Upon arriving on Ile Plate, what strikes you is not only the flat sand cays exposed at low tide and the far-reaching lagoon outlined by a foamy white barrier where the ocean meets the coral reef, but also the lush green vegetation that conceals all human habitation.

Upon closer inspection, one is surprised to note that apart from coconut trees, the greenery is mostly attributed to Castor oil (Ricinus communis) or ‘Tantan’ in Creole. This introduced species is believed to occupy an area of 5,000 square meters, which is roughly the size of a football pitch. It is considered one of the most dominant invasive species on Ile Plate, an island slightly bigger than Ile Moyenne. What is worrying to conservationists is that the plant is now widespread, and there are no indications that it is slowing down.

This has prompted the Island Conservation Society (ICS) to implement a vigorous eradication program to contain this species, which, as on other islands of Seychelles, was introduced and cultivated for its medicinal properties and is now escaping into the wild.

“We cleared this area as part of our first project on the island. And look how it is now! They’ve all grown back,” says Diary Rakotondrazara, the Conservation Officer of ICS, as she points to a growing patch of thick Castor oil. So thriving is this species on Ile Plate that a tree measuring 5.10 meters - the height of a two-storey building - has gone down as the tallest ever recorded.   

“The best way to eradicate Castor oil without disrupting the environment is to do it manually,” says Rakotondrazara, adding that this necessitates uprooting each plant one after the other. As part of their weekly routine, the team remove Castor oil plants regularly, with an ambitious target of clearing a 5-meter square area per week. “In one month, we can remove as many as 340 plants from fruiting trees to different sizes,” she adds.  With a flowering season that spans throughout the year, the task is harder than the team initially thought it would be.

So far, castor oil is found almost everywhere, but they are most abundant in the northwest to southwest of the island. Since ancient times, the medicinal properties of the Castor oil plant have been documented, and to this day, in several countries, different parts of the plant are still used for such purposes. The seeds, for example, are known to purge worms whilst the leaves can be crushed to make ointment to cure wounds. On the other hand, Castor oil is also very toxic if ingested in large quantities, and it is also used as a natural insecticide in agriculture. But when left in the wild as on Ile Plate, this species can also become very invasive.

“The seeds can stay in the soil for a very long time and re-sprout again even after a short drizzle,” says Rakotondrazara. “We have noticed that several areas which have been cleared have already been recolonized by the plants. In addition, many trees have fruits, and these are easily dispersed by birds and people but also by wind to other areas.” As part of their strategy, the team always remove the seeds first before uprooting the plants. An astounding 3 kilograms of Castor oil seeds have been collected and disposed of by ICS since their arrival on the island late last year.  

These past 6 months have been a learning curve for the team as they learnt to tackle this species and assist in restoring the biodiversity of the island. The project is also of great interest to other partners on the island, as Castor oil plants also harbour a species of caterpillars from the genus Euproctis - a yellowish-black caterpillar with stinging hairs or “hairy caterpillars,” locally referred to as “Senir plim,” which can cause incessant itching. Spraying these hairy caterpillars is not encouraged as this could also hurt insects and other biodiversity of the island, including the abundant diadem butterflies.

Such projects are also vital for other restoration projects that ICS wishes to implement on Ile Plate. Another plant species on ICS’s radar is the Coco grass (Cyperus rotundus), or “Lerb Zonyon” in Creole which is an indigenous plant that has also grown in abundance on the island. This plant species is referred to as one of the most invasive weeds in the world and is widespread on several continents. Similar to Castor oil, Coco grass is also a conservationist’s nightmare, as it is difficult to control, since its tubers can grow up to 8 inches below the ground surface, and it is also highly resistant to herbicides. 
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ICS is dedicated to safeguarding the biodiversity of Ile Plate, one of the smallest islands under its care, with a strong focus on preserving its terrestrial ecosystem. New bird species, such as the Brown Noddy (Anous stolidus), Lesser Noddy (A.tenuirostris), Wedge-tailed Shearwater (Ardenna pacifica) and the Red-tailed Tropicbird (Phaethon rubricauda), have already shown interest in recolonising the island. Improving the island's plant life is expected to further increase the likelihood of other species establishing themselves on this small yet significant island, located just a few kilometers from Mahé and at the edge of the Outer Islands group.

The Island Conservation Society (ICS) has started to map Seychelles’ fourth-largest known seagrass meadows located around Ile Plate, a vital carbon store and mitigation mechanism against climate change.

Seagrass have evolved from land plants and, like terrestrial plants, have veins, roots and leaves. As true plants growing on the ocean floor or seabed, they also have a flowering season and can reproduce underwater. They form meadows on the ocean floor, which provide food and shelter to different marine life, from sea turtles to crabs. Yet, not much is known about these green barriers that, similar to mangroves, help to keep our oceans clean by removing harmful algae and stabilising the sand. More importantly, seagrass creates a highly efficient carbon sink by storing significant amounts of carbon in their sediments and biomass and playing a crucial role in global carbon cycling and climate change mitigation.  

In 2020, a project to map the seagrass meadows in Seychelles was launched. The Seychelles Seagrass Mapping and Carbon Assessment Project revealed that there are 1,599 square kilometers of seagrass in the Seychelles Exclusive Economic Zone (EEZ). Surprisingly, it also revealed that Ile Plate accounts for 7.9% of this total area, ranking it as the fourth largest area where seagrass was found in Seychelles, surpassing other areas renowned for their high biodiversity, such as Aldabra Atoll, Farquhar Atoll and Cosmoledo Atoll. Only Providence (14.4%), Mahé Rim (24.5%), and Amirantes Bank (34.1%) outranked Ile Plate in the density of seagrass found through this project. Despite the significance of this project, several questions remain about the areas which had been mapped, for example, what the meadows were made of, how widespread they were and what habitat they were supporting.   

Looking at the lagoon from the air or even from the beach, “we could see these large expansive meadows – in some areas all you can see is seagrass. You can take only a few steps towards the ocean and end up knee-deep in seagrass here,” says Diary Rakotondrazara, who is the Conservation Officer of ICS on Ile Plate.
To better understand this habitat, the team has initiated an in-depth review of seagrass meadows around the lagoon. At low tide, the meadows around Ile Plate are easily accessible, and the team does not have to snorkel to view underwater environments.

“We use a 50-meter line across an area which is checked at every 5-meter interval. At each interval, we observe an area of one meter square where we identify the species we found, the amount of seagrass there is, the height of the seagrass and if there are any algae. We then take pictures and record the GPS coordinates of the area first at the beginning and then at the end.”

By analysing all this information, the team will be able to confirm the density and distribution of the island’s seagrass. There are at least 72 known species of seagrass globally, 12 of which are found in Seychelles.
So far, the team has identified at least three seagrass species around the island, but their density varies. The most common species of seagrass found in the lagoon are Thalassodendron ciliatum, known as “Gomon zerb levantay” or Fan seagrass and Thalassia hemprichii, known as “Gomon torti” or “Gomon zerb torti” or Turtle seagrass. In addition, the team has also identified several patches of Syringodium filiforme, known as “Gomon zerb sed” or “Gomon zerb spageti” in Creole or Casuarina seagrass or Spaghetti seagrass. These are mostly located a few meters from the beach and, according to the initial mapping exercise, are not common in the Outer Islands, such as Ile Plate.

Seagrass “was always a target of our conservation strategy on Ile Plate,” says Rakotondrazara, adding that unlike the other five islands where ICS has a conservation center, the role of seagrass towards the thriving marine life around the island could not be overlooked. 

“Thanks to these meadows, we can now confirm that Ile Plate is a nursery and foraging area for juvenile sea turtles and that they are actively using the island for nesting throughout the year. We can also confirm that the island is a major hub for elasmobranchs, which is another major milestone for conservation of the island.”

As helpful as seagrass is to the marine ecosystem, ICS is also enlisting the help of its partners on the island to help improve their understanding and find ways to protect these seagrass meadows against marine activities such as anchoring and snorkeling. Visitors are already being sensitised about seagrass through informational displays that provide more information about the different seagrasses they may encounter during their stay on the island.

“We’re just beginning to realise how important the seagrass meadows are,” Rakotondrazara says. “As such, unlike other places in the world where seagrass is underrated or overlooked, we want to make this a priority for conservation on Ile Plate.”
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Whilst the survey will be an extensive exercise and part of the regular monthly conservation activities by ICS on Ile Plate, it will also build on the initial Seychelles Seagrass Mapping and Carbon Assessment Project. Furthermore, the details about what’s in the meadows will help to inform future projects around Ile Plate and feed into Seychelles’ national database of information on seagrass. 

My name is Cai, and I’m from Cambridge, UK. I studied Natural Science at university and have had the privilege of volunteering on Aride Island for the past 4 months. This article is a glimpse into the wonderful life I have discovered here in the Seychelles.

Life on Aride is surprisingly difficult to describe. Before I came here, I expected that nature would be at my doorstep, but I didn’t quite realise that it would also be in my hair and between my toes. My sleep schedule is decided by shearwaters, my kitchen overrun by skinks and my free time controlled by turtles. Every night I fall asleep to the sound of mosquitos in my ear and wake up to the insistent call of fodys at my door. I wash my clothes and hang them outside my window to dry, however the constant monsoon weather means that they remain as wet as the day I put them out.

To those who have never been to Aride, these may sound like complaints, but strangely, they are some of the many reasons I find it so hard to leave. There are few places in the world that feel quite so alive. Wherever you look there are creatures staring curiously back at you. Whether it's the white tail chick hiding beneath a boulder, the tortoises demanding a neck scratch or the charming magpie robin following you dutifully through the forest - it is apparent that while we may be there to monitor the wildlife, more times than not, we are the ones being monitored by them.

Coming from the UK, I had experienced island life before. Of course in my case, I had shared the island with 65 million other people as opposed to the 11 neighbours I currently have. My old layers of evening jumpers have been replaced by layers of suncream, and my salt and pepper spice drawer has exploded with the colours of turmeric and chilli. As you might expect, I have adapted enthusiastically to warm weather and tasty food, although life here is not always stress-free.

Following the plane ride, ferry trip and motorboat journey it took to get me here, the extreme disconnect with my life back home became evermore apparent. I found myself waking up with new bites and bruises every single night as the forces of the island took their toll on my soft English feet. I would try to call my family for a bit of comfort, but the broken phone signal would leave me feeling even further away. However, these challenges were quickly forgotten as I began to know the island. The warmth of the Aride community made me realise that while I might be far from home, I had found a second home right here. As was explained to me after a particularly unsuccessful fishing trip, my family might be far away, but the islanders were happy to step in and take their place in the meantime.

If there is one thing I have learnt from my time here, it is that Seychelles culture is best explored through food. Through island barbecues outside Steve’s house and fresh fried fish at Jean Claude and Laurette’s, I quickly learned that the colourful, warm culture I experienced with the islanders was perfectly mirrored by the food they eat. Having enjoyed a selection of especially tasty meals, I found myself eager to absorb as much of their culture as possible. As it turned out, the Secyhellois’ desire to teach and share matched perfectly with my own desire to learn and eat. I found myself being generously welcomed aboard the fishing boat and I learnt how to detangle my line and even catch an occasional fish for dinner. Mealtimes became the perfect excuse for weekly social gatherings. It was around these barbecues that we would spend hours discussing the details of our past lives while enjoying a seemingly endless supply of freshly grilled fish.

Around the world, Aride is known for its pristine white beaches and stunning variety of seabirds. While this is undoubtedly true, what made it so special to me were the people who inhabit it. I would like to take this chance to thank everyone on Aride for making this small granitic island so extraordinary.

In 1787 Jean-Baptiste Malavois provided the first written description of Aride as “…just a pile of rocks covered with some bushes.” He could not have been more wrong.