Aldabra Expeditions - Eco and Dive cruise with Silhouette Cruises Ltd

The Aldabra kestrel is the absolutely close relative of the Malagasy (Madagascar) spotted kestrel, only slightly smaller, and it was previously considered the same species as the Seychelles kestrel, in Creole katiti. It can reach a size of 30 cm. The wings are 170 mm to 183 mm at the males, and slightly wider at the females. 

The habitat of the Aldabra kestrel is the Aldabran Island of Grande Terre, and feeds mainly on insects, usually taken them during the flight. They occasionally eat small birds and mammals, taken on the ground.

If hungry, the mostly herbivore tortoises would eat anything, even the carcass of others.
In the southern atolls they find less food, than in the inner islands, therefore they often get supplement to their habitual diet.

A Madagascar Turtle-dove has learnt not to go too close to a reptile the next time. The bird managed to escaped with only losing a few feathers, which clearly ended in the mouth of this giant.

Photo and source: SIF

1. Sharks are vital to the ocean food chain, and in keeping the overall population healthy with weeding out sick or injured animals. They are also key elements in maintaining the right ratio between species.

2. Sharks can also boost tourism. Ok, not in the Hollywood movies, but in real life shark diving is a growing industry.

3. Sharks are perfectly-engineered. Scientists study sharks for several reasons: for their efficient moving in the water, their skin, and even bacteria-resistant surfaces.

4. Sharks can help reduce carbon in seas by eating dead fish that collect on the seafloor.

+1. They are one of the earthlings, and part of the biodiversity. :)

We eliminated one of the points as it was about eating sharks, as in our opinion this is absolutely unacceptable.

Two tropicbirds, a red-tailed and a white-tailed incubating their eggs.

When it comes to breeding site, Red-Tailed and White-Tailed Tropicbirds prefers Aldabra... The two species nest mainly on islets in Passe Femme, south of Picard. The collected information in the past 7 years' monitoring program helps to investigate the factors that influence breeding success and why they might be different for each species.

Source: SIF FB

Under the #timingiseveything a new photo collage was posted on the SIF Aldabra Reserach Team's FB page. The post reminds us how fragile a turtle population is.

The number of eggs in a nest (clutch) varies by species. On average, turtles lay 110 eggs in a nest. The largest clutches are laid by hawksbills, which may lay over 200 eggs in a nest. Once the female completed the nesting, she never returns to it. 

The nest's temperature determines the hatchling's gender. Warmer temperature produces mostly females, and cooler temperature produces a majority of males. (Another unfortunate side effect of global warming can be it's result on future population's gender rate.) Turtle eggs look like ping-pong balls, with a soft shell.  
Mortality rates for turtle eggs are high due to predation by ghost crabs or humans. Some nests are laid to close to the tide line and if not relocated will be lost.

When the time comes and hatchlings break free from their shell inside the egg chamber, they stimulate the others to emerge from their eggs too. Once most hatchlings have emerged from their shells, they climb on top of each other and the discarded eggshells til they reach the top of the chamber. They emerge either en masse or in small groups, but emerging together increases the chance of survival. Sea turtles are attracted to light, therefore they are guided by the moonlight reflecting on the sea. As a result of light pollution (street lights, house & hotel lights) they may become victims of predators or accident. If hatchlings delay in emerging from the nest, the heat of the sun also may harm them. On the way to the sea
The dangers are not over,  on their way to the sea, predators as crabs, birds, fish and sharks are waiting for them. If they survive all these, human caused threats as fishing gear (long line), ingestion of marine debris, boat strikes, trash on beaches and pollution also harms the population.
As a result, only one hatchling in a thousand make it to adulthood (15-25 yrs).

In Aldabra itself, crabs, crows and herons are waiting for the newly emerged hatchlings on the shore, and many blacktip reef sharks in the shallows. Only a very lucky few reach the open sea's "safety".

Source: Sea Turtle Conservancy
Photo: SIF Aldabra FB page

For many years we are aware of it, that most chemicals are harmful for underwater life, but the study, that even one drop of sunscreen is enough to damage fragile coral reef systems is only known since the past years.

Above we are talking about one drop, but in reality some 14,000 tons of sunscreen lotions wind up in coral reefs around the world each year. The ingredient oxybenzone is causing coral bleaching, and it can also disrupt the development of fish and other wildlife.

Scientists conducted the study in the U.S. Virgin Islands, Hawaii and Israel, but the results are worldwide. Reefs are in general at risk, due to destructive fishing, pollution, global warming and development all pose threats to the coral reef.
"The use of oxybenzone-containing products needs to be seriously deliberated in islands and areas where coral reef conservation is a critical issue," co-author Craig Downs said according to the Washington Post. "Any small effort to reduce oxybenzone pollution could mean that a coral reef survives a long, hot summer, or that a degraded area recovers."

Local economies, as ours in Seychelles depend on the tourism that coral reefs attract. As a result, we shall completely ban the use of harmful sunscreen in their waters. There are good examples, in Akumal, Mexico, an area known for its reefs and sea turtles, visitors are warned against wearing sunscreen and are restricted to certain areas to prevent too much disruption of reef life.

Damaging sunscreen from beachgoers is just part of the concern. When people wear sunscreen, it is anyway going to end up in the waterways, after cleaning it off, just like other chemicals used by in household cleaning products. These are all washed down into the sewage systems.
"People come inside and step into the shower. People forget it goes somewhere," co-author John Fauth told the Post.

To avoid harming coral reefs, use "reef friendly" sunscreen (those made with titanium oxide or zinc oxide, which are natural mineral ingredients) and wear clothing and hats to protect the skin from the sun.

I was recently browsing for news on a turtle we found drifting between two of our boats, and bumped in some great blogs about wildlife conservation.

Both blogs are written by MCSS, the Marine Conservation Society Seychelles, and the posts are about the every day life and tasks of the volunteers.
Following the blogs, readers can get updates about recent environmental projects and also about rescued turtles, recovering in the rehabilitation center.


The links:
http://seychelles-turtles.blogspot.com/  and
http://seychelles-whale-sharks.blogspot.com/

In addition to above blogs, every now and than there are some interesting news on the Nature Seychelles webpage at http://www.natureseychelles.org/ which also worth regular visit.

Happy reading!

The photo above is taken from the MCSS FB page. He is not Barnie, the turtle, we found at our base, in the Inter-Island Quay, but a success story, Eden. He has been a patient at the MCSS rehabilitation center for about four months now. It was found around the Eden Island marina, bleeding from a propeller cut on its carapace. When MCSS team got him, he was having problems eating by itself and also problem with its buoyancy. After intensive treatment Eden got stronger. He is now eating on his own, and has also started to dive under water.

Barnie, our rescued Hawksbill turtle died after two weeks of MCSS' careful nursing. He was very week, when we found him, he couldn't lift his head above water and unfortunately he did not make it.

Recent video, published by SIF spotlights dugongs at Aldabra. However the atoll is their last refuge in the Seychelles, the featured dugong allowed the SIF team to get quite close. The encounter took place at the lagoon near Ile Esprit.
The Animal Diversity Web's summarizes a wide range of information about these mammals.

(Photo was made by T Mahoune, and featured on FB, meanwhile the video was edited by AJ Burt)

​The photo was caught in February 2016 by Kenneth “Wayne” MacWilliams, in Florida.
Kenneth said: “Since it appears as the shark is smiling, it made me smile.
The lemon shark is known as the "friendliest" shark. The International Shark Attack File lists 10 unprovoked lemon shark bites, none of which was fatal.

Source

Although we have been thinking for a long time to write in details about the residents of Aldabra, a recent post about a cute litte Aldabra rail chick on the SIF FB page made us feature these pictures in a blog post.

The Aldabra rail is believed to be the last surviving flightless bird in the western Indian Ocean, after the extinction of its distant relatives, the Mauritian dodo and the Rodrigues solitaire. It is the flightless subspecies of the white-throated rail (Dryolimnas cuvieri) or Cuvier's rail, from te family Rallidae. (Another subspecies was the D. c. abbotti (Assumption rail), from Assumpption, which went extinct in the early 20th century due to introduced predators.)

The Aldabra rail has a slender build, with a long neck, legs and feet. The plumage is chestnut coloured on the body and head, and white on the throat. The fairly long, straight bill is dark, with bright pink base at females, and dull or dark red base at males. Juveniles generally have darker plumage than adults. The wings are short and are often held close to the body. (Description from wikipeadia and Arkive.org)

Its natural habitats are subtropical or tropical moist lowland and mangrove forests.

A researcher at the Seychelles Islands Foundation (SIF), Dr Janske van de Crommenacker was working on proving that the Aldabra rail is a separate species of bird endemic to Aldabra. She has extracted DNA from museum specimens of the three rail sub-species; Aldabra Rails, Assumption Rails and Madagascar Rails. Many of the samples date back to 100 years ago and were supplied by the Natural History Museum of London.
Aldabra rails previously became extinct on Picard due to the introduction of cats, and has been re- introduced from other islands of the atoll, Polymnie, Malabar and Ile aux Cedres in 2002. 

Source: Seychelles  News Agency

"On a hillside in Victoria, Mahé’s historic center, stands an unusual church clock that chimes twice—once on the hour, then again a few minutes later. I think of it as a metaphor for Seychelles: a second chime for a second chance, ringing out the rescue of robins, beetles, pitcher plants, and palms, a celebration of nature restored." - Kennedy Warne

Great article about restoration, protection of native species and environment, written by Kennedy Warne, published by National Geographic. Photographer: Thomas P. Peschak

In Nov 2016 came the news: the photographer, Thomas Pechak is among the finalists in the Wildlife Photographer of the Year competition in the Invertebrate category. The photo 'Crabzilla' was taken at Aldabra as part of a trip to the atoll for a feature length article on Seychelles for National Geographic magazine. (The full gallery of winning images can be seen here.)

The official launching of the 30-minutes long National Geographic film took place last Friday at the STC Conference Room.

In September 2014, Bill Clinton, former president of the USA announced, that Seychelles will be one of the destinations of the NatGeo's Pristine Seas project.

Only 6 months later, the team of 10, including 4 scientists, arrived to Seychelles to conduct the program: an interesting amalgam of scientific research, popularly presented by the efficient media tools of National Geographic. The result is a viewer-friendly film for any audience, with footage made with deep-cameras, drop-cameras, pelagic cameras and our mini-helicopters for aerial photography. The project's not-hidden aim is to influence decision-makers to protect certain regions of the sea.

BBC journalist Paul Rose, the expedition's leader knows the islands profoundly, having been worked for many years on a marine science project in Seychelles. 
He told in the NSA interview that the coral bleaching events of 1998 really damaged the marine ecosystem, but it is slowly recovering, which shows the health of the Seychelles waters. He also added "… you never see this color of water anywhere else in the world" and during one of the dives, a chief scientist just stopped his work – while recording fish – just to enjoy the dive, rating it as one of his top ten dives in the world.

Hajira Amla's article, the "National Geographic expedition leader rates Seychelles ocean, coral health among best in the world" (March 21, 2015) is available on the Seychelles News Agency's webpage.

More information and video about the National Geographic expedition is available here.