Posidonia Oceanica – the secret of Messinia’s crystal clear waters!

Marine Life

Posidonia Oceanica – the secret of Messinia’s crystal clear waters

Written by Scuba Turtles   |   03 Jan 2024

A macro photo of posidonia oceanica in the deep.

One of the main attractions of Messinia lies in their crystal clear waters. The sea often takes on a vibrant turquoise hue, reminiscent of the Caribbean, creating a surreal experience. Interestingly, this breathtaking phenomenon is attributed to Posidonia oceanica, one of the world’s largest and oldest living organisms thriving on the sandy sea floor.

Named after the Greek sea god, Posidonia oceanica is a type of seagrass abundantly found throughout the Mediterranean. Posidonia Oceanica or Neptune grass, is often confused with seaweed because of its shape and colour, but it is actually an underwater plant with fruits, flowers, leaves, stem and roots. It is also an important indicator of the health of the marine ecosystem as it only lives in clean water.

The lungs of the Mediterranean.

Posidonia plays a pivotal role in our marine ecosystem, acting as a vital habitat for a diverse array of species, including fish and seahorses. These organisms depend on Posidonia for essential activities such as feeding, breeding, and seeking shelter. Beyond its ecological importance, Posidonia serves as an exceptionally efficient carbon sink, with seagrass capable of storing up to 15 times more carbon than the equivalent area of terrestrial forest. This carbon sequestration occurs at an accelerated rate, with the carbon trapped for extended periods, spanning millions of years.

The plant further contributes to water purification and oxygenation processes. Through its metabolic activity, Posidonia filters impurities and releases oxygen into the water, constituting more than half of the atmospheric oxygen essential for terrestrial life. Consequently, Posidonia is aptly termed the “lungs of the Mediterranean,” reflecting its critical role in carbon sequestration and oxygen production within the marine environment.


Ensuring the preservation of Posidonia is imperative, given its multifaceted environmental benefits. Posidonia meadows host over 1,000 species of animals and plants in the Mediterranean, serving as crucial spawning grounds for various commercially significant species. Each square meter of these meadows contributes up to 20 liters of oxygen daily, emerging as a primary source of sea and atmospheric oxygenation. Additionally, these meadows function as CO2 sinks, capturing substantial quantities of this greenhouse gas. Notably, they also play a protective role, safeguarding the coastline from erosion. The comprehensive ecological services provided by Posidonia underscore the necessity for its conservation and sustainable management.

Under threat.

Posidonia, an abundant marine plant in the Mediterranean Sea, confronts a precipitous decline attributable to various causative factors. The mechanical damage stemming from trawling, boat anchoring, turbidity, coastal development, and agricultural nutrient discharges, coupled with pollution and climate change, collectively imperil its existence. The plant’s vulnerability to these stressors is heightened by its limited genetic variability and protracted growth, rendering it inherently less resilient in the face of disturbances.


Regrettably, notwithstanding its stature as a paramount natural asset, Posidonia finds itself in a precarious state of endangerment. Over the preceding four decades, the western Mediterranean has experienced a noteworthy depletion, losing approximately one-third of its meadows. Climate change emerges as a formidable threat, with escalating sea temperatures triggering seagrass deterioration once the critical threshold of 28°C is surpassed. Recent observations underscore peak temperatures reaching as high as 29°C.

The escalating pollution in the water, compounded by unregulated boat anchoring, compounds the challenges faced by Posidonia Oceanica. Given its exceptionally sluggish growth rate, measuring less than one centimeter annually, the impact of a solitary vessel deploying its anchor can result in a denuded patch, necessitating centuries for rehabilitation. Urgent and concerted conservation efforts are imperative to safeguard this invaluable marine species and address the multifaceted threats contributing to its precipitous decline.

Taking Action.

To ensure the preservation of Posidonia oceanica, a range of proactive measures and initiatives have been implemented, reflecting a collective commitment to its conservation. Various regulatory frameworks, including EU legislation, the Bern and Barcelona Conventions, as well as national legislations, provide legal safeguards for this species. Additionally, EU fishing regulations impose restrictions on trawling activities near the shore, and several marine protected areas have been established along the Mediterranean Sea to secure the habitats of Posidonia oceanica.


To actively contribute to the protection of Posidonia oceanica, individuals can adopt the following practices:

1. Advocate Responsible Boating:

When embarking on a boat trip, passengers are encouraged to communicate with their captains, urging them to avoid anchoring in Posidonia meadows. The utilization of the Posidonia MAPS app can assist captains in identifying safe anchoring zones, minimizing the impact on these critical habitats.

2. Choose Environmentally Friendly Sunscreen:

Opt for environmentally conscious, chemical-free sunscreen options. Conventional sunscreens often contain pollutants that can contaminate water and pose a threat to seagrass health. Locally produced alternatives, such as those by Sol de Ibiza and Ibisun, offer sustainable choices, with a percentage of proceeds contributing to conservation efforts by organizations like IbizaPreservation.

3. Support Posidonia Protection Projects:

Contribute to Posidonia protection initiatives by making donations through designated platforms available on websites dedicated to conservation projects. Financial support directly aids in implementing and sustaining programs aimed at preserving Posidonia meadows.

4. Become a Posidonia Ambassador:

Actively engage in spreading awareness about the significance of Posidonia oceanica. By becoming a Posidonia ambassador, individuals can play a crucial role in educating others about the importance of this marine plant and advocating for practices that ensure its long-term survival.

Through collaborative efforts and individual commitments, the conservation of Posidonia oceanica can be advanced, safeguarding not only this remarkable species but also the broader marine ecosystems it sustains.

5 Fun facts about Nudibranchs

Marine Life

5 Fun facts about Nudibranchs

Written by Scuba Turtles   |   04 Aug 2023


Step into the world of nudibranchs, those delightful and fascinating marine creatures! Picture this: soft-bodied gastropod molluscs, gliding gracefully through the ocean, shedding their shells like a symbol of transformation after their playful larval stage.

Now, here’s where things get truly magical! Nudibranchs are nature’s artists, donning the most extraordinary colors and striking forms. Their vibrant appearances have earned them some pretty charming nicknames like “clown,” “marigold,” “splendid,” “dancer,” “dragon,” and even the whimsical “sea rabbit”!

Guess what? We have quite the nudibranch club with around 3,000 unique species known so far. Each one seems to outshine the other with its own flair and personality.

Curious about their name origin? Well, “nudibranch” is a delightful blend of the Latin word “nudus,” meaning “naked,” and the Ancient Greek word “bránkhia,” referring to their cute little gills.

So, next time you catch a glimpse of these splendid sea creatures, remember their fascinating journey from being shell-less wonders to the crowned jewels of the ocean floor!

Here are 5 fun facts about “Nudis” to get you all excited for your next dive!

1. Nudibranchs are like underwater fashionistas

Step into the mesmerizing world of nudibranchs, where tiny sea creatures undergo a remarkable transformation! During their larval phase, these adorable marine mollusks bid farewell to their shells, embracing a newfound sense of freedom.

Sporting the most eye-catching and vivid colors you’ve ever seen! It’s not just for show though; these vibrant hues serve a vital purpose. They’re nature’s warning signs, cautioning potential predators to think twice before taking a bite.

How do they do it? Well, nudibranchs have a secret weapon – toxins and nasty chemicals stashed away in their colorful outfits! It’s like a “taste me at your own risk” signal that keeps them safe and sound in the vast ocean.


2. Nudibranchs have an adorable pair of tentacles called “rhinophores.”

These special tentacles, perched on their cute little heads, are like nature’s scent detectives. With their scent receptors, nudibranchs can sniff out yummy food or even detect other nudibranchs nearby.

But hey, life in the ocean isn’t all rainbows and sunshine. Hungry fish are always on the lookout for a tasty treat, and those rhinophores can be like a bullseye for them. So, nudibranchs have a clever defense mechanism – they can quickly tuck those rhinophores away into a hidden pocket in their skin when danger lurks.

Imagine having a secret retractable nose! It’s just one more reason these colorful critters are so amazing. Nature’s creativity knows no bounds, and nudibranchs are here to show us how they roll in the big blue playground!


3. These adorable sea creatures have quite the unique love story going on

You see, nudibranchs are true hermaphrodites, and that means they’ve got both male and female reproductive organs! But here’s the kicker – nudibranchs are not the speediest swimmers in the ocean. So, they’ve adapted a rather convenient way to handle their love life. Whenever they happen to cross paths with another nudibranch, it’s like instant romance!

Their slow pace makes it necessary to be ready for reproduction at any moment, and they can effortlessly switch roles from being the male to the female in the blink of an eye. It’s like they’re always prepared for a little underwater dance of love!

Nature sure knows how to create fascinating creatures with fascinating solutions for life’s challenges. So, next time you spot these charming nudibranchs, remember they’re masters of love, ready to embrace any romantic encounter that comes their way!


4. These little ocean wonders have found a way to harness the power of the sun by indulging in a special diet – coral!

Here’s how it works: the corals they munch on are teeming with algae. When these slugs eat the corals, they absorb the algae’s chloroplasts, which are like tiny green powerhouses. Now, get this – the slugs can actually perform photosynthesis just like plants do!

It’s like they’ve become mini solar panels, converting sunlight into precious nutrients that fuel their survival. With this incredible adaptation, these slugs can go on for several months without needing to eat anything else!


5. Radula that works just like a toothed tongue!

Nudibranchs use this cool structure to scrape off scrumptious meals from the rocks they call home. Some take things up a notch by predigesting their prey’s tissues with special enzymes and then sucking out the goodness. Now, what’s on their menu? These carnivorous cuties have quite the diverse palate. From sponges and corals to anemones, barnacles, fish eggs, and even fellow nudibranchs, nothing seems to escape their voracious appetite.

But wait, here’s the twist – nudibranchs can be real foodies, too! Some have particular tastes and will stick to just one type of prey. It’s like they have their own gourmet preferences.

Oh, and those dazzling colors they wear like a fashion statement? They owe it all to the food they eat! These vibrant hues can serve as camouflage or even a warning sign to predators, telling them to beware of the hidden poison within.

It’s a gourmet feast and a colorful fashion show all rolled into one with these charismatic creatures of the sea! Nature sure knows how to surprise us with its little wonders, and nudibranchs are here to steal the spotlight!

Top favorite Ionian Sea Species

Marine Life

Top favourite Ionian Sea Species

Written by Scuba Turtles   |   16 July 2023


The Ionian Sea and its extraordinary marine life if one of the reason why we decided to open our dive centre in this region. In this article, we’ll take you on a journey to discover some of our favourite Ionian Sea species.

From vibrant fish to seafloor dwellers, let’s dive right in!

1. Colorful Mediterranean Parrotfish

One of the most striking creatures you’ll encounter in the Ionian Sea is the Mediterranean Parrotfish. With their vibrant colors and beak-like teeth these fish add a splash of brightness to the underwater landscape. Their incredible teeth are fused to their jawbone. When tested for fracture resistance, their teeth would beat gold, copper, and silver.

Keep an eye out for their playful behaviour and unique ability to change colors!


2. Lovely Loggerhead Sea Turtles

The Ionian Sea is home to the majestic Loggerhead Sea Turtles, a true wonder to behold. These gentle giants navigate the waters, captivating divers with their peaceful presence. Swimming alongside these magnificent creatures is an inspiring experience you won’t soon forget.


3. Camouflaged Scorpionfish

Prepare to be amazed by the camouflage skills of the Scorpionfish, a master of disguise in the Ionian Sea. These creatures blend seamlessly with their surroundings, making them quite a challenge to spot. Take your time and keep an eye to witness the hidden beauty of these unique fish.


4. Psychedelic Cuttlefish

There is a population of cuttlefish in the Ionian Sea, a species characterized by its remarkable intelligence and psychedelic geometric displays. Watch as they change colors and patterns, showcasing their incredible communication skills. Observing these mystical creatures in their natural habitat is a true privilege.


5. Playful Common Dolphins

While exploring the Ionian Sea, don’t be surprised if you encounter a pod of playful Common Dolphins. These intelligent and social mammals often delight divers with their acrobatic displays and curiosity. Swimming alongside these energetic creatures is an exhilarating experience that will leave you with unforgettable memories.


As you can see, the Ionian Sea is teeming with an abundance of fascinating species, all of which contribute to the vibrant tapestry of marine life. Our planet is full of wonders, and exploring its depths and encountering these captivating creatures is a privilege we should never take for granted. Join us at PADI Scuba Turtles Dive Center to embark on an unforgettable journey, immersing yourself in the beauty of the Ionian Sea and its incredible species.

Start your adventure today and discover the Ionian sea species that await you beneath the surface! Book your dive experience now and dive into the magical world.

The most threatened species in the Mediterranean Sea

Marine Life

The most threatened species in the Mediterranean Sea

Written by Scuba Turtles   |   31 March 2023


Although the Mediterranean Sea is an orchard ecosystem with about 7% of the world’s fish species and the world’s second largest biodiversity, the number of threatened species is constantly increasing. In accordance with Maritime Crimes “More than 8% of Mediterranean fish species are affected”.

The International Union for Conservation of Nature have developed a list of endangered species. The Mediterranean Red List is managed by the IUCN Centre for Mediterranean Cooperation. Nearly 700 scientists from across the region have contributed to the Mediterranean Red List of Species.

This Red List points that there are 14 species critically endangered. Let us show you some of them.

1. Sharks

Six shark species are on the Red List, making them one of the most threatened. Annually, the region catches 1.5 million tons of fish for international trade. These activities have resulted in the destruction of reef systems and the depletion of essential fish stocks. Therefore, to protect the important role that sharks play in the Mediterranean ecosystem, drastic measures must be taken to reduce commercial fishing and prevent the destruction of their habitats.

The critically endangered list include: three different types of Angel Shark, Sand Tiger Shark, Great Hammerhead and School shark. Read more on ocean conservation and shark protection in Greece here.

2. Rays

For rays, the biggest threat is also the fishing industry. Six species were red-listed between 2015 and 2020, and the population continues to decline. Two types of Eagle Rays (Common and Duckbill), Maltese Ray, Lusitanian Cownose Ray and two types of Guitarfish are now in the critical endangered category.


3. Sea Turtles

Over the past decade, sea turtles have been protected, and some have shifted from endangered to vulnerable. The Hawksbill turtle was not that lucky and is on the list of species in critical danger of extinction. A few of the biggest threats are tourism, aquaculture, and oil drilling.

If you wish to know how you could help protect this species in Greece, visit this Archelon page they need any help they can get.

4. Sturgeon

This species is known to be the offspring of earlier acipenseriform fish, which date from the early Jurassic period. Being aware of this fact, it is really sad to learn that there are four different species of sturgeon on the EC List: Ship Sturgeon, Stellate Sturgeon, Adriatic Sturgeon and Russian Sturgeon. Besides the other threats, we also encounter alteration of the natural system such as dams and other problematic diseases that have emerged over the past years.


There is a lot of work to be done to protect our oceans, and all we need to do is learn about them. We need more legislation and protected areas to recover species at risk. It is up to us to help our sea get back on its feet. If you would like to find out more about the Mediterranean Sea and its species, we have the right course for you here.

8 Facts about the Loggerhead Sea Turtle

Marine Life

8 Facts you need to know about Loggerhead Sea Turtle

Written by Scuba Turtles   |   10 Aug 2022

loggerhead turtle swimming underwater

The loggerhead sea turtle, also known as Caretta Caretta, is found in the Atlantic, Indian and Pacific Oceans, as well as the Mediterranean Sea. This turtle lives most of their lives in saltwater. Only females come ashore to lay eggs.

The loggerhead sea turtle has a low reproductive rate, the age of sexual maturity (within 17–33 years) plus the short lifespan of this kind of sea turtle (47–67 years), have put them on the list of Endangered Species.

Let us give you some curious facts about this turtle that inhabit the coast of the Ionian Sea, and win the space on the logo of our dive center.

1. The biggest hard-shelled turtle

You got that right, loggerhead sea turtle in the largest hard-shell sea turtle in the world. There are seven types of sea turtle, the largest being the leatherback turtle. However, leatherback turtles have a soft shell, making Caretta Caretta the largest of its kind. Despite the fact that Mediterranean loggerheads are smaller on average than other loggerhead sea turtles.

2. Under the protection of the Endangered Species

Caretta Caretta was originally listed as an endangered species in 1973. Several factors have placed this turtle on the list. Loss of nesting habitat due to holidays and human tourism patterns is the greatest threat. This in combination with turtles trapped in fishing nets or ingesting other plastics make humans the primary enemy for their survival.

Greece is the most popular nesting site along the Mediterranean, due to legislation on the protection of nesting areas, with more than 3000 nests annually. Being, Zakynthos and Kyparissia Bay, the biggest Mediterranean breeding grounds.


3. Salty Tears

Did you ever wonder how the sea turtles keep their osmotic balance? The loggerhead sea turtle has a lachrymal gland behind each eye that eliminates the excess salt gained from ingesting sea water. When they exiting the water, this secretion gives the impression that the turtle is crying.

4. Female Fights

While female aggression is unusual in marine vertebrates, it is fairly common in Caretta Caretta. The ritualized fight over feeding grounds can go from a simple threat to a full battle with different results. Make sure you stay away if you ever encounter one!


5. Too cold to swim!

If you are a big fun of movies and blanket winter days, you will understand this turtle. When the water gets too cold (13 to 15ºC), the loggerhead comes in a lethargic state. Floating in the same position for up to 7 hours, coming up to breathe for only 7 minutes, the longest dives recorded for marine vertebrates that breathe air.

6. Who is the father?

This kind of turtle has a differs way to see paternity. Females have sperm storage, where they can hold sperm from different males until ovulation. Multiple fatherhood is frequent along sea turtles, having the same hatch different fathers.


7. Baby Boom

The first reproduction of loggerhead turtles takes place between 17 and 33 years of age, with a mating period of two months. Using a mating-induced ovulation that is rarely seen outside mammals, the female fertilized the eggs. The average female will produce 4 clutches of 112 eggs each, before becoming two to three years tranquil without producing eggs.

Breeding grounds grow annually around the Ionian coast of Greece, thanks to the creation of protected areas and the support of the Conservation Organizations.

You can see baby turtles hatching on all of Messinia’s nesting beaches from July through September.

8. Tell me what you eat…

As human beings, the sea turtles are omnivorous. Their main food is sea-bottom invertebrates, but there are other curious meals on their menu. For example, the famous jellyfish, Portuguese men of war, squids, corals and even hatching turtles from their own species.

Now that you have all the information, it’s time to take a plunge and go swimming and admire these creatures by your side.