Ascension Island: A Rock in the Ocean
Nesting Green Turtle
All pictures, video & content by Stefan Hunt (01/03/17)
You might think that a small, isolated, island in the middle of the Atlantic Ocean, made up of the tip of an undersea volcano and thousands of miles from the next land mass would be devoid of wildlife and life in general for that matter... but you'd be mistaken! Ascension Island is a real secret gem when it comes to wildlife.
Ascension is located equidistant from both Brazilian and the African coasts, just south of the equator. Geologically the island is young, being formed only a million years ago, with the sun beating down on sweeping golden beaches and idyllic turquoise blue sea. You have to pinch yourself to remember that Ascension is one of the UK’s overseas territories and that you’re on British soil. It’s not like this in Weston Super Mare! Contrasting with the picturesque coastline, as you move inland, dramatic jagged lava flows appear and the peaks of volcanoes break up the horizon. The rocky landscape, lack of rainfall, and limited soil all mean that the island has very little natural vegetation.
Despite this, the island does have some spectacular wildlife. Ascension has the second largest Green Turtle nesting population in the Atlantic! Over 5000 individuals visited the island in 2015. They mate in the warm waters surrounding the island and then lay their eggs on the sandy beaches. As a result it’s a really important site for the conservation of Green Turtles globally.
Green Turtle Nest Hatching
Hatching Green Turtle
Nesting Green Turtle
Alongside the sea turtle population, the island also hosts amazing sea bird colonies and is the only place in the world where the endemic Ascension Island Frigate bird nests.
Kenickie conducting bird surveys
Sooty Terns form large colonies, nesting right on top of each other, and dive bombing anyone who gets too close to their chicks. The noise and smell from the colonies is overwhelming.
Sooty Tern Colony
Conducting bird surveys
Conversely the nests of the Masked Booby’s are much more generously spaced with the adults gently whistling and barking to their chicks. They seem much more civilised compared to the Sooty Terns despite the precise circle of excrement which surrounds their nest.
Nesting Masked Booby
Another one of Ascension Island’s extraordinary and unique wildlife species is its Land Crabs. This is the largest native land animal on Ascension and they complete remarkable mass spawning events.
Male Land Crab
Spawning Land Crabs
The female Land Crabs migrate vast distances across the island to specific beaches on particular nights of the year in order to lay their eggs in the shallow surf. Also, Sally Light Foot crabs cover the beaches and are spectacular due to the bright colouration across their shell.
Sally Lightfoot Crab
Sally Lightfoot Crab caught in the surf
They often feed on turtle eggs as well as unsuspecting hatchlings attempting to make their way to sea.
Sally Lightfoot Crab with a turtle egg
The isolation of Ascension is definitely one of the secrets to it's success in terms of it's wildlife. The island never had a native human population, it was first discovered in the 16th century by the Portuguese before being settled by the British in the 19th century. Charles Darwin stopped at Ascension during the voyage of the Beagle in 1836 while botanist Joseph Hooker also stopped at the island a few years later. He and Darwin were supposedly upset by the conditions people were forced to live in on the island, with hot temperatures, very little vegetation and water. Together, along with the help of Kew Gardens in London, they selected specific plant species from across the world to be shipped to the island.
Green turtle hatchling
Ascension island lily
They hoped to convert the barren island into a more habitable environment. The trees they imported, such as bamboo, eucalyptus and banana, were selected in order to try and catch moisture from the passing cloud cover, thereby increasing rainfall and improving soil quality. The intervention has had a significant impact, transforming the higher parts of the island from an arid wasteland into a tropical cloud forest, making the island much more sustainable for human life. It’s remarkable to see how effective their work has been.
Ficus trees on Green Mountain
In 2015 I went to Ascension for 6-months to work as a Marine Turtle Conservation Intern for the Ascension Island Government Conservation Department.
Turtle Team (Holly, Jacqui, Bryony, Stefan)
It was an incredible experience living and working on the island and it was amazing to see the conservation work being conducted. I worked primarily with the turtle population but also helped with the conservation of other species across the island. From planting small endemic plant species, monitoring land crab spawning events, and surveying seabird colonies. My main role was working alongside the Turtle Team* to count the number of Green Turtle tracks on the beaches, in order to calculate how many individuals came onto the beach the night before, and to count the number of nests. The population is closely monitored this way and the data is published in order to keep a track of the population trends.
Nesting green turtle at night
One of the more exciting and challenging tasks with the conservation department was rescuing stranded sea turtles across the island. Many turtles would come onto the beach to lay their nests and get cut off from the sea by rocks or were trapped in rock pools. If they were left all day in the heat of the sun they would most likely not survive. In the 6-months of my internship the conservation team returned 309 turtles back to the sea. Some individuals simply needed to be guided back to sea, others had to be pulled across the beach on a purpose built ‘turtle sled’. On more than one occasion a group of burly builders, who were working near by, had to be called over to help lift a Green Turtle, weighing over 100kg, out of a rock pool in order to get them back to the sea.
Turtle team rescuing a stranded turtle
Alongside rescuing stranded sea turtles, excavating hatched turtle nests was always an interesting task. If you ever thought working in Turtle conservation was glamourous, try digging up a nest of over 100 unsuccessful turtle eggs that have been slowly rotting under the hot sand for 2-months! It’s not a pleasant experience. It is really important to excavate hatched nests to calculate hatching success, however it is definitely a particularly foul smelling task.
Turtle Nest Excavation (ft. Turtle Team)
Historically, the vast Green Turtle population that nested on the island were heavily exploited by passing British ships who would take the turtles as a source of fresh meat. The population crashed severely until the harvesting of meat finally stopped in the 1930s. In 1977 there were around 1,000 Green Turtle nests on Long Beach, the main nesting beach on Ascension. In 2015 when I was volunteering on the island, the Conservation Department recorded over 14,000 nests on the same beach! The population is now flourishing at a time when many sea turtle populations in other parts of the world are struggling due to beachfront development destroying nesting habitat and adult Sea Turtles becoming entangled in fishing nests etc.
With humans visiting the island so a population of feral cats became established that devastated the native sea bird colonies. Following a controversial eradication programme in 2003, the sea bird colonies have really bounced back. Species that had previously only nested on small islands off Ascension, that were cat free, returned to the main land to nest. Most notably the endemic frigate bird began nesting on the island, which was a great success for wildlife conservation.
It was an amazing experience to spend time on the island and help contribute to the conservation work being done there. It’s a really interesting time for Ascension as the waters around the island have been recently declared a marine protected area. Marine protected areas have often been accused of being paper parks and historically have had really mixed success. Hopefully in the case of Ascension, it will help to protect the spectacular wildlife found across the island and in the waters surrounding it.
Ask Stef about this turtally awesome photo story below!
Want to learn more about Ascension Island? Check these out!
Interesting Articles &Websites
- Ascension Island Government Conservation Department Page
- More information from the RSPB on the marine protected area
- Recovery of the South Atlantic’s largest green turtle nesting population
- Time-lapse of the conservation team clearing invasive plants
- Learn more about the British overseas territories from Stewart McPherson's great series
- Don't believe crabs eat turtles..
- 2015 green turtle season film