A Prime Nesting Ground​

The beaches of Mayotte welcome thousands of green sea turtles each year, coming ashore to lay their eggs. These marine turtles travel thousands of kilometers to return to the beaches of their birth, a phenomenon known as natal homing. This migration, which can take several years, remains one of the greatest mysteries of marine biology.

​The nesting period extends from November to March, when the turtles come ashore on the island’s fine sandy beaches to lay their eggs. After digging a nest, they deposit between 100 and 200 eggs, which they carefully bury before heading back to the sea, leaving the embryos to develop under the warmth of the sand. Once the eggs hatch, the tiny turtles, fragile and vulnerable, face numerous dangers, but many will make their way to the nourishing waters, where they will spend several years before returning themselves.

Green Sea Turtles and Their Ecological

RoleGreen sea turtles play a vital role in maintaining the health of marine ecosystems, especially coral reefs. Their feeding habits mainly consist of seagrasses, aquatic plants found on sandy and rocky bottoms. By grazing on these seagrasses, turtles help regulate their growth, allowing these thriving ecosystems to remain healthy.
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Seagrass meadows are crucial habitats for many marine species, providing food and shelter for young fish and other marine life. By maintaining the balance of these meadows, turtles indirectly foster marine biodiversity, creating a more stable environment for other underwater creatures.

A 50 Million Year Journey

Green sea turtles have existed for over 50 million years, surviving through the ages with remarkable resilience. Their bodies, perfectly adapted for marine life, allow them to swim great distances with ease. Their flattened, rigid shells act as the ultimate defense against predators, while their flipper-like limbs propel them gracefully through the water.
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These turtles can travel thousands of kilometers in open waters, often at depths where they feed on aquatic plants. Yet, despite their great endurance, these marine reptiles face numerous threats. Climate change, plastic pollution, and the destruction of their natural habitats are constant dangers that threaten their survival.

Threats and Conservation: A Fight for Survival​

While Mayotte provides an ideal environment for green sea turtle nesting, these creatures face numerous threats. Uncontrolled tourism development, accidental entanglements in fishing nets, and marine pollution are all challenges to their population. The consumption of turtles by humans in some cultures also represents a significant threat.

One of the most alarming threats comes from climate change. Rising global temperatures directly affect the sex of the turtles. The sex of sea turtles, including green turtles, is determined by the temperature of the sand where their eggs are incubated. Warmer temperatures favor the birth of females, while cooler temperatures produce males. If global warming continues, it could lead to a significant imbalance in turtle populations, with a predominance of females and a shortage of males, which would jeopardize reproduction and the survival of the species.
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However, efforts are being made to protect these magnificent creatures. Conservation programs, such as monitoring nesting beaches and establishing marine sanctuaries, have been launched to safeguard turtles and their habitats. Awareness campaigns are also being conducted among local communities and visitors to reduce the impact of human activity on these vulnerable animals.

Conclusion: Preserving the Ocean’s Beauty

Green sea turtles of Mayotte are more than just a tourist attraction or a biological wonder. They are the sentinels of a fragile ecosystem that, like them, is struggling for survival. Their protection depends on collective awareness and ongoing conservation efforts to ensure that future generations can also marvel at the beauty of these iconic marine creatures.
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By protecting Mayotte’s turtles and their habitat, we are contributing to the preservation of the island’s marine wealth and maintaining the balance of the Indian Ocean. Through their eyes, we can see the urgency of protecting what remains of our planet, because, just like these turtles, the Earth itself is in peril.

The Invasion of the Lionfish: A Silent Marine Crisis

The lionfish (Pterois volitans and Pterois miles), with its striking red and white stripes and venomous spines, is a stunning yet destructive predator wreaking havoc in the Atlantic Ocean and the Caribbean Sea.

​Native to the Indo-Pacific, this species was introduced to non-native waters through the aquarium trade, with the first recorded sightings in Florida in the 1980s. Since then, lionfish populations have exploded, threatening coral reef ecosystems and the economic livelihoods dependent on them.

A Relentless Predator with No Natural Enemies​

Lionfish are voracious hunters, consuming a wide variety of marine species, including shrimp, juvenile fish, and commercially important species like snapper and grouper.

​With no natural predators in their invaded habitats, they have multiplied at an alarming rate. Studies have shown that a single lionfish can reduce the population of native reef fish by up to 79% in just five weeks, disrupting the delicate balance of marine ecosystems.

​The lionfish is a formidable predator that consumes about 10 to 20% of its body weight daily. On average, an adult lionfish weighs between 1 to 2 kg. Therefore, a 1.5 kg lionfish would eat between 150 to 300 grams of food each day, primarily small fish and crustaceans. This voracious appetite, combined with its ability to invade large marine areas, has made the lionfish an invasive species, disrupting ecosystems, especially in the Caribbean and Indo-Pacific regions.

​Lionfish reproduction is indeed rapid and produces a large number of eggs. Females can lay up to 30,000 eggs per reproductive cycle, and they can spawn every 4 to 6 days throughout the year under optimal conditions. This ability to produce large quantities of eggs, combined with their rapid reproduction rate, allows lionfish populations to multiply quickly. This contributes to their spread into new habitats, exacerbating their ecological impact. Due to their prolific reproduction and the absence of natural predators in many regions where they have been introduced, lionfish become a major problem for marine ecosystems.

The Economic and Environmental Cost of the Lionfish Invasion :

The unchecked spread of lionfish poses severe ecological and economic threats:
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• Damage to Coral Reefs: By preying on herbivorous fish that help control algae growth, lionfish indirectly contribute to reef degradation, leading to coral die-offs and loss of biodiversity.

 

• Impact on Commercial Fisheries: The decline of native fish populations affects commercial fishing industries, reducing catches and threatening the livelihoods of local fishers.

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• Threat to Tourism: Diving tourism, a crucial revenue source in many Caribbean and Atlantic coastal regions, suffers when reefs decline and fish populations dwindle.

Lionfish and Climate Change: A New Threat in the Mediterranean

Traditionally confined to warm waters, lionfish have recently been observed in the Mediterranean Sea, a phenomenon linked to rising sea temperatures due to climate change. The warming of the Mediterranean has created a more hospitable environment for this invasive species, allowing it to spread rapidly.

​This expansion poses a new ecological threat, as lionfish prey on native Mediterranean species that have not evolved defenses against them. The arrival of lionfish in this region further underscores the far-reaching consequences of climate change on marine biodiversity.

Innovative Solutions to Control the Invasion : 

Efforts to manage lionfish populations have led to creative and effective strategies

• Culinary Consumption: Encouraging the consumption of lionfish as a sustainable seafood option has gained traction, with restaurants featuring lionfish dishes to create demand.

 

• Organized Culling Programs: Many coastal communities have implemented lionfish hunting tournaments, rewarding divers for removing as many lionfish as possible.

 

• Predator Training Initiatives: Scientists and conservationists are experimenting with training sharks and other native predators to recognize lionfish as prey.

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• Mechanical Removal Techniques: Specially designed traps are being tested to capture lionfish in deeper waters, where divers cannot reach them.

A Call for Conservation Action

Addressing the lionfish invasion requires a collaborative effort among governments, scientists, conservation organizations, and local communities. Public awareness campaigns, research funding, and policy changes supporting sustainable fishing practices are crucial in mitigating the ecological and economic damage caused by this invasive species.
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The battle against the lionfish invasion is ongoing, but with innovative solutions and continued dedication, we can protect vital marine ecosystems and preserve the biodiversity of our oceans for future generations.

Off the eastern coast of Tanzania, Zanzibar emerges like a dream—an island paradise where history and nature intertwine in a captivating harmony.
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Famous for its pristine beaches and crystal-clear waters, Zanzibar is far more than a tropical getaway. It’s a living mosaic of ancient cultures, shaped by centuries of Arab, African, and European influence. For the curious traveler, the island offers more than just the allure of its shores. Wandering through its narrow streets, discovering its unique wildlife, and exploring its natural treasures reveals a world as rich in stories as it is in beauty.

Stone Town: A Journey into the Heart of Zanzibar’s History

​There is nothing quite like the magic of Stone Town, Zanzibar’s ancient city, where every stone whispers tales of trade, slavery, and cultural conquest. This labyrinth of narrow alleyways and timeworn buildings stands as a living testimony to the island’s golden era—when Zanzibar thrived as a hub for the spice and slave trades.

Around Every Corner: A Living Mosaic of Cultures
Wander through a narrow alley and suddenly, ornate wooden doors and whitewashed walls reveal a spectacular backdrop—a true architectural patchwork blending Arab, Indian, and European styles. Strolling through Stone Town is like walking into the past.
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Must-see highlights include:
The House of Wonders – Housed in a 19th-century building, this museum traces Zanzibar’s rich history, from its sultans to its pivotal role in the spice and slave trades.
Darajani Market – Here, local life pulses through stalls overflowing with tropical fruits, freshly caught fish, and fragrant spices. It’s a vibrant feast for the senses, where every color, scent, and sound tells a story.

Zanzibar’s Beaches: Nungwi and the Allure of the Ocean
But Zanzibar is also an island of dreamlike beaches. Among the most iconic is Nungwi Beach, located on the island’s northern tip. Fringed with powder-white sand and lapped by crystal-clear waters, it remains one of the archipelago’s true gems.
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Unlike other parts of the coast, Nungwi enjoys calm seas that are unaffected by the tides—making it a perfect haven for water activities all day long, from sailing and snorkeling to simply floating in the turquoise shallows.

Underwater Encounters and Coastal Life
For diving and snorkeling enthusiasts, Nungwi offers an exceptional marine playground. Its coral reefs are teeming with life—tropical fish, graceful sea turtles, and even manta rays glide through these vibrant underwater worlds.
But Nungwi is also a gateway to local life. Just steps from the beach, the nearby fishing village welcomes visitors into an authentic world of tradition—where fishermen return with the day’s catch and handcrafted souvenirs carry the soul of the island.

Wildlife and Wilderness: An Ecosystem Like No Other
Zanzibar is home to a rare and fascinating biodiversity, offering travelers the chance to encounter endemic species and protected habitats. At the heart of the island lies the Jozani Forest, where the endangered red colobus monkeys live hidden among the lush vegetation. Spotting them is a quiet, powerful moment—one that stays with you.

Nature lovers will also be enchanted by the island’s color-changing chameleons and giant tortoises, creatures that reflect the rich and fragile natural heritage of Zanzibar.

Mystical Caves and Hidden DepthsThe Mtoni and Pemba caves offer visitors a glimpse into Zanzibar’s more mysterious side. These natural formations, shaped over centuries, invite a more intimate exploration of the island—far from the tourist crowds, and deep into its quiet, ancient heart.

The Zanzibar Archipelago: Cultures, Islands, and AdventureBeyond the main island, Zanzibar unfolds into a constellation of smaller islands and atolls, each with its own set of wonders. One standout is Prison Island, just a short boat ride from Stone Town. Once used to detain slaves, this island now shelters a population of giant tortoises, offering a surreal mix of history and wildlife.
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The archipelago is also the beating heart of a vibrant culinary tradition, where local spices, Arab influences, and African flavors blend into unforgettable dishes. Strolling through local markets or dining in small family-run restaurants is the best way to taste Zanzibar’s soul—whether through a fragrant plate of pilau or a bold and colorful Zanzibari biryani.

Prison Island: A Stop Steeped in History and Nature
Just a few kilometers off the coast of Stone Town, Prison Island is a small landmass that holds a rich and complex past. Once used as a prison for slaves and criminals, the island has transformed into one of Zanzibar’s most intriguing destinations.

Beyond its haunting history, the island is home to a colony of giant tortoises, some of which can live up to 200 years. Introduced in the 19th century, these gentle giants have become a living symbol of longevity and Zanzibar’s biodiversity.
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With secluded beaches, coral reefs, and clear waters perfect for snorkeling and diving, Prison Island offers a unique blend of historical depth, natural beauty, and outdoor adventure—an unforgettable stop for curious travelers.

Why Zanzibar Deserves a Place on Your Map
Zanzibar is more than just a destination—it’s a journey through time, culture, and nature. From its powdery white beaches to its storied past, the island offers an experience that awakens all the senses.
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Whether you come for the turquoise waters, the winding alleys of Stone Town, or the chance to encounter rare wildlife, Zanzibar captivates through its authenticity. It’s a place where history whispers from every wall, where nature speaks in colors and silence, and where every moment invites you to slow down, breathe, and reconnect—with the world, and with yourself.

What Might Disappoint Some Travelers
Like any popular destination, Zanzibar also has its challenges. Some beaches—such as Kiwengwa or Paje—can become crowded with mass tourism, which may take away from the sense of tranquility many visitors seek.

While infrastructure is generally sufficient for a comfortable stay, it can feel a bit rustic in more remote areas. For those looking for a more untouched experience, heading to places like Nungwi or the more isolated neighboring islands might be a better choice.
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Despite ongoing efforts to protect the environment, plastic pollution remains an issue in certain parts of the island, particularly around urban areas. It’s a reminder that even in paradise, the balance between tourism and preservation is a delicate one.

Zanzibar: An Island of Striking Contrasts
Zanzibar is a place where history, nature, and culture intertwine to create an unforgettable experience. If you’re seeking a destination that goes beyond postcard-perfect beaches, Zanzibar will surprise you with its rich heritage, diverse ecosystems, and mesmerizing atmosphere.
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Though not without its flaws, the island’s authenticity and unique charm make it one of the most beautiful and meaningful stops in any journey across the Indian Ocean.

Mayotte's Lagoon: An Underwater Gem Waiting to Be DiscoveredA true jewel of the Comoros archipelago, Mayotte is an island of rare beauty, fringed by one of the largest and most pristine lagoons in the Indian Ocean. This vast sanctuary, spanning over 1,500 square kilometers, shelters a dazzling array of marine life. From vibrant coral reefs to graceful sea turtles, playful dolphins, and stealthy sharks, Mayotte is not only a diver’s paradise but also a breathtaking experience for anyone seeking to connect with an extraordinary underwater world.
One of the Most Beautiful Lagoons in the WorldEncircled by a coral barrier and protected by law, Mayotte’s lagoon is a haven where fragile marine ecosystems are preserved and allowed to thrive. At once calm and teeming with life, this aquatic expanse is a stage for some of the ocean’s most spectacular biodiversity. Whether you're diving beneath the surface, snorkeling through coral gardens, or simply relaxing on its white sandy shores, the lagoon is open to all—inviting exploration, wonder, and respect for the natural world.

The Coral Reef: Mayotte’s Vibrant Living WallThe coral reef is one of Mayotte’s greatest treasures. It shelters a multitude of tropical fish and marine mollusks, offering divers a colorful ballet of clownfish, surgeonfish, and bluespotted stingrays. Green and hawksbill turtles are frequent visitors in the lagoon’s calm waters, often spotted while diving or on boat excursions.
Must-See Dive Sites in MayotteMayotte’s lagoon is home to several iconic dive sites, each with its own unique features and marine encounters. Among the most renowned are:

• S Pass (Passe en S)
  A spectacular site where strong currents attract an abundance of marine life, including reef sharks, dolphins, and butterflyfish. Due to the powerful currents, this dive is best suited for experienced divers.
  
• Embouchure Bank (Banc de l'Embouchure)
  Known for encounters with majestic manta rays and blacktip reef sharks, this site also offers mesmerizing views of large schools of fish weaving through vibrant coral formations.
  
• M’Tsamboro Pass (Passe de M'tsamboro)
  A favorite among those seeking deeper dives and a rich variety of marine life. Divers often spot sea turtles, dolphins, and moray eels in this stunning underwater landscape.
  

Shark Encounters: Majestic Guardians of the Deep
Diving in Mayotte is also renowned for its encounters with sharks—mysterious giants of the ocean that play a vital role in maintaining the delicate balance of the underwater ecosystem. Far from the myths that surround them, these apex predators are essential to the health and resilience of marine life in the lagoon.

A Protected and Preserved Natural Haven
Mayotte’s lagoon is part of the Marine Natural Park of Mayotte, a sanctuary created to safeguard this extraordinary environment. Covering a vast portion of the archipelago and its surrounding waters, the park provides essential protection to preserve biodiversity and ensure the long-term vitality of its fragile marine ecosystems.

Unforgettable Encounters with Marine Wildlife
​Mayotte’s lagoon is also a privileged site for extraordinary marine encounters. Beyond sharks, turtles, and manta rays, it is a key migration route for humpback whales, which return each year to these warm waters to breed. Snorkeling near the beaches reveals a vibrant underwater world filled with clownfish schools, curious seahorses, and even playful dolphins that often enjoy interacting with swimmers and divers.

Whale watching is becoming increasingly popular, offering visitors the rare chance to witness these gentle giants in a serene setting, often just a few meters from the boat—a moment of pure connection with the ocean.

Why Dive in Mayotte?
​Diving in Mayotte’s lagoon is more than just an aquatic activity—it’s an immersion into a preserved marine world. The site offers an exceptional diversity of ecosystems, from coral reefs to mangrove-lined shores, teeming with marine life and rich flora. The lagoon is a true sanctuary, offering one of the most rewarding dive experiences for those willing to venture off the beaten path. Though not as widely known as other destinations, its untouched beauty makes it all the more extraordinary.

Challenges Facing Mayotte’s LagoonDespite its untouched beauty, Mayotte’s lagoon is not immune to threats. Climate change, rising sea temperatures, and plastic pollution are major challenges affecting the marine ecosystem. Coral reefs, in particular, are highly vulnerable to ocean warming and bleaching. However, conservation efforts led by the Marine Park and local initiatives to reduce environmental impact are vital in preserving this delicate balance and protecting the lagoon for future generations.

A Deeper Thing: A Submarine Paradise Worth Protecting
​Mayotte, with its pristine lagoon and biodiversity-rich waters, is undeniably a must-visit destination for divers in search of extraordinary underwater experiences. This preserved yet fragile ecosystem stands as a living testament to the beauty and diversity of the Indian Ocean. Whether you're a seasoned diver or simply a nature enthusiast, Mayotte offers an incomparable journey—where underwater adventure blends with stunning ecological richness.
It’s a place to explore with respect and responsibility, so that its marine wonders may endure for generations to come.

The sun rises over the turquoise waters of Zanzibar, casting golden hues on the ocean's surface. Small wooden fishing boats, packed with tourists, speed towards a pod of dolphins. Excited voices, camera shutters, and the splash of hurried snorkelers disturb the morning calm. This scene, played out daily, is a stark reminder of how human fascination with marine life often comes at a cost.
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Recent documentaries have shed light on the uncontrolled pressure that dolphin populations in Zanzibar endure due to mass tourism. Swimmers chase them, boats corner them, and respect for their natural behavior is often disregarded. It is easy to condemn such practices, to label them as reckless or damaging. But in a world where marine life is increasingly under threat, are these encounters always the worst alternative? If not for tourism, would these same dolphins face an even darker fate—hunted for food, captured for aquariums, or turned into aphrodisiac powders, as is the case in parts of Asia?

Selective Outrage: A Double Standard in Wildlife Reporting​
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This issue extends beyond Zanzibar. If a TV network chooses to expose the human impact on marine wildlife, shouldn’t it also hold a mirror to other problematic practices elsewhere? Madagascar, for example, has a booming whale shark tourism industry. While some operators respect the animals, others encourage behavior that disrupts their natural movements. In French Polynesia, divers routinely make contact with bottlenose dolphins in Rangiroa, yet these interactions rarely spark media outrage. The question then arises: why are some forms of wildlife tourism vilified while others are glamorized? And why does mainstream media choose to highlight some issues while remaining silent on others?

The Instagram Effect: When Nature Becomes a Trophy

Social media has fueled the desire for up-close, dramatic encounters with wildlife. For many, the goal is no longer the experience itself but the validation that comes with posting it online. Whether it's tourists chasing dolphins for the perfect selfie or divers pushing ethical boundaries for an award-winning shot, the ocean is often reduced to a backdrop for human ego. The truth is, no documentary will stop irresponsible tourists from doing whatever it takes for a viral moment.

A Photographer’s Reflection: Ethics in Marine Photography

​Watching these reports, I can't help but reflect on my own journey as an underwater photographer. Why do I take these images? For likes? For recognition? No. I capture the ocean’s beauty to share its wonders, to tell its story, and to remind people why it deserves protection. The joy for me is not in the instant gratification of an image but in the hours spent observing, waiting, and earning the trust of marine life.
In Mayotte, I have the privilege of stepping into the ocean at dawn, swimming out from the shore, and simply waiting. I don’t chase animals—they come to me. Whether it's dolphins, turtles, or sharks, every approach is deliberate, respectful, and based on an understanding of their behavior. Over time, I have even learned to mimic certain movements—a circular swim pattern to communicate with turtles, subtle fin movements to signal to dolphins that I am not a threat. These techniques take patience and commitment, something a rushed tourist encounter will never replicate.

The Race for the Perfect Shot: When Photography Becomes Exploitation​
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Beyond tourism, there is another conversation to be had—one about the pressure of wildlife photography competitions. In an industry that rewards the most striking, rare, and sensational images, photographers are sometimes tempted to cross ethical lines. Should an image of a dolphin staring directly into the lens be celebrated if it was only achieved by disturbing the animal? Should we admire a close-up of a whale shark if it was obtained by a diver who got too close? These are difficult questions, and perhaps ones best left for another article.

​Using Photography to Support Conservation Efforts
Photography has the power to go beyond simple aesthetic appeal and can play a vital role in conservation efforts. As photographers, we have the opportunity to make our work useful by collaborating with associations and scientists who are dedicated to protecting the natural world.
One powerful example is my friend Nils, who works with the Manta Trust to photograph manta rays for identification purposes. Each photo becomes a valuable data point, helping the organization track and catalogue manta populations based on their geographic location. This kind of collaboration ensures that our passion for underwater photography serves a greater purpose.
Instead of focusing solely on capturing the perfect shot to post on social media, we can choose to be more intentional and thoughtful about how our images are used. By connecting with conservation organizations and offering our skills for scientific documentation, we can make a meaningful difference. Let’s use our art to support research, raise awareness, and ultimately contribute to the preservation of marine life.
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The Story Behind a Whale Photo​

A few years ago, I was alone in the lagoon of Mayotte when I took a photo of a humpback whale. No one else was there—just me, the ocean, and this giant of the sea gliding peacefully through the crystal-clear waters. It was a rare moment, one of those encounters that stays with you forever.
Later, I sold that image through a stock photography agency. And sometime after, I found out that my photo—taken in Mayotte—had been used in a promotional booklet for whale-watching tourism... in Madagascar. The irony wasn’t lost on me.

This is the paradox of wildlife photography. You can capture an image with the utmost respect, yet once it’s out in the world, it can be repurposed, reshaped, and sometimes even used to promote practices that contradict your own ethics.
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That experience reinforced an important lesson: as photographers, we don’t just take pictures. We shape narratives. We influence perceptions. And that comes with responsibility.

The Responsibility of Wildlife Photographers and Conservationists

There’s another discussion to be had here—about the role of photography competitions and the increasing drive for more sensational images. But that’s a topic for another day.

For now, my message is this: respect nature. Leave your GoPro aside and simply enjoy the moment, not for the likes, but for yourself. The most valuable memories are the ones you carry in your soul, not the ones you post online.
If you truly want to make a difference, go beyond fleeting experiences. Commit yourself to real conservation. Make it your profession. Follow ethical guidelines. And if you want to expose human impact on wildlife, be thorough—tell the full story, not just the convenient parts.

Because in the end, the most powerful legacy we can leave is in the awe of future generations—the wonder in their voices when they say, “I want this to last. I want my children to see what I have seen.”
Otherwise, don’t pretend to be a conservationist. Be one.

With its turquoise waters and incredible biodiversity, Mayotte’s lagoon is one of the most pristine in the world. Nils Bertrand, head of Seablue Safari, has been exploring these waters for 25 years. He shares the unique experience of his sea excursions with us.

• NGT: Hello Nils, can you tell us about the Seablue Safari experience?
• Nils Bertrand: The Seablue experience is 25 years of passion for Mayotte’s lagoon, its unique marine ecosystem, and the extraordinary encounters it offers. Here, every excursion is an immersion into a still-preserved world, where nature reigns supreme. My goal is to bring visitors as close as possible to this exceptional wildlife while adopting an environmentally respectful approach.

What Can You Expect to See on a Seablue Safari Excursion?

One of Mayotte’s greatest assets is its incredible marine diversity. Whether snorkeling or simply observing from the boat, you’ll witness a true mosaic of species.
The coral reefs are teeming with life, forming a vibrant ecosystem. Sea turtles are everywhere, offering magical moments as they peacefully graze on seagrass beds.
Then, there are the dolphins—several resident species inhabit these waters, including Indo-Pacific bottlenose dolphins (Tursiops aduncus), spinner dolphins (Stenella longirostris), spotted dolphins, short-finned pilot whales, and even the rare humpback dolphins (Sousa plumbea).

Whale season, from July to October, is a highlight. You can witness fascinating behaviors, such as male escort displays, tender interactions between mothers and calves, and young whales exploring their environment.
From February to June, majestic manta rays take center stage. With just a mask and snorkel, you can watch them gracefully spiral above the reefs.
For thrill-seekers, we also offer special shark excursions, allowing you to observe these fascinating predators in their natural habitat.
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And occasionally, we’re lucky enough to encounter truly exceptional visitors—orca, sperm whales, and even dugongs… Here, anything is possible!

What Has Been Your Most Memorable Encounter at Sea?

Without hesitation, the orcas in 2015. During peak whale season, a group of about fifteen orcas entered the lagoon to hunt. The spectacle lasted for more than three weeks—an absolutely timeless moment. We were able to witness their intelligence, their hunting strategies, and even incredible interactions with other species.

​A memory etched forever!

A Full Immersion into Mayotte’s Lagoon

Can you tell us about the different experiences offered by Seablue Safari?

• Nils Bertrand: Our excursions are full-day expeditions. We don’t offer short boat trips of just a few hours because truly exploring Mayotte’s lagoon takes time. Each outing is an adventure—an immersion into one of the richest ecosystems of the Indian Ocean.

All year round, we set out in search of dolphins. They are ever-present and offer magical encounters. We also explore the coral reefs, perfect for snorkeling, and make stops on pristine white sand islets, the true gems of the lagoon.
Certain times of the year offer unique experiences:

• From March to June, it's manta ray season. With just a mask and snorkel, you can watch them glide through the water with mesmerizing grace.
• From July to October, humpback whales take center stage—an awe-inspiring spectacle that never fails to amaze.
• We also organize sunrise excursions, where we navigate through the tranquil early morning atmosphere. This is a special time to observe wildlife in the peacefulness of dawn.

For those looking to explore the full diversity of the lagoon, we offer complete island tours. This circuit takes visitors to must-see sites such as the mangroves, Soulou waterfall, the iconic "S Pass," and the white sand islets. These excursions are less focused on wildlife encounters but provide a broader perspective on Mayotte’s history and landscapes.

And for thrill-seekers, we have created the Big Fish Out expeditions—a quest for sharks, without scuba tanks, only snorkeling. We search for reef sharks, bull sharks, and even tiger sharks. It’s an adrenaline-packed experience, always conducted with the utmost respect and safety.

A Lagoon in Danger?

How do you see the evolution of the lagoon since your arrival? Is it in danger?

• Nils Bertrand: Yes, clearly, Mayotte’s lagoon is facing many challenges. I’ve seen its waters change over 25 years of exploration. Some reefs are suffering from climate change, human pressure, and pollution. Growing urbanization and uncontrolled development pose real threats.

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But it’s not all lost. There are still incredibly well-preserved areas, and we’re lucky to have one of the world’s richest lagoons in terms of biodiversity. We must act quickly, raise awareness, and encourage a more respectful approach to tourism. At Seablue Safari, we try to contribute by educating our visitors and minimizing our impact.
Mayotte still has so much to offer, but its beauty is fragile. It’s up to all of us to take care of it.

A Changing Lagoon, A Fragile Balance

NGT: You’ve been observing Mayotte’s lagoon for over 20 years. Have you noticed any changes in the underwater fauna?

Nils Bertrand: Yes, and unfortunately, the difference is striking. Twenty years ago, we used to see many more large fish, particularly the Napoleon wrasse, which used to populate the S Pass in large numbers. Today, their presence has become much rarer.

The main cause? Excessive fishing pressure. Some iconic fish, which were once an integral part of our excursions, are now harder to observe. Fortunately, Mayotte remains a relatively preserved sanctuary. Compared to other lagoons in the Indian Ocean, our human impact is still limited. We have vast areas where nature is still thriving, but it’s crucial that we ensure we don’t cross a critical threshold.

From a Childhood Passion to a Marine Vocation

NGT: Can you tell us about your journey? How did you end up in Mayotte?

Nils Bertrand: My love for the sea comes from my father, a passionate sailor. With my brothers, who are an integral part of the Seablue team, we grew up on the water. My father even built us an Optimist, our first boat. This passion gradually became a bigger part of my life. However, at first, nothing indicated that I would turn it into a profession. I eventually trained to become a sailing instructor, before specializing as a skipper and yacht delivery captain.

It was this path that led me to the Indian Ocean. When I discovered Mayotte and its lagoon, it was a revelation. I was fascinated by the tropical marine world, and especially by marine mammals: dolphins, whales… From that moment, sailing became a means of exploration, rather than an end in itself.
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I realized that what truly captivated me was the encounter with wildlife, the connection with these animals in their natural habitat. That’s how Seablue Safari was born—an adventure driven by curiosity, respect, and the desire to share this passion.

What are Corals and Their Role in the Marine Ecosystem?

Corals are marine animals belonging to the class Cnidaria, closely related to jellyfish and sea anemones. They live primarily in warm, clear waters of the tropics, forming reefs that can stretch for hundreds of kilometers. Their role in the marine ecosystem is multifaceted. They serve as a refuge and breeding ground for a wide range of marine creatures, including fish, crustaceans, and mollusks. Coral reefs also act as natural barriers, reducing the strength of waves and protecting shorelines from storms and erosion.
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Beyond their ecological role, corals contribute to marine biodiversity. Their ability to recycle nutrients and maintain ecological balance in marine environments is essential for the survival of many marine organisms. Coral reefs are, therefore, both centers of biodiversity and crucial environmental regulators for the stability of ocean ecosystems.

El Niño, Coral Bleaching, and the Climate Crisis

​However, these fragile structures are now threatened by both natural and human-induced factors, with the most alarming being the impact of ocean warming. One of the most devastating effects of warming is coral bleaching, a phenomenon where corals expel the symbiotic algae (zooxanthellae) that live inside their tissues. These algae provide the majority of the coral's energy through photosynthesis. Without them, corals turn white, become weakened, and struggle to survive without external intervention.
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The El Niño phenomenon, which causes temporary ocean warming, exacerbates this issue. During these climatic events, water temperatures can rise significantly, causing intense thermal stress for corals. As a result, coral reefs can suffer severe damage, losing much of their biodiversity and impacting local populations that rely on the health of these ecosystems.

What Are Scientists Doing to Combat Coral Bleaching?

In the face of this crisis, scientists worldwide are working tirelessly to save coral reefs. Their approach combines laboratory research, field monitoring, and innovative strategies for reef restoration.

One promising solution is coral breeding in laboratories. Researchers have developed methods to cultivate heat-resistant corals. By crossbreeding different coral species or exposing larvae to higher temperatures, they hope to create corals that are more resilient and capable of surviving in warmer waters. These corals can then be transplanted into declining reefs as part of restoration programs.

Scientists also monitor reef conditions in real-time, using underwater sensors to measure water temperature and coral health. This data allows for rapid alerts to authorities and local communities, enabling protective measures, such as marine protected areas or activity restrictions, to be implemented.

On a global scale, coral protection and restoration initiatives are also supported by international organizations and governments, working to reduce greenhouse gas emissions, plastic pollution, and overfishing—three major factors contributing to coral decline.
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While these efforts provide hope for restoration, the situation remains urgent. Coral reefs, these biodiversity treasures, continue to suffer under the combined effects of climate change and pollution. Scientific solutions, though promising, can only succeed if accompanied by collective action to combat climate change. Protecting corals has become a global challenge, a test for humanity's ability to safeguard the natural wonders that connect us to our planet.

Immersion in the Lagoon of Mayotte: Just Below the Surface

Mayotte, a pearl of the Indian Ocean, is a sanctuary where marine life thrives under crystalline light. This project could have taken a completely different turn. I was in contact with the BBC for a collaboration with Blue Planet, but things did not go as planned. The person who was supposed to provide scientific validation for our project took advantage of the situation to push their own project forward, ultimately leading to the cancellation of ours.

I had believed that the world of wildlife documentaries was driven by a shared love for nature, but reality is quite different: some are willing to do anything to take someone else's place. It was a disillusionment, but it did not stop me from pursuing my work with the same determination.
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For my first episode dedicated to the marine depths, I chose to explore this fragile and fascinating world that exists just below the surface, where sunlight dances with the water and reveals an ecosystem of incredible richness.

The Genesis of the Project​
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The idea for this short film was born from a desire to capture the raw beauty and harmony that reign in these preserved waters. Unlike deep dives that reveal mysterious abysses, I wanted to showcase what is accessible to everyone, just a few meters below the surface. This is where the spectacle begins, where coral reefs teem with life, and marine creatures move in a natural choreography.

Filming at the Rhythm of Nature

Creating this film required a patient and respectful approach. Working exclusively with natural light, I sought to capture every detail with optimal clarity. The sunlight filtered through the water provided vibrant colors and an almost surreal rendering, where the blue of the lagoon blends with the vivid hues of fish and corals.

From the moment I arrived in Mayotte, I had the idea of creating a 30-minute short film. It ultimately took more than four years to gather all the pieces of the puzzle and turn it into a full-fledged documentary. It is important to highlight the time required to bring such a project to life, as some people think that all it takes is to jump into the water to capture extraordinary images. In reality, one must traverse the lagoon extensively, listen to rumors about the presence of animals, go out, wait, and return empty-handed over and over again, until the perfect moment presents itself—or until the frustration of a missed opportunity sets in.

In this regard, the presence of Nils Bertrand from Seablue Safari was invaluable. He knows the lagoon and the behaviors of its marine inhabitants inside out, having observed them in Mayotte for over twenty years. His experience and deep understanding of the environment allowed us to execute exceptional approaches and capture rare, authentic moments.
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The main challenge was anticipating the movements of marine life to film unique moments. The curiosity of sea turtles, the grace of stingrays, and the frenzy of juvenile fish schools provided magical scenes that only prolonged immersion can truly capture.

A Visual and Auditory Narrative

Until now, I had always worked on short clips or projects lasting three to four minutes. This time, I had to find the right balance between images, music, voice-over, and silence. Creating a smooth and immersive narrative required not only a different approach but also having the necessary footage to perfectly construct the story's flow.

Additionally, this project demanded real teamwork. I collaborated with Mathilde Hangard for storytelling and with Nils for the scientific aspects. Nils, who values precision, significantly raised the level of rigor I had set for myself. His expertise brought an essential level of accuracy to the film's information and sequences.
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Ultimately, nearly a year was needed for editing and the final cut. Removing scenes, adding others, using certain necessary but subtle effects—it was meticulous work and an ambitious project that required both time and discipline to produce a film that remains faithful to the beauty and complexity of Mayotte's lagoon.