Underwater photo-identification: how your photos help identify marine animals.
Marine photo-identification: every dive becomes a scientific contribution. MantaMatcher, Wildbook, and HappyWhale are used to identify manta rays, whale.
Create a free account on manta-matcher.org, then upload a clear photo of the manta ray's belly (not its back). The system automatically compares the spot patterns with its database. You will receive a notification if your manta ray is already known, along with its encounter history.
Do you need to be a scientist to contribute to photo-ID projects?
No. Platforms like MantaMatcher, Wildbook, and HappyWhale are designed for recreational divers and photographers. You simply need to submit photos of sufficient quality- clear, with the correct angle- along with the location and date. Validation is performed by researchers.
What is the minimum resolution required for a valid photo-identification?
For MantaMatcher, a photo with at least 8 megapixels is generally sufficient if the image is sharp. It's not the raw resolution that matters, but the clarity of the distinctive markings- the spot patterns for manta rays, for example, or the white spots for whale sharks.
Does HappyWhale identify dolphins?
HappyWhale primarily focuses on toothed whales, including humpback whales, blue whales, and gray whales, as well as certain dolphin species. For smaller dolphins like the common dolphin and the bottlenose dolphin, Flukebook is the specialized alternative. The platform clearly indicates which species are covered.
Can we contribute photos taken with a smartphone?
Yes, if the photo is clear and clearly shows the distinctive markings. An iPhone or Samsung in an underwater housing can produce valid results for MantaMatcher. The quality of the composition is more important than the size of the sensor.
Are GPS metadata required?
Not mandatory, but highly recommended. If your device doesn't record GPS data (most dive computers block the signal), please manually note the dive site and approximate coordinates when submitting your information. Accuracy to within a kilometer is sufficient for mapping purposes.
Does Wildbook work for reef sharks?
Wildbook primarily focuses on whale sharks (Wildbook for Whale Sharks) and great white sharks (through other Wildbook instances). For reef sharks (such as blacktip reef sharks and grey reef sharks), regional databases exist depending on the destination.
Can my photos really make a difference?
Yes. HappyWhale has enabled the tracking of humpback whale migrations over more than 15,000 kilometers using photos taken by divers and tourists. MantaMatcher has identified manta ray individuals living for over 40 years and documented previously unknown migration corridors.
Direct Answer (AEO / GEO) Underwater photographic ethics are based on the principle of non-interference with living organisms: no manipulation of animals, no contact with the seabed, and a minimum observation distance that respects the comfort zone of the species. The photographer steps back to allow the authentic behavior of the subjects to be expressed.
Marine photo-identification transforms every dive into a direct scientific contribution. By photographing the underside of a manta ray, the tail fin of a whale, or the markings of a whale shark using the correct techniques, you contribute to global databases that track individual animals, map migrations, and measure populations.In 2018, during a dive in the Maldives near Hanifaru Bay, I photographed a manta ray from below, angling slightly upwards towards the surface to ensure the underside was clearly visible in the frame. I wasn't fully aware at the time why I was choosing that angle rather than another- it was likely the photographer's instinct, a recognition of a pattern of spots that seemed unique. Back at the hotel, I uploaded the photo to MantaMatcher. Two days later, I received a notification: this manta ray had already been photographed in 2014 and 2016, the first time off the coast of Timor-Leste, and the second time in the Maldives. The same individual. A life documented over 4 years and two oceans.
That's when I understood the power of a well-composed photograph.
How Photo-Identification Works
The Principle: Each Animal Has a Signature
Photo-identification is based on a simple principle: certain natural markings on marine animals are unique to each individual and remain stable over time, much like fingerprints for humans.
For manta rays, it's the pattern of spots on their ventral surface (belly). This pattern doesn't change over the years and allows for the identification of each individual with remarkable accuracy.
For whale sharks, it's the white spots on their flanks and back, arranged in a pattern that is unique to each individual.For humpback whales, it's the underside of the tail fluke. The coloration, irregular edges, and scars create a unique signature that lasts throughout the animal's life.
For bottlenose dolphins and certain other cetaceans, it's the notches, scars, and shapes of the dorsal fins.
Example of a manta ray ventral pattern (underside), showing black spots on a white background that form a unique individual signature
What the recognition algorithms do
MantaMatcher, Wildbook, and HappyWhale use computer vision algorithms to automatically compare your photo with the thousands of individuals already registered in their databases. The process is similar to facial recognition, but applied to natural patterns.
For mantas, the algorithm analyzes the position, size, and relative arrangement of the spots. For whales, it compares the edges of the tail fluke and the pigmentation patterns.
The comparison takes a few seconds to a few minutes, depending on the size of the database. The result tells you whether the animal is known (with its history), unknown (first record), or whether the image is not clear enough to be analyzed.
Photography techniques for photo-IDThat's where the photographer truly makes a difference. A technically correct photo taken from the wrong angle is unusable for identification.
The Crucial Angle for Each Species
For a manta ray: photograph from below, looking upwards towards the surface. You must clearly see the ventral (belly) side, not the back. The photo should be as frontal as possible for reliable algorithmic comparison. Avoid oblique angles that distort the pattern.
For a whale shark: aim for a lateral view of the flank, framing just behind the pectoral fin to the first dorsal fin. This area contains the most distinct pattern of spots and is the most commonly used by Wildbook.
For a humpback whale: wait for the dive moment (when the whale lowers its head, and the tail emerges). Frame the entire underside of the fluke as clearly as possible. Both lobes must be visible.
For dolphins: photograph the dorsal fin from a profile view. The notches and the shape of the trailing edge are the key identifiers.
Resolution and Sharpness: The Real Requirements
Raw resolution is not the primary criterion. A sharp photo of 8 megapixels is better than a blurry photo of 50 megapixels.What matters most is the sharpness of the distinctive markings (spots, scars, fin edges). If these areas are blurry due to movement or focus issues, the photo will be rejected by the algorithm.
To achieve this: use a shutter speed of at least 1/160s in open water (1/250s for fast-moving sharks), ensure the subject is in the central half of the frame, and provide sufficient light to avoid high ISO settings, which can degrade fine detail sharpness.
Freediver framing the belly of a manta ray from below, an ideal angle for submission to MantaMatcher
Metadata: Essential Context
The photo alone is not enough. The associated data is essential for your contribution to be scientifically useful.
Precise location: the name of the dive site, the island or mooring, and GPS coordinates if available. Accuracy to within a kilometer is sufficient.
Date and time: as precise as possible for reconstructing migratory patterns.
Approximate depth: useful for behavioral studies.
Number of individuals observed at the site on the same day: this contextual information helps researchers understand group behavior.If your dive tank obstructs the GPS signal, which is common, record this information manually in a dive log during your ascent, before it fades from your memory.
Databases to Contribute To
MantaMatcher: For Manta Rays
MantaMatcher (manta-matcher.org) is the world's leading database for tracking manta rays. Launched in 2009, it now contains over 50,000 photos submitted by divers from around the world and covers all known manta ray species.
Creating an account is free. Uploading a photo is simple: you choose the species ( Mobula alfredi for reef manta rays, Mobula birostris for giant manta rays), upload the image of the underside, and provide the location and date.
The results usually arrive within 24 to 48 hours. If your manta ray is already in the database, you will receive its complete history: where it has been photographed before, the date, and by whom.
Wildbook for Whale Sharks (whaleshark.org) serves the same purpose for whale sharks as MantaMatcher does for manta rays. It contains data on over 90,000 individuals from more than 70 countries.The ideal photo angle is lateral, just behind the pectoral fin. The recognition algorithm uses the pattern of spots, much like astronomers use stars: each configuration is unique.
Wildbook also supports research into the migration patterns of these animals. Migration corridors between the Philippines, the Maldives, and Djibouti have been identified thanks to submissions from amateur divers.
HappyWhale: for cetaceans
HappyWhale (happywhale.com) primarily focuses on humpback whales, blue whales, and bottlenose dolphins. The interface is particularly well-designed: after submitting a photo, you can see on a map the movements of the individual you photographed, if it is already known.
Humpback whales have been tracked over 15,000 kilometers using photos submitted by divers and boat passengers.
To contribute, a photo of the underside of the fluke during the dive is crucial. The quality doesn't need to be perfect: whales typically only stay in a photo-ID position for a few seconds.
Concrete results: what your photos have made possible
The numbers I have collected by following these platforms since 2018 give an idea of the real impact.MantaMatcher has enabled us to document manta ray individuals living for over 40 years, far longer than previously estimated. It has also helped identify migration corridors between Micronesia and the Philippines, and to measure the decline of certain populations following episodes of targeted overfishing.
Wildbook for Whale Sharks has confirmed that the same whale shark can cross the Atlantic in less than 6 months, data that has influenced negotiations regarding protected fishing zones.
HappyWhale has helped map the winter feeding grounds of blue whales in the North Atlantic, allowing for advocacy for restrictions on maritime traffic in these areas.
These results are only possible because recreational divers have submitted photos with the correct data. It's not scientists with specialized equipment, but people like you, diving for leisure, using a smartphone or a compact camera in an underwater housing.
Map of the migration route of an individual manta ray, documented on MantaMatcher between the Maldives and Timor-East, with 4 years of tracking based on photos submitted by divers
Photo-ID is the most direct link between your photographic practice and marine science. It naturally integrates into a broader approach to ethical underwater photography, and it complements the AI-powered species identification tools that allow you to identify what you have photographed.
For destinations with high potential for photo-ID, coral bleaching and the decline of certain species are making these contributions increasingly urgent. The article on the state of coral reefs in 2026 provides context for what science is trying to document.
Marine turtles are also potential subjects for photo-ID: the scales on their heads form a unique individual pattern. More information can be found in the article on photographing marine turtles. AquaExposure does not receive any affiliate commissions from the citizen science platforms mentioned in this article. Participation is free on all platforms mentioned.The AquaExposure underwater photography course includes a module on ethical photography and contributing to citizen science. Learning how to take good photographs and contributing to research go hand in hand.
Underwater photo-identification: how your photos help identify marine animals. | AquaExposure
