The secrets of the seas are crucial to the future of life on Earth. The ocean is our life support system, producing most of our oxygen and regulating the climate. The better we know the ocean, the better we can protect the planet.
These articles report on the importance of protecting the ocean, as well as the impact of Rolex’s Perpetual Planet initiative, which supports outstanding individuals and organizations that are implementing novel solutions to the world’s most pressing environmental challenges.
The initiative highlights the Rolex Awards for Enterprise, a program that for over four decades has recognized changemakers from around the world, including Luiz Rocha, who is featured here, alongside fellow pioneering ocean explorers Cristina Mittermeier and Vicki Ferrini.
Venturing
into the void
The gloomy Mesophotic Zone of the ocean is among our least-explored ecosystems. Scientist Luiz Rocha is trying to change that — but it requires some dangerous diving, and an embrace of the unknown. All photography for “Venturing into the void” © Franck Gazzola/Rolex
Deeper than the standard safety limit for scuba divers, but shallower than the lightless ink-black of deep sea, there exists in the ocean a mysterious, shadowy layer of half-light. At 30 to 150 meters below the ocean’s surface, the Mesophotic Zone, from the Greek for “middle-light,” is both difficult and expensive to explore with high-tech submersibles and extremely dangerous to dive in, and so has remained largely inscrutable. Until now.
Scientist Luiz Rocha is not discouraged by what he admits are “very risky” dives to the middle-light. Rocha grew up on the coast of Brazil and quickly developed a fascination for the ocean and its many mysteries; he’d decided on a career in biology by the third grade. Today, he is an ichthyology curator and co-director of the Hope for Reefs initiative with San Francisco’s California Academy of Sciences, spending his days documenting and discovering fish. He’s logged more than 6,000 diving hours across more than 70 expeditions around the globe. But for Rocha, nothing beats exploring that cryptic twilight, regardless of the risks.
As a result, Rocha is a leading expert on the world’s mesophotic coral reefs. These colorful ecosystems pulse with life below the surface of tropical and subtropical waters, yet much of that life remains undiscovered, due to the difficult-to-reach depths. Rocha is one of only a handful of specially trained divers capable of taking the plunge.
Each of these expeditions requires hours of preparation and almost 200 pounds of equipment, including innovative “rebreathers” that supply divers with a special mixture of gases. Even then, Rocha is typically only able to spend 15 minutes exploring the Mesophotic Zone before making a grueling five- to six-hour ascent to the surface, helping the human body readjust safely to the atmospheric pressure.
If that sounds like a lot of work for little payoff, consider also that Rocha and team have no idea what they’ll encounter. “As we’re going down, we’re thinking: are we going to find anything?” Rocha said. “Are we even going to find a reef?” It’s not unheard of to make the dive and find only sand.
But then there are the many dives where they do find something. And that, Rocha said, is nothing less than “magic.”
“Even with the limitation of the time we can spend down there, we find one or two new species with each dive.”
Protecting
the undiscovered
When Rocha’s team finds new life, it typically raises more questions than answers. A cursory glance at Rocha’s Instagram shows mesophotic reef fish are every bit as bright as their shallow reef counterparts. It’s not what a scientist would expect. “The only wavelength available at these depths is blue,” Rocha explained. “All these red and yellow and pink and purple species — it’s so strange.”
The vibrancy Rocha and team find down here makes the less beautiful sights they encounter more disappointing. “Even at these depths, on these reefs where no one has been, we find a piece of trash, we find dying coral, we find human impact,” he said.
It’s no secret the world’s shallow water coral reefs are in trouble. Nicknamed “the rainforests of the sea” for the biodiverse marine ecosystems they uphold, scientists estimate we have lost more than half of our coral reefs to climate change since 1950. Yet, according to Rocha, mesophotic reefs are even more fragile.
Fewer species can survive at these depths, so the loss of just one has a devastating impact on the ecosystem. Added to that, “The water is colder, the corals’ metabolism is slower, so they grow slower. This means that if you break a mesophotic coral, it’s going to take longer for it to grow back.”
For Rocha, there’s no question these reefs urgently need protection. But, he said, “It’s really hard to make the case to protect them because they’re unknown.” That, then, is why Rocha makes those grueling dives: “What we’re really trying to do here is raise awareness that they even exist.”
Championing ownership
The most effective way to raise awareness and encourage protection, Rocha has found, is to foster local ownership of mesophotic reefs. In 2021, Rocha was named a Rolex Awards for Enterprise Laureate, which helped him to embark on his most recent project, a literal deep dive into the Maldives. His team worked closely with the Maldives Ministry of Fisheries and local scientists, with unprecedented results.
“Being very unexplored in terms of deep reefs, it wasn’t surprising to find new species,” Rocha said. “But it was surprising to find the amount that we did in such a short time. We explored for about two weeks and found eight new species.”
It was during this trip that, in a historic first, a Maldivian scientist named a new Maldivian species. Ahmed Najeeb chose Cirrhilabrus finifenmaa, referencing the species' pink face markings (finifenmaa means “rose” in the Maldives’ national language, Dhivehi, and is also a nod to the Maldives’ national flower).
The impact of the naming was immediate. “The Maldivians, without us even writing a report or trying to do anything, are already talking about protecting the reefs,” Rocha said. “They already took ownership of it because it was described by a Maldivian scientist and has a Maldivian name.”
The local knowledge of Rocha’s Maldivian partners proved invaluable, too. According to Rocha, this region of the Indian Ocean lacked even detailed sonar scans of what lies beneath. Working in such uncharted territory can lead to frustrating dives where, Rocha said, “we dive down and just find sand.” Not so in the Maldives, where a member of the local Coast Guard joined the team. “He would say, ‘I think there’s a reef here,’ and every time he said that we found one.”
Rocha’s mission to understand more about the world’s mesophotic reefs promises to help scientists better understand deep-water ecosystems, the interplay between shallow and deep reefs, and the impacts of climate change on the health of the seas.
Because there’s one thought that drives Rocha as he returns time and again to the twilight: “There’s just so much we don’t know.”
listen
PLANET VISIONARIES PODCAST: SEASON 2, EPISODE 6
Hear Luiz Rocha in conversation with "Free Solo" star Alex Honnold. Honnold hosts this podcast series, which explores the extraordinary work of pioneers who are safeguarding our planet for future generations.
Inside Earth’s
life support system
The ocean is the engine of life, regulating both the climate and amount of oxygen needed to sustain Earth as we know it. A healthy and productive ocean perpetuates a healthy and productive planet.Dive into this interactive experience with marine biologist, renowned
conservation photographer and ocean activist Cristina Mittermeier to experiment
with how “chain reactions” that start in the ocean impact the rest of the Earth.All photography for “Inside Earth’s life support system” © Cristina Mittermeier
Circle of Life
Marine ecosystems are complex, diverse, and deeply interconnected. This means that everything within a given ecosystem — from plants, animals, and microbes to the amount of sunlight, oxygen, and nutrients in the water — must be properly balanced for these ecosystems to remain healthy and thrive.
“Working together, these interconnected systems deliver a disproportionately large array of services to planet Earth,” said Mittermeier.
Try balancing the following ecosystems to see how it works.
Coral reefs
A good example of a marine ecosystem is a coral reef.
“From the tiniest shrimp to the largest shark, sea creatures find both food and protection on coral reefs,” said Mittermeier. “Without these critical habitats, fish and sea life will diminish drastically.”
Complete the Chain:
Click/tap the items to move through the chain
Corals provide a protected environment, and the conditions needed for oxygen-producing photosynthesis, to algae. In return, the algae produce food for the coral.
Millions of sea creatures depend on coral reefs for shelter and food. In return, many fish species help keep coral free of seaweed and parasites.
Some small reef fish and cleaner shrimp eat harmful parasites off larger reef dwellers, such as sharks and rays.
Keystone species
“Every ecosystem has certain species that are critical to the survival of other species in the system,” Mittermeier explained. “These are known as keystone species and can be anything from huge predators like tiger sharks, to a fungus or a plant. The point is that without them, the ecosystem cannot survive.”
Complete the Chain:
Click/tap the items to move through the chain
This ochre sea star, a keystone species of some tidal plains, feeds on mussels and barnacles.
Keeping mussel and barnacle populations in check maintains healthy populations of seaweeds.
These seaweeds sustain communities of sea urchins, sea snails, limpets and more.
One study in the tidal plain of Tatoosh Island, Washington found that removing ochre sea stars from the ecosystem halved the plain’s biodiversity within a year.
Early warning systems
Clean and healthy oceans are defined by clean and healthy marine ecosystems. “We cannot protect just one ecosystem,” Mittermeier explained. “They are all connected and all imperative to the survival of the whole.”
Indicator species are an early warning system that signal when environmental changes in an ecosystem are causing the habitat — ie, the ocean — to suffer.
Complete the Chain:
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Chesapeake Bay oysters filter water as they strain it for food.
Excess carbon dioxide, nitrogen and phosphorus are absorbed by the oyster.
The water is now left cleaner for other marine life.
If the health of oyster populations in Chesapeake Bay were to deteriorate, the rest of the ecosystem and the quality of the water itself would also be in trouble.
Producing oxygen
So, healthy marine ecosystems maintain a healthy ocean. And, in turn, a healthy ocean maintains a healthy atmosphere that supports life on Earth.
“Over half of the oxygen we breathe is created by marine organisms,” Mittermeier explained, adding the ocean absorbs carbon dioxide through photosynthesis. The byproduct of this process is the same as on land: oxygen.
Complete the Chain:
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Microscopic plants called phytoplankton absorb CO2 as they grow near the ocean surface.
Just like trees on land, this phytoplankton photosynthesizes, meaning it also releases oxygen into the atmosphere.
It’s estimated one species, Prochlorococcus — the smallest photosynthetic organism on Earth — produces up to 20 percent of the oxygen in our biosphere.
In addition, larger organisms snack on phytoplankton. Their waste eventually falls to the deep ocean, where it decomposes, releasing CO2 into the cold water of the deep.
“The ocean also absorbs carbon dioxide through a simple chemical truth: CO2 dissolves in water,” Mittermeier added. “An astonishing 83 percent of the global carbon cycle is circulated through marine waters, making it the world’s largest carbon store.”
However, as carbon dioxide reacts with seawater, it creates carbonic acid; the more carbon dioxide in the atmosphere, the more carbonic acid in the ocean.
“This is why our oceans are turning acidic and unsuitable for many forms of life, including corals,” Mittermeier said. “While we strive to protect marine ecosystems that support oxygen production, we must also halt new emissions.”
Making
the weather
The ocean regulates our weather systems, too. “Without the ocean, planet Earth would be too hot and dry for life to exist,” Mittermeier said.
Complete the Chain:
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Radiation from the sun is absorbed by the ocean.
Warmed water evaporates, forming rain and storms that are carried over ocean and land by trade winds.
The more the air is heated by the sun from above and by the ocean from below, the stronger winds and storms become.
Ocean
Currents
Ocean currents also control the weather.
Complete the Chain:
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Ocean currents are influenced by temperature, salinity, surface winds and tides.
Currents transport warm water and rain from the equator to the poles.
Currents transport cold water from the poles back to the tropics.
Without these currents, regional temperatures would be more extreme (ie, hotter at the equator and colder at the poles), making less of Earth’s land habitable.
“Heat and salinity are the two main forces influencing ocean currents and both are affected by climate change,” Mittermeier said.
“As the ocean becomes hotter, evaporation will happen more quickly, providing the atmosphere with more fuel for storms.”
How to Help
As these chain reactions show, we all need to take action to maintain a healthy ocean and a healthy planet.
These are Mittermeier’s top, immediately actionable tips for making a difference.
Complete the Chain:
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“Start thinking of yourself as an ocean creature. Our planet is dominated by an ecosystem called the ocean. Therefore, we are all ocean creatures. This slight adjustment in our attitude will take us a long way toward appreciating its value and health.”
“Curb the use of plastic bags, plastic bottles and single-use plastics. One way or another, much of that stuff ends up in the ocean, where it is choking an already stressed ecosystem.”
“Do your part to curb emissions by driving less, buying less, wasting less food and paying to offset your carbon footprint.”
“Use your voice and your wallet to demand a faster transition into renewable energy sources, more efficient systems and a circular economy.”
“Stop consuming wild fish. Opt for land-based, closed-system aquaculture products or mariculture products that are low on the food chain, like oysters, mussels and seaweed.”
Cristina Mittermeier is aligned with Rolex’s Perpetual Planet initiative on collaborative efforts to preserve the natural world. She is also the co-founder of sealegacy.org, a global network of storytellers who use their art and expertise in media and communications to fuel a community focused on restoring the ocean's health and abundance. Find out more about Mittermeier’s work here.
Diving deep
It’s estimated only 23 percent of the world’s ocean floor has been mapped,
which means we know Mars in more detail than our own planet. But what we do know of Earth’s largest biome is far stranger than anything we’ve found in space.
The Sunlight Zone
0 - 200m
The Twilight Zone
200 - 1,000m
The Midnight Zone
1,000 - 4,000m
The Abyssal Zone
4,000 - 6,000m
The Hadal Zone
6,000 - 10,935m
The pressure of water on the body increases the deeper you dive, causing nitrogen gas to absorb into blood and tissue. If a diver ascends too fast, the body cannot safely expel the absorbed nitrogen. For this reason, frequent decompression stops become necessary at just six meters.
Some animals, such as bottlenose dolphins, have an adaptation called “countershading,” meaning they are dark on top but lighter on their undersides. When a predator looks down on them from above, they blend into the darker waters below; when looked at from below, they blend into the lighter waters above.
Shallow water coral reefs are generally found no deeper than 30 meters. Often described as the “rainforests of the sea,” they provide millions of marine plants and animals with food and shelter.
Specialist scuba divers have reached the very upper section of this zone, but they need high-tech equipment to do so, breathing a mix of gases that account for the massive increase in atmospheric pressure. The world’s deepest scuba dive plunged to 332 meters and required an almost 15-hour ascent for safe decompression.
The “stoplight” loosejaw fish sports two specialized light-producing organs located below each eye; one is green, and one is red. The red organ is especially useful because most species at these depths cannot see red light, helping the loosejaw to hunt and hide.
Many species in The Twilight Zone, including coral, are bioluminescent, meaning they glow like neon lights. But Twilight Zone deep-sea shrimp have an extra-special adaptation: they expel bioluminescent fluid from their mouths when attacked, startling and confusing predators.
The angler fish has a dorsal spine tipped with luminous flesh that dangles over its mouth like a fishing rod, luring prey close enough to the light to be gulped.
Scientists can only visit The Midnight Zone in high-tech submersibles. The human body is subject to one atmosphere of pressure at sea level; at 4,000 meters deep, that pressure increases to a (literally) crushing 400.
The giant squid remains mostly a mystery to scientists. The largest ever found was the length of a school bus and weighed nearly a ton. They have the largest eyes in the animal kingdom, measuring 10 meters in diameter, allowing them to see more in the lightless depths.
In the sparsely populated Abyssal Zone, many organisms rely on the remains of deceased upper-level species drifting down for sustenance. The viperfish has a hinged skull that it can rotate upwards to swallow any large portions that pass by, and an oversized stomach for stockpiling food.
Giant tube worms thrive on the toxic combination of chemicals expelled from deep-sea hydrothermal vents. The worms have no mouth or digestive tract, but instead contain bacteria that converts the chemicals into food. They can grow up to eight feet long.
Only a limited number of high-spec vehicles can reach these depths, which means that while humans have some knowledge of The Abyssal Zone, most of this layer is a mystery.
A benthic comb jellyfish found at 7,217 meters holds the record for the deepest living species of comb jelly. The unique creature flies like a kite on the end of two long threads attached to the seafloor.
In 2012, filmmaker, explorer and Rolex Testimonee James Cameron completed a record-breaking solo mission to The Hadal Zone’s Mariana Trench, in the Pacific Ocean, the deepest location in the world. (Read more about Cameron’s feat here.) Despite the remoteness of this zone, in 2019 a researcher reported spotting a plastic bag in the Mariana Trench.
The Sunlight Zone
There is little significant sunlight in the ocean beyond 200 meters,
making this the ocean’s warmest layer, home to many familiar
species. It is also the only zone where all-important, oxygen-
producing photosynthesis can occur.
The Twilight Zone
Light is in short supply in this murky, mysterious and chilly (41-39F) midwater zone, which remains largely unseen by humans. It’s here that creatures begin to twinkle with bioluminescence.
The Midnight Zone
Sunlight does not penetrate the ocean deeper than 1,000 meters, cloaking The Midnight Zone in complete darkness. The only light down here comes from the many bioluminescent creatures that emit their own glow.
The Abyssal Zone
The middle layer of the deep ocean, the temperature here is near freezing, and few known creatures can survive the immense pressure. It’s estimated that about 75 percent of the global ocean floor is found in this zone, but it doesn’t yet mark the very deepest reaches of the sea.
The Hadal Zone
Named for Hades, the ancient Greek god of the underworld, this zone is home to the deepest locations on Earth. It comprises trenches and canyons in which, at its deepest, it’s said the pressure is equivalent to having an elephant stand on a human thumb. For decades, scientists assumed little could exist in this nutrient-poor, frigid pitch-black. But the few exploratory missions that have made it down here have found plenty of signs of life.
A mission to
map the ocean
Named as part of The Explorers Club Fifty People Changing the World, Vicki Ferrini is collaboratively creating the
first-ever complete map of the global ocean — a crucial tool for fighting climate change.
Visualization highlighting portions of the Atlantic and Indian Oceans that remain unmapped and unexplored. Black portions of the ocean in this image lack direct observations, while shades of blue represent portions of the ocean that have been mapped. This image was created based on information made available as part of the Nippon Foundation – GEBCO Seabed 2030 Project, and represent data that have been contributed by organizations and groups around the world.
Credit: Hayley Drennon & Vicki Ferrini, LDEO / The Nippon Foundation - GEBCO Seabed 2030 Project
Among her many achievements, Vicki Ferrini has made the daring journey to the bottom of the Pacific Ocean, braving the blanket darkness and crushing pressure from the cramped cockpit of a high-tech submersible. But perhaps a more daunting challenge is the one the oceanographer is working on right now: a project to create the first complete map of the global ocean by 2030.
Ferrini, a Senior Research Scientist at Columbia University’s Lamont-Doherty Earth Observatory, was named in the inaugural class of the Explorers Club: 50 People Changing the World the World Needs to Know About.
In her quest to map the Earth’s largest — and least-known — territory, Ferrini has traveled to remote, unexplored parts of the ocean, working tirelessly to amass a detailed picture that will help us better understand, and preserve, our planet and our climate.
Here, she tells us why conserving the ocean starts with a map, and how we can all be better stewards of our seas.
In this visualization, bright colors overlain on darker blue areas of the ocean represent portions of the ocean that have been mapped with direct measurement. This shows how little of the ocean has been mapped with direct measurement.
Credit: EVNautilus/Ocean Exploration Trust
You’ve personally traveled to some of the most remote depths of the ocean. What’s that like?
Exploring and mapping uncharted territory is exhilarating. Seeing the details of the seafloor come into focus and knowing that it’s being revealed to human eyes for the first time is such a gift. My first dive in a deep-sea submersible took me to a depth of 2,511 meters at the East Pacific Rise, a well-studied site home to spectacular hydrothermal vents (ocean-floor geysers) that are teeming with life. I took a moment to pause and recognize that these otherworldly giant tube worms were, literally, just an arm’s length away from me.
Visualization of the East Pacific Rise, a mid-ocean ridge on the floor of the Pacific Ocean. The ridge crest rises to a depth of roughly 2,500 meters and is home to many hydrothermal vents. Adjacent to this portion of the ridge is a chain of underwater volcanoes called the Lamont Seamounts. Data in this visualization are the combination of ship-based data assembled into the Global Multi-Resolution Topography Synthesis, and higher resolution data acquired along the ridge crest with the Autonomous Underwater Vehicle (AUV) 'Sentry' that visited the site repeatedly between 2019 and 2021.
Credit: Hayley Drennon, LDEO.
How can a map of the ocean help tackle climate change?
The ocean is critical to life on Earth. If we are to effectively and sustainably manage and conserve ocean resources, we need to identify, characterize and understand the distribution of those resources. Having a map is the foundational first step.
Knowledge of the shape of the ocean floor improves our understanding of ocean currents [which determine weather patterns], reveals habitats, and is important for establishing marine protected areas. It’s important when considering the feasibility and impact of installing offshore renewable energy infrastructure [replacing fossil fuels with renewable energy is key to mitigating the climate crisis]. We also need to understand the shape of the seafloor to predict things like geohazard impacts and tsunami propagation.
Comparison of one kilometer resolution and 100 meter resolution data gathered off the east coast of the U.S, acquired and made available by the National Oceanic and Atmospheric Administration and the University of New Hampshire’s Center for Coastal and Ocean Mapping as part of the Atlantic Margin Extended Continental Shelf Project. Seafloor depth in this image ranges from 15 to 5,500 meters.
Credit: Hayley Drennon, LDEO
Given we’ve only mapped 23 percent of the global ocean — less than we’ve mapped of Mars — creating a complete map by 2030 sounds near impossible. What are the main challenges, and how are you meeting them?
Of course, the first challenge is confronting problems of scale. More than 70 percent of the planet is covered by ocean, and only about a quarter of the ocean has been mapped, at resolutions of 100 to 400 meters. While that does reveal some stunning details about the shape of the seafloor, it is still very crude. Technology innovation in the coming years will help us gather more detailed data.
Mapping the entire ocean also requires a truly “all-hands-on-deck” approach. Ocean processes extend well beyond national boundaries, so it only makes sense to unite data from the global community. It’s also important to remember the ocean connects us all, literally and figuratively: from the air we breathe, to the food we eat, to the data transmitted on undersea cables from our phones and computers.
This example from the Pacific Ocean shows how details of the seafloor are brought into focus with direct sonar measurements. Research Vessel Marcus G Langseth, operated by the Lamont-Doherty Earth Observatory, passed over this previously unmapped seafloor in 2017. Prior to this, only crude low-resolution estimates of seafloor depth were available for this area.
Credit: Vicki Ferrini, LDEO
How optimistic do you feel about our ability to better understand and become better stewards of the ocean going forward?
Studying the ocean is expensive and challenging, largely because of the water itself. It obscures our ability to see, conditions can be treacherous, and deploying electronics in saltwater requires extensive engineering. None of these challenges are insurmountable but investing in ocean science has not been sufficiently prioritized.
That said, there is so much momentum toward bringing the international community of ocean scientists and technologists together, it’s hard not to be optimistic about the future. We’re seeing more data and knowledge sharing, more engagement, and more investment, all of which is important to delivering impactful solutions.
Continuation of the visualization of the East Pacific Rise, a mid-ocean ridge on the floor of the Pacific Ocean. The ridge crest rises to a depth of roughly 2,500 meters and is home to many hydrothermal vents. Adjacent to this portion of the ridge is a chain of underwater volcanoes called the Lamont Seamounts. Data in this visualization are the combination of ship-based data assembled into the Global Multi-Resolution Topography Synthesis, and higher resolution data acquired along the ridge crest with the Autonomous Underwater Vehicle (AUV) 'Sentry' that visited the site repeatedly between 2019 and 2021.
Credit: Hayley Drennon, LDEO.
What can we all do on an everyday basis to help preserve the ocean?
Know that even if you live far from the ocean, the ocean impacts you every day. I encourage people to explore and connect with the oceans, through documentaries, online resources, even live feeds from underwater vehicles. There is so much to explore and discover, and technology is making it easy for people around the world to participate and engage.
Learn more about how global communities are working together to create a complete map of the global ocean by 2030 here.
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Video footage of the first time a solumbellula sea pen was spotted in the Pacific Ocean, filmed at 2,994 meters on the 2022 E/V Nautilus expedition. The animal is a relative of coral and has stinging feeding tentacles that capture marine snow and food particles drifting by its home on an underwater mountain sedimented saddle. Learn more about the expedition and view 24/7 live video at nautiluslive.org.
Credit: EVNautilus/Ocean Exploration Trust