbs to a perfectly good tennis racquet. With these small reflections of human civilisation, we are reminded that our actions can be felt far and wide, and that, even you, thousands of miles away from here, are in some way connected with this special place.