Photo-ID turns every dive into a scientific contribution. MantaMatcher, Wildbook, HappyWhale: how your photos identify manta rays, whale sharks and cetaceans.
Marine photo-identification turns every dive into a direct scientific contribution. By photographing the belly of a manta ray, the tail fluke of a whale or the spots of a whale shark at the right angle, you feed global databases that track individuals, map migrations and measure populations.
In 2018, during a dive in the Maldives near Hanifaru Bay, I photographed a manta ray from below, rising slightly towards the surface to get a clean shot of the belly. I did not fully understand yet why I was choosing that angle over any other: photographer's instinct, I suppose, that spot pattern that seemed unique. Back at the hotel, I uploaded the photo to MantaMatcher. Two days later I received a notification: this manta had already been photographed in 2014 and 2016, the first time off the coast of Timor-East, the second time in the Maldives. The same individual. A life documented across four years and two oceans.
That is when I understood what a well-composed photo can actually do.
Photo-identification rests on a simple principle: certain natural markers on marine animals are unique to each individual and stable over time, like fingerprints for humans.
For manta rays, it is the spot pattern on the belly (ventral surface). This motif does not change over the years and allows each individual to be identified with remarkable precision.
For whale sharks, it is the white spots on the flanks and back, arranged in a pattern unique to each individual.
For humpback whales, it is the underside of the tail fluke. The colouration, irregular edges and scars form a signature that lasts the animal's entire life.
For bottlenose dolphins and some cetaceans, it is the notches, scars and shapes of the dorsal fins.
MantaMatcher, Wildbook and HappyWhale use computer vision algorithms to automatically compare your photo against the thousands of individuals already recorded in their databases. The process resembles facial recognition, applied to natural patterns.
For mantas, the algorithm analyses the position, size and relative arrangement of the spots. For whales, it compares the fluke edges and pigmentation zones.
The comparison takes a few seconds to a few minutes depending on database size. The result tells you whether the animal is known (with its history), unknown (first record), or whether the image is not sharp enough to be analysed.
This is where the photographer genuinely makes the difference. A technically correct photo taken at the wrong angle is unusable for identification.
For a manta ray: photograph from below, rising towards the surface. You must clearly see the ventral surface (belly), 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 at the flank, laterally, framing just behind the pectoral fin to the first dorsal fin. This is the zone containing the most distinct spot pattern used by Wildbook.
For a humpback whale: wait for the moment of the dive (when the whale dips its head, the tail emerges). Frame the entire underside of the fluke as sharply as possible. Both lobes must be visible.
For dolphins: the dorsal fin, photographed in profile. The notches and the shape of the trailing edge are the key markers.
Raw resolution is not the main criterion. A sharp 8-megapixel photo is worth more than a blurry 50-megapixel one.
What matters: the sharpness of the distinctive markers (spots, notches, fluke edges). If these areas are blurred by motion or missed focus, the photo will be rejected by the algorithm.
To achieve this: a shutter speed of at least 1/160s in open water (1/250s for fast sharks), the subject in the central half of the frame, and sufficient light to avoid the high ISO values that degrade fine detail sharpness.
!Freediver framing the belly of a manta ray from below, ideal angle for MantaMatcher submission
The photo alone is not enough. The associated data are essential for your contribution to be scientifically usable.
Precise location: the name of the dive site, island or mooring, GPS coordinates if available. Kilometre-level accuracy is sufficient.
Date and time: as precise as possible for the reconstruction of movement patterns.
Approximate depth: useful for behavioural studies.
Number of individuals observed at the site on the same day: this contextual information helps researchers understand gregarious habits.
If your housing blocks the GPS signal (common with most housings), note this information manually in a dive log at the moment of surfacing, before it fades from memory.
MantaMatcher (manta-matcher.org) is the global reference for manta ray tracking. Launched in 2009, it now contains over 50,000 photos submitted by divers worldwide and covers all known manta species.
Creating an account is free. Uploading a photo is straightforward: you select the species (Mobula alfredi for the reef manta, Mobula birostris for the giant oceanic manta), upload the ventral image, and provide location and date.
Results typically arrive within 24 to 48 hours. If your manta is known, you receive its complete history: where it was photographed before your encounter, by whom, and on which date.
For specific framing tips for mantas, the article on photographing manta rays and whale sharks in the Maldives provides the field context.
Wildbook for Whale Sharks (whaleshark.org) does for whale sharks what MantaMatcher does for mantas. Over 90,000 individuals recorded in more than 70 countries.
The ideal photo angle: lateral, just behind the pectoral fin. The recognition algorithm uses the constellation of spots like astronomers use stars: each configuration is unique.
Wildbook data has fed research on migration patterns showing corridors between the Philippines, the Maldives and Djibouti that were previously unknown, identified solely through amateur diver photo submissions.
HappyWhale (happywhale.com) mainly covers humpback whales, blue whales and large dolphins. The interface is particularly well designed: after submission, you can see on a map the movements of the individual you photographed, if it is already known.
Humpback whales have been tracked over more than 15,000 kilometres thanks to photos submitted by divers and boat passengers.
To contribute, the fluke underside photo at the moment of the dive is the key. Quality does not need to be perfect: whales generally remain in photo-ID position for only a few seconds.
The figures I have tracked following these platforms since 2018 give a sense of the real impact.
MantaMatcher has documented manta individuals living over 40 years (well beyond earlier estimates), identified migration corridors between Micronesia and the Philippines, and measured population declines following targeted fishing pressure in specific areas.
Wildbook for Whale Sharks has confirmed that the same whale shark individual can cross the Atlantic in under 6 months, data that influenced negotiations on protected fishing zones.
HappyWhale has helped map the winter feeding grounds of blue whales in the North Atlantic, supporting advocacy for maritime traffic restrictions in these corridors.
These results are only possible because amateur divers submitted photos with the right data. Not scientists with specialist equipment. People like you, on leisure dives, with a smartphone or a compact in a housing.
Photo-ID is the most direct bridge between your photography practice and marine science. It sits naturally within a broader approach to ethical underwater photography, and it complements AI-based species identification tools that help you name what you have photographed.
For destinations with strong photo-ID potential, coral bleaching and the decline of certain species make these contributions increasingly urgent. The article on the state of reefs in 2026 provides context for what science is trying to document.
Sea turtles are also potential photo-ID subjects: the head scales form a unique individual pattern. More information in the article on sea turtle photography.
AquaExposure receives no affiliate commissions from any citizen science platform mentioned in this article. Participation is free on all platforms listed.
The AquaExposure underwater photography course includes a module on ethical photography and citizen science contribution. Learning to shoot well and to contribute to research: the two go together.
Create a free account at manta-matcher.org, then upload a sharp photo of the manta ray's belly (ventral side, not the back). The system automatically compares the spot patterns with its database. You receive a notification if your manta is already known, with its full encounter history.
No. Platforms like MantaMatcher, Wildbook and HappyWhale are designed for recreational divers and photographers. You just need to submit photos of sufficient quality (sharp, at the right angle) with location and date. Validation is done by researchers.
For MantaMatcher, a photo from 8 megapixels upwards is generally sufficient if the image is sharp. It is not the raw resolution that matters, it is the sharpness of the distinctive markers (spot patterns for mantas, white spots for whale sharks).
HappyWhale mainly covers baleen whales (humpback, blue, grey) and some great dolphins. For smaller dolphins (common dolphin, bottlenose), Flukebook is the specialised alternative. The platform clearly states which species are covered.
Yes, if the photo is sharp and clearly shows the distinctive markers. An iPhone or Samsung in a housing produces valid results for MantaMatcher. Composition quality matters more than sensor size.
Not mandatory, but very useful. If your housing blocks the GPS signal (common with most housings), note the dive site and approximate coordinates manually at the time of submission. Kilometre-level precision is sufficient for migration mapping.
Wildbook mainly covers whale sharks (Wildbook for Whale Sharks) and great white sharks (via other Wildbook instances). For reef sharks (blacktip reef, grey reef), regional databases exist depending on the destination.
Yes. HappyWhale has tracked humpback whale migrations over more than 15,000 km thanks to photos from divers and tourists. MantaMatcher has identified individuals living over 40 years and documented previously unknown migration corridors.
