Dolphin ID Project Maldives

Spinner dolphin 'Ekko'

Marine Savers Dolphin Diaries

Guest excursion - dolphin spotting

2018 - 2019

The start of our dedicated dolphin diary, documenting details of daily encounters with Cetaceans in the open ocean.

Spinner dolphins leaping Marine Savers Maldives

2020 - 2021

We photograph dolphins as they break the water surface, to capture close-ups of their dorsal fins for analysis.

Dolphin dorsal fin ID photos Marine Savers Maldives

2022 - 2023

Our photo database is growing, allowing positive ID of individual dolphins with many confirmed resightings.

Maldives Dolphin ID Project Details

dolphin safari Marine Savers Maldives

Spinner dolphins

During our guest dolphin cruises, we have started to take photographs of the cetaceans we encounter, to use for identification purposes. We take as many photos as possible at each encounter, especially on the calm, clear days.

We use only high quality photographs (correct angle, sharpness, lighting) for the identification process, but we do keep the lower quality images of any marked fins to use for future comparisons. Re-sightings are recorded in an excel sheet and the photos added to the individual dolphin’s collection. Periodically, we look through our archive of old photos to look for possible matches and re-sightings, and to remove any poor quality or indistinguishable images.

Guest excursion – dolphin spotting (0848)
FB – Dolphins
Dolphin dorsal fin ID photos Marine Savers Maldives
Dolphin identification project Marine Savers Maldives (0312)

We photograph close-ups of dolphin dorsal fins
to record and identify the unique patterns

Taking good ID shots can be challenging under the variable conditions onboard (sun’s position, choppy sea) and it’s often not possible to angle the shot perpendicular to the dolphin’s body (to see the full outline of the dorsal fin). On average, out of 100 photographs taken, only 30 are good for analysis.

Dolphin identification project Maldives - database software

Software used to ID and catalogue our dolphin photographs

The photographs of the dorsal fin are cropped and analysed using image-matching software (Darwin’ and I3S ‘Interactive Individual Identification System’). Dolphins can be identified individually based on the notches, scars and markings present on their dorsal fin. Small wounds are known to heal within months, while large wounds caused by predation attempts or human impacts tend to persist (Lockyer & Morris, 1990 [PDF]). As missing tissue does not regenerate, dorsal fin mutilations are permanent marks that can be used for identification purposes.

Dolphin ID Bottlenose Marine Savers Maldives (IMGP1326)

Bottlenose Dolphins

We have created photographic databases for each of the four most commonly sighted Cetacean species in Maldives:

Spinner dolphins (Stenella longirostri) are by far the most commonly encountered Cetacean species in Maldivian waters. They are usually observed in pods of 40 to 100 individuals, exhibiting active and social behaviours including playing in the wake behind the boat and showing off their acrobatic skills (jumping, spinning, porpoising and bow-riding). They are the only species to actually spin in the air whilst jumping.
Young calves (30-90cm length) are often seen swimming alongside their protective mothers, and on some occasions even practising their jumping and spinning skills. Spinner dolphins are difficult to identify individually as most have “clean” dorsal fins with a smooth outline, lacking any distinct markings.

Bottlenose dolphins (Tursiops truncates and T.aduncus) are larger than Spinners, and often have more identifiable scars. They live and travel in much smaller family groups (even individually). Bottlenose are the most common species globally, and they have more fat so they can live in colder waters. They are sometimes seen jumping from the water, but never spin.
There are 2 different species sighted in Maldives – the ‘Common Bottlenose’ (Tursiops truncates) and the ‘Indo-Pacific Bottlenose’ (Tursiops aduncus), both very similar in appearance and difficult to tell part (‘Common’ is larger and found worldwide).

Dolphin safari – Marine Savers Maldives (2) 16×9

False killer whales

False killer whales (Pseudorca crassidens) are sighted seasonally in the Maldives, and are not so common. They can reach around 6 metres in length, although cold water populations have more fat insulation making them larger and heavier. They are usually sighted in family groups of 10-20 members (occasionally in huge groups of 500+) and often have uniquely identifying scars.
The mother is head of the group (‘matrifocal’ family structure) compared to pilot whales where the father plays a more important role.

Short-finned pilot whales (Globiocephala macrorhynchus) are sighted in family groups of around 15-30 members, but they will often migrate larger distances in groups of 100+. Here in the Maldives, pilot whales are often seen travelling together with pods of dolphins. Their large size and fat insulation means they can live in colder waters, and they often have many scars which makes for easier identification of individuals.
They were named ‘pilot’ whales as they follow a leader, and sometimes if that leader becomes sick or disoriented, the whole pod can end up stranding on a beach.

Maanee marine biologist Maldives Pilot whales

Pilot Whales (compare the difference in fin shape to the false killer whales, above)

Marine Savers Dolphin Diaries

Guest excursion - dolphin spotting

2018 - 2019

The start of our dedicated dolphin diary, documenting details of daily encounters with Cetaceans in the open ocean.

Spinner dolphins leaping Marine Savers Maldives

2020 - 2021

We photograph dolphins as they break the water surface, to capture close-ups of their dorsal fins for analysis.

Dolphin dorsal fin ID photos Marine Savers Maldives

2022 - 2023

Our photo database is growing, allowing positive ID of individual dolphins with many confirmed resightings.

Dolphin excursion - Risso's dolphins Maldives

A rare sighting of Risso’s dolphins! Photo taken at Kuda Huraa, 2019

Pod of Pilot Whales

Sighted at Kuda Huraa, 2021
Share this page:
FacebooktwitterlinkedinmailFacebooktwitterlinkedinmail