Posted by Santorini is known for its white houses, spectacular sunsets, and black sand beaches – but the island also offers a unique underwater natural experience.
This volcanic island lies in the heart of the southern Aegean Sea, surrounded by deep, clear waters. Volcanic activity has created impressive rock formations, lava caves, and underwater cliffs. These provide ideal habitats for a variety of marine life – from tiny crabs to dolphins and sea turtles.
Those who snorkel or dive here will discover an astonishingly rich marine life, hidden among dark lava rocks and seagrass meadows.
The Marine Landscape Around Santorini
Santorini is of volcanic origin, and this is evident underwater. The coasts often drop off steeply, and the caldera reaches depths of over 300 meters in some places. At the same time, there are shallow bays, small islands, and protected areas where fish and other marine life thrive.
Important habitats around Santorini:
Lava cliffs and caves – perfect retreats for octopuses, moray eels, and sponges
Sandy bays with seagrass – home to red mullet, snails, and small fish
Steep underwater cliffs – where larger fish hunt
Coastal islands like Thirassia, Nea Kameni, and Aspronisi – rich in marine life
The water is crystal clear, especially in summer. Visibility of over 30 meters is not uncommon – ideal conditions for observing marine life.
The fascinating wildlife of Santorini
1. Sea turtles – rare, but possible
Santorini is not a breeding island for sea turtles like Zakynthos or Crete, but the loggerhead sea turtle (Caretta caretta) is also found here.
It regularly swims through the southern Aegean Sea and is sighted primarily in summer in the bays around Perissa, Kamari, and Vlychada.
Lifestyle: migrates between the Cyclades and Crete
Appearance: robust shell, reddish-brown coloration
Sighting: especially early in the morning or in quieter bays
Sometimes you can also see them in the caldera, where they surface in the clear water to breathe.
Tip: Never touch or chase turtles – they are protected and sensitive to noise.
2. Dolphins – Visitors in the Caldera
Dolphins are also part of the wildlife around Santorini.
With a bit of luck, you can observe them from boats, especially on trips between Fira, Thirassia, and Akrotiri.
Species:
Bottlenose Dolphin (Tursiops truncatus)
Common Dolphin (Delphinus delphis)
Striped Dolphin (Stenella coeruleoalba)
Best time to see them: Spring to autumn, especially in the morning
Dolphins love the currents on the outer edge of the caldera, where small fish congregate. They sometimes accompany ferries to Ios or Crete.
A quiet boat trip without loud music offers the best chance of seeing them in their natural habitat. See also: Dolphins in Greece
3. Fish of the Aegean Sea – colorful, diverse, and numerous
The volcanic rocks around Santorini are home to countless species of fish.
Here are some typical species you can easily spot while snorkeling or diving:
Sea bream (Sargos, Diplodus spp.) – silvery fish in small groups
Parrotfish (Sparisoma cretense) – colorful, found among rocks and seaweed
Groupers (Epinephelus marginatus) – large predatory fish, found in caves or reefs
Red mullet (Mullus surmuletus) – sift through the sand for food
Striped char (Sarpa salpa) – recognizable by their golden stripes
Barracuda (Sphyraena sphyraena) – long, silvery predators, usually found in deeper water
The fish benefit from the nutrients that enter the sea through volcanic vents – resulting in an abundance of plankton and small prey.
While diving in the caldera at Nea Kameni, you can even see small schools of fish swimming through volcanic gas bubbles – a truly unique spectacle.
4. Octopuses, Squid & Cuttlefish
The rocky coast around Santorini is ideal for octopuses, cuttlefish, and squid.
Octopuses (Octopus vulgaris) hide in crevices or under rocks.
Cuttlefish (Sepia officinalis) move gracefully across the seabed.
Squid often come closer to the shore at night, especially when the harbor lights are on.
These animals are very intelligent and adaptable. If you want to observe them, swim calmly and slowly – they sometimes change color in a flash to camouflage themselves.
5. Sponges, Sea Urchins & Small Coastal Creatures
Santorini’s lava coast is teeming with small creatures that can be found just a few meters deep.
Sponges – yellow, red, or purple, attached to rocks
Sea urchins – common, but be careful when swimming barefoot!
Starfish – mostly orange or red, often found on rocky cliffs
Anemones – colorful tentacled creatures in shallow waters
Clams and snails – hidden among rocks
These tiny inhabitants are incredibly important to the ecosystem: they purify the water and serve as food for larger fish.
6. Sharks and rays – harmless and rare
Sharks also live in the sea around Santorini, but as everywhere in the Aegean Sea, they are small and harmless.
Catsharks (Scyliorhinus canicula) – 60 to 80 cm long, nocturnal
Angel sharks (Squatina squatina) – live in shallow water and are well camouflaged in the sand
Blue sharks (Prionace glauca) – live far out at sea, never near the shore
Ray species such as the stingray and the eagle ray are also found, mostly over sandy bottoms at depths of 10–20 meters.
There is no danger for swimmers – sharks avoid humans, and rays are peaceful as long as they are not disturbed. See also: Sharks in Greece
7. Moray eels, lobsters & other reef inhabitants
Moray eels with snake-like bodies live in the crevices of the lava rock. They are nocturnal and mostly harmless.
Lobs and crabs can also be found in deeper rocky areas.
Many of these animals live, especially around the small islands of Aspronisi and Palea Kameni – a paradise for divers and underwater photographers.
8. Coastal animals and shallow-water life
A whole world of its own thrives right on the beaches of Santorini.
Crabs crawl across lava rocks.
Mini shrimp and small fish live in rock pools.
Nemoluna cling to rocks where the waves break.
Sea urchins sit underwater on rocky edges.
Clams and small snails sometimes form colorful carpets.
At beaches like Perivolos, Kamari, or Vlychada, these animals can be observed even in shallow water – ideal for children and families.
Other pages about Santorini: Santorini Buses, Santorini Ferries, Santorini Beaches, Santorini Attractions
Best Time of Year & Conditions
The sea around Santorini is calmest and clearest from May to October.
May–June: many fish, few tourists
July–August: warm water (25°C), good visibility
September–October: fewer boats, best time for diving
Winter: only for experienced divers, but surprisingly calm and clear
In the mornings, the sea is usually still, the sun is low – perfect conditions for observing and photographing marine life.
Animal Behavior & Protection
Santorini doesn’t yet have large marine protected areas like Zakynthos, but respect for nature is growing.
If you want to see marine life, remember:
Never touch or feed them.
Do not take shells or sea urchins.
Swim and dive calmly.
Leave no trash behind.
Only snorkel with organic sunscreen to avoid polluting the sea.
Sustainable tourism helps preserve the biodiversity around the island.
Threats & Environmental Protection
Like everywhere in the Mediterranean, Santorini’s marine life is under pressure.
Main threats:
Plastic waste and microplastics carried by currents.
Overfishing, especially during the winter months.
Shipping and cruise ship tourism, which cause noise and exhaust fumes.
Climate change, which alters temperature and oxygen levels.
Conservation Projects & Initiatives:
Archipelagos Institute and Aegean Rebreath collect trash and research local species.
Local dive centers conduct regular clean-up operations.
A small marine ecology information center is being established in Vlychada.
Every respectful encounter with an animal helps raise awareness about the need to protect these fascinating habitats.
Conclusion – Santorini’s Wild Underwater Side
Those who only know Santorini from above the water have little idea of the beauty that lies beneath the surface.
A diverse array of wildlife thrives between black lava rock and turquoise sea – fish, octopuses, dolphins, and even turtles.
The combination of volcanic landscape and marine life makes Santorini a unique destination for nature lovers, divers, and photographers.
Next time you visit Perissa or Ammoudi Bay, take your time. Look closely.
Often, the most beautiful things only reveal themselves when you remain still – beneath the surface.
Santorini – all articles
| Santorini overview | Thira |
| Oia | Perissa |
| Kamari | Akrotiri |
| Beaches Santorini | Sights Santorini |
| Marine life Santorini | Ferries Santorini |